Littérature scientifique sur le sujet « BSA protein »
Créez une référence correcte selon les styles APA, MLA, Chicago, Harvard et plusieurs autres
Consultez les listes thématiques d’articles de revues, de livres, de thèses, de rapports de conférences et d’autres sources académiques sur le sujet « BSA protein ».
À côté de chaque source dans la liste de références il y a un bouton « Ajouter à la bibliographie ». Cliquez sur ce bouton, et nous générerons automatiquement la référence bibliographique pour la source choisie selon votre style de citation préféré : APA, MLA, Harvard, Vancouver, Chicago, etc.
Vous pouvez aussi télécharger le texte intégral de la publication scolaire au format pdf et consulter son résumé en ligne lorsque ces informations sont inclues dans les métadonnées.
Articles de revues sur le sujet "BSA protein"
1
Ottnad, E., D. P. Via, H. Sinn, E. Friedrich, R. Ziegler, and H. A. Dresel. "Binding characteristics of reduced hepatic receptors for acetylated low-density lipoprotein and maleylated bovine serum albumin." Biochemical Journal 265, no. 3 (1990): 689–98. http://dx.doi.org/10.1042/bj2650689.
Texte intégralRésumé :
The binding characteristics of reduced hepatic membrane proteins for acetylated low-density lipoprotein (acetyl-LDL) and maleylated bovine serum albumin (Mal-BSA) have been examined. Two receptor activities were extracted from hepatic membranes in the presence of octyl beta-D-glucoside and beta-mercaptoethanol, and were separated by chromatography on Mal-BSA-Sepharose 4B. The receptors were revealed by ligand blotting. The active binding proteins had apparent molecular masses of 35 and 15 kDa in SDS/polyacrylamide gels. Equilibrium studies with protein-phosphatidylcholine complexes indicated that the reduced 35 kDa protein expresses two binding sites for Mal-BSA and one for acetyl-LDL, whereas the 15 kDa protein-phosphatidylcholine complex binds 131I-Mal-BSA and 131I-acetyl-LDL with a 4:1 stoichiometry. 131I-Mal-BSA binding was linear with both proteins, with a Kd of 4.8 nM at the 35 kDa protein and a Kd of 5.6 nM at the 15 kDa protein. The 35 kDa protein displayed saturable binding of 131I-acetyl-LDL with a Kd of 5 nM; the 15 kDa binding protein bound 131I-acetyl-LDL with a Kd of 2.3 nM. A 85 kDa protein was obtained by Mal-BSA-Sepharose chromatography when the hepatic membranes had been solubilized with Triton X-100 in presence of GSH/GSSG. This protein displayed saturable 131I-Mal-BSA binding with a Kd of 30 nM and 131I-acetyl-LDL binding with a Kd of 6.5 nM. The 131I-Mal-BSA binding capacity was four times higher than that of 131I-acetyl-LDL. Competition studies with the 35 kDa, 15 kDa and 85 kDa proteins binding Mal-BSA, acetyl-LDL, formylated albumin and polyanionic competitors provide evidence for the existence of more than one class of binding sites at the reduced binding proteins.
2
Bhatt, Anant Narayan, Yogesh Rai, Amit Verma, et al. "Non-Enzymatic Protein Acetylation by 7-Acetoxy-4-Methylcoumarin: Implications in Protein Biochemistry." Protein & Peptide Letters 27, no. 8 (2020): 736–43. http://dx.doi.org/10.2174/0929866527666200305143016.
Texte intégralRésumé :
Background: The semi-synthetic acetoxycoumarins are known to acetylate proteins using novel enzymatic Calreticulin Transacetylase (CRTAase) system in cells. However, the nonenzymatic protein acetylation by polyphenolic acetates is not known. Objective: To investigate the ability of 7-acetoxy-4-methyl coumarin (7-AMC) to acetylate proteins non-enzymatically in the test tube. Methods: We incubated 7-AMC with BSA and analyzed the protein acetylation using Western blot technique. Further, BSA induced biophysical changes in the spectroscopic properties of 7-AMC was analyzed using Fluorescence spectroscopy. Results: Using pan anti-acetyl lysine antibody, herein we demonstrate that 7-AMC acetylates Bovine Serum Albumin (BSA) in time and concentration dependent manner in the absence of any enzyme. 7-AMC is a relatively less fluorescent molecule compared to the parental compound, 7- hydroxy-4-methylcoumarin (7-HMC), however the fluorescence of 7-AMC increased by two fold on incubation with BSA, depending on the time of incubation and concentration of BSA. Analysis of the reaction mixture of 7-AMC and BSA after filtration revealed that the increased fluorescence is associated with the compound of lower molecular weight in the filtrate and not residual BSA, suggesting that the less fluorescent 7-AMC undergoes self-hydrolysis in the presence of protein to give highly fluorescent parental molecule 7-HMC and acetate ion in polar solvent (phosphate buffered saline, PBS). The protein augmented conversion of 7-AMC to 7-HMC was found to be linearly related to the protein concentration. Conclusion: Thus protein acetylation induced by 7-AMC could also be non-enzymatic in nature and this molecule can be exploited for quantification of proteins.
3
Nomani, Alireza, Hamed Nosrati, Hamidreza Manjili, Leila Khesalpour, and Hossein Danafar. "Preparation and Characterization of Copolymeric Polymersomes for Protein Delivery." Drug Research 67, no. 08 (2017): 458–65. http://dx.doi.org/10.1055/s-0043-106051.
Texte intégralRésumé :
AbstractBiodegradable copolymeric polymersomes have been used for controlled drug delivery of proteins. These polymersomes important areas to overcome formulation associated problems of the proteins. The aim of this study was to develop polymersomes using biodegradable copolymers for delivery of bovine serum albumin (BSA) as a model protein. Encapsulated BSA by mPEG-PCL polymersomes led to formation of BSA-loaded mPEG-PCL polymersomes. The polymersomes synthesized with the protein-polymer ratio of 1:4 at 15 000 rpm gave maximum loading, minimum polydispersion with maximally sustained protein release pattern, among the prepared polymersomes. Investigation on FTIR and DSC results revealed that such a high encapsulation efficiency is due to strong interaction between BSA and the copolymer.The particles size and their morphology of polymersomes were determined by DLS and AFM.The encapsulation efficiency of BSA was 91.02%. The results of AFM showed that the polymersomes had spherical shapes with size of 49 nm.The sizes of BSA-loaded polymersomes ranged from 66.06 nm to 84.97 nm. The results showed that polymersomes exhibited a triphasic release, for BSA. Overall, the results indicated that mPEG–PCL polymersomes can be considered as a promising carrier for proteins.
4
Palacio, L., C. C. Ho, P. Prádanos, A. Hernández, and A. L. Zydney. "Fouling with protein mixtures in microfiltration: BSA–lysozyme and BSA–pepsin." Journal of Membrane Science 222, no. 1-2 (2003): 41–51. http://dx.doi.org/10.1016/s0376-7388(03)00143-1.
Texte intégral
5
Guan, D., and G. M. Green. "Significance of peptic digestion in rat pancreatic secretory response to dietary protein." American Journal of Physiology-Gastrointestinal and Liver Physiology 271, no. 1 (1996): G42—G47. http://dx.doi.org/10.1152/ajpgi.1996.271.1.g42.
Texte intégralRésumé :
The importance of peptic digestion of dietary protein in pancreatic enzyme secretion and cholecystokinin (CCK) release was investigated in conscious rats. Native casein and native bovine serum albumin (BSA) were infused intragastrically and intra-intestinally, and the effect of peptic predigestion on the pancreatic secretory and plasma CCK responses to BSA were determined (all infused at 450 mg/h). When dietary proteins were infused intraduodenally, native casein was a much stronger stimulant of CCK release (5.8 +/- 0.6 vs. 1.6 +/- 0.2 pM) and pancreatic protein secretion [5,592 +/- 736 vs. 750 +/- 461 (0-180)mg.kg-1.min] than native BSA. Infusion by the intragastric route markedly increased pancreatic protein secretion for BSA but not for casein. HCl-pepsin treatment of BSA significantly increased its ability to increase pancreatic secretion and plasma CCK. Pancreatic protease binding to native BSA was inferior compared with casein. Peptic digestion of BSA increased its protease binding activity more than threefold. The results indicate that peptic digestion of dietary proteins enhances the proteins' ability to elicit the pancreatic feedback stimulatory response.
6
Lv, Ying Hai, Gui Jiang Li, Li Qiang Cui, Hua Xiao Yan, and Shi Xue Zhou. "The Study of Existential State of Protein in Protein/Montmorillonite Complexes." Advanced Materials Research 194-196 (February 2011): 1647–51. http://dx.doi.org/10.4028/www.scientific.net/amr.194-196.1647.
Texte intégralRésumé :
The existential state of protein in complexes directly affects the performance and applications of the composite materials. The interlayer space changes of montmorillonite in the protein / montmorillonite (MMT) composite were identified by X-ray diffraction (XRD). And the interaction between protein and MMT were analyzed by Fourier transform infrared spectrometry (FT-IR) and UV/vis spectrophotometry. The loading amount of bovine serum albumin (BSA) onto MMT was calculated from the TG data. The types of adsorption isotherm of BSA onto montmorillonite were analyzed. From the above analysis, it can be concluded that the structure of proteins in the montmorillonite interlayers has been changed, and the hydrogen bond and Van der Waals force between the BSA molecules and montmorillonite crystal layers are intensified. The α-helix content of BSA molecules reduces while random coil increases. The protein shows a state of being squashed.
7
Deffebach, M. E., C. J. Bryan, and C. M. Hoy. "Protein movement across cultured guinea pig trachea: specificity and effect of transcytosis inhibitors." American Journal of Physiology-Lung Cellular and Molecular Physiology 271, no. 5 (1996): L744—L752. http://dx.doi.org/10.1152/ajplung.1996.271.5.l744.
Texte intégralRésumé :
Airway surface liquid (ASL) is a complex fluid with solutes including electrolytes, lipids, mucins, and proteins. The proximal airways are absorptive for most solutes, including proteins. We investigated the process of protein movement across confluent primary cultures of guinea pig trachea grown on filters using fluorescent-labeled bovine serum albumin (BSA), ovalbumin (OA), and 70-kDa dextran (Dex). We found marked asymmetry of BSA and OA transepithelial flux, with apical-to-basolateral flux (JA-->B) 10 times greater than the opposite direction (JB-->A) for both proteins. The apparent permeability for Dex was the same as that for proteins in the basolateral-to-apical direction and showed no asymmetry. Increasing concentrations of unlabeled BSA, OA, or transferrin inhibited JA-->B for both BSA and OA without affecting Dex movement. Cooling reduced JA-->B for BSA without affecting JB-->A. Monensin and nocodazole each reduced JA-->B for BSA and OA without affecting JB-->A. Monensin eliminated all asymmetry for BSA movement. Brefeldin A did not affect JA-->B for either protein but did increase JB-->A for BSA. Treatment with the protease inhibitors increased JA-->B for BSA. Western immunoblotting demonstrated immunologically intact protein in the downstream compartment. We conclude that there is transcytosis of proteins across cultured trachea epithelium in the apical-to-basolateral direction, which is monensin sensitive, involves microtubules, is not dependent on proteolysis, and is not protein species specific. This process may be important for maintenance of the ASL, and defects in this process may contribute to the abnormally thickened airway secretion seen in airway diseases.
