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Journal articles on the topic 'Lipid order'

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Published: 4 June 2021
Last updated: 8 June 2023

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1

Lafleur, Michel, Myer Bloom, and Pieter R. Cullis. "Lipid polymorphism and hydrocarbon order." Biochemistry and Cell Biology 68, no. 1 (January 1, 1990): 1–8. http://dx.doi.org/10.1139/o90-001.

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The use of 2H nuclear magnetic resonance for the characterization of the polymorphic behavior of lipids is illustrated. Different lipid phase preferences may be expected to influence the orientational order and its variation along the acyl chains. Several results are presented to support that view. An increase of motional freedom and a redistribution of the order along the acyl chains are observed during the lamellar-to-hexagonal phase transition, showing that the order profile is sensitive to the lipid phase symmetry. In addition, if the preferences for nonlamellar phases are not expressed explicitly, the presence of "nonbilayer" lipids constrained in bilayer environment induces increased hydrocarbon order. This suggests that order parameters of the acyl chains and lipid polymorphic tendencies are intimately related.Key words: lipid, polymorphism, 2H nuclear magnetic resonance, hydrocarbon order.
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2

Leonard, Catherine, Hélène Pollet, Christiane Vermylen, Nir Gov, Donatienne Tyteca, and Marie-Paule Mingeot-Leclercq. "Tuning of Differential Lipid Order Between Submicrometric Domains and Surrounding Membrane Upon Erythrocyte Reshaping." Cellular Physiology and Biochemistry 48, no. 6 (2018): 2563–82. http://dx.doi.org/10.1159/000492700.

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Background/Aims: Transient nanometric cholesterol- and sphingolipid-enriched domains, called rafts, are characterized by higher lipid order as compared to surrounding lipids. Here, we asked whether the seminal concept of highly ordered rafts could be refined with the presence of lipid domains exhibiting different enrichment in cholesterol and sphingomyelin and association with erythrocyte curvature areas. We also investigated how differences in lipid order between domains and surrounding membrane (bulk) are regulated and whether changes in order differences could participate to erythrocyte deformation and vesiculation. Methods: We used the fluorescent hydration- and membrane packing-sensitive probe Laurdan to determine by imaging mode the Generalized Polarization (GP) values of lipid domains vs the surrounding membrane. Results: Laurdan revealed the majority of sphingomyelin-enriched domains associated to low erythrocyte curvature areas and part of the cholesterol-enriched domains associated with high curvature. Both lipid domains were less ordered than the surrounding lipids in erythrocytes at resting state. Upon erythrocyte deformation (elliptocytes and stimulation of calcium exchanges) or membrane vesiculation (storage at 4°C), lipid domains became more ordered than the bulk. Upon aging and in membrane fragility diseases (spherocytosis), an increase in the difference of lipid order between domains and the surrounding lipids contributed to the initiation of domain vesiculation. Conclusion: The critical role of domain-bulk differential lipid order modulation for erythrocyte reshaping is discussed in relation with the pressure exerted by the cytoskeleton on the membrane.
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3

Lafleur, M., M. Bloom, E. F. Eikenberry, S. M. Gruner, Y. Han, and P. R. Cullis. "Correlation between lipid plane curvature and lipid chain order." Biophysical Journal 70, no. 6 (June 1996): 2747–57. http://dx.doi.org/10.1016/s0006-3495(96)79844-2.

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4

de Santis, Augusta, Ernesto Scoppola, Maria Francesca Ottaviani, Alexandros Koutsioubas, Lester C. Barnsley, Luigi Paduano, Gerardino D’Errico, and Irene Russo Krauss. "Order vs. Disorder: Cholesterol and Omega-3 Phospholipids Determine Biomembrane Organization." International Journal of Molecular Sciences 23, no. 10 (May 10, 2022): 5322. http://dx.doi.org/10.3390/ijms23105322.

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Lipid structural diversity strongly affects biomembrane chemico-physical and structural properties in addition to membrane-associated events. At high concentrations, cholesterol increases membrane order and rigidity, while polyunsaturated lipids are reported to increase disorder and flexibility. How these different tendencies balance in composite bilayers is still controversial. In this study, electron paramagnetic resonance spectroscopy, small angle neutron scattering, and neutron reflectivity were used to investigate the structural properties of cholesterol-containing lipid bilayers in the fluid state with increasing amounts of polyunsaturated omega-3 lipids. Either the hybrid 1-stearoyl-2-docosahexaenoyl-sn-glycero-3-phosphocholine or the symmetric 1,2-docosahexaenoyl-sn-glycero-3-phosphocholine were added to the mixture of the naturally abundant 1-palmitoyl-2-oleyl-sn-glycero-3-phosphocholine and cholesterol. Our results indicate that the hybrid and the symmetric omega-3 phospholipids affect the microscopic organization of lipid bilayers differently. Cholesterol does not segregate from polyunsaturated phospholipids and, through interactions with them, is able to suppress the formation of non-lamellar structures induced by the symmetric polyunsaturated lipid. However, this order/disorder balance leads to a bilayer whose structural organization cannot be ascribed to either a liquid ordered or to a canonical liquid disordered phase, in that it displays a very loose packing of the intermediate segments of lipid chains.
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5

Ho, Cojen, Simon J. Slater, and Christopher D. Stubbs. "Hydration and Order in Lipid Bilayers." Biochemistry 34, no. 18 (May 1995): 6188–95. http://dx.doi.org/10.1021/bi00018a023.

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6

Park, Soohyung, and Wonpil Im. "Analysis of Lipid Order States and Domains in Lipid Bilayer Simulations." Journal of Chemical Theory and Computation 15, no. 1 (November 23, 2018): 688–97. http://dx.doi.org/10.1021/acs.jctc.8b00828.

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7

Yordanova, Vesela, Rusina Hazarosova, Victoria Vitkova, Aneliya Kostadinova, Miglena Angelova, Albena Momchilova, Plamen Krastev, and Galya Staneva. "Oxidized Lipids Control Lipid Order and Phospholipase A2 Activity in Model Membranes." Proceedings of the Bulgarian Academy of Sciences 75, no. 4 (May 2, 2022): 581–89. http://dx.doi.org/10.7546/crabs.2022.04.13.

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Oxidative stress is an important etiologic factor in the pathogenesis of various diseases. The formation of oxidized phospholipid species in vivo induces membrane remodelling with direct pathological implications with a prominent inflammatory component. Secretory phospholipases A2 (sPLA2) are involved in the regulation of inflammation and immune response. Their activity is highly dependent on the lipid membrane composition, structure and organization. In this work, we studied the impact of oxidized phosphatidylcholines (OxPCs) on the membrane lipid order and the sPLA2 activity. The effects of two of the most physiologically active OxPCs, 1-palmitoyl-2-(5′-oxo-valeroyl)-sn-glycero- 3-phosphocholine (POVPC) and 1-palmitoyl-2-glutaroyl-sn-glycero-3- phosphocholine (PGPC) were compared using 1-palmitoyl-2-oleoyl-sn-glycero- 3-phosphocholine (POPC) vesicles. Both OxPCs reduce the membrane lipid order and sPLA2 activity at physiological temperature. Moreover, these changes depend on the chemical nature of the oxidized chains.
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8

Raggi, Carla, Marco Diociaiuti, Giulio Caracciolo, Federica Fratini, Luca Fantozzi, Giovanni Piccaro, Katia Fecchi, et al. "Caveolin-1 Endows Order in Cholesterol-Rich Detergent Resistant Membranes." Biomolecules 9, no. 7 (July 17, 2019): 287. http://dx.doi.org/10.3390/biom9070287.

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Cholesterol-enriched functional portions of plasma membranes, such as caveolae and rafts, were isolated from lungs of wild-type (WT) and caveolin-1 knockout (Cav-1 KO) mice within detergent resistant membranes (DRMs). To gain insight into their molecular composition we performed proteomic and lipid analysis on WT and Cav-1 KO-DRMs that showed predicted variations of proteomic profiles and negligible differences in lipid composition, while Langmuir monolayer technique and small and wide-angle X-ray scattering (SAXS-WAXS) were here originally introduced to study DRMs biophysical association state. Langmuir analysis of Cav-1 containing DRMs displayed an isotherm with a clear-cut feature, suggesting the coexistence of the liquid-ordered (Lo) phase typical of the raft structure, namely “cholesterol-rich Lo phase”, with a phase fully missing in Cav-1 KO that we named “caveolin-induced Lo phase”. Furthermore, while the sole lipid component of both WT and KO-DRMs showed qualitatively similar isotherm configuration, the reinsertion of recombinant Cav-1 into WT-DRMs lipids restored the WT-DRM pattern. X-ray diffraction results confirmed that Cav-1 causes the formation of a “caveolin-induced Lo phase”, as suggested by Langmuir experiments, allowing us to speculate about a possible structural model. These results show that the unique molecular link between Cav-1 and cholesterol can spur functional order in a lipid bilayer strictly derived from biological sources.
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9

Delamere, N. A., C. A. Paterson, D. Borchman, K. L. King, and S. A. Cawood. "Calcium transport, Ca2(+)-ATPase, and lipid order in rabbit ocular lens membranes." American Journal of Physiology-Cell Physiology 260, no. 4 (April 1, 1991): C731—C737. http://dx.doi.org/10.1152/ajpcell.1991.260.4.c731.

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Calcium transport was monitored by measuring ATP-dependent 45Ca uptake into membrane vesicles prepared from rabbit lens cortex. Calcium-stimulated adenosinetriphosphatase (Ca2(+)-ATPase) activity was also measured in the same membrane preparation. Both uptake and Ca2(+)-ATPase activity were inhibited by vanadate. Calcium activation of the uptake process was similar to that of the Ca2(+)-ATPase. Calcium uptake was prevented by calcium ionophore A23187, suggesting that the calcium transported into the vesicles remains diffusible. The ATP-dependent calcium uptake probably represents the transport of calcium into “inside-out” membrane vesicles by the Ca2(+)-ATPase mechanism that normally shifts calcium outward from the lens cytoplasm. The temperature dependence of the Ca2(+)-ATPase and the calcium uptake process was determined. Because lipid order can influence Ca2(+)-ATPase function, we attempted to correlate calcium transport with the physical state of the membrane lipids. Infrared spectroscopy was used to determine the temperature dependence of the CH2 symmetric stretching frequency (an order parameter) in the lipids. A similarity was noted between the temperature-dependence curves for lipid order, Ca2(+)-ATPase, and calcium uptake rate. Entropy, enthalpy, and transition temperature calculated for the Ca2(+)-ATPase and calcium uptake process were in the same range as those parameters calculated for the lipid-phase transition.
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10

Becker, Kevin W., Felix J. Elling, Marcos Y. Yoshinaga, Andrea Söllinger, Tim Urich, and Kai-Uwe Hinrichs. "Unusual Butane- and Pentanetriol-Based Tetraether Lipids in Methanomassiliicoccus luminyensis, a Representative of the Seventh Order of Methanogens." Applied and Environmental Microbiology 82, no. 15 (May 13, 2016): 4505–16. http://dx.doi.org/10.1128/aem.00772-16.

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ABSTRACTA new clade of archaea has recently been proposed to constitute the seventh methanogenic order, theMethanomassiliicoccales, which is related to theThermoplasmatalesand the uncultivated archaeal clades deep-sea hydrothermal ventEuryarchaeotagroup 2 and marine group IIEuryarchaeotabut only distantly related to other methanogens. In this study, we investigated the membrane lipid composition ofMethanomassiliicoccus luminyensis, the sole cultured representative of this seventh order. The lipid inventory ofM. luminyensiscomprises a unique assemblage of novel lipids as well as lipids otherwise typical for thermophilic, methanogenic, or halophilic archaea. For instance, glycerol sesterpanyl-phytanyl diether core lipids found mainly in halophilic archaea were detected, and so were compounds bearing either heptose or methoxylated glycosidic head groups, neither of which have been reported so far for other archaea. The absence of quinones or methanophenazines is consistent with a biochemistry of methanogenesis different from that of the methanophenazine-containing methylotrophic methanogens. The most distinctive characteristic of the membrane lipid composition ofM. luminyensis, however, is the presence of tetraether lipids in which one glycerol backbone is replaced by either butane- or pentanetriol, i.e., lipids recently discovered in marine sediments. Butanetriol dibiphytanyl glycerol tetraether (BDGT) constitutes the most abundant core lipid type (>50% relative abundance) inM. luminyensis. We have thus identified a source for these unusual orphan lipids. The complementary analysis of diverse marine sediment samples showed that BDGTs are widespread in anoxic layers, suggesting an environmental significance ofMethanomassiliicoccalesand/or related BDGT producers beyond gastrointestinal tracts.IMPORTANCECellular membranes of members of all three domains of life,Archaea,Bacteria, andEukarya, are largely formed by lipids in which glycerol serves as backbone for the hydrophobic alkyl chains. Recently, however, archaeal tetraether lipids with either butanetriol or pentanetriol as a backbone were identified in marine sediments and attributed to uncultured sediment-dwelling archaea. Here we show that the butanetriol-based dibiphytanyl tetraethers constitute the major lipids inMethanomassiliicoccus luminyensis, currently the only isolate of the novel seventh order of methanogens. Given the absence of these lipids in a large set of archaeal isolates, these compounds may be diagnostic for theMethanomassiliicoccalesand/or closely related archaea.
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11

Sankaram, M. B., and D. Marsh. "Chain order profile in lipid HII phases." Biophysical Journal 56, no. 5 (November 1989): 1043–44. http://dx.doi.org/10.1016/s0006-3495(89)82750-x.

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12

Soubias, Olivier, Walter E. Teague, and Klaus Gawrisch. "Lipid Lateral Diffusion and Hydrocarbon Chain Order." Biophysical Journal 100, no. 3 (February 2011): 331a. http://dx.doi.org/10.1016/j.bpj.2010.12.2008.

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13

Mouritsen, Ole G., and Kent Jørgensen. "Dynamical order and disorder in lipid bilayers." Chemistry and Physics of Lipids 73, no. 1-2 (September 1994): 3–25. http://dx.doi.org/10.1016/0009-3084(94)90171-6.

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14

McConnell, Mark, John R. Downs, and Chester B. Good. "Decrease the Incentives to Order Lipid Panels." JAMA Internal Medicine 174, no. 3 (March 1, 2014): 473. http://dx.doi.org/10.1001/jamainternmed.2013.12872.

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15

Gretskaya, Nataliya, Mikhail Akimov, Dmitry Andreev, Anton Zalygin, Ekaterina Belitskaya, Galina Zinchenko, Elena Fomina-Ageeva, Ilya Mikhalyov, Elena Vodovozova, and Vladimir Bezuglov. "Multicomponent Lipid Nanoparticles for RNA Transfection." Pharmaceutics 15, no. 4 (April 20, 2023): 1289. http://dx.doi.org/10.3390/pharmaceutics15041289.

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Despite the wide variety of available cationic lipid platforms for the delivery of nucleic acids into cells, the optimization of their composition has not lost its relevance. The purpose of this work was to develop multi-component cationic lipid nanoparticles (LNPs) with or without a hydrophobic core from natural lipids in order to evaluate the efficiency of LNPs with the widely used cationic lipoid DOTAP (1,2-dioleoyloxy-3-[trimethylammonium]-propane) and the previously unstudied oleoylcholine (Ol-Ch), as well as the ability of LNPs containing GM3 gangliosides to transfect cells with mRNA and siRNA. LNPs containing cationic lipids, phospholipids and cholesterol, and surfactants were prepared according to a three-stage procedure. The average size of the resulting LNPs was 176 nm (PDI 0.18). LNPs with DOTAP mesylate were more effective than those with Ol-Ch. Core LNPs demonstrated low transfection activity compared with bilayer LNPs. The type of phospholipid in LNPs was significant for the transfection of MDA-MB-231 and SW 620 cancer cells but not HEK 293T cells. LNPs with GM3 gangliosides were the most efficient for the delivery of mRNA to MDA-MB-231 cells and siRNA to SW620 cells. Thus, we developed a new lipid platform for the efficient delivery of RNA of various sizes to mammalian cells.
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16

Mazeres, Serge, Etienne Joly, Andre Lopez, and Catherine Tardin. "Characterization of M-laurdan, a versatile probe to explore order in lipid membranes." F1000Research 3 (November 19, 2014): 172. http://dx.doi.org/10.12688/f1000research.4805.2.

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Microdomains corresponding to localized partition of lipids between ordered and less ordered environments are the subject of intensive investigations, because of their putative participation in modulating cellular responses. One popular approach in the field consists in labelling membranes with solvatochromic fluorescent probes such as laurdan and C-laurdan. In this report, we describe a high-yield procedure for the synthesis of laurdan, C-laurdan and two new fluorophores, called MoC-laurdan and M-laurdan, as well as their extensive photophysical characterization. We find that the latter probe, M-laurdan, is particularly suited to discriminate lipid phases independently of the chemical nature of the lipids, as measured by both fluorescence Generalized Polarization (GP) and anisotropy in large unilamellar vesicles made of various lipid compositions. In addition, staining of live cells with M-laurdan shows a good stability over time without any apparent toxicity, as well as a wider distribution in the various cell compartments than the other probes.
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17

Sheng, J., R. Vannela, and B. E. Rittmann. "Disruption of Synechocystis PCC 6803 for lipid extraction." Water Science and Technology 65, no. 3 (February 1, 2012): 567–73. http://dx.doi.org/10.2166/wst.2012.879.

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In order to extract intracellular lipids from cyanobacterial Synechocystis PCC 6803 for biofuel production, seven cell-disruption methods – autoclaving, bead beating, freeze drying, French press, microwave, pulsed electric fields (PEF), and ultrasound – were tested prior to lipid extraction to make intracellular lipids more accessible by organic solvents. The different methods brought about distinct disruption effects to the cell envelope, plasma membrane, and thylakoid membranes that were related to extraction efficiency. Microwave, PEF, and ultrasound with temperature control had significant enhancement of lipid extraction (9–13% increases). Bead beating, freeze drying, and French press did not provide significant enhancement of lipid extraction. Furthermore, autoclaving, French press, and ultrasound treatments caused significant release of lipid into the medium, which may increase solvent usage and make medium recycling difficult. In order to minimize the cost of cell-disruption and lipid-extraction steps, microwave and PEF (with temperature control) might be best suited for large-scale cell disruption among all techniques investigated.
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18

Kao, Yu-Chia, Pei-Chuan Ho, Yuan-Kun Tu, I.-Ming Jou, and Kuen-Jer Tsai. "Lipids and Alzheimer’s Disease." International Journal of Molecular Sciences 21, no. 4 (February 22, 2020): 1505. http://dx.doi.org/10.3390/ijms21041505.

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Lipids, as the basic component of cell membranes, play an important role in human health as well as brain function. The brain is highly enriched in lipids, and disruption of lipid homeostasis is related to neurologic disorders as well as neurodegenerative diseases such as Alzheimer’s disease (AD). Aging is associated with changes in lipid composition. Alterations of fatty acids at the level of lipid rafts and cerebral lipid peroxidation were found in the early stage of AD. Genetic and environmental factors such as apolipoprotein and lipid transporter carrying status and dietary lipid content are associated with AD. Insight into the connection between lipids and AD is crucial to unraveling the metabolic aspects of this puzzling disease. Recent advances in lipid analytical methodology have led us to gain an in-depth understanding on lipids. As a result, lipidomics have becoming a hot topic of investigation in AD, in order to find biomarkers for disease prediction, diagnosis, and prevention, with the ultimate goal of discovering novel therapeutics.
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19

Morton, John M., Roy L. Kirkpatrick, David W. Howerter, Thomas H. Eason, and Christine M. Long. "Depletion of lipid, lean, and ash masses in food-restricted American black ducks." Canadian Journal of Zoology 72, no. 8 (August 1, 1994): 1492–96. http://dx.doi.org/10.1139/z94-197.

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We investigated the rate and order of depletion of lipid depots and other body components in American black ducks (Anas rubripes) responding to food restriction. Forty-one hatching-year ducks were placed on one of four diets to induce high variability in body composition. Regression analyses suggest that for every 1-g decrease in body mass, lipids decreased 0.53 g, water decreased 0.36 g, ash-free nonlipid dry mass (NLDM) decreased 0.05 g, and ash decreased 0.02 g. However, depletion rates were not uniform among lipid sources. Both lipid mass and lipid depletion rate were ranked in descending order: subcutaneous, carcass, omental, and visceral. Despite disproportionately low depletion rates, intraperitoneal depots were depleted before subcutaneous or carcass lipids. We also found evidence of a sexual difference in endogenous nutrient utilization by American black ducks in response to food restriction. Males reduced NLDM (mostly breast muscle), visceral lipids, and subcutaneous lipids concomitantly. In contrast, females did not utilize NLDM but depleted visceral and subcutaneous lipids at rates 146–175% higher than males. These data suggest that relationships between depot and total body lipid masses are not necessarily uniform. Furthermore, it may not be possible to apply some measures of physiological condition equitably to both sexes of Anatinae.
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Armstrong, Clare L., Laura Toppozini, Hannah Dies, Antonio Faraone, Michihiro Nagao, and Maikel C. Rheinstädter. "Incoherent Neutron Spin-Echo Spectroscopy as an Option to Study Long-Range Lipid Diffusion." ISRN Biophysics 2013 (March 31, 2013): 1–9. http://dx.doi.org/10.1155/2013/439758.

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Diffusion is the fundamental mechanism for lipids and other molecules to move in a membrane. It is an important process to consider in modelling the formation of membrane structures, such as rafts. Lipid diffusion is mainly studied by two different techniques: incoherent neutron scattering and fluorescence microscopy. Both techniques access distinctly different length scales. While neutron scattering measures diffusion over about 3 lipid diameters, microscopic techniques access motions of lipids over micrometer distances. The diffusion constants which are determined by these two methods often differ by about an order of magnitude, with the neutrons usually seeing a faster lipid diffusion. Different theories are used to describe lipid diffusion in the two experiments. In order to close the “gap” between these two techniques, we propose to study lipid diffusion at mesoscopic length scales using a neutron spin-echo (NSE) spectrometer. We have conducted an experiment