Letteratura scientifica selezionata sul tema "SDR enzyme"
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Articoli di riviste sul tema "SDR enzyme"
1
Ferrandi, Erica Elisa, Ivan Bassanini, Susanna Bertuletti, Sergio Riva, Chiara Tognoli, Marta Vanoni e Daniela Monti. "Functional Characterization and Synthetic Application of Is2-SDR, a Novel Thermostable and Promiscuous Ketoreductase from a Hot Spring Metagenome". International Journal of Molecular Sciences 23, n. 20 (12 ottobre 2022): 12153. http://dx.doi.org/10.3390/ijms232012153.
Testo completoAbstract (sommario):
In a metagenome mining-based search of novel thermostable hydroxysteroid dehydrogenases (HSDHs), enzymes that are able to selectively oxidize/reduce steroidal compounds, a novel short-chain dehydrogenase/reductase (SDR), named Is2-SDR, was recently discovered. This enzyme, found in an Icelandic hot spring metagenome, shared a high sequence similarity with HSDHs, but, unexpectedly, showed no activity in the oxidation of the tested steroid substrates, e.g., cholic acid. Despite that, Is2-SDR proved to be a very active and versatile ketoreductase, being able to regio- and stereoselectively reduce a diversified panel of carbonylic substrates, including bulky ketones, α- and β-ketoesters, and α-diketones of pharmaceutical relevance. Further investigations showed that Is2-SDR was indeed active in the regio- and stereoselective reduction of oxidized steroid derivatives, and this outcome was rationalized by docking analysis in the active site model. Moreover, Is2-SDR showed remarkable thermostability, with an apparent melting temperature (TM) around 75 °C, as determined by circular dichroism analysis, and no significant decrease in catalytic activity, even after 5 h at 80 °C. A broad tolerance to both water-miscible and water-immiscible organic solvents was demonstrated as well, thus, confirming the potential of this new biocatalyst for its synthetic application.
2
Mineo, Chieko, Yun-Shu Ying, Christine Chapline, Susan Jaken e Richard G. W. Anderson. "Targeting of Protein Kinase Cα to Caveolae". Journal of Cell Biology 141, n. 3 (4 maggio 1998): 601–10. http://dx.doi.org/10.1083/jcb.141.3.601.
Testo completoAbstract (sommario):
Previously, we showed caveolae contain a population of protein kinase Cα (PKCα) that appears to regulate membrane invagination. We now report that multiple PKC isoenzymes are enriched in caveolae of unstimulated fibroblasts. To understand the mechanism of PKC targeting, we prepared caveolae lacking PKCα and measured the interaction of recombinant PKCα with these membranes. PKCα bound with high affinity and specificity to caveolae membranes. Binding was calcium dependent, did not require the addition of factors that activate the enzyme, and involved the regulatory domain of the molecule. A 68-kD PKCα-binding protein identified as sdr (serum deprivation response) was isolated by interaction cloning and localized to caveolae. Antibodies against sdr inhibited PKCα binding. A 100–amino acid sequence from the middle of sdr competitively blocked PKCα binding while flanking sequences were inactive. Caveolae appear to be a membrane site where PKC enzymes are organized to carry out essential regulatory functions as well as to modulate signal transduction at the cell surface.
3
Cassetta, Alberto, Ivet Krastanova, Katja Kristan, Mojca Brunskole Švegelj, Doriano Lamba, Tea Lanišnik Rižner e Jure Stojan. "Insights into subtle conformational differences in the substrate-binding loop of fungal 17β-hydroxysteroid dehydrogenase: a combined structural and kinetic approach". Biochemical Journal 441, n. 1 (14 dicembre 2011): 151–60. http://dx.doi.org/10.1042/bj20110567.
Testo completoAbstract (sommario):
The 17β-HSD (17β-hydroxysteroid dehydrogenase) from the filamentous fungus Cochliobolus lunatus (17β-HSDcl) is a NADP(H)-dependent enzyme that preferentially catalyses the interconversion of inactive 17-oxo-steroids and their active 17β-hydroxy counterparts. 17β-HSDcl belongs to the SDR (short-chain dehydrogenase/reductase) superfamily. It is currently the only fungal 17β-HSD member that has been described and represents one of the model enzymes of the cP1 classical subfamily of NADPH-dependent SDR enzymes. A thorough crystallographic analysis has been performed to better understand the structural aspects of this subfamily and provide insights into the evolution of the HSD enzymes. The crystal structures of the 17β-HSDcl apo, holo and coumestrol-inhibited ternary complex, and the active-site Y167F mutant reveal subtle conformational differences in the substrate-binding loop that probably modulate the catalytic activity of 17β-HSDcl. Coumestrol, a plant-derived non-steroidal compound with oestrogenic activity, inhibits 17β-HSDcl [IC50 2.8 μM; at 100 μM substrate (4-oestrene-3,17-dione)] by occupying the putative steroid-binding site. In addition to an extensive hydrogen-bonding network, coumestrol binding is stabilized further by π–π stacking interactions with Tyr212. A stopped-flow kinetic experiment clearly showed the coenzyme dissociation as the slowest step of the reaction and, in addition to the low steroid solubility, it prevents the accumulation of enzyme–coenzyme–steroid ternary complexes.
4
FRANSEN, Marc, Paul P. VAN VELDHOVEN e Suresh SUBRAMANI. "Identification of peroxisomal proteins by using M13 phage protein VI phage display: molecular evidence that mammalian peroxisomes contain a 2,4-dienoyl-CoA reductase". Biochemical Journal 340, n. 2 (25 maggio 1999): 561–68. http://dx.doi.org/10.1042/bj3400561.
Testo completoAbstract (sommario):
To elucidate unknown mammalian peroxisomal enzymes and functions, we subjected M13 phage expressing fusions between the gene encoding protein VI and a rat liver cDNA library to an immunoaffinity selection process in vitro (biopanning) with the use of antibodies raised against peroxisomal subfractions. In an initial series of biopanning experiments, four different cDNA clones were obtained. These cDNA species encoded two previously identified peroxisomal enzymes, catalase and urate oxidase, and two novel proteins that contained a C-terminal peroxisomal targeting signal (PTS1). A primary structure analysis of these novel proteins revealed that one, ending in the tripeptide AKL, is homologous to the yeast peroxisomal 2,4-dienoyl-CoA reductase (EC 1.3.1.34; DCR), an enzyme required for the degradation of unsaturated fatty acids, and that the other, ending in the tripeptide SRL, is a putative member of the short-chain dehydrogenase/reductase (SDR) family, with three isoforms. Green fluorescent protein (GFP) fusions encoding GFP-DCR-AKL, GFP-DCR, GFP-SDR-SRL and GFP-SDR were expressed in mammalian cells. The analysis of the subcellular location of the recombinant fusion proteins confirmed the peroxisomal localization of GFP-DCR-AKL and GFP-SDR-SRL, as well as the functionality of the PTS1. That the AKL protein is indeed an NADPH-dependent DCR was demonstrated by showing DCR activity of the bacterially expressed protein. These results demonstrate at the molecular level that mammalian peroxisomes do indeed contain a DCR. In addition, the results presented here indicate that the protein VI display system is suitable for the isolation of rare cDNA clones from cDNA libraries and that this technology facilitates the identification of novel peroxisomal proteins.
5
Nguyen, Giang Thu, Shinae Kim, Hyeonseok Jin, Dong-Hyung Cho, Hang-Suk Chun, Woo-Keun Kim e Jeong Ho Chang. "Crystal Structure of NADPH-Dependent Methylglyoxal Reductase Gre2 from Candida Albicans". Crystals 9, n. 9 (10 settembre 2019): 471. http://dx.doi.org/10.3390/cryst9090471.
Testo completoAbstract (sommario):
Gre2 is a key enzyme in the methylglyoxal detoxification pathway; it uses NADPH or NADH as an electron donor to reduce the cytotoxic methylglyoxal to lactaldehyde. This enzyme is a member of the short-chain dehydrogenase/reductase (SDR) superfamily whose members catalyze this type of reaction with a broad range of substrates. To elucidate the structural features, we determined the crystal structures of the NADPH-dependent methylglyoxal reductase Gre2 from Candida albicans (CaGre2) for both the apo-form and NADPH-complexed form at resolutions of 2.8 and 3.02 Å, respectively. The CaGre2 structure is composed of two distinct domains: the N-terminal cofactor-binding domain and the C-terminal substrate-binding domain. Extensive comparison of CaGre2 with its homologous structures reveals conformational changes in α12 and β3′ of the NADPH-complex forms. This study may provide insights into the structural and functional variation of SDR family proteins.
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Pampa, Kudigana J., Neratur K. Lokanath, Naoki Kunishima e Ravishankar Vittal Rai. "The first crystal structure of NAD-dependent 3-dehydro-2-deoxy-D-gluconate dehydrogenase fromThermus thermophilusHB8". Acta Crystallographica Section D Biological Crystallography 70, n. 4 (19 marzo 2014): 994–1004. http://dx.doi.org/10.1107/s1399004713034925.
Testo completoAbstract (sommario):
2-Keto-3-deoxygluconate (KDG) is one of the important intermediates in pectin metabolism. An enzyme involved in this pathway, 3-dehydro-3-deoxy-D-gluconate 5-dehydrogenase (DDGDH), has been identified which converts 2,5-diketo-3-deoxygluconate to KDG. The enzyme is a member of the short-chain dehydrogenase (SDR) family. To gain insight into the function of this enzyme at the molecular level, the first crystal structure of DDGDH fromThermus thermophilusHB8 has been determined in the apo form, as well as in complexes with the cofactor and with citrate, by X-ray diffraction methods. The crystal structures reveal a tight tetrameric oligomerization. The secondary-structural elements and catalytically important residues of the enzyme were highly conserved amongst the proteins of the NAD(P)-dependent SDR family. The DDGDH protomer contains a dinucleotide-binding fold which binds the coenzyme NAD+in an intersubunit cleft; hence, the observed oligomeric state might be important for the catalytic function. This enzyme prefers NAD(H) rather than NADP(H) as the physiological cofactor. A structural comparison of DDGDH with mouse lung carbonyl reductase suggests that a significant difference in the α–loop–α region of this enzyme is associated with the coenzyme specificity. The structural data allow a detailed understanding of the functional role of the conserved catalytic triad (Ser129–Tyr144–Lys148) in cofactor and substrate recognition, thus providing substantial insights into DDGDH catalysis. From analysis of the three-dimensional structure, intersubunit hydrophobic interactions were found to be important for enzyme oligomerization and thermostability.
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Prasad, Kailash. "Importance of Flaxseed and its Components in the Management of Hypertension". International Journal of Angiology 28, n. 03 (22 febbraio 2019): 153–60. http://dx.doi.org/10.1055/s-0039-1678691.
Testo completoAbstract (sommario):
AbstractThis review paper describes the effects of flaxseed and its components (flax oil, secoisolariciresinol diglucoside [SDG], flax lignan complex [FLC], and flaxseed protein hydrolysate [FPH]) on blood pressure (BP) in Sprague Dawley rats (SDR), spontaneously hypertensive rats (SHR), and humans. Flaxseed, flax oil, and FLC had variable effects on BP in humans, while SDG and FPH significantly reduced the BP in SDR and SHR. The effect of SDG was dose-dependent and long lasting. The lowering of BP is mediated through inhibition of soluble epoxide by α-linolenic acid in flax oil, stimulation of guanylate cyclase and inhibition of angiotensin converting enzyme (ACE) by SDG, and inhibition of renin and ACE activity by FPH. Flaxseed, flax oil, and FLC have variable effects on BP (none, slight, and significant). They are effective in lowering BP in individuals with hypertension and metabolic syndrome but ineffective in healthy individuals' ineffectiveness of flaxseed and its compounds in lowering BP may be due to their low doses, long interval of dosing, short duration of consumption, and patient status. In conclusion, the data at present suggest that flaxseed, flax oil, and FLC cannot serve as therapeutic agents for the treatment of hypertension. However, they can be used as an adjunct in the treatment of hypertension. A clinical trial should be conducted of these agents with higher doses which would be given twice daily for long duration. Pure SDG and FPS may serve as therapeutic agents for the treatment of hypertension but they have not been tried in humans.
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Da Costa, Matthieu, Ophelia Gevaert, Stevie Van Overtveldt, Joanna Lange, Henk-Jan Joosten, Tom Desmet e Koen Beerens. "Structure-function relationships in NDP-sugar active SDR enzymes: Fingerprints for functional annotation and enzyme engineering". Biotechnology Advances 48 (maggio 2021): 107705. http://dx.doi.org/10.1016/j.biotechadv.2021.107705.
Testo completo
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Shah, Bhumika S., Sasha G. Tetu, Stephen J. Harrop, Ian T. Paulsen e Bridget C. Mabbutt. "Structure of a short-chain dehydrogenase/reductase (SDR) within a genomic island from a clinical strain ofAcinetobacter baumannii". Acta Crystallographica Section F Structural Biology Communications 70, n. 10 (25 settembre 2014): 1318–23. http://dx.doi.org/10.1107/s2053230x14019785.
Testo completoAbstract (sommario):
Over 15% of the genome of an Australian clinical isolate ofAcinetobacter baumanniioccurs within genomic islands. An uncharacterized protein encoded within one island feature common to this and other International Clone II strains has been studied by X-ray crystallography. The 2.4 Å resolution structure of SDR-WM99c reveals it to be a new member of the classical short-chain dehydrogenase/reductase (SDR) superfamily. The enzyme contains a nucleotide-binding domain and, like many other SDRs, is tetrameric in form. The active site contains a catalytic tetrad (Asn117, Ser146, Tyr159 and Lys163) and water molecules occupying the presumed NADP cofactor-binding pocket. An adjacent cleft is capped by a relatively mobile helical subdomain, which is well positioned to control substrate access.
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van Hylckama Vlieg, Johan E. T., Lixia Tang, Jeffrey H. Lutje Spelberg, Tim Smilda, Gerrit J. Poelarends, Tjibbe Bosma, Annet E. J. van Merode, Marco W. Fraaije e Dick B. Janssen. "Halohydrin Dehalogenases Are Structurally and Mechanistically Related to Short-Chain Dehydrogenases/Reductases". Journal of Bacteriology 183, n. 17 (1 settembre 2001): 5058–66. http://dx.doi.org/10.1128/jb.183.17.5058-5066.2001.
Testo completoAbstract (sommario):
ABSTRACT Halohydrin dehalogenases, also known as haloalcohol dehalogenases or halohydrin hydrogen-halide lyases, catalyze the nucleophilic displacement of a halogen by a vicinal hydroxyl function in halohydrins to yield epoxides. Three novel bacterial genes encoding halohydrin dehalogenases were cloned and expressed in Escherichia coli, and the enzymes were shown to display remarkable differences in substrate specificity. The halohydrin dehalogenase ofAgrobacterium radiobacter strain AD1, designated HheC, was purified to homogeneity. The k cat andK m values of this 28-kDa protein with 1,3-dichloro-2-propanol were 37 s−1 and 0.010 mM, respectively. A sequence homology search as well as secondary and tertiary structure predictions indicated that the halohydrin dehalogenases are structurally similar to proteins belonging to the family of short-chain dehydrogenases/reductases (SDRs). Moreover, catalytically important serine and tyrosine residues that are highly conserved in the SDR family are also present in HheC and other halohydrin dehalogenases. The third essential catalytic residue in the SDR family, a lysine, is replaced by an arginine in halohydrin dehalogenases. A site-directed mutagenesis study, with HheC as a model enzyme, supports a mechanism for halohydrin dehalogenases in which the conserved Tyr145 acts as a catalytic base and Ser132 is involved in substrate binding. The primary role of Arg149 may be lowering of the pKa of Tyr145, which abstracts a proton from the substrate hydroxyl group to increase its nucleophilicity for displacement of the neighboring halide. The proposed mechanism is fundamentally different from that of the well-studied hydrolytic dehalogenases, since it does not involve a covalent enzyme-substrate intermediate.
Tesi sul tema "SDR enzyme"
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Kowalik, Dorota [Verfasser], Jerzy [Akademischer Betreuer] [Gutachter] Adamski e Johannes [Gutachter] Buchner. "SDR- und AKR- Enzyme in der Arzneimittelentwicklung und Suche nach der Funktion neuer SDR-Enzyme / Dorota Kowalik ; Gutachter: Jerzy Adamski, Johannes Buchner ; Betreuer: Jerzy Adamski". München : Universitätsbibliothek der TU München, 2017. http://d-nb.info/1127225286/34.
Testo completo
2
Haapalainen, A. (Antti). "Structure-function studies of the mammalian peroxisomal multifunctional enzyme type 2 (MFE-2)". Doctoral thesis, University of Oulu, 2002. http://urn.fi/urn:isbn:9514268385.
Testo completoAbstract (sommario):
Abstract
Mammalian peroxisomes contain two parallel multifunctional enzymes (MFE), MFE type 1 and MFE type 2 (MFE-2), which are responsible for the degradation of fatty acids. They both catalyze the second and third reactions of the β-oxidation pathway, but through reciprocal stereochemical courses. MFE-2 possesses (2E)-enoyl-CoA hydratase-2 and (3R)-hydroxyacyl-CoA dehydrogenase activities. In addition, the carboxy-terminal part is similar to the sterol carrier protein type 2 (SCP-2).
The purpose of this work was to study the structure-function relationship of functional domains of mammalian MFE-2 by recombinant DNA technology, enzyme kinetics and X-ray crystallography. The work started with the identification of conserved regions in MFE-2. This information was utilized when dehydrogenase, hydratase-2 and/or SCP-2-like domain were produced as separate recombinant proteins. Subsequently, both dehydrogenase and SCP-2-like domains were crystallized and their crystal structures were solved.
The structure of the dehydrogenase region of rat MFE-2 contains the basic α/β short-chain alcohol dehydrogenase/reductase (SDR) fold and the four-helix bundle at the dimer interface, which is typical of dimeric SDR enzymes. However, the structure has a novel carboxy-terminal domain not seen among the known structures. This domain lines the active site cavity of the neighbouring monomer, reflecting cooperative behaviour within a homodimer.
The monomeric SCP-2-like domain of human MFE-2 has the same fold as rabbit SCP-2. The structure includes a hydrophobic tunnel occupied by an ordered Triton X-100 molecule, demonstrating the ligand-binding site. Compared to the unliganded rabbit SCP-2 structure, the position of the carboxy-terminal helix is different. The movement of this helix in the liganded human SCP-2-like domain resulted in the exposure of a peroxisomal targeting signal, suggesting ligand-assisted protein import into peroxisomes.
The roles of conserved protic residues in the hydratase-2 region of human MFE-2 were studied by mutating them to alanine. In the first step, the ability of mutated variants to utilize oleic acid in vivo was tested with Saccharomyces cerevisiae fox-2 cells (devoid of endogenous MFE-2). Subsequently, in vitro characterization of the mutant enzymes revealed two amino acid residues, Glu366 and Asp510, vital for hydratase-2 activity. The results indicate that the acid-base catalysis is valid for hydratase-2.
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Ylianttila, M. (Mari). "Structure-function studies of the peroxisomal multifunctional enzyme type 2 (MFE-2)". Doctoral thesis, University of Oulu, 2005. http://urn.fi/urn:isbn:9514278968.
Testo completoAbstract (sommario):
Abstract
Multifunctional enzyme type 2 (MFE-2) catalyses the second and the third reactions in the eukaryotic peroxisomal β-oxidation cycle, which degrades fatty acids by removing a two-carbon unit per each cycle. In addition to the 2-enoyl-CoA hydratase 2 and (3R)-hydroxyacyl-CoA dehydrogenase activities, mammalian MFE-2 has also a sterol carrier protein type 2-like (SCP-2L) domain. In contrast, yeast MFE-2 has two (3R)-hydroxyacyl-CoA dehydrogenases, one 2-enoyl-CoA hydratase 2 and no SCP-2L domain.
The physiological roles of yeast (3R)-hydroxyacyl-CoA dehydrogenases (A and B) were tested by inactivating them in turn by site-directed mutagenesis and testing the complementation of Saccharomyces cerevisiae fox-2 cells (devoid of endogenous MFE-2) with mutated variants of Sc MFE-2. Growth rates were lower for fox-2 cells expressing only a single functional domain than for those expressing the Sc MFE-2. Kinetic studies with purified Candida tropicalis MFE-2 and its mutated variants show that dehydrogenase A catalyzes the reaction more efficiently with the medium- and long-chain substrates than dehydrogenase B, which in turn is the only one active with the short chain fatty acids.
The structural basis of the substrate specificity difference of these two dehydrogenases was solved by X-ray crystallography together with docking studies. Protein engineering was used to produce a stabile, homogenous recombinant protein of C. tropicalis dehydrogenases in one polypeptide. The heterodimeric structure contains the typical fold of the short-chain alcohol dehydrogenase/reductase (SDR) family. Docking studies suggest that dehydrogenase A binds medium chain-length substrates as bended, whereas short chain substrates are dislocated, because they do not reach the hydrophobic contacts needed for anchoring the substrate to the active site, but are instead attracted by L44. Dehydrogenase B has a more shallow binding pocket and thus locates the short chain-length substrates correctly for catalysis. Thus the data provide clues for structural basis of the different substrate specificities.
The molecular basis of the patient mutations of MFE-2 (DBP deficiency) was studied using the recently solved crystal structures of rat (3R)-hydroxyacyl-CoA dehydrogenase, human 2-enoyl-CoA hydratase and SCP-2L. The predicted effect of the mutations on protein structure could in several cases be explained, and these data supported the conclusion that a genotype-phenotype correlation exists for DBP deficiency.
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Koski, K. (Kristian). "Structural studies on the enzymatic units of the peroxisomal multifunctional enzyme type 2 (MFE-2)". Doctoral thesis, University of Oulu, 2004. http://urn.fi/urn:isbn:9514274652.
Testo completoAbstract (sommario):
Abstract
Multifunctional enzyme type 2 (MFE-2) is a peroxisomal enzyme participating in the breakdown of fatty acids in eukaryotes. Depending on the organism, MFE-2 is composed of two to four functional units, out of which the two enzymatic ones, 2-enoyl-coenzyme A (CoA) hydratase 2 and (3R)-hydroxyacyl-CoA dehydrogenase, are found in the all MFE-2s. These units are responsible for the catalysis of the second and third steps of the peroxisomal β-oxidation of various CoA thioesters of fatty acids and fatty acyl derivatives. Their (R)-stereospecificity and ability to accept a broad range of fatty acid CoA esters as substrates, in addition to the fact that they do not share any sequence similarity with the classical mitochondrial counterparts, make the enzymatic units of MFE-2 structurally very interesting. In this study, the three-dimensional structures of the (3R)-hydroxyacyl-CoA dehydrogenase and 2-enoyl-CoA hydratase 2 units were solved by crystallographic methods.
The crystal structure of the (3R)-hydroxyacyl-CoA dehydrogenase unit of rat MFE-2 reveals a dimeric enzyme with an α/β short-chain alcohol dehydrogenase/reductase (SDR) fold. A unique feature of (3R)-hydroxyacyl-CoA dehydrogenase, however, is the separate C-terminal domain, which completes the active site cavity of the adjacent monomer and extends the dimeric interactions. The 2-enoyl-CoA hydratase 2 unit is a dimer with a unique two-domain structure proposed to evolve via gene duplication. The fold consists of two side-by-side arranged repeats of the hot-dog fold motifs, thus being highly reminiscent of the tertiary structures of the (R)-specific 2-enoyl-CoA hydratase of the polyhydroxyalkanoate synthesis pathway and the β-hydroxydecanoyl thiol ester dehydrase of fatty acid synthesis type II, both from prokaryotic sources. The importance of the N-domain in the binding of bulky substrates was shown by the enzyme-product complex structure, which also indicates the active site. For the first time, it was shown that the eukaryotic hydratase 2 uses an Asp/His catalytic dyad in catalysis. Moreover, a novel catalytic mechanism was proposed for (R)-specific hydration/dehydration.
The solved structures also provide a molecular basis for understanding the effects of the patient mutations of MFE-2. They also allow disussion of the possible organisation of the three units in full-length MFE-2 of mammals.
5
Kongsaeree, Puapong Kelly Christine. "Optimization of recombinant ligninolytic enzyme production in Pichia pastoris". Related electronic resource: Current Research at SU : database of SU dissertations, recent titles available full text, 2004. http://wwwlib.umi.com/cr/syr/main.
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Grossová, Marie. "Produkce polyhydroxyalkanoátů s využitím odpadních substrátů a jejich následná izolace". Master's thesis, Vysoké učení technické v Brně. Fakulta chemická, 2011. http://www.nusl.cz/ntk/nusl-216717.
Testo completoAbstract (sommario):
The aim of this work is to study the possibility of microbial production of polyhydroxyalkanoates (PHA). PHA can be used as biodegradable materials. Bacterial strain Cupriavidus necator was used for laboratory production of PHA. This bacterium was cultivated in medium with various precursors to produce copolymers of 3HB with 3HV or 4HB. Another part of the work was aimed at cultivation of C. necator on different waste substrates, especially oils, with the aim to achieve the highest production of polymer. Another large part of the thesis is dedicated to isolation strategies of PHA using enzymes. Commercially used proteases – alcalase and pancreatin – can be used with advantages for digestion of bacterial cells. A number of optimization experiments showed that application of proteases leads to enhancement of PHA purity to about 13%. Purity increase up to 90 % was achieved by adding a surfactant, which promotes the solubility of non-PHA forming polymer. This surfactant increases the purity of 20 % when compared to control. The last part of presented work deals with the use of enzyme solution isolated from Bacillus subtilis medium. Its application to C. necator culture led to the yield of polymer at a purity exceeding 95 %. These results could represent the basis for new isolation strategies, which can lead to more efficient yield of PHA.
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Romanová, Kristýna. "Proteomická identifikace enzymů degradující rostlinnou biomasu". Master's thesis, Vysoké učení technické v Brně. Fakulta chemická, 2011. http://www.nusl.cz/ntk/nusl-216797.
Testo completoAbstract (sommario):
The theoretical part of work is focused on the issue of biomass which can be used for energy purposes, inparticular agricultural waste, as well as can serve as a substrate for biogas station. It also deals with proteomics, its goals and approaches, separation methods. The aim of this work was to measure each sample of enzyme activity of biomass, which are used as a raw materials for biogas plants and their proteomic identification.
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Dong, Yan. "Enzyme responses of Serengeti grasses to defoliation coupling plant cellular processes and Serengeti ecosystem processes /". Related electronic resource: Current Research at SU : database of SU dissertations, recent titles available full text, 2005. http://wwwlib.umi.com/cr/syr/main.
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Ashtekar, Amruta Ashtekar. "A role for mitochondrial enzymes SDH and SOD2 in thyroid cancer". The Ohio State University, 2018. http://rave.ohiolink.edu/etdc/view?acc_num=osu152355138828804.
Testo completo
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Júnior, Fábio Lino Soares. "Descrição e caracterização de uma nova ?-N-acetil-hexosaminidase (GH3) por metagenômica de solo de manguezal". Universidade de São Paulo, 2015. http://www.teses.usp.br/teses/disponiveis/64/64133/tde-27012016-141443/.
Testo completoAbstract (sommario):
Bactéria e fungos são as principais fontes de enzimas envolvidas na transformação de compostos chave para o fluxo de carbono em solos de manguezal, caracterizado por alta prevalência de anaerobiose, salinidade e elevado teor de matéria orgânica. A decomposição de plantas ou resíduos de animais nestas condições é muito lenta, devido à pressão seletiva sobre a evolução de enzimas envolvidas nos processos de mineralização de nutrientes. A metagenômica, permiti o acesso a grande maioria da diversidade microbiana no ambiente, por meio da geração de bibliotecas de clones, o que resulta em um cenário promissor para bioprospecção de novas atividades enzimáticas. Neste estudo, foi relatada a descrição e caracterização de uma nova ?-N-acetil-hexosaminidase (EC 3.2.1.52) da família GH3, envolvida na degradação da matéria orgânica em solo de manguezal contaminado por derramamento de óleo localizado no município de Bertioga-SP, por meio de uma triagem de 12.960 clones metagenômicos. O clone positivo para a atividade celulolítica foi sequenciado e um total de 1.175.586 reads foram gerados com tamanho médio de 198 pb. As sequencias foram trimadas com base na qualidade de índice PHRED >= 30.0, e remoção de sequencias do hospedeiro (E. coli) e do vetor (fosmídeo), originando um contig final com 39.586 Kb. Entre as ORF\'s anotadas a partir do contig gerado, uma sequencia de 1.065 nucleotídeos foi identificada como codificante para a enzima ?-N-acetil-hexosaminidase, evidenciando baixa similaridade (32 %) com as demais encontradas no bancos de dados comparativos. A enzima foi expressa e purificada, onde uma banda isolada foi visualizada por SDS-PAGE com massa molecular prevista de 43 kDa. Por fim, as atividades ótimas da enzima (30 °C; pH 5.0; 0.5 M de NaCl; diminuição de atividade após 3hs de incubação) foram caracterizadas por meio do indicador p-nitrophenol (pNP) ligados aos substratos GlNac, GalNac e Glc. A detecção da enzima por meio da metagenômica, evidenciou que os manguezais são reservatórios de novas enzimas com características diferenciadas e altos potenciais de aplicabilidades biotecnológicasBacteria and fungi are major sources of enzymes involved in the transformation of key compounds for the carbon fluxes on mangrove soils, characterized by the high prevalence of anaerobiosis salinity and high content of organic matter. The decomposition of plant or animals residues under these conditions is very slow, acting as a selective pressure on the evolution of enzymes involved in the mineralization process of nutrients. Metagenomics has provided access to the vast majority of the microbial diversity in the environment through the generation of fosmid libraries, resulting in a promising scenario for bioprospection enzymatic activities. In this study, we report the description and characterization of a novel ?-N-acetylhexosaminidase (EC 3.2.1.52) of GH3 family, involved in the degradation of organic matter in mangrove soils contaminated by oil spill located in the city of Bertioga-SP through of a screening of 12.960 metagenomic clones. The positive clone for cellulolytic activitie was sequenced and a total of 1.175.586 reads were generated with measuring size 198 bp. The sequences were trimmed based on the index of quality PHRED >= 30.0 and removing the sequences to host (E. coli) and vector (fosmid) resulting in a contig of 39.586 Kb. Between the anoted ORF\'s from generated contig a sequence of 1.065 nucleotides was identified coding for a ?-N-acetylhexosaminidase showing low similatrity (32 %) with the other found in comparatives databases. The enzyme was expressed and purified where an isolated band can be visualized by SDS-PAGE with molecular mass of 43 kDa. Finally, as optimum activity of the enzyme (30 °C; pH 5.0; 0.5M NaCl; decreased activity after 3 h incubation) were characterized by the indicator p-nitrophenol (pNP) linked to the substrates GlNac, GalNac and Glc. The detection of the enzyme through metagenomics indicated that mangroves are reservoirs of novel enzymes with different characteristics and high potential for biotechnological applicability
Libri sul tema "SDR enzyme"
1
Manchenko, Gennady P. Handbook of detection of enzymes on electrophoretic gels. 2a ed. Boca Raton, FL: CRC Press, 2002.
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Handbook of detection of enzymes on electrophoretic gels. 2a ed. Boca Raton: CRC Press, 2003.
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Manchenko, Gennady P. Handbook of detection of enzymes on electrophoretic gels. Boca Raton, Fla: CRC Press, 1994.
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Silva Gebim, Anna Beatriz, Renato Massaharu Hassunuma, Patrícia Carvalho Garcia e Sandra Heloísa Nunes Messias. 7QXS: o segredo do vampiro, livro-jogo sobre a telomerase. Canal 6 Editora, 2022. http://dx.doi.org/10.52050/9788579175817.
Testo completoAbstract (sommario):
Várias pesquisas sugerem que uma das causas do processo de envelhecimento seja o encurtamento dos telômeros, que correspondem à extremidade dos cromossomos. O comprimento dos telômeros é regulado por uma enzima denominada telomerase e várias outras proteínas que formam um complexo junto à telomerase. Neste jogo, você pode ser um cientista ou um vampiro que podem descobrir o segredo da imortalidade encontrando as proteínas que fazem parte do complexo telômero-telomerase. Com uma breve explicação e algumas partidas, você irá se familiarizar com os nomes destas biomoléculas e suas estruturas bioquímicas.
Capitoli di libri sul tema "SDR enzyme"
1
Oppermann, Udo, Samina Salim, Malin Hult, Guenther Eissner e Hans Jörnvall. "Regulatory Factors and Motifs in SDR Enzymes". In Advances in Experimental Medicine and Biology, 365–71. Boston, MA: Springer US, 1999. http://dx.doi.org/10.1007/978-1-4615-4735-8_45.
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Jörnvall, Hans. "Multiplicity and Complexity of SDR and MDR Enzymes". In Advances in Experimental Medicine and Biology, 359–64. Boston, MA: Springer US, 1999. http://dx.doi.org/10.1007/978-1-4615-4735-8_44.
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Persson, Bengt, Erik Nordling, Yvonne Kallberg, Dan Lundh, Udo C. T. Oppermann, Hanns-Ulrich Marschall e Hans Jörnvall. "Bioinformatics in Studies of SDR and MDR Enzymes". In Advances in Experimental Medicine and Biology, 373–77. Boston, MA: Springer US, 1999. http://dx.doi.org/10.1007/978-1-4615-4735-8_46.
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Viña-Gonzalez, Javier, e Miguel Alcalde. "In vivo site-directed recombination (SDR): An efficient tool to reveal beneficial epistasis". In Enzyme Engineering and Evolution: General Methods, 1–13. Elsevier, 2020. http://dx.doi.org/10.1016/bs.mie.2020.04.021.
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Jung, K. W., e A. S. Nagle. "Enzyme-Catalyzed Transcarbonylation". In Four Carbon-Heteroatom Bonds, 1. Georg Thieme Verlag KG, 2005. http://dx.doi.org/10.1055/sos-sd-018-00417.
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Fallis, A. G., e M. S. Souweha. "Enzyme-Mediated Reactions". In Polyynes, Arynes, Enynes, and Alkynes, 1. Georg Thieme Verlag KG, 2008. http://dx.doi.org/10.1055/sos-sd-043-00252.
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Krueger, A. "Enzyme-Catalyzed Rearrangements". In Polyynes, Arynes, Enynes, and Alkynes, 1. Georg Thieme Verlag KG, 2008. http://dx.doi.org/10.1055/sos-sd-043-00461.
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Ziegler, T. "By Enzyme Catalysis". In Three Carbon-Heteroatom Bonds: Esters and Lactones; Peroxy Acids and R(CO)OX Compounds; R(CO)X, X=S, Se, Te, 1. Georg Thieme Verlag KG, 2005. http://dx.doi.org/10.1055/sos-sd-021-00039.
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Mahrwald, R., e B. Schetter. "Enzyme-Catalyzed Aldol Additions". In Alcohols, 1. Georg Thieme Verlag KG, 2008. http://dx.doi.org/10.1055/sos-sd-036-00694.
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Chemler, S. R., e T. P. Zabawa. "Enzyme-Catalyzed Enantioselective Reduction". In Three Carbon-Heteroatom Bonds: Acid Halides; Carboxylic Acids and Acid Salts, 1. Georg Thieme Verlag KG, 2007. http://dx.doi.org/10.1055/sos-sd-020-00474.
Testo completoAtti di convegni sul tema "SDR enzyme"
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Menasni, S., W. Hornebeck, L. Robert e Y. Legrand. "ELASTASE TYPE ACTIVITY OF ENDOTHELIAL CELLS". In XIth International Congress on Thrombosis and Haemostasis. Schattauer GmbH, 1987. http://dx.doi.org/10.1055/s-0038-1643360.
Testo completoAbstract (sommario):
Elastin degrading enzymes have been reported in the vessel wall and both fibroblasts and smooth muscle cells have been shown to produce elastase type enzymes in culture. Data is presented here showing that porcine aortic endothelial cells produce enzyme activities hydrolyzing elastin and synthetic substrates I Sue Ala Ala Ala nitroanilide, SAPNAI considered specific for elastase. Enzyme activity against the SAPNA but not against H-elastin was found to be associated with the cells after triton lysis .This activity was not secreted into the culture medium . The elastolytic activity has been partially characterized in relation to the kinetic of hydrolysis, pH optimum and susceptibility to different inhibitors. These studies revealed the presence of at least two enzymes: a metalo-protease with a pH optimum of 7.5 which accounts for approx. 80% of the total activity, and a serine protease with pH optimum of 8.0 which accounts for the remaining 20% . When the conditioned culture medium was studied, virtually no proteolytic activity could be detected even after activation with an organomercurial agent. However fractionation of the culture medium by gel filtration on HPLC resulted in elastolytic activity both against H-elastin and SAPNA. Proteolytic activity against casein could also be revealed after separation on SDS-PAGE. It is likely that these separation techniques remove an inhibitor also produced by the endothelial cells and allow the expression of proteolytic activity. That the elastolytic activity and the caseinolytic activity revealed by HPLC and PAGE respectively represent the activity of the same enzyme hase not yet been determined, and its relationship to the Stromelysin described by Herron et al(J. Biol. Chem. , 1986, 261. 2810-2813) in rabbit brain capillary endothelial cells is being investigated.
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Heckel, A., e K. M. Hasselbach. "PREDICTION OF THE THREE-DIMENSIONAL STRUCTURE OF THE ENZYMATIC PART OF T-PA". In XIth International Congress on Thrombosis and Haemostasis. Schattauer GmbH, 1987. http://dx.doi.org/10.1055/s-0038-1644407.
Testo completoAbstract (sommario):
Up to now the three-dimensional structure of t-PA or parts of this enzyme is unknown. Using computer graphical methods the spatial structure of the enzymatic part of t-PA is predicted on the hypothesis, the three-dimensional backbone structure of t-PA being similar to that of other serine proteases. The t-PA model was built up in three steps:1) Alignment of the t-PA sequence with other serine proteases. Comparison of enzyme structures available from Brookhaven Protein Data Bank proved elastase as a basis for modeling.2) Exchange of amino acids of elastase differing from the t-PA sequence. The replacement of amino acids was performed such that backbone atoms overlapp completely and side chains superpose as far as possible.3) Modeling of insertions and deletions. To determine the spatial arrangement of insertions and deletions parts of related enzymes such as chymotrypsin or trypsin were used whenever possible. Otherwise additional amino acid sequences were folded to a B-turn at the surface of the proteine, where all insertions or deletions are located. Finally the side chain torsion angles of amino acids were optimised to prevent close contacts of neigh bouring atoms and to improve hydrogen bonds and salt bridges.The resulting model was used to explain binding of arginine 560 of plasminogen to the active site of t-PA. Arginine 560 interacts with Asp 189, Gly 19 3, Ser 19 5 and Ser 214 of t-PA (chymotrypsin numbering). Furthermore interaction of chromo-genic substrate S 2288 with the active site of t-PA was studied. The need for D-configuration of the hydrophobic amino acid at the N-terminus of this tripeptide derivative could be easily explained.
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Lipinski, B., J. Ewaskiewicz, S. Niewiarowski e A. Z. Budzynski. "STRUCTURE AND FUNCTIONAL PROPERTIES OF A FIBRINOGEN EERIVATIVE FORMED BY LIMITED PROTEOLYSIS WITH RED BLOOD CELL". In XIth International Congress on Thrombosis and Haemostasis. Schattauer GmbH, 1987. http://dx.doi.org/10.1055/s-0038-1643329.
Testo completoAbstract (sommario):
Normal human plasma contains, in addition to fibrinogen (Mr 340,000), two major thranbin-coagulable fibrinogen derivative of Mr 320,000 and 300,000. Previous investigations demonstrated that these derivatives do not originate from plasmic cleavages, however, no enzyme(s) responsible for the cleavages have been identified. The purpose of this study was to investigate a possible role of red blood cells (RBC) in the formation of these physiologic fibrinogen derivatives. RBC ghosts were prepared from ACD blood obtained from normal donors after removal of leukocytes and platelets. Purified human fibrinogen, that contained only one band of Mr 340,000 as judged by SD6-PAGE, was incubated with RBC ghosts at 37°C. SDS-PAGE of the supemate revealed the presence of a single band of approximate Mr 275,000 after one hour of incubation. Proteolytic degradation of fibrinogen by RBC ghosts was inhibited by STI but not by trasylol, leupeptin or EDTA suggesting that putative enzyme is distinct frcm plasmin and calpain. Polypetide chain ánalysis of Mr 275,000 derivative demonstrated degradation of its A alpha chain. The derivative shewed an impaired binding to AEP-activated platelets as shown by decreased number of fibrinogen binding sites calculated frcm Scatchard plots.Study of polymerization reaction of Mr 275,000 derivative catalyzed by thrombin revealed significantly impaired kinetics.The maximum polymerization rate of Mr 275,000 monomers was 51% of that of intact fibrinogen. The data suggest that RBC ghosts contain enzyme (s) that are capable to induce a limited proteolytic degradation of fibrinogen that may contribute to alteration of its biologic functions inportant in hemostasis and thrombosis.
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Hijikata-Okunomiya, A., S. Okamoto, R. Kikumoto e Y. Tamao. "STEREOGEOMETRY OP THE ACTIVE SITES OF SERINE ENZYMES GATHERED FROM SYNTHETIC THROMBIN-INHIBITORS". In XIth International Congress on Thrombosis and Haemostasis. Schattauer GmbH, 1987. http://dx.doi.org/10.1055/s-0038-1644606.
Testo completoAbstract (sommario):
MD-805 is a potent thrombin-inhibitor having the structure of tri-pods; Arg skeletone, N-terminal side and C-terminal side. MD-805 showed weaker inhibitory activity to other enzymes than thrombin. In this report, to gather more detailed informations about the structural features of serine enzymes concerning the specificity, we experimentally examined the structure-activity relationship (SAR) of a number of arginine derivatives including MD-805 and theoretically generated a MD-805-trypsin complex model using the results of X-ray crystallography of MD-805 and BPTI-trypsin complex by calculation in principle to minimize van der Waals contacts, and thus we discussed to interpret SAR from the molecular level. SAR of C-terminal side of arginine derivatives was obtained with the inhibitory activity to trypsin, plasmin, and glandular kallikrein and compared with the previous results of thrombin, the followings being indicated: (1) The hydrophobic binding pocket (HBP), which was reported by us to be at least partly similar in stereogeometry between trypsin and thrombin, had the depth corresponded to the length of ethylpiperidine, (2) concerning the site (termed the P site) next to HBP, there were large differences in stereogeometry between trypsin and thrombin; the P site of trypsin could accept propyl and phenyl group attached to 4-position of piperidine, while that of thrombin was unable to accept them and (3) the P sites of plasmin and glandular kallikrein resembled that of trypsin in being able to accept phenyl group. MD-805-trypsin complex model supported the reasonable understanding that the stereogeometrical similarity in HBP between thrombin and trypsin was attributable to the high homology in amino acid sequences in Ser-195 loop and that the dissimilarity in the P sites between thrombin and the others was attributable to 9 amino acids insertion found only in thrombin (Loop B). Furthermore, many dansylarginine derivatives showed very strong inhibition for pseudocholinesterase, however, SAR for C-terminal side of these derivatives revealed the similarity and dissimilarity in HBP and the P site between pseudocholinesterase and the proteases described above.
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Asakura, S., N. Yoshida e M. Matsuda. "MONOCLONAL ANTIBODIES AGAINST THROHBIN-ANTITHROMBIN III COMPLEX: EPITOPE SPECIFICITY AND EFFECT ON THROMBIN-ANTITHROMBIN III INTERACTION". In XIth International Congress on Thrombosis and Haemostasis. Schattauer GmbH, 1987. http://dx.doi.org/10.1055/s-0038-1643673.
Testo completoAbstract (sommario):
Among monoclonal antibodies (MCA´s) raised against human thrombin (T)-antithrombin m (AT) complex (TAT), two MCA´s designated as JITAT-16 and 17 with high affinity, Kd = 4.6nMand 4.1 nfi, respectively, were selected and characterized for specificity and functions. Their respective immunoglobulin subclasses are IgGi and IgG2a, and epitopes were found to be different from each Dther as shown by crisscross inhibition experiments. Immuno-alotting of normal plasma and serum electrophoresed on non-SDS aolyacrylamide gel showed that these antibodies reacted with normal serum but not with plasma. This was verified by an anzyme-linked differential antibody immunosorbent assay using aither one of the MCA´s as the first antibody and the other MCA labeled with peroxidase as the second one. By immunoblotting after SDS-PAGE, we found that both antibodies reacted with TAT, nut not with its respective nascent constituent, AT or T. However, they reacted with reactive site-cleaved AT (or thrombin-nodified AT, ATM) and also a complex of AT with activated factor K (Xa-AT). These results indicate that both of these antibodies recognize enzyme-treated forms of AT, including AT molecules :omplexed with enzymes reversibly or irreversibly as well as ATM. Jpon incubation of T with AT in the presence of JITAT-16, T activity remained nearly unchanged and formation of irreversible rAT did not proceed as expected. Moreover, AT was preferentially :onverted to ATM. When JITAT-16 was added after completion of FAT formation, however, neither recovery of T activity nor generation of ATM was observed. These findings were not obtained vhen JITAT-17 had been substituted for JITAT-16. These data suggest that JITAT-16 may have converted AT from an inhibitor to a substrate for T after having recognized a possible intermediate reversible complex of AT with T. Undoubtedly, in the presence of a polyclonal antibody against AT, neither TAT formation nor ATM neneration was observed at all. The mechanism of the unique Function of JITAT-16 has not been fully clarified as yet, but this antibody seems to give us new information on the kinetic study of TAT formation and ATM generation when AT was allowed to react with enzymes.
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Gribkova, I. N. "Technological approaches for processing brewer's grains for the purpose of greening production". In SCIENCE OF RUSSIA: GOALS AND OBJECTIVES. L-Journal, 2020. http://dx.doi.org/10.18411/sr-10-12-2020-28.
Testo completoAbstract (sommario):
This article discusses the issues of brewing industry ecologization, namely the processing brewer's spent grain possibility for the beverages industry needs. The prospects of processing brewer's spent grain, which have sparingly soluble useful various natures compounds, including polyphenols in both free and bound forms, have been shown. The authors investigated the possibility of processing brewer's spent grain using complex treatment with ECA-water at the first stage and with an enzyme preparation at the second. The catholyte positive effect on the various bound polyphenolic substances release during the first 4-10 hours was shown. Further treatment with a complex cytolytic enzyme preparation allows, after 4 hours, to obtain an increase in the content of polyphenols - by 33%, and anthocyanogens - by 6 times. As a result of brewing waste complex processing, it is possible to achieve the various groups presence of bound brewer's spent grain polyphenols in the extract.
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Lee, Yu Jin, Changhwan Ju e In-Hwan Kim. "Novel Strategy for Synthesis of Stearidonic Acid Enriched Triacylglycerol from Ahiflower Seed Oil via a Two-step Enzyme Reaction". In 2022 AOCS Annual Meeting & Expo. American Oil Chemists' Society (AOCS), 2022. http://dx.doi.org/10.21748/uhjd7801.
Testo completoAbstract (sommario):
Stearidonic acid (SDA) is a plant-based n-3 polyunsaturated fatty acids (PUFAs) with several positive therapeutic effects on human health such as reducing risks of cardiovascular diseases, obesity, inflammation, and cancer. Moreover, the conversion efficiency of SDA to EPA is significantly higher than α-linolenic acid to EPA, in the human body. Plant oils with SDA, such as ahiflower seed oil and echium seed oil, exhibit substantially higher oxidative stability than fish oil with EPA and DHA, the most popular n-3 PUFA. The present study has successfully carried out the enrichment of SDA and the synthesis of triacylglycerol (TAG) consecutively via two lipase-catalyzed reactions, which are selective hydrolysis and esterification, while most of n-3 PUFAs studies have separately employed its enrichment and the synthesis of TAG. SDA was enriched into a glyceride fraction from ahiflower seed oil by Candida rugosa lipase-catalyzed selective hydrolysis, and the SDA-enriched glycerides were separated from the reaction mixture using molecular distillation. SDA was enriched up to 40.7 mol% in glyceride fraction from an initial value of 21.6 mol% under the optimum conditions of 35 oC, and 0.1% enzyme loading relative to the weight of the total substrate. Then, SDA-enriched TAG was synthesized from the SDA-enriched glycerides and the fatty acid obtained from part of the SDA-enriched glycerides by saponification via esterification using an in-house immobilized lipase as a biocatalyst. The in-house immobilized lipase was prepared from Eversa® Transform 2.0 (liquid form) using Lewatit VP OC 1600 as a carrier. The maximum TAG yield of ca. 94% was achieved after 12 h under the optimum conditions, which are the temperature of 50 oC, the enzyme loading of 10 % relative to the weight of the total substrate, and the vacuum of 10 torr."
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Kuyas, C., A. Haeberli e P. W. Straub. "SEPARATION OF FIBRINOGEN FRAGMENTS ON GLYPRQARGPROLYS-FRACTOGEL". In XIth International Congress on Thrombosis and Haemostasis. Schattauer GmbH, 1987. http://dx.doi.org/10.1055/s-0038-1642885.
Testo completoAbstract (sommario):
The tetrapeptide GlyProArgPro, which corresponds to the newly exposed N-terminal sequence of fibrin a-polypeptide chain after the action of thraribin, has a binding site in the C-terminal part of the ;-chain as suggested by several authors. Using Gly-ProArgProLys-Fractogel (GPRPK) chrcmatography we tried to isolate a fibrinogen fragment, obtained with different enzymes and conditions, which includes the binding site for GPRP. Human fibrinogen was digested by plasmin in presence and absence of Ca-ions, and the resulting lysates were applied in 0.05 M triethanolamine (TEA), 0.1 M NaCl pH 7.4 to the GPRPK-Fractogel. The gel was washed extensively with TEA-buffer and the adsorbed protein was eluted with 6M urea in TEA-buffer. The protein containing fractions were analyzed iiununologically with anti-fragment E- and with anti-fragment D antibodies. Human fibrinogen was also digested with endopeptidase Arg-C in O.IM NaHco3 pH 8.0 at 37C over night. The enzyme cleaves fibrinogen to fragments, one of which comprising the y-chain sequence 275-375 which is said to contain the fibrin polymerization site. The Arg C-lysate was chromatographed on GPRPK-Fractogel. All fragments were analyzed by SDS-electrophoresis and by reversed-phase HPLC.Fragment D1 was the only fibrinogen fragment which was adsorbed on GPRPK-Fractogel. All other assayed fibrinogen fragments obtained by enzymatic cleavage, showed no affinity to GPRPK-Fractogel. These results demonstrate that for the binding of GPRP to fibrinogen a conformationally intact γ-chain remnant of the fragment D is required.One step chrcmatography using GPRPK-Fractogel can thus also be used to isolate fragment D1 in high purity fran plasmin lysates of fibrinogen.
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Arruda, Paulo, e Lucas Adjafre. "Use of Site-directed mutagenesis in the understanding of the catalytic domain activity of the human SDH enzyme". In XXIII Congresso de Iniciação Científica da Unicamp. Campinas - SP, Brazil: Galoá, 2015. http://dx.doi.org/10.19146/pibic-2015-38296.
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Siebra, Carolina Costa, e Maria Júlia De Sousa Silva. "SÍNDROME DA DISFUNÇÃO COGNITIVA CANINA: REVISÃO DE LITERATURA". In I Congresso On-line Nacional de Clínica Veterinária de Pequenos Animais. Revista Multidisciplinar em Saúde, 2021. http://dx.doi.org/10.51161/rems/1836.
Testo completoAbstract (sommario):
Introdução: Hoje os cães são vistos não só como animais de companhia, mas como membros da família, o que proporciona mais acesso a cuidados médicos e consequentemente uma vida prolongada. Com uma maior população de cães idosos, a decorrência da Síndrome da Disfunção Cognitiva (SDC) tem se tornado frequente. A SDC é uma doença neurodegenerativa que acomete cães senis, onde lesões cerebrais são manifestadas. Objetivos: Diante do crescente número de pacientes geriátricos na clínica veterinária, o presente trabalho tem por objetivo realizar uma revisão de literatura visando facilitar a compreensão da Síndrome da Disfunção Cognitiva, analisando sua patogenia, diagnóstico e tratamento. Material e métodos: Para isso, foi realizada busca de artigos acadêmicos recentes, utilizando as palavras-chave “disfunção”, “cognitiva”, “canina”, “alterações”, “comportamentais”, “cães”, “age-related”, “brain” e “canine” nas plataformas – SciELO e PubMED. Resultados: A SDC é comparada ao Alzheimer em humanos já que seus fatores patogênicos são semelhantes, os quais se referem a deposições de proteína β amilóide agrupadas em placas senis, e angiopatia amiloide cerebral. Os principais sinais nos cães são demência, desorientação e alterações comportamentais, como a mudança na interação social. Apesar do diagnóstico definitivo em cães ser obtido apenas no post-mortem, o diagnóstico presuntivo feito com testes neuropsicológicos deve ser realizado precocemente para que se possa impedir a evolução da doença. No tratamento pode ser feita a utilização da selegilina, neuromodulador inibidor seletivo da enzima monoamina oxidase, possuindo efeito antioxidante, diminuindo a morte celular. Ainda, é usada a adenosilmetionina, droga que se mostra eficaz na melhora da função cognitiva em animais senis e a propentofilina, vasodilatador que melhora a irrigação cerebral. Conclusão: Compreender a SDC é fundamental para um diagnóstico precoce nos pacientes, realizando o quanto antes os tratamentos paliativos indicados, para a garantia de uma melhor qualidade de vida dos animais afetados, fazendo o uso de fármacos, dietas ricas em antioxidantes e enriquecimento ambiental.
Rapporti di organizzazioni sul tema "SDR enzyme"
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Wong, Eric A., e Zehava Uni. Nutrition of the Developing Chick Embryo: Nutrient Uptake Systems of the Yolk Sac Membrane and Embryonic Intestine. United States Department of Agriculture, giugno 2012. http://dx.doi.org/10.32747/2012.7697119.bard.
Testo completoAbstract (sommario):
We have examined the developmental changes in composition, amount, and uptake of yolk nutrients (fat, protein, water and carbohydrates) and the expression ofnutrient transporters in the yolk sac membrane (YSM) from embryonic day 11 (Ell) to 21 (E21) and small intestine from embryonic day 15 (E15) to E21 in embryos from young (22-25 wk) and old (45-50 wk) Cobb and Leghorn breeder flocks. The developmental expression profiles for the peptide transporter 1 (PepTl), the amino acid transporters, EAAT3, CAT-1 and BOAT, the sodium glucose transporter (SGLTl), the fructose transporter (GLUT5), the digestive enzymes aminopeptidase N (APN) and sucraseisomaltase (SI) were assayed by the absolute quantification real time PCR method in the YSM and embryonic intestine. Different temporal patterns of expression were observed for these genes. The effect of in ovo injection of peptides (the dipeptide Gly-Sar, purified peptides, trypsin hydrolysate) on transporter gene expression has been examined in the embryonic intestine. Injection of a partial protein hydrolysate resulted in an increase in expression of the peptide transporter PepT2. We have initiated a transcriptome analysis of genes expressed in the YSM at different developmental ages to better understand the function of the YSM.
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Zilberstein, Aviah, Bo Liu e Einat Sadot. Studying the Involvement of the Linker Protein CWLP and its Homologue in Cytoskeleton-plasma Membrane-cell Wall Continuum and in Drought Tolerance. United States Department of Agriculture, giugno 2012. http://dx.doi.org/10.32747/2012.7593387.bard.
Testo completoAbstract (sommario):
The study has been focused on proline-rich proteins from the HyPRP family. Three proline-rich proteins have been characterized with the CWLP as the main objective. We showed that this unique protein is assembled in the plasma membrane (PM) and forms a continuum between the cell wall (CW) and cytosol via the PM. While spanning the PM, it is arranged in lipid rafts as CWLP-aquaporin complexes that recruit PP2A-β”, as a part of PP2A enzyme, close to the aquaporin moiety where it dephosphorylates two crucial Ser residues and induces closure of the aquaporin water channels. The closure of water channels renders cells more tolerant to plasmolysis and plants to dehydration. This unique effect was observed not only in Arabidopsis, but also in potato plants over expressing the CWLP, suggesting a possible usage in crop plants as a valve that reduces loss of water or/and elevates cold resistance. The CWLP is a member of the HyPRP protein family that all possess structurally similar 8CM domain, predicted to localize to PM lipid rafts. In this study, two additional highly homologous HyPRP proteins were also studied. The GPRP showed the same localization and it’s over expression increased tolerance to lack of water. However, the third one, PRP940, despite sharing high homology in the 8CM domain, is completely different and is assembled in parallel to cortical microtubules in the cell. Moreover, our data suggest that this protein is not involved in rendering plants resistant to lack of water. We suggest implying CWLP as a tool for better regulation of water maintenance in crop plants.
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Fridman, Eyal, e Eran Pichersky. Tomato Natural Insecticides: Elucidation of the Complex Pathway of Methylketone Biosynthesis. United States Department of Agriculture, dicembre 2009. http://dx.doi.org/10.32747/2009.7696543.bard.
Testo completoAbstract (sommario):
Plant species synthesize a multitude of specialized compounds 10 help ward off pests. and these in turn may well serve as an alternative to synthetic pesticides to reduce environmental damage and health risks to humans. The general goal of this research was to perform a genetic and biochemical dissection of the natural-insecticides methylketone pathway that is specific to the glandular trichomes of the wild species of tomato, Solanumhabrochaites f. glabratum (accession PI126449). Previous study conducted by us have demonstrated that these compounds are synthesized de novo as a derivate pathway of the fatty acid biosynthesis, and that a key enzyme. designated MethylketoneSynthase 1 (MKS 1). catalyzes conversion of the intermediate B-ketoacyl- ACPs to the corresponding Cn-1 methylketones. The approach taken in this proposed project was to use an interspecific F2 population. derived from the cross between the cultivated lV182 and the wild species PIl26449. for three objectives: (i) Analyze the association between allelic status of candidate genes from the fatty acid biosynthesis pathway with the methylketone content in the leaves (ii) Perform bulk segregant analysis of genetic markers along the tomato genome for identifying genomic regions that harbor QTLs for 2TD content (iii) Apply differential gene expression analysis using the isolated glands of bulk segregant for identifying new genes that are involved in the pathway. The genetic mapping in the interspecific F2 population included app. 60 genetic markers, including the candidate genes from the FAS pathway and SSR markers spread evenly across the genome. This initial; screening identified 5 loci associated with MK content including the candidate genes MKS1, ACC and MaCoA:ACP trans. Interesting observation in this genetic analysis was the connection between shape and content of the glands, i.e. the globularity of the four cells, typical to the wild species. was associated with increased MK in the segregating population. In the next step of the research transcriptomic analysis of trichomes from high- and 10w-MK plants was conducted. This analysis identified a new gene, Methy1ketone synthase 2 (MKS2), whose protein product share sequence similarity to the thioesterase super family of hot-dog enzymes. Genetic analysis in the segregating population confirmed its association with MK content, as well as its overexpression in E. coli that led to formation of MK in the media. There are several conclusions drawn from this research project: (i) the genetic control of MK accumulation in the trichomes is composed of biochemical components in the FAS pathway and its vicinity (MKS 1 and MKS2). as well as genetic factors that mediate the morphology of these specialized cells. (ii) the biochemical pathway is now realized different from what was hypothesized before with MKS2 working upstream to I\1KS 1 and serves as the interface between primary (fatty acids) and secondary (MK) metabolism. We are currently testing the possible physical interactions between these two proteins in vitro after the genetic analysis showed clear epistatic interactions. (iii) the regulation of the pathway that lead to specialized metabolism in the wild species is largely mediated by transcription and one of the achievements of this project is that we were able to isolate and verify the specificity of the MKS1 promoter to the trichomes which allows manipulation of the pathways in these cells (currently in progress). The scientific implications of this research project is the advancement in our knowledge of hitherto unknown biochemical pathway in plants and new leads for studying a new family in plants (hot dog thioesterase). The agricultural and biotechnological implication are : (i) generation of new genetic markers that could assist in importing this pathway to cultivated tomato hence enhancing its natural resistance to insecticides, (ii) the discovery of MKS2 adds a new gene for genetic engineering of plants for making new fatty acid derived compounds. This could be assisted with the use of the isolated and verified MKS1 promoter. The results of this research were summarized to a manuscript that was published in Plant Physiology (cover paper). to a chapter in a proceeding book. and one patent was submitted in the US.
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Spiegel, Yitzhak, Michael McClure, Itzhak Kahane e B. M. Zuckerman. Characterization of the Phytophagous Nematode Surface Coat to Provide New Strategies for Biocontrol. United States Department of Agriculture, novembre 1995. http://dx.doi.org/10.32747/1995.7613015.bard.
Testo completoAbstract (sommario):
Chemical composition and biological role of the surface coat (SC) of the root-knot nematodes, Meloidogyne spp. are described. SC proteins of M. incognita race 3 infective juveniles (J2) were characterized by electrophoresis and western blotting of extracts from radioiodine and biotin-labelled nematodes. J2 labelled with radioiodine and biotin released 125I and biotin-labelled molecules into water after 20 hours incubation, indicating that SC proteins may be loosely attached to the nematode. Antiserum to the principal protein reacted with the surface of live J2 and with surface proteins previously separated by electrophoresis. Human red blood cells (HRBC) adhered to J2 of several tylenchid nematodes over the entire nematode body. HRBC adhered also to nylon fibers coated with SC extracted from M. javanica J2; binding was Ca++/Mg++ dependent, and decreased when the nylon fibers were coated with bovine serum albumin, or pre-incubated with fucose and mannose. These experiments support a working hypothesis that RBC adhesion involves carbohydrate moieties of HRBC and carbohydrate-recognition domain(s) (CRD) distributed on the nematode surface. To our knowledge, this is the first report of a surface CRD i the phylum Nematoda. Gold-conjugated lectins and neoglycoproteins combined with silver enhancement have been used for the detection of carbohydrates and CRD, respectively, on the SC of M. javanica J2. Biotin reagents were used to trace surface proteins, specifically, on live J2. The labile and transitory nature of the SC was demonstrated by the dynamics of HRBC adherence to detergent-treated J2, J2 at different ages or fresh-hatched J2 held at various temperatures. SC recovery was demonstrated also by a SDS-PAGE profile. Monoclonal antibodies developed to a cuticular protein of M. incognita J2 gave a slight, but significant reduction in attachment of Pasteuria penetrans spores. Spore attachment as affected by several enzymes was inconsistent: alcian blue, which specifically blocks sulfyl groups, had no afffect on spore attachment. Treatment with cationized ferritin alone or catonized ferritin following monoclonal antibody caused significant decreases in spore attachment. Those results suggest a role in attachment by negatively charged groups.
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Pesis, Edna, Elizabeth J. Mitcham, Susan E. Ebeler e Amnon Lers. Application of Pre-storage Short Anaerobiosis to Alleviate Superficial Scald and Bitter Pit in Granny Smith Apples. United States Department of Agriculture, gennaio 2013. http://dx.doi.org/10.32747/2013.7593394.bard.
Testo completoAbstract (sommario):
There is increased demand for high quality fruit produced and marketed with reduced chemical inputs to minimize toxic effects on human health and the environment. Granny Smith (GS) apple quality is reduced by two major physiological disorders, superficial scald and bitter pit (BP). These disorders cause great loss to apple growers worldwide. Superficial scald is commonly controlled by chemical treatments, mainly the antioxidant diphenylamine (DPA) and/or the ethylene action inhibitor, 1-methylcyclopropene (1–MCP). Both chemicals are ineffective in controlling bitter pit incidence. We proposed to investigate the beneficial use of non-chemical, abiotic stress with low O2 (LO2) applied for 10d at 20°C on GS apple fruit. During the project we expanded the treatment to more apple cultivars, Golden Delicious (GD) and Starking Delicious (SD) and another pome fruit, the pear. Apple and pear have similar physiological disorders that develop during cold storage and we examined if the LO2 treatment would also be effective on pear. Application of 0.5% LO2 atmosphere for 10d at 20°C or 500ppb 1-MCP at 20°C prior to cold storage at 0°C, was effective in reducing superficial scald in GS apple. Moreover, LO2 pretreatment was also effective in reducing bitter pit (BP) development in California GS and Israeli GD and SD apples The BP symptoms in GS from California were much more prominent, so the effect of LO2 was more dramatic than the effect on the Israeli cvs. GD and SD, nevertheless the LO2 treatment showed the same trend in all cultivars in reducing BP. The LO2 and 1-MCP -treated fruit exhibited lower levels of ethylene, - farnesene and its oxidation product, 6-methyl-5-hepten-2-one (MHO), as determined by SPME/GC-MS analysis. In addition, LO2 pretreatment applied to California Bartlett or Israeli Spadona pears was effective in reducing superficial scald, senescent scald and internal breakdown after 4 m of cold storage at 0°C. For GS apple, low-temperature storage resulted in oxidative stress and chilling injury, caused by increased production of superoxide anions which in turn led to the generation of other dangerous reactive oxygen species (ROS). Using confocal laser-scanning microscopy and H2O2 measurements of apple peel, we observed ROS accumulation in control fruit, while negligible amounts were found in LO2 and 1-MCP treated fruit. Gene-expression levels of ROS-scavenging enzymes were induced by the various pretreatments: catalase was induced by LO2 treatment, whereas Mn superoxide dismutase was induced by 1-MCP treatment. We assume that LO2 and 1-MCP pretreated fruit remained healthier due to reduced production of ethylene and reactive oxygen substances, such as MHO, during cold storage. The LO2-treated apple exhibited greener peel and firmer fruit after 6 m of cold storage, and the fruit had high crispiness leading to high taste preference. In both pear cultivars, the LO2 treatment led to a reduction in internal breakdown and browning around the seed cavity. We tested the LO2 pre-storage treatment on a semi-commercial scale that would be applicable to a small organic grower by sealing the fruit within the plastic field bins. The treatment was most effective with a continuous flow of nitrogen through the bins; however, a single 6 hour flush of nitrogen was also fairly effective. In addition, we determined that it was very important to have the oxygen levels below 0.5% for approximately 10 days to achieve good scald control, not counting the time required to reduce the oxygen concentration. Our LO2 technology has been proven in this project to be effective in reducing several physiological disorders developed in pome fruit during cold storage. We hope that our non-chemical treatment which is friendly to the environment will be used in the near future for the organic apple and pear industry. The next step should be an analysis of the cost-benefits and commercial feasibility.