8
Yu, Jing, Yun Chen, Liqun Xiong, Xiaoyue Zhang, and Yue Zheng. "Conductance Changes in Bovine Serum Albumin Caused by Drug-Binding Triggered Structural Transitions." Materials 12, no. 7 (2019): 1022. http://dx.doi.org/10.3390/ma12071022.
Texte intégralRésumé :
Proteins, due to their binding selectivity, are promising candidates for fabricating nanoscale bio-sensors. However, the influence of structural change on protein conductance caused by specific protein-ligand interactions and disease-induced degeneration still remains unknown. Here, we excavated the relationship between circular dichroism (CD) spectroscopy and conductive atomic force microscopy (CAFM) to reveal the effect of the protein secondary structures changes on conductance. The secondary structure of bovine serum albumin (BSA) was altered by the binding of drugs, like amoxicillin (Amox), cephalexin (Cefa), and azithromycin (Azit). The CD spectroscopy shows that the α-helical and β-sheet content of BSA, which varied according to the molar ratio between the drug and BSA, changed by up to 6%. The conductance of BSA monolayers in varying drug concentrations was further characterized via CAFM. We found that BSA conductance has a monotonic relation with α-helical content. Moreover, BSA conductance seems to be in connection with the binding ability of drugs and proteins. This work elucidates that protein conductance variations caused by secondary structure transitions are triggered by drug-binding and indicate that electrical methods are of potential application in protein secondary structure analysis.
9
Gekle, M., S. Mildenberger, R. Freudinger, and S. Silbernagl. "Long-term protein exposure reduces albumin binding and uptake in proximal tubule-derived opossum kidney cells." Journal of the American Society of Nephrology 9, no. 6 (1998): 960–68. http://dx.doi.org/10.1681/asn.v96960.
Texte intégralRésumé :
To avoid renal loss of large amounts of proteins, filtered proteins are reabsorbed by endocytosis along the proximal tubule. However, although protein reabsorption is a task of proximal tubular cells, it is also a threat because it may cause cell injury. This study determines whether exposure to bovine serum albumin (BSA) leads to regulatory changes in endocytosis of FITC-BSA in proximal tubule-derived opossum kidney cells. Preincubation with BSA led to a decrease of FITC-BSA endocytosis with an IC50 value of 0.58 g/L. Specific binding of FITC-BSA to the apical membrane was also reduced (IC50 = 0.69 g/L). Kinetic analyses revealed that maximal uptake rate and maximal binding capacity were decreased with no change in affinity. Similar effects were observed after preincubation with equimolar amounts of other proteins (lactalbumin, transferrin, and conalbumin), but not after preincubation with dextran. The effect of preincubation with BSA could be mimicked by preincubation with some amino acids. Preincubation with L-Ala, L-Gln, or NH4Cl, but not with L-Leu, L-Glu, or L-Asp, reduced FITC-BSA endocytosis and binding. Preincubation with BSA, but not with dextran, reduced protein degradation and increased ammonia production, vesicular pH, as well as the rate of lactate dehydrogenase release. Apical fluid-phase endocytosis and apical uptake of neutral amino acids were not reduced. It is concluded that proximal tubular cells reduce the uptake rate for proteins, but not for other substrates, in response to increased protein load. This reduction is achieved by reducing the number of apical binding sites, partially in response to increased ammoniagenesis with deranged vesicular pH and enzyme activities. Thus, increased protein filtration could result in reduced protein reabsorption, thereby enhancing proteinuria.
10
Alhazmi, Hassan. "FT-IR Spectroscopy for the Identification of Binding Sites and Measurements of the Binding Interactions of Important Metal Ions with Bovine Serum Albumin." Scientia Pharmaceutica 87, no. 1 (2019): 5. http://dx.doi.org/10.3390/scipharm87010005.
Texte intégralRésumé :
Proteins play crucial roles in the transportation and distribution of therapeutic substances, including metal ions in living systems. Some metal ions can strongly associate, while others show low affinity towards proteins. Consequently, in the present work, the binding behaviors of Ca2+, Ba2+, Ag+, Ru3+, Cu2+ and Co2+ with bovine serum albumin (BSA) were screened. BSA and the metal ions were allowed to interact at physiological pH and their binding interactions were screened by using FT-IR spectroscopy. Spectra were collected by using hydrated films over a range of 4000–400 cm−1. The interaction was demonstrated by a significant reduction in the spectral intensities of the amide I (C=O stretching) and amide II bands (C–N stretching coupled to NH bending) of the protein after complexation with metal ions. The binding interaction was further revealed by spectral shifting of the amide I band from 1651 cm−1 (free BSA) to 1653, 1654, 1649, 1655, 1655, and 1654 cm−1 for BSA–Ca2+, BSA–Ba2+, BSA–Ag+, BSA–Ru3+, BSA–Cu2+ and BSA–Co2+ complexes, respectively. The shifting of the amide I band was due to the interactions of metal ions with the O and N atoms of the ligand protein. Estimation of the secondary protein structure showed alteration in the protein conformation, characterized by a marked decrease (12.9–40.3%) in the α-helix accompanied by increased β-sheet and β-turn after interaction with the metal ions. The interaction results of this study were comparable with those reported in our previous investigation of metal ion–BSA interactions using affinity capillary electrophoresis (ACE), which has proven the accuracy of the FT-IR technique in the measurement of interactions between proteins and metal ions.
Thèses sur le sujet "BSA protein"
1
Hecker, Dominic, Daniel Gloess, Peter Frach, and Gerald Gerlach. "Electrospray ionization deposition of BSA under vacuum conditions." SPIE, 2015. https://tud.qucosa.de/id/qucosa%3A35187.
Texte intégralRésumé :
Vacuum deposition techniques like thermal evaporation and CVD with their precise layer control and high layer purity often cannot be applied for the deposition of chemical or biological molecules. The molecules are usually decomposed by heat. To overcome this problem, the Electrospray ionization (ESI) process known from mass spectroscopy is employed to transfer molecules into vacuum and to deposit them on a substrate. In this work, a homemade ESI tool was used to deposit BSA (Bovine serum albumin) layers with high deposition rates. Solutions with different concentrations of BSA were prepared using a methanol:water (MeOH:H2O) mixture (1:1) as solvent. The influence of the substrate distance on the deposition rate and on the transmission current was analyzed. Furthermore, the layer thickness distribution and layer adhesion were investigated.
2
Sales, Elisa Morandé. "Estudo das interações proteína-proteína, proteína-membranas e proteína-agentes desnaturantes por espalhamento de raios-X a baixos ângulos." Universidade de São Paulo, 2018. http://www.teses.usp.br/teses/disponiveis/43/43134/tde-22052018-152931/.
Texte intégralRésumé :
Neste trabalho estudamos por espalhamento de raios-X a baixos ângulos (SAXS) quatro diferentes sistemas de interesse biológico. Visamos investigar a auto-agregação de proteínas e de complexos proteicos que darão origem a fibras amilóides, interação proteína-proteína, simulando ambientes altamente concentrados, interação proteína-membrana simulando vesículas de matriz extracelular (MVs) de sistemas de biomineralização e interações proteína-agentes desnaturantes. No caso de formação de amilóides, investigamos a agregação do domínio GTPase da septina 6 (SEPT6G) e do complexo formado com o domínio GTPase da septina 2 (SEPT2G-SEPT6G). A temperaturas de até 15°C, tanto SEPT6G quanto SEPT2G-SEPT6G apresentam-se predominantemente diméricas em solução. Já a 25°C, o heterodímero SEPT2G-SEPT6G permanece estável enquanto agregados maiores de SEPT6G evoluem e coexistem em solução com SEPT6G-SEPT6G dimérica, sendo que a proporção de dímeros diminui com a temperatura. No estudo das MVs, mostramos que miméticos lipossomais de DPPC e DPPC:DPPS (9:1) possuem as mesmas características estruturais na ausência e presença de cálcio na solução. A interação da proteína anexina V humana (A5), envolvida em processos de biomineralização, impacta na membrana modelo induzindo a formação de nanoporos. A adição da fosfatase alcalina tecido não-específico (TNAP) não altera as propriedades estruturais do proteolipossomo na presença de A5. A ação do surfactante dodecil sulfato de sódio (SDS) a 30 mM não altera a conformação da albumina soro bovina (BSA), de maneira que é observada a formação de micelas de SDS coexistindo com a proteína livre em solução. Já a adição de 50 mM de SDS induz um desenovelamento parcial da proteína, identificado pela análise das curvas de SAXS via modelo de \"colar de pérolas\". A ação de uréia a 3 M e 8 M promove um desenovelamento parcial e total da BSA, respectivamente, com subsequente agregação de proteína dependente da temperatura (T > 30°C). A adição de 6 mM de SDS em proteínas parcialmente desenoveladas pela ação da uréia promove um desenovelamento mais acentuado. O potencial efetivo resultante da interação entre duas proteínas distintas, BSA e lisozima a concentração total de 100 mg/mL em solução, pH 7.0, foi obtido da análise de curvas de SAXS. Para isto, utilizou-se uma análise simplificada (em primeira aproximação) considerando um potencial efetivo de interação entre BSA-BSA, lisozima-lisozima e lisozima-BSA. Variamos a razão molar BSA:LISO até 1:42. No pH estudado, BSA tem uma carga residual superficial de -11e, enquanto a lisozima possui +9e. Conforme variamos a razão molar BSA:LISO, observamos dois regimes para o potencial efetivo resultante: i) até BSA:LISO 1:2, a carga efetiva do sistema é praticamente nula com um potencial resultante de caráter atrativo e ii) para razões entre BSA:LISO 1:3 a 1:42, a carga efetiva aumenta e o potencial resultante tem caráter repulsivo. Assim, lisozima e BSA coexistem sem agregar, através de um delicado balanço de forças atrativas e repulsivas no sistema.<br>In this work we have used small-angle x-ray scattering (SAXS) to study four systems of biological interest. We aim to investigate the self aggregation of proteins and protein complexes that would form amyloid fibers; protein/protein interaction, simulating high concentrations; protein/cell-membrane interaction, simulating extracellular matrix vesicles (MVs) from biomineralizing systems; and protein/denaturating-agents interactions. On the case of amyloid formation, we have investigated the aggregation of G-domain of septin-6 (SEPT6G) and the protein complex formed with G-domain of septin-2 (SEPT2G-SEPT6G). At temperatures lower than 15°C, both SEPT6G and SEPT2G-SEPT6G were found predominantly as dimers. At 25°C, SEPT2G-SEPT6G heterodimer is still stable while aggregates of SEPT6G grow. Both coexist in solutions of SEPT2G-SEPT6G dimers, with the percentage of dimers decreasing the higher the temperature. As for the study of MVs, we have shown that DPPC and DPPC:DPPS (9:1) liposomal mimetics have the same structural characteristics at the absence or presence of Calcium. The interaction with human annexin V protein (A5), related to biomineralization processes, affects the model membrane by the creation of nanopores. The addition of tissue-nonspecific alkaline phosphatase (TNAP) does not change the structural properties of the proteoliposome when A5 is present. The addition of SDS surfactant (30 mM) does not alters the conformation of bovine serum albumin (BSA), and we have observed the formation of SDS micelles coexisting with free protein in solution. The addition of 50 mM of SDS, on the other hand, induces the partial unraveling of the protein, as seen by the analysis of SAXS data via the pearl necklace\'\' model. The effect of adding 3M and 8M urea is, respectively, the partial and total unraveling of BSA, with ensuing aggregation of the protein dependent on the temperature (T > 30°C). The introduction of SDS 6mM promotes further unraveling in proteins that were previously partially unraveled by urea. The resulting effective potential for the interaction between BSA and lysozyme at total concentration of 100mg/ml and 7.0 pH has been obtained from the analysis of SAXS curves. In order to obtain this result we have used a simplified analysis (first order approximation) in which were considered the effective potentials for the interactions between BSA-BSA, lysozyme-lysozyme and lysozyme-BSA. We have varied the BSA:LISO molar ratio up to 1:42. At the studied pH, BSA has a surface residual charge of -11e, and lysozyme has +9e. As we changed the BSA:LISO molar ratio, we have found two regimens for the resulting effective potential: i) up to BSA:LISO 1:2, the effective charge of the system is virtually zero and the resulting potential is attractive; and ii) for BSA:LISO between 1:3 and 1:42 the effective charge increases, and the resulting potential is repulsive. Therefore, both lysozyme and BSA coexist without forming aggregates, by a delicate balance of attractive and repulsive forces.
3
McKeon, Kristin Dianne. "Albumin Adsorption: Inferences of Protein Interactions Measured by Sedimentation both Between Species and Induced by Denaturing." Thesis, Virginia Tech, 2008. http://hdl.handle.net/10919/32082.
Texte intégralRésumé :
Biological development and progression are managed by a diverse macromolecular group called proteins. Protein structure results from a complex folding process that leads to a final active form. This protein state is susceptible to changes in the surrounding environment and an incorrect structure can be produced. Changes in the protein conformation can lead to the formation of protein aggregates. Adsorption of proteins onto surfaces is utilized in many research analyses, but is capable of irreversibly changing the protein structure and causing aggregation. Albumin is a plasma protein that adsorbs on many different surfaces because the structure easily rearranges. The structure of albumin once adsorbed has been shown to deteriorate; however, outcomes of both stabilization and aggregation have been found.
<p>
A dynamic laser light scattering instrument will be utilized to measure the differences in size and determine the amount of aggregation. Our lab has developed a z-axis translating laser light scattering device (ZATLLS) that has been used to measure the sedimentation velocity of several different materials in solution. In this case, bovine serum albumin (BSA) will be adsorbed onto polystyrene particles and the particle settling velocity determined. The settling solution viscosity and density will also be ascertained, so Stokeâ s law can infer the average aggregate size of each experiment. BSA-coated polystyrene particles displayed a more controlled settling behavior compared to non-coated polystyrene particles. Although the BSA-coated particles had a smaller sedimentation velocity, a larger aggregate size was found due to the greater solution viscosity. Therefore, the ZATLLS instrument can be employed to measure sedimentation velocities of multiple interactions and the aggregation level inferred.
<p>
Although most albumin molecules are remarkably similar, there are subtle differences in amino acid residues, length, and charge. Sedimentation velocities for human serum albumin (HSA) coated polystyrene particles and BSA-coated polystyrene particles only had a small difference. However an almost 50% higher solution viscosity was measured in BSA experiment solutions, and resulted in the slower settling of the larger aggregates compared to HSA-coated particles. Viscosity calibration curves for each albumin species were used to determine the amount of protein desorbed from the particles during the settling process. The larger solution viscosity for BSA-coated particle experiments led to a much larger degree of desorption. HSA was shown to be the more stable albumin species when adsorbed onto polystyrene particles.
<p>
Temperature denaturing was performed to aid in the determination of the stability of BSA. Reversible and irreversible conformational changes in BSA were produced at 46ºC and 76ºC respectively. The solutions were cooled to room temperature before adsorption onto polystyrene particles and the sedimentation velocities measured. A 50% difference in average viscosity between the reversibly and irreversibly changed BSA was found. This caused the larger aggregates formed in the 76ºC BSA experiments to have an almost equivalent sedimentation velocity to those in the reversibly denatured BSA experiments. Average aggregate size for reversibly denatured BSA was well within the ranges found for non-denatured BSA. In conclusion, irreversibly denatured BSA formed larger aggregates and was more likely to desorb from the polystyrene particles than reversibly changed BSA.<br>Master of Science
4
Silva, Sueli Maria da. "Estudo da interação entre albumina do soro bovino (BSA) e nanopartículas de maghemita (Y-Fe2O3) funcionalizadas com três diferentes ligantes aniônicos." Universidade Federal de Goiás, 2017. http://repositorio.bc.ufg.br/tede/handle/tede/7803.
Texte intégralRésumé :
Submitted by Franciele Moreira (francielemoreyra@gmail.com) on 2017-09-25T17:05:30Z
No. of bitstreams: 2
Tese -Sueli Maria da Silva - 2017.pdf: 3261955 bytes, checksum: 92803d6e2ab36c8abe127a4441b033bd (MD5)
license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5)<br>Approved for entry into archive by Luciana Ferreira (lucgeral@gmail.com) on 2017-09-26T12:04:50Z (GMT) No. of bitstreams: 2
Tese -Sueli Maria da Silva - 2017.pdf: 3261955 bytes, checksum: 92803d6e2ab36c8abe127a4441b033bd (MD5)
license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5)<br>Made available in DSpace on 2017-09-26T12:04:50Z (GMT). No. of bitstreams: 2
Tese -Sueli Maria da Silva - 2017.pdf: 3261955 bytes, checksum: 92803d6e2ab36c8abe127a4441b033bd (MD5)
license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5)
Previous issue date: 2017-07-06<br>Fundação de Amparo à Pesquisa do Estado de Goiás - FAPEG<br>Biological applications of nanoparticles require understanding the interaction between proteins and nanoparticles. In this thesis were performed studies of interaction between the protein BSA and maghemite nanoparticles functionalized with different anionic ligands (citrate ions, tripolyphosphate ions and bilayer laurate ions ), by three analytical techniques: isothermal titration calorimetry (ITC), adsorption isotherm by hydrodynamic diameter measurements using dynamic light scattering (DLS) and fluorescence spectroscopy. The values of the interaction constants (Ka) of BSA association on nanoparticles surface by DLS measurements were similar to those obtained by ITC, for the three systems. On the other hand, the study by ITC did not allows determining of the stoichiometry values (Nmax) of the association processes. The results obtained by the fluorescence technique are highly discrepant of the results obtained by the other two techniques. The evaluation of the functionalizing agent effect on the interaction between magnetite nanoparticles and BSA showed that there are differences in the Ka values, and in the energetic profiles of the interactions for the three systems studied. The Ka value for the interaction between BSA and citrate functionalized nanoparticles was in the order of 106 M-1, whereas for the other systems the values of Ka were 104 M-1. The energetic profile of the interactions, was endothermic in the system BSA-NP-Citrate, and exothermic for BSA-NP-Laurato and for BSA-NP-Tripolyphosphate. From the analysis of the thermodynamic parameters, it was possible to suggest that the interaction in the BSA-NP-citrate system was predominantly electrostatic, whereas the interaction in the other systems predominantly involved hydrogen bonds. The albumin estearase activity was reduced by the interaction with the nanoparticles, and was dependent upon the nanoparticles concentration. The reduction in stearase activity was higher for the -BSA-NP-Laurate system. In this work, the dynamic light scattering technique (DLS) was used, for the first time, to study of adsorption of BSA on functionalized maghemite nanoparticles. In addition, under the experimental conditions used, DLS was the only technique that provided (Nmax) values similar to those estimated.<br>Aplicações biológicas de nanopartículas inorgânicas demandam o entendimento das interações entre as nanopartículas e as proteínas. Nessa tese foram realizados estudos de interação entre a proteína BSA e nanopartículas de maghemita funcionalizadas com diferentes ligantes aniônicos (íons citrato, íons tripolifosfato e bicamada de íons laurato), por três técnicas analíticas: titulação de calorimetria isotérmica (ITC), isoterma de adsorção por medidas de diâmetro hidrodinâmico, empregando espalhamento de luz dinâmico (DLS) e espectroscopia de fluorescência. Os valores das constantes de interação (Ka) obtidos pelos estudos de adsorção da BSA sobre as nanopartículas por medidas de DLS foram semelhantes aos obtidos por ITC, para os três sistemas. Por outro lado, os estudos por ITC, não permitiram a determinação dos valores das estequiometrias de reação (Nmax). Os resultados obtidos pela técnica de fluorescência são altamente discrepantes em relação aos resultados obtidos pelas outras duas técnicas. A avaliação do papel do agente funcionalizante sobre a interação entre as nanopartículas e a BSA mostrou que há diferenças no perfil das interações nos três sistemas estudados. O valor da constante de associação para o sistema BSA-NP-Citrato foi da ordem de 106 mol.L-1, enquanto que para os demais sistemas foi de 104 mol.L-1. Os parâmetros termodinâmicos obtidos para o sistema BSA-NP-Citrato (ΔH = 5x103 cal.mol-1; ΔS+ +45 cal.mol-1; ΔG= -8410 cal.mol-1) sugerem que o processo de adsorção foi predominantemente de natureza eletrostática. Por outro lado, os parâmetros termodinâmicos obtidos para os sistemas, BSA-NP-Laurato (ΔH=-1,38x105 cal.mol-1; ΔS= -441cal.mol-1; ΔG= -6582 cal.mol-1) e BSA-NP-Tripolifosfato (ΔH = - 1,86x104 cal.mol-1; ΔS= -41 cal.mol-1; ΔG= -6352 cal.mol-1) sugerem que o processo de adsorção nesses sistemas tenha ocorrido predominantemente por pontes de hidrogênio. A atividade de esterase da albumina foi reduzida pela interação com as nanopartículas, e foi dependente da concentração das mesmas. A redução na atividade da esterase ocorreu em maior extensão para o sistema BSA-NP-Laurato. Nesse trabalho, a técnica de espalhamento de luz dinâmico (DLS) foi empregada pela primeira vez para o estudo de adsorção de BSA sobre nanopartículas de maghemita funcionalizadas, e se mostrou adequada. Além disso, nas condições experimentais utilizadas, foi a única técnica que forneceu valores da estequiometria de reação (Nmax) semelhante aos valores estimados.
5
Lapinska, Urszula. "Microfluidics and chemical kinetics to analyse protein interactions, aggregation, and physicochemical properties." Thesis, University of Cambridge, 2019. https://www.repository.cam.ac.uk/handle/1810/284929.
Texte intégralRésumé :
Proteins play a major role in living systems and present a wide spectrum of functionalities. Many different types of proteins are involved into biological processes, such as the catalysis of biochemical reactions, cellular membrane transport, immune system response and DNA replication. However, some proteins and peptides might become harmful to living organisms; for example, their abnormal aggregation causes neurodegenerative disorders including Alzheimer disease (AD). One of the causes of AD is the presence of amyloid beta peptides Aβ(1-42), Aβ(1-40), which self-assemble into insoluble fibrils and plaques, which surround neuronal cells impeding synapsis. The number of AD patients is increasing, but a cure has not been founded yet. Therefore, it is crucial to investigate the mechanisms underlying amyloid aggregation and screening for compounds able to prevent this irreversible process. Microfluidics permits characterising the physicochemical properties of proteins, investigate their aggregation and study their interactions with other molecules. Chemical kinetics allows studying the microscopic events occurring during protein self-assembly. The combination of these two techniques provides a powerful tool for the identification of compounds inhibiting the aggregation process. In this thesis by using microfluidics, chemical kinetics and other biophysical assays, I have investigated the proteins isoelectric point (pI) and the inhibition of aberrant Aβ(1-42) self-assembly process. Firstly, I describe the development of a microfluidic platform allowing for the measurement of the protein pI, in a gradient-free manner. This approach overcomes a fundamental limitation of convectional techniques that is the achievement of a stable and well-controlled pH gradient. Secondly, I investigate the inhibiting effect of llama nanobodies on Aβ(1-42) aggregation. The findings from this study show that nanobodies target monomeric species with high affinity whereas interactions with fibril surfaces are weak. Finally, I discuss the use of other compounds inhibiting specific nucleation stages. These include the chaperones clusterin and brichos, as well as soot and pure carbon nanoparticles. Importantly, the addition of both chaperones to Aβ(1-42) solutions has an additive inhibitory effect on aggregation. My findings will improve the characterization of the physicochemical properties of proteins as well as providing promising candidates for the inhibition of specific stages of amyloid beta aggregation opening the way to possible cures for AD disease.
6
Tetzner, Tatiane Almeida Drummond [UNESP]. "Efeitos da substituição do soro fetal bovino (SFB) e da albumina sérica bovina (BSA) pela ovalbumina (OVA) na produção in vitro de embriões bovinos." Universidade Estadual Paulista (UNESP), 2007. http://hdl.handle.net/11449/98201.
Texte intégralRésumé :
Made available in DSpace on 2014-06-11T19:29:16Z (GMT). No. of bitstreams: 0
Previous issue date: 2007-02-26Bitstream added on 2014-06-13T19:38:29Z : No. of bitstreams: 1
tetzner_tad_me_jabo.pdf: 994984 bytes, checksum: dc3b9f9b3b09f1b6ee7040b88cd31ad8 (MD5)<br>Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)<br>Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)<br>O presente trabalho objetivou avaliar os efeitos da substituição do SFB e do BSA pela OVA na PIV, por estudos nas etapas de maturação, fecundação e cultivo in vitro. Observamos que durante a etapa de maturação, a concentração 4mg/mL de OVA não afetou a maturação nuclear (82,66%) e a migração de grânulos corticais (GC) para a periferia dos oócitos (54,21%), sendo, portanto, utilizada nos experimentos subseqüentes. Foi observado que as fontes protéicas SFB, BSA, OVA, e BSA com OVA (BO) não afetaram (p>0,05) as taxas de maturação nuclear e migração de GC. Para a sigla dos tratamentos, as fontes protéicas foram identificadas pelas iniciais (SFB=S, BSA=B e OVA=O). Cada tratamento foi abreviado com a primeira letra referente à etapa de maturação, a segunda à fecundação, e a terceira ao cultivo. Quanto às taxas de formação de pronúcleo (PN) observamos que o grupo SO (76,67% de 2 PN) foi semelhante (p>0,05) ao grupo controle (82,95% de 2 PN). A etapa de CIV permitiu avaliar que os diferentes tratamentos foram semelhantes (p>0,05) quanto à taxa de clivagem. Entretanto, quanto à taxa de produção de blastocistos, o grupo OOO (26,0%) foi semelhante (p>0.05) aos grupos SOS (33,8%), BBB (35,8%), BOB (32%), e OBO (33%), mas foi inferior (p<0,05) aos grupos CONT (45%) e SBS (42,8%). Quanto à taxa de eclosão, o grupo OOO (20,4%), foi inferior (p<0,05) aos grupos CONT (46,2%), SBS (43,4%), SOS (38,4%), BBB (41,6%), e semelhante aos grupos BOB (28,2%) e OBO (25,4%). Concluímos que é possível produzir embriões bovinos na ausência de SFB e/ou BSA, com a fonte protéica OVA, embora tanto a quantidade como a qualidade dos blastocistos tenham se apresentado inferiores em relação àqueles produzidos na presença de SFB e/ou BSA.<br>The present work aimed to evaluate the effects of FCS and BSA substitution for OVA on in vitro production of bovine embryos, studying in vitro maturation, fertilization, and development. For maturation, we observed that the concentration 4mg/mL of OVA didn't affect nuclear maturation (82.66%), and cortical granule (CG) migration (54.21%), which indicated its use in the subsequent experiments. It was observed that the protein sources FBS, BSA, OVA and BO didn't significantly affect (p>0.05) the rates of nuclear maturation and CG migration. For evaluation of pronucleus (PN) formation rates, we observed that the SO group (the first letter means the protein source for the maturation stage, the second for the fertilization, and the third for the development), (76.67% of 2 PN) was similar (p>0.05) to the control group (82.95% of 2 PN). However, two pronucleus formation rates in BB (56.98%), BO (39.02%), OB (37.36%) and OO (39.24%) were different (p<0.05) from the control group (82.95% of 2 PN). Different treatments (CONT, SBS, SOS, BBB, BOB, OOO, OBO) were similar (p>0.05) in cleavage rates. However, regarding to blastocyst production rates, the OOO group (26.0%) was similar (p>0.05) to the SOS group (33.8%), BBB (35.8%), BOB (32%), and OBO (33%) groups, but it was inferior (p <0.05) compared to the CONT (45%) and SBS (42.8%) groups. In relation to blastocyst hatching rate, the OOO group (20.4%) was inferior (p<0.05) when compared to the CONT (46.2%), SBS (43.4%), SOS (38.4%), BBB (41.6%) groups, and it was to BOB (28.2%) and OBO (25.4%) groups. We concluded that it s possible to produce bovine embryos in the absence of FBS and/or BSA using ovalbumin (OVA) as the protein source, even though decreased quantity and quality rates of bovine blastocysts were observed.
7
Tetzner, Tatiane Almeida Drummond. "Efeitos da substituição do soro fetal bovino (SFB) e da albumina sérica bovina (BSA) pela ovalbumina (OVA) na produção in vitro de embriões bovinos /." Jaboticabal : [s.n.], 2007. http://hdl.handle.net/11449/98201.
Texte intégralRésumé :
Orientador: Joaquim Mansano Garcia<br>Banca: César Roberto Esper<br>Banca: Simone Cristina Méo Niciura<br>Resumo: O presente trabalho objetivou avaliar os efeitos da substituição do SFB e do BSA pela OVA na PIV, por estudos nas etapas de maturação, fecundação e cultivo in vitro. Observamos que durante a etapa de maturação, a concentração 4mg/mL de OVA não afetou a maturação nuclear (82,66%) e a migração de grânulos corticais (GC) para a periferia dos oócitos (54,21%), sendo, portanto, utilizada nos experimentos subseqüentes. Foi observado que as fontes protéicas SFB, BSA, OVA, e BSA com OVA (BO) não afetaram (p>0,05) as taxas de maturação nuclear e migração de GC. Para a sigla dos tratamentos, as fontes protéicas foram identificadas pelas iniciais (SFB=S, BSA=B e OVA=O). Cada tratamento foi abreviado com a primeira letra referente à etapa de maturação, a segunda à fecundação, e a terceira ao cultivo. Quanto às taxas de formação de pronúcleo (PN) observamos que o grupo SO (76,67% de 2 PN) foi semelhante (p>0,05) ao grupo controle (82,95% de 2 PN). A etapa de CIV permitiu avaliar que os diferentes tratamentos foram semelhantes (p>0,05) quanto à taxa de clivagem. Entretanto, quanto à taxa de produção de blastocistos, o grupo OOO (26,0%) foi semelhante (p>0.05) aos grupos SOS (33,8%), BBB (35,8%), BOB (32%), e OBO (33%), mas foi inferior (p<0,05) aos grupos CONT (45%) e SBS (42,8%). Quanto à taxa de eclosão, o grupo OOO (20,4%), foi inferior (p<0,05) aos grupos CONT (46,2%), SBS (43,4%), SOS (38,4%), BBB (41,6%), e semelhante aos grupos BOB (28,2%) e OBO (25,4%). Concluímos que é possível produzir embriões bovinos na ausência de SFB e/ou BSA, com a fonte protéica OVA, embora tanto a quantidade como a qualidade dos blastocistos tenham se apresentado inferiores em relação àqueles produzidos na presença de SFB e/ou BSA.<br>Abstract: The present work aimed to evaluate the effects of FCS and BSA substitution for OVA on in vitro production of bovine embryos, studying in vitro maturation, fertilization, and development. For maturation, we observed that the concentration 4mg/mL of OVA didn't affect nuclear maturation (82.66%), and cortical granule (CG) migration (54.21%), which indicated its use in the subsequent experiments. It was observed that the protein sources FBS, BSA, OVA and BO didn't significantly affect (p>0.05) the rates of nuclear maturation and CG migration. For evaluation of pronucleus (PN) formation rates, we observed that the SO group (the first letter means the protein source for the maturation stage, the second for the fertilization, and the third for the development), (76.67% of 2 PN) was similar (p>0.05) to the control group (82.95% of 2 PN). However, two pronucleus formation rates in BB (56.98%), BO (39.02%), OB (37.36%) and OO (39.24%) were different (p<0.05) from the control group (82.95% of 2 PN). Different treatments (CONT, SBS, SOS, BBB, BOB, OOO, OBO) were similar (p>0.05) in cleavage rates. However, regarding to blastocyst production rates, the OOO group (26.0%) was similar (p>0.05) to the SOS group (33.8%), BBB (35.8%), BOB (32%), and OBO (33%) groups, but it was inferior (p <0.05) compared to the CONT (45%) and SBS (42.8%) groups. In relation to blastocyst hatching rate, the OOO group (20.4%) was inferior (p<0.05) when compared to the CONT (46.2%), SBS (43.4%), SOS (38.4%), BBB (41.6%) groups, and it was to BOB (28.2%) and OBO (25.4%) groups. We concluded that its possible to produce bovine embryos in the absence of FBS and/or BSA using ovalbumin (OVA) as the protein source, even though decreased quantity and quality rates of bovine blastocysts were observed.<br>Mestre
8
Coffin, Jared M. "THE ROLE OF PROTEIN AS A FOAM BOOSTER IN THE PRESENCE OF OIL." Miami University / OhioLINK, 2019. http://rave.ohiolink.edu/etdc/view?acc_num=miami1564440064244048.
Texte intégral
9
Nadhom, Hama. "Protein Microparticles for Printable Bioelectronics." Thesis, Linköpings universitet, Biosensorer och bioelektronik, 2015. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-119637.
Texte intégralRésumé :
In biosensors, printing involves the transfer of materials, proteins or cells to a substrate. It offers many capabilities thatcan be utilized in many applications, including rapid deposition and patterning of proteins or other biomolecules.However, issues such as stability when using biomaterials are very common. Using proteins, enzymes, as biomaterialink require immobilizations and modifications due to changing in the structural conformation of the enzymes, whichleads to changes in the properties of the enzyme such as enzymatic activity, during the printing procedures andrequirements such as solvent solutions. In this project, an innovative approach for the fabrication of proteinmicroparticles based on cross-linking interchange reaction is presented to increase the stability in different solvents.The idea is to decrease the contact area between the enzymes and the surrounding environment and also preventconformation changes by using protein microparticles as an immobilization technique for the enzymes. The theory isbased on using a cross-linking reagent trigging the formation of intermolecular bonds between adjacent proteinmolecules leading to assembly of protein molecules within a CaCO3 template into a microparticle structure. TheCaCO3 template is removed by changing the solution pH to 5.0, leaving behind pure highly homogenous proteinmicroparticles with a size of 2.4 ± 0.2 μm, according to SEM images, regardless of the incubation solvents. Theenzyme model used is Horse Radish Peroxidase (HRP) with Bovine Serum Albumin (BSA) and Glutaraldehyde (GL)as a cross-linking reagent. Furthermore, a comparison between the enzymatic activity of the free HRP and the BSAHRPprotein microparticles in buffer and different solvents are obtained using Michaelis-Menten Kinetics bymeasuring the absorption of the blue product produced by the enzyme-substrate interaction using a multichannelspectrophotometer with a wavelength of 355 nm. 3,3’,5,5’-tetramethylbenzidine (TMB) was used as substrate. As aresult, the free HRP show an enzymatic activity variation up to ± 50 % after the incubation in the different solventswhile the protein microparticles show much less variation which indicate a stability improvement. Moreover, printingthe microparticles require high microparticle concentration due to contact area decreasing. However, usingmicroparticles as a bioink material prevent leakage/diffusion problem that occurs when using free protein instead.
10
Silva, Junaine Vasques da. "Dinâmica de proteínas: efeitos da hidratação em estrato córneo e de detergentes em albumina." Universidade Federal de Goiás, 2002. http://repositorio.bc.ufg.br/tede/handle/tede/7618.
Texte intégralRésumé :
Submitted by Cássia Santos (cassia.bcufg@gmail.com) on 2017-07-25T13:32:13Z
No. of bitstreams: 2
Dissertação - Junaine Vasques da Silva - 2002.pdf: 3727327 bytes, checksum: 4cb8c1db4d3fb95798779f39aae78673 (MD5)
license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5)<br>Approved for entry into archive by Luciana Ferreira (lucgeral@gmail.com) on 2017-07-26T12:05:00Z (GMT) No. of bitstreams: 2
Dissertação - Junaine Vasques da Silva - 2002.pdf: 3727327 bytes, checksum: 4cb8c1db4d3fb95798779f39aae78673 (MD5)
license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5)<br>Made available in DSpace on 2017-07-26T12:05:00Z (GMT). No. of bitstreams: 2
Dissertação - Junaine Vasques da Silva - 2002.pdf: 3727327 bytes, checksum: 4cb8c1db4d3fb95798779f39aae78673 (MD5)
license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5)
Previous issue date: 2002-12-19<br>Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - CAPES<br>The main function of the most superficial layer of the epidermis, the Stratum Corneum (SC), is to provide a physical barrier that controls the transepidermal water loss as well as the permeation of another substances in both directions across the skin. The SC is formed by anabolically dead cells, the terminally differentiated corneocyte, and its function is essentially accomplished by forming a highly insoluble protein structure on the surface of the corneocytes, termed the cornified cell envelope, and by impeding water diffusion across the SC by mortaring the corneocytes together by layers of skin-specific lipids, essentially ceramide, cholesterol and fatty acid. In this work the cell envelope of the SC was spin labeled with a sulfhydryl-specific nitroxide reagent to investigate the water content effects upon the protein dynamics directly in the intact tissue. A two-state model for the nitroxide side chain described the coexistence of two spectral components in the electron paramagnetic resonance (EPR) spectra. The so-called strongly immobilized component, S, is associated with the EPR signal of a motionally restricted nitroxide fraction having its N-O group hydrogen bonded to protein (rigid structure) while the weakly immobilized component, W, corresponds to the signal provided by the spin labels with higher mobility (~10 times greater) exposed to the aqueous environment. The relative populations between these two mobility states, S and W, are in thermodynamic equilibrium. The standard Gibbs free energy, enthalpy and entropy changes for transferring the nitroxide side chain from the state contacting the solvent, W, to the one contacting protein, S, indicated that the reduction of the SC water content to below ~h 0.69, g H2O per g dry SC, stabilizes the protein interacting state, S. Upon decreasing the SC hydration level below ~h 0.69 the segmental motion of the polypeptide chains and the rotational motion of the spin-labeled side chain were also constrained. To test our methodology in a pure and very well known protein, we also studied the effects of two types of detergents on the bovine serum albumin (BSA). Both detergents, the anionic sodium dodecyl sulfate (SDS) and the zwitterionic N-hexadecyl-N,N-dimethyl-3-ammonium-1-propanesulfonate (HPS) increase the mobility of the protein backbone and of the nitroxide side chain. The thermodynamic parameters indicated that these detergents destabilize the protein favoring less compact conformations. This work can also be useful to improve the spectral analysis of site-directed spin labeling, especially for a more quantitative description in terms of thermodynamic parameters.<br>A camada mais superficial da epiderme, o Estrato Córneo (EC), tem como função principal a formação de uma barreira física que controla a perda de água do corpo bem como a permeação de outras substâncias em ambas as direções da pele. O EC é formado por células anabolicamente mortas, os corneócitos, os quais sofreram diferenciação celular terminal, e sua função é realizada formando uma estrutura de proteínas altamente insolúveis na superfície do corneócito, chamada de envelope celular, e também uma matriz lipídica, essencialmente ceramídios, colesterol e ácidos graxos, que dificultam a difusão da água. Neste trabalho, o EC foi marcado com marcadores de spin específicos para reagir com os grupos sulfidrilas das proteínas, para investigar os efeitos do conteúdo de água na dinâmica de proteínas diretamente no tecido intacto. Um modelo de dois estados para a cadeia lateral do nitróxido descreveu a coexistência de duas componentes espectrais de ressonância paramagnética eletrônica (RPE). A componente denominada fortemente imobilizada (S), surge de uma fração de marcadores com o átomo de oxigênio do nitróxido ligado à proteína (estrutura rígida) enquanto a componente fracamente imobilizada é gerada pelos marcadores com mobilidade mais alta (~10 vezes maior) e expostos ao ambiente aquoso. As populações relativas entre estes dois estados de mobilidade, S e W, estão em equilíbrio termodinâmico. Os parâmetros da termodinâmica: energia livre padrão de Gibbs, entalpia e entropia, envolvidos na transferência da cadeia lateral do nitróxido do estado W, contatando ao solvente, para o estado S, contatando a proteína, indicaram que a redução do conteúdo de água para abaixo de ~0.69g de H2O por g de EC seco, estabiliza o estado S (cadeia lateral do nitróxido dobrada sobre a cadeia principal da proteína). Ao diminuir o nível de hidratação para abaixo de ~ h 0.69 (g H2o/g EC seco) o movimento local da cadeia polipeptídica e o movimento rotacional da cadeia lateral do marcador de spin foram ambos reduzidos. Para testar nossa metodologia em uma proteína pura e bem conhecida, estudamos os efeitos de dois tipos de detergentes sobre a albumina do soro bovino (BSA). Ambos os detergentes, o aniônico dodecil sulfato de sódio (SDS) e o ziteriônico N-hexadecil-N,N-dimetil-3-amônio-1-propanosulfonato (HPS) aumentaram a mobilidade da cadeia principal da proteína e da cadeia lateral do nitróxido. Os parâmetros termodinâmicos indicaram que estes detergentes desestabilizam a proteína favorecendo conformações menos compactas. Os resultados do presente trabalho também podem contribuir para aprimorar a
Livres sur le sujet "BSA protein"
1
Hope, James, and Mark P. Dagleish. Prion-protein-related diseases of animals and man. Oxford University Press, 2011. http://dx.doi.org/10.1093/med/9780198570028.003.0041.
Texte intégralRésumé :
Scrapie, bovine spongiform encephalopathy (BSE), Creutzfeldt–Jakob disease (CJD), and related diseases of mink (transmissible mink encephalopathy), mule deer and elk (chronic wasting disease) are the founder members of a group of diseases called the transmissible degenerative (or spongiform) encephalopathies (TSE). These diseases can be transmitted by prions from affected to healthy animals by inoculation or by feeding diseased tissues. Prions are cellular proteins that can transfer metabolic and pathological phenotypes vertically from parent to progeny or horizontally between cells and animals. TSEs are characterised by the accumulation of the prion form of the mammalian prion protein (PrPC) in the central nervous system or peripheral tissues of animals and humans. Mutations of the human PrP gene are linked to rare, familial forms of disease and prion-protein gene polymorphisms in humans and other species are linked to survival time and disease characteristics in affected individuals. Iatrogenic transmission of CJD in man has occurred, and a variant form of CJD (vCJD) is due to cross-species transmission of BSE from cattle to humans. Atypical forms of scrapie and BSE have been identified during large-scale monitoring for TSEs worldwide. This chapter outlines our current understanding of scrapie, BSE, CJD and other TSEs and highlights recent progress in defining the role in disease of the prion protein, PrP.
2
Textbook of Protein Engineering: For BE/B. TECH/BCA/MCA/ME/M. TECH/Diploma/B. Sc/M. Sc/BBA/MBA/Competitive Exams and Knowledge Seekers. Independently Published, 2021.
Trouver le texte intégral
3
Eder-Ramsauer, Andreas, Seongcheol Kim, Andy Knott, and Marina Prentoulis, eds. Populism, Protest, and New Forms of Political Organisation. Nomos Verlagsgesellschaft mbH & Co. KG, 2022. http://dx.doi.org/10.5771/9783748931669.
Texte intégralRésumé :
The past decade saw new forms of protest in public squares around the world: from Zuccotti Park to Maidan, from the Yellow Vests’ roundabout occupations to the Querdenker anti-lockdown protests. The performative enactment of an unredeemed ‘people’ reclaiming its rightful sovereignty in such locations suggests intersections with both populism—whose meteoric rise also defined the decade—as well as new forms of political organisation that emerged in the wake of the post-2010 protest wave, from ‘digital parties’ to ‘movement parties’. This edited volume explores these intersections and the manifold tensions underlying them, drawing on numerous theoretical approaches and case studies ranging from South America to Southern Europe. With contributions by Marwan Attalah, M.A.; Morgane Belhadi, M.A.; Dr. Lluis de Nadal; Williames de Sousa da Costa; Dr. Seongcheol Kim; Étienne Levac, B.A.; Marieluise Mühe, M.A.; Prof. Dr. Marina Prentoulis; Dr. Céline Righi; Héctor Ríos-Jara, M.A.; Florian Skelton, B.A. and Dr. Thomás Zicman de Barros.
4
Ehrenreich-Risner, Veronica. Bantu Authorities. The Rowman & Littlefield Publishing Group, 2022. https://doi.org/10.5040/9781666985467.
Texte intégralRésumé :
In Bantu Authorities: Apartheid's System of Race and Ethnicity, Veronica Ehrenreich-Risner provides the first holistic study of the Bantu Authorities (BA) system that implemented rural apartheid. The system extended segregation by including ethnos theory to establish underfunded “self-governing” homelands to curb the expense of “native” administration yet retain control of the cheap labor upon which white capital depended. Based on over sixty interviews with Zulus and former commissioners, and archival research, Bantu Authorities proves the primary objective of the system was to protect white capital, with white racial purity secondary. Ehrenreich-Risner argues that the system disrupted the Brownlee tradition of guardianship for commissioners and the tradition of reciprocity for ubukhosi. Bantu Authorities ends by examining the lingering consequences of rural apartheid and asks what rural Africans have gained with majority rule when they remain bound to BA structures.
5
Coelho, Francisco. Disfarces do medo: Da desinformação aos equívocos sobre as drogas. Brazil Publishing, 2021. http://dx.doi.org/10.31012/978-65-5861-506-4.
Texte intégralRésumé :
O que é o medo? Certamente é algo que mexe conosco. Sejamos adolescentes ou adultos, por vezes ele nos aprisiona. Chega sorrateiro e se instala. Ele nos faz de refém. Ele nos inibe. E o mais perspicaz de seus disfarces: pode nos afastar do conhecimento. Assim, se deixamos de conhecer, podemos nos tornar receosos para conversar sobre alguns assuntos que fazem parte da vida dos jovens. O tema “drogas” é um bom exemplo. O medo faz você ter “medo” de conversar sobre drogas, por exemplo. Alguns preferirão evitar o papo. Talvez, como forma de proteção. Mas, será que ignorar o assunto, de fato, protege? Ou ele apenas nos aterroriza? Será que conversar sobre a maconha e outras drogas não seria um ato de cuidado e proteção, que nos libertaria dos preconceitos e dos equívocos naturalizados em nossa sociedade? A conversa entre Paulo, pai de Gabriel, e Marcos, um professor bem informado, revela como a interação entre os pais e professores pode ser divertida e acolhedora. Será que os pais também aprendem na escola? Será que a informação pode reduzir o medo que os pais têm de falar sobre alguns assuntos? Que tal descobrir isso nas páginas desta obra? Boa leitura e boas reflexões!
6
Gerke, Barbara. Buddhist Healing and Taming in Tibet. Edited by Michael Jerryson. Oxford University Press, 2016. http://dx.doi.org/10.1093/oxfordhb/9780199362387.013.38.
Texte intégralRésumé :
This chapter centers on Tibetan Buddhist patterns and themes of healing and addresses the inter-relationship of medicine and religion in the practice of Tibetan medicine, also called Sowa Rigpa (gso ba rig pa), the “science of healing,” and how Buddhist rituals are employed to enhance the potency of medicines and to protect the pharmacy and the people working in it from accidents and obstacles during difficult manufacturing processes. Examples focus on the refinement of mercury in mercury sulphide ash for use in “precious pills” (rin chen ril bu). The chapter establishes an argument for a parallel between Buddhist ideas of “taming” demons into becoming protectors of the religious teachings and the pharmacological transformation of poisonous substances, especially the pharmacological practices of “taming” mercury into a potent elixir, and what this tells us about Tibetan medical approaches to what is considered “beneficial” and “harmful.”
Chapitres de livres sur le sujet "BSA protein"
1
Xu, Yan, Changjun Zhou, Qiang Zhang, and Bin Wang. "3D Protein Structure Prediction with BSA-TS Algorithm." In Trends in Applied Knowledge-Based Systems and Data Science. Springer International Publishing, 2016. http://dx.doi.org/10.1007/978-3-319-42007-3_38.
Texte intégral
2
Yoshida, Hiroyuki, and Yuichi Fujiwara. "Chitosan Dextran-DEAE Composite for Separation of Proteins: Adsorption of BSA." In The Kluwer International Series in Engineering and Computer Science. Springer US, 1996. http://dx.doi.org/10.1007/978-1-4613-1375-5_131.
Texte intégral
3
Walker, John M. "The Bicinchoninic Acid (BCA) Assay for Protein Quantitation." In Springer Protocols Handbooks. Humana Press, 1996. http://dx.doi.org/10.1007/978-1-60327-259-9_3.
Texte intégral
4
Walker, John M. "The Bicinchoninic Acid (BCA) Assay for Protein Quantitation." In Springer Protocols Handbooks. Humana Press, 2009. http://dx.doi.org/10.1007/978-1-59745-198-7_3.
Texte intégral
5
Sultana, Rukhsana, Marzia Perluigi, and D. Allan Butterfield. "Proteomics Identification of Oxidatively Modified Proteins in Bra." In Proteomics. Humana Press, 2009. http://dx.doi.org/10.1007/978-1-60761-157-8_16.
Texte intégral
6
Andrade, J. D., V. Hlady, and S. I. Jeon. "Poly(ethylene oxide) and Protein Resistance." In Advances in Chemistry. American Chemical Society, 1996. http://dx.doi.org/10.1021/ba-1996-0248.ch003.
Texte intégral
7
Blank, Martin. "Electric Stimulation of Protein Synthesis in Muscle." In Electromagnetic Fields. American Chemical Society, 1995. http://dx.doi.org/10.1021/ba-1995-0250.ch009.
Texte intégral
8
Stayton, Patrick S., Jill M. Olinger, Susan T. Wollman, Paul W. Bohn, and Stephen G. Sligar. "Engineering Proteins for Electrooptical Biomaterials." In Molecular and Biomolecular Electronics. American Chemical Society, 1994. http://dx.doi.org/10.1021/ba-1994-0240.ch019.
Texte intégral
9
Hong, Felix T. "Retinal Proteins in Photovoltaic Devices." In Molecular and Biomolecular Electronics. American Chemical Society, 1994. http://dx.doi.org/10.1021/ba-1994-0240.ch022.
Texte intégral
10
Mines, Gary A., Benjamin E. Ramirez, Harry B. Gray, and Jay R. Winkler. "Electron Tunneling in Engineered Proteins." In Photochemistry and Radiation Chemistry. American Chemical Society, 1998. http://dx.doi.org/10.1021/ba-1998-0254.ch004.
Texte intégralActes de conférences sur le sujet "BSA protein"
1
Basha, Shaik, Shanmukha Sreeya Devarakonda, Darshan Chikkanayakanahalli Mukunda, et al. "Investigation of Protein Thermal Aggregation Using Autofluorescence Spectroscopy." In Frontiers in Optics. Optica Publishing Group, 2024. https://doi.org/10.1364/fio.2024.jd4a.6.
Texte intégral
2
Hansen, Douglas C., and Stephen C. Dexter. "A Novel Biopolymer and Its Application as an Anticorrosive for Stainless Steel Alloys in Seawater." In CORROSION 1993. NACE International, 1993. https://doi.org/10.5006/c1993-93491.
Texte intégralRésumé :
Abstract The adhesive protein of the common blue mussel, Mytilus edulis(L) is a novel biopolymer in that it contains a catechol, L,3,4-dihydroxy-phenylalanine (L-Dopa) in its primary sequence. Adsorption of this protein onto S30403 stainless steel coupons imparts a significant resistance to corrosion when the test coupons are immersed in 3% NaCl and with an applied potential up to +350 mV (SCE). Comparison with other proteins and polymers such as serum albumin (BSA), a low molecular weight catechol (DHBA), and poly-L-lysine indicates that none are as effective as the mussel protein at inhibiting corrosion of the stainless steel alloy tested. This indicates that the adhesive protein may have an advantage over other organic polymers in use at the present time in corrosion control technology.
3
Karimi, Shima, and Akram Alfantazi. "Bovine Serum Albumin Adsorption on AISI 316L in Phosphate-Buffered Saline Solutions." In CORROSION 2016. NACE International, 2016. https://doi.org/10.5006/c2016-07182.
Texte intégralRésumé :
Abstract Ion release and bovine serum albumin (BSA) adsorption on AISI 316L (UNS S31603) electrodes was investigated by performing cyclic voltammetry experiments and electrochemical quartz crystal microbalance (EQCM) analyses simultaneously. The quartz crystals were immersed in phosphate-buffered saline (PBS) solutions containing 2 g L-1 BSA and the potential was swept from 0.1 to -1.2 V vs. Ag/AgCl with scan rates of 50, 75, and 100 mV s-1. The results of cyclic voltammetry tests revealed one anodic and one cathodic peak. These peaks could show iron dissolution and BSA adsorption on 316L resonators. These findings were confirmed by EQCM results in which the 316L gained and lost weight loss during cathodic and anodic scans. In addition, the EQCM results indicated Faradaic dissolution of iron and adsorption of protein-water complexes on 316L. The amount of iron release and protein/water complexes adsorption were 1.49 μg cm-2 in 8.4 s and 590.6 μg cm-2 in 21.4 s, respectively.
4
Thornley, Blake, Anne Neville, Mike Bryant, and Robert Beadling. "Investigation into the Repassivation Kinetics of CoCrMo for Applications in a Simulated Biological Environment." In CORROSION 2019. NACE International, 2019. https://doi.org/10.5006/c2019-13232.
Texte intégralRésumé :
Abstract The re-passivation kinetics and composition of the passive film of CoCrMo alloys in simulated body fluids have been investigated, with key emphasis being to assess the effect that proteins have on these features. The kinetics were analyzed using potentiostatic polarization, applying a second order exponential decay to the current transients obtained, which consists of two phases: coverage and thickening. Repassivation occurred quickest in a phosphate environment with presence of bovine serum albumin (BSA) hindering the process as it inhibits access of the oxidant. By using X- ray photoelectron spectroscopy (XPS) the composition of the re-passivated layer was studied. As expected, the film is mainly composed of chromium (III) oxide with small amounts of cobalt (II) oxide and molybdenum oxides (IV-VI). When exposed to BSA the percentage of molybdenum in the passive film decreases. This is shown to be due to the protein having a high affinity for the element causing it to be lost to solution when the metal was exposed to corrosion.
5
Chen, Pin-Chuan, Hong Wang, Daniel S. Park, et al. "Protein Adsorption in a Continuous Flow Microchannel Environment." In ASME 2008 International Mechanical Engineering Congress and Exposition. ASMEDC, 2008. http://dx.doi.org/10.1115/imece2008-68094.
Texte intégralRésumé :
Protein adsorption is a critical issue in microfluidic devices especially for those reactions depending on proteins like the polymerase chain reaction (PCR). Understanding protein absorption phenomena in different geometry microchannels and evaluating the efficiency of dynamic coating, which has been using as a method to prevent protein adsorption, are important tasks. Two different sets of microchannels were designed and fabricated on polymers. Bovine serum albumin (BSA) was used as a model protein for quantification of and monitoring the protein loss in different microchannel geometries. Up to 58% of the BSA was lost after flowing a 2030 mm long microchannel. The BSA adsorption rate changed along the microchannel. Smaller microchannels required a longer time to achieve protein saturation point. Dynamic coating was shown to be a time consuming and inefficient method to prevent protein adsorption in a continuous flow environment.
6
Kim, Sungwon S., Tom T. Huang, Timothy S. Fisher, and Michael R. Ladisch. "Effects of Carbon Nanotube Structure on Protein Adsorption." In ASME 2005 International Mechanical Engineering Congress and Exposition. ASMEDC, 2005. http://dx.doi.org/10.1115/imece2005-81395.
Texte intégralRésumé :
Outstanding transport characteristics and high surface-to-volume ratios are several advantages that carbon nanotubes possess that make them attractive candidates for protein immobilization matrices in biosensor applications. A further advantage of using carbon nanotubes is that their structure (e.g., diameter, length, density) can potentially be controlled during synthesis. In the present study, the effects of carbon nanotube structure on enzyme immobilization onto carbon nanotube arrays are investigated. Bovine serum albumin (BSA) serves as both a blocking agent for prevention of nonspecific adsorption and as a support for anchoring bioreceptors. BSA, a globular protein having a 4 to 6 nm characteristic dimension, is stably adsorbed through mechanisms that involve hydrophobic interactions between surfaces presented by the carbon nanotubes and the spacing between the nanotubes with the protein. Protein adsorption is confirmed by fluorescence microscopy of surfaces that have been exposed to fluourescein isothiocyanate (FITC) labeled BSA. The adsorption of biotinylated BSA can be used, through a sandwich immobilization scheme, to provide an anchor for streptavidin, which in turn has at least one other adsorption site that is specific for other biotinylated proteins such as glucose oxidase that would form a biorecognition or catalytic element in a functional biosensor. Correlation between carbon nanotube structure and protein adsorption at the nano-bio interface could eventually lead to growth conditions that yield carbon nanotubes for biosensor applications with optimal protein adsorption characteristics.
7
Coelho, Carlos D. F., João A. Jesus, Daniela C. Vaz, Ricardo Lagoa, and Maria João Moreno. "BSA-PEG Hydrogel: A Novel Protein-Ligand Binding 3D Matrix." In Biosystems in Toxicology and Pharmacology – Current Challenges. MDPI, 2022. http://dx.doi.org/10.3390/bitap-12878.
Texte intégral
8
Tseng, F. G., H. M. Huang, C. S. Liu, C. Y. Huang, S. C. Lin, and C. C. Chieng. "Micro Protein Arrays Prepared by Microfabricated Stamps." In ASME 2000 International Mechanical Engineering Congress and Exposition. American Society of Mechanical Engineers, 2000. http://dx.doi.org/10.1115/imece2000-1160.
Texte intégralRésumé :
Abstract A novel protein arraying method is proposed by utilizing micro stamps to spot proteins on a bio-absorption surface. The method can pick up various protein solutions to spot onto a desired substrate for protein immobilization. The fabrication process of the micro stamp combines surface micromachining and molding process. Successful transfer of BSA protein solution onto a PVDF (Polyvinylidene difluoride) surface has been demonstrated by using the micro fabricated stamps. The size of stamped protein spot in this stage is about 20–50% larger than that of the stamp. To quickly verify the protein binding ability to two different substrates: PVDF and PhastGel® Pad, a chopstick system is used to pickup protein solution for stamping. Result shows that appreciable amount protein retention is achieved for at least 6 hours on both substrates. Improved spotting size and position control on micro stamping process has also been carried out by stamp surface coating with aluminum/aluminum oxide and stamp picking up protein-solutions from a protein-solution pre-wetted clean room tissue.
9
Mihalcea, Elena, Gabi Drochioiu, Stefania-Claudia Jitaru, Violeta Mangalagiu, and Robert �Vasile Gradinaru. "PROTEIN AND PEPTIDE DETERMINATION BASED ON THE MODIFIED BIURET PROCEDURE: IMPLICATIONS FOR VARIOUS BIOTECHNOLOGIES." In 22nd SGEM International Multidisciplinary Scientific GeoConference 2022. STEF92 Technology, 2022. http://dx.doi.org/10.5593/sgem2022/6.1/s25.14.
Texte intégralRésumé :
Spectrophotometric methods for total protein analysis are generally simple, rapid and sensitive. Such sensitive protein assays may have applications in forensic science, in the detection of protein contaminants in drugs and in a number of other applications of research interest. Biuret reaction with proteins and peptides is widely used in clinical and biological laboratories. In this work, instead of copper sulphate, sodium hydroxide and Seignette salt, we used insoluble copper phosphate, potassium or sodium hydroxide and ethyl alcohol for the preparation of the biuret reagent. Absorbance of the biuret complex was recorded both at 219-230 nm (after dilution) and around 550 nm against a reagent blank. Amino acid interference was investigated around 550 nm at the same concentration as proteins. The sensitivity of the method at 226 nm was greater than those of other spectrophotometric assays (old biuret method, Lowry, and BCA) with a LOD of about 0.5 �g mL?1 BSA. The new variants of the biuret method for total protein analysis eliminate the need for precise reagent addition and vortexing inherent in the widely used Lowry method, providing flexibility of application. The method developed, which uses an alkaline-alcoholic reagent and insoluble copper phosphate, is simple, rapid, reproducible and sensitive; it is not influenced by detergents, solvents and buffers containing ammonium and is flexible enough to change the analytical protocol when necessary. A discussion was made on the applications of protein and peptide determination with the new biuret assay.
10
Kesić, Ana S., Snežana R. Radisavljević, Jovana V. Bogojeski, and Biljana V. Petrović. "The interaction studies of novel diaminophenazine gold(III) complex and Bovine Serum Albumin (BSA-ibuprofen and BSA-Eozine Y)." In 2nd International Conference on Chemo and Bioinformatics. Institute for Information Technologies, University of Kragujevac, 2023. http://dx.doi.org/10.46793/iccbi23.407k.
Texte intégralRésumé :
It is well known that gold(III) complexes have found applications in medicinal inorganic chemistry. Considering this, the right choice of inert ligands in the structure of Au(III) complexes is crucial for predicting their properties and reactivity, especially towards biomolecules. Here are presented the results of the study of the interactions between the new gold(III) complex [Au(DAP)Cl3], with 2,3-diaminophenazine (DAP) as an inert ligand, and BSA. Specifically, serum albumin is the main soluble protein in the circulatory system of humans. The metabolism of drugs, their distribution, free concentration, and effectiveness strongly depend on the drug-albumin interaction. Investigation of the interactions of the [Au(DAP)Cl3] complex with bovine serum albumin (BSA) under physiological conditions was performed by fluorescence spectroscopy. This method was also used to identify the binding site on the BSA molecule, with eosin Y as a marker for site I (subdomain IIA), and ibuprofen as a marker for site II (subdomain IIIA). The results have shown that the complex moderately reacts with the BSA molecule with just one binding site for the complex on the protein. Additionally, based on the results with site markers, especially with eosin Y, it can be concluded that the studied complex binds to site I of the BSA molecule.
Rapports d'organisations sur le sujet "BSA protein"
1
Kanner, Joseph, Edwin Frankel, Stella Harel, and Bruce German. Grapes, Wines and By-products as Potential Sources of Antioxidants. United States Department of Agriculture, 1995. http://dx.doi.org/10.32747/1995.7568767.bard.
Texte intégralRésumé :
Several grape varieties and red wines were found to contain large concentration of phenolic compounds which work as antioxidant in-vitro and in-vivo. Wastes from wine production contain antioxidants in large amounts, between 2-6% on dry material basis. Red wines but also white wines were found to prevent lipid peroxidation of turkey muscle tissues stored at 5oC. The antioxidant reaction of flavonoids found in red wines against lipid peroxidation were found to depend on the structure of the molecule. Red wine flavonoids containing an orthodihydroxy structure around the B ring were found highly active against LDL and membrane lipid peroxidation. The antioxidant activity of red wine polyphenols were also found to be dependent on the catalyzer used. In the presence of H2O2-activated myoglobin, the inhibition efficiency was malvidin 3-glucoside>catechin>malvidin>resveratol. However, in the presence of an iron redox cycle catalyzer, the order of effectiveness was resveratol>malvidin 3-glucoside = malvidin>catechin. Differences in protein binding were found to affect antioxidant activity in inhibiting LDL oxidation. A model protein such as BSA, was investigated on the antioxidant activity of phenolic compounds, grape extracts, and red wines in a lecithin-liposome model system. Ferulic acid followed by malvidin and rutin were the most efficient in inhibiting both lipid and protein oxidation. Catechin, a flavonal found in red-wines in relatively high concentration was found to inhibit myoglobin catalyzed linoleate membrane lipid peroxidation at a relatively very low concentration. This effect was studied by the determination of the by-products generated from linoleate during oxidation. The study showed that hydroperoxides are catalytically broken down, not to an alcohol but most probably to a non-radical adduct. The ability of wine-phenolics to reduce iron and from complexes with metals were also demonstrated. Low concentration of wine phenolics were found to inhibit lipoxygenase type II activity. An attempt to understand the bioavailability in humans of antocyanins from red wine showed that two antocyanins from red wine were found unchanged in human urine. Other antocyanins seems to undergo molecular modification. In hypercholesterolemic hamsters, aortic lipid deposition was significantly less in animals fed diets supplemented with either catechin or vitamin E. The rate of LDL accumulation in the carotid arteries was also significantly lower in the catechin and vitamin E animal groups. These results suggested a novel mechanism by which wine phenolics are associated with decreased risk of coronary heart diseases. This study proves in part our hypothesis that the "French Paradox" could be explained by the action of the antioxidant effects of phenolic compounds found at high concentration in red wines. The results of this study argue that it is in the interest of public health to increase the consumption of dietary plant falvonoids. Our results and these from others, show that the consumption of red wine or plant derived polyphenolics can change the antioxidant tone of animal and human plasma and its isolated components towards oxidative reactions. However, we need more research to better understand bioavailability and the mechanism of how polyphenolics affect health and disease.
2
Oldberg, Nick. BCA Protein Quantitation Assay (Using Thermo Fisher #23227). ResearchHub Technologies, Inc., 2024. http://dx.doi.org/10.55277/researchhub.don45ekv.
Texte intégral
3
จันทร์ประทีป, พีระศักดิ์, สุมลยา กาญจนะพังคะ, ประโยชน์ ตันติเจริญยศ та กัลยาณี ตันศฤงฆาร. ความเป็นมาและสถานภาพปัจจุบันของโรคสมองฟ่ามในโค (โคบ้า) : รายงานการวิจัย. จุฬาลงกรณ์มหาวิทยาลัย, 1998. https://doi.org/10.58837/chula.res.1998.81.
Texte intégralRésumé :
โรคสมองฟ่ามหรือโคบ้า (Bovine Spongiform Encephalopathy, BSE) เป็นโรคระบาดร้ายแรงที่เกิดขึ้น.ในสหราชอาณาจักรเป็นส่วนใหญ่ ทำความเสียหายทางเศรษฐกิจอย่างมหาศาล จำเป็นต้องกำจัดโคถึง 1 ล้านตัวเพื่อกำจัด BSE ให้หมดไป ยิ่งไปกว่านั้น BSE อาจเป็นอันตรายแก่สุขภาพและชีวิตมนุษย์ด้วย BSE เป็นโรคหนึ่งใน transmissible spongiform encephalopathies (TSEs) โดยมี prion protein เป็นสารก่อโรคที่ทำความเสียหายแก่ระบบประสาท และทำให้คนหรือสัตว์ตายในที่สุด พบเนื้อสมองทั้งส่วน cerebrum และ cerebellum เป็นรูพรุน และอาจพบ plaques และ scrapie-associated fibrils (SAF) ในเนื้อสมองด้วย การศึกษาทางระบาดวิทยาชี้แนะว่าการแพร่ของ BSE เกิดจากโคกินอาหารที่มีสารก่อโรคปนเปื้อนอยู่ และการเปลี่ยนแปลงที่ไม่เหมาะสมในกระบวนการแปรรูปโปรตีนจากซากสัตว์ เพื่อใช้เป็นอาหารเลี้ยงโคก็ช่วยเพิ่มปัจจัยเสี่ยงต่อการกระจายโรค BSE ด้วย prion protein อาจสะสมอยู่ในเลือด เส้นประสาทหรือระบบน้ำเหลืองของโคที่เป็น BSE ก่อนที่จะกระจายไปสู่ระบบประสาทส่วนกลาง แต่เดิมพบเฉพาะสมอง ไขสันหลังและจอตาเท่านั้นที่ก่อให้เกิดโรค BSE ได้ ขณะนี้กำลังรอผลที่ Spongiform Encephalopathy Advisory Committee (SEAC) ดำเนินการให้ตรวจเนื้อ น้ำนม อวัยวะระบบน้ำเหลืองจากโคที่เป็น BSE โดยใช้ลูกโคเป็นสัตว์ทดลอง ซึ่งมีความไวกว่าการฉีดสารก่อโรคเข้าหนู mice ถึง 1000 เท่า รายงานฉบับนี้ได้รวบรวมเหตุการณ์สำคัญ ระบาดวิทยา มาตรการควบคุมกำจัดและป้องกันโรค BSEและวิธีการตรวจวินิจฉัยโรคด้วยวิธีต่าง ๆ รวมทั้งแนวความคิดในการรักษา TSEs ในอนาคตไว้ด้วย Creutzfeldt-Jakob's Disease (CJD) เป็นโรคเกี่ยวกับระบบประสาทในคนและเป็นโรคหนึ่งในกลุ่ม TSEs พบว่า new variant CJD (nvCJD) มีรอยโรคและอาการเฉพาะต่างไปจาก CJD เมื่อใช้เทคนิค Western blot สรุปได้ว่า nvCJD คล้ายกับ BSE แต่ต่างจาก sporadic CJD เป็นไปได้มากว่า nvCJD เกิดขึ้นจากการที่ผู้ป่วยเคยได้รับสารก่อโรค BSE การปลูกถ่ายอวัยวะ เยื่อหุ้มสมอง กระจกตากหรือการใช้เครื่องมือผ่าตัดเกี่ยวกับระบบประสาทที่มี PrPsc ปนเปื้อน ก็ทำให้เกิดการถ่ายทอด CJD ได้ โดยเฉพาะอย่างยิ่งในกลุ่มคนที่มี homozygous gene ที่ codon 129 นอกจากนี้ยังพบมีผู้ป่วยเป็น CJD 90 ราย (1985-1996) ที่มีประวัติเคยได้รับ growth hormone และ 54 ราย (1989-1993) ที่เคยไดัรับการรักษาด้วย gonadotropin ยิ่งไปกว่านั้น เมื่อต้นปี 1997 องค์การอนามัยโลกได้สรุปว่าพบสารก่อโรค CJD ใน plasma ของหนู mice จากหลักฐานต่าง ๆ เหล่านี้ จึงควรจะระมัดระวังการรับถ่ายเลือดและการรับบริจาคอวัยวะจากกลุ่มคน ที่มีประวัติญาติพี่น้องที่มีอาการทางประสาท รวมทั้งจากกลุ่มคนที่เคยได้รับ human-derived growth hormone และ gonadotropin ด้วย
4
Zhang S. Y. Proton Beam Emittance in the BTA Line. Office of Scientific and Technical Information (OSTI), 1996. http://dx.doi.org/10.2172/1132428.
Texte intégral
5
Erdman, Richard, Geoffrey Dahl, Hanina Barash, Israel Bruckental, Avi Shamay, and Anthony Capuco. Management Strategies to Maximize Skeletal Growth Rate in Dairy Heifers. United States Department of Agriculture, 2002. http://dx.doi.org/10.32747/2002.7695848.bard.
Texte intégralRésumé :
The objectives of this study were to determine the effects of recombinant bovine somatotropin (bST) and added dietary rumen undegradable protein (RUP) on organ and tissue weights and body composition in growing dairy heifers. A total of 32 Holstein heifers, 3 months of age at the beginning of the study were used in the experiment. Eight heifers were slaughtered at 3 mo of age to determine pre- treatment body composition. The remaining heifers were randomly assigned to treatments (n=6) consisting of 0.1 mg/kg body weight per day of bST and 2% added dietary RUP (dry matter basis) applied in a 2X2 factorial design. A total of six heifers per treatment group (3 each at 5 and 10 mo of age), were slaughtered to determine body composition an organ masses. There was a trend for increased live and empty body weights (EB:W), carcass and non-carcass components for heifers treated with bST or fed RUP. Added RUP increased rumen and reticulum weights whereas administration of bST tended to increase the weights of small and large intestine at 10 months of age by 22 % and 26%, respectively. Spleen, heart, and kidney weights at 10 months of age were increased 36%, 28% and 23% for bST treatments respectively, compared with controls. Rates of ash and protein deposition between 3 and 10 months of age were increased by bST by 7.2 g/d and 28.9 g/d, respectively, while no treatment differences were observed for rates of fat and energy deposition. Bovine somatotropin significantly altered the metabolism of growing heifers in a manner that led to increased protein and ash deposition, and tended to reduce fat percentage, and there was a similar tendency observed with added RUP. This suggests that nutritional and endocrine manipulations could increase growth rates of skeletal and lean tissues without increasing fat deposition in prepubertal dairy heifers.
6
Matthew, Gray. Data from "Winter is Coming – Temperature Affects Immune Defenses and Susceptibility to Batrachochytrium salamandrivorans". University of Tennessee, Knoxville Libraries, 2021. http://dx.doi.org/10.7290/t7sallfxxe.
Texte intégralRésumé :
Environmental temperature is a key factor driving various biological processes, including immune defenses and host-pathogen interactions. Here, we evaluated the effects of environmental temperature on the pathogenicity of the emerging fungus, Batrachochytrium salamandrivorans (Bsal), using controlled laboratory experiments, and measured components of host immune defense to identify regulating mechanisms. We found that adult and juvenile Notophthalmus viridescens died faster due to Bsal chytridiomycosis at 14 ºC than at 6 and 22 ºC. Pathogen replication rates, total available proteins on the skin, and microbiome composition likely drove these relationships. Temperature-dependent skin microbiome composition in our laboratory experiments matched seasonal trends in wild N. viridescens, adding validity to these results. We also found that hydrophobic peptide production after two months post-exposure to Bsal was reduced in infected animals compared to controls, perhaps due to peptide release earlier in infection or impaired granular gland function in diseased animals. Using our temperature-dependent infection results, we performed a geographic analysis that suggested that N. viridescens populations in the northeastern United States and southeastern Canada are at greatest risk for Bsal invasion. Our results indicate that environmental temperature will play a key role in the epidemiology of Bsal and provide evidence that temperature manipulations may be a viable Bsal management strategy.
7
Freid, Michael. Topics in Proton Structure: BSM answers to its radius puzzle and latticesubtleties within its momentum distribution. Office of Scientific and Technical Information (OSTI), 2019. http://dx.doi.org/10.2172/1594873.
Texte intégral
8
Michaels, Trevor. Red-tailed boa (Boa constrictor) surveys at Salt River Bay National Park, St. Croix U.S. Virgin Islands: 2023 report of activities. National Park Service, 2024. http://dx.doi.org/10.36967/2303799.
Texte intégralRésumé :
St. Croix is home to a variety of threatened and endangered (T&E) species that are at risk for predation by the invasive red-tailed boa (Boa constrictor), such as the St. Croix ground lizard (Amevia polyps), the ground-nesting least tern (Sterna antillarum), and the hawksbill sea turtle (Eretmochelys imbricata). Genetic analysis determined the original red-tailed boa population on St. Croix sourced from a single female released by a pet owner and its range expands every year. Presently, the main population of red-tailed boa is established on the west end of St. Croix and extends as far east as Salt River. One individual was found in Salt River Marina and additional sightings have occurred in Salt River Bay National Historical Park and Ecological Preserve (SARI) more recently. This inventory aims to search for red-tailed boas in two focal areas that park staff are actively restoring. The park will use information from this inventory to develop a boa removal program and protect sensitive native species like the ground-nesting least tern, the St. Croix ground lizard and the hawksbill sea turtle nests and increase the success of restoration. Snakes are cryptic species, often occurring in low density, and utilize complex habitat patterns. To increase the likelihood of detecting red-tailed boa, the Maryland/Delaware/D.C. Wildlife Services detector dog handling team partnered with the USDA-APHIS National Detector Dog Training Center to train and develop detector dogs to assist in determining the presence/absence of red-tailed boa for this project. Canines were trained to locate red-tailed boa and indicate its presence to the handler via barking three times near the identified target. Two dog detector teams traveled to Salt River Bay National Park (SARI) in St. Croix to conduct surveys for red-tailed boa in habitats likely to contain red-tailed boa in June 2023. Habitat varied throughout the surveys. Close to the bay, mangrove forests dominated and, as elevation increased, transects took place in almost exclusively dry tropical shrub forest. Each transect was surveyed by one dog team. The canine teams had no red-tailed boa detections within SARI. Canines showed proficiency at surveying for red-tailed boa populations in SARI. Given the proximity of confirmed detections to SARI, it is likely red-tailed boa will be in the park in the future, if they are not already. Additional surveys, whether by humans, canines, or both, are recommended in areas of the park that have not been previously surveyed.
9
MacKinnon, John, Mingxiang Zhang, and Mark Bezuijen. Strengthening Biodiversity Conservation in the Yellow River Basin of Henan Province, the People’s Republic of China. Asian Development Bank, 2023. http://dx.doi.org/10.22617/brf230406-2.
Texte intégralRésumé :
This brief outlines a two-year project to protect the biodiversity of the Yellow River Basin and the ecosystem services it provides that help support sustainable economic development in the People’s Republic of China (PRC). It explains the methodology and findings of the draft biodiversity strategy and action plan (BSAP) that centers on a stretch of river in Henan Province. It analyzes the financial value of ecosystem services and the drivers of biodiversity loss. It shows the need to strengthen local conservation laws, mainstream biodiversity protection, and rally multisector support to effectively scale up ecosystem protection and restoration.
10
Weller, Joel I., Harris A. Lewin, and Micha Ron. Determination of Allele Frequencies for Quantitative Trait Loci in Commercial Animal Populations. United States Department of Agriculture, 2005. http://dx.doi.org/10.32747/2005.7586473.bard.
Texte intégralRésumé :
Individual loci affecting economic traits in dairy cattle (ETL) have been detected via linkage to genetic markers by application of the granddaughter design in the US population and the daughter design in the Israeli population. From these analyses it is not possible to determine allelic frequencies in the population at large, or whether the same alleles are segregating in different families. We proposed to answer this question by application of the "modified granddaughter design", in which granddaughters with a common maternal grandsire are both genotyped and analyzed for the economic traits. The objectives of the proposal were: 1) to fine map three segregating ETL previously detected by a daughter design analysis of the Israeli dairy cattle population; 2) to determine the effects of ETL alleles in different families relative to the population mean; 3) for each ETL, to determine the number of alleles and allele frequencies. The ETL on Bostaurusautosome (BT A) 6 chiefly affecting protein concentration was localized to a 4 cM chromosomal segment centered on the microsatellite BM143 by the daughter design. The modified granddaughter design was applied to a single family. The frequency of the allele increasing protein percent was estimated at 0.63+0.06. The hypothesis of equal allelic frequencies was rejected at p<0.05. Segregation of this ETL in the Israeli population was confirmed. The genes IBSP, SPP1, and LAP3 located adjacent to BM143 in the whole genome cattle- human comparative map were used as anchors for the human genome sequence and bovine BAC clones. Fifteen genes within 2 cM upstream of BM143 were located in the orthologous syntenic groups on HSA4q22 and HSA4p15. Only a single gene, SLIT2, was located within 2 cM downstream of BM143 in the orthologous HSA4p15 region. The order of these genes, as derived from physical mapping of BAC end sequences, was identical to the order within the orthologous syntenic groups on HSA4: FAM13A1, HERC3. CEB1, FLJ20637, PP2C-like, ABCG2, PKD2. SPP, MEP, IBSP, LAP3, EG1. KIAA1276, HCAPG, MLR1, BM143, and SLIT2. Four hundred and twenty AI bulls with genetic evaluations were genotyped for 12 SNPs identified in 10 of these genes, and for BM143. Seven SNPs displayed highly significant linkage disequilibrium effects on protein percentage (P<0.000l) with the greatest effect for SPP1. None of SNP genotypes for two sires heterozygous for the ETL, and six sires homozygous for the ETL completely corresponded to the causative mutation. The expression of SPP 1 and ABCG2 in the mammary gland corresponded to the lactation curve, as determined by microarray and QPCR assays, but not in the liver. Anti-sense SPP1 transgenic mice displayed abnormal mammary gland differentiation and milk secretion. Thus SPP 1 is a prime candidate gene for this ETL. We confirmed that DGAT1 is the ETL segregating on BTA 14 that chiefly effects fat concentration, and that the polymorphism is due to a missense mutation in an exon. Four hundred Israeli Holstein bulls were genotyped for this polymorphism, and the change in allelic frequency over the last 20 years was monitored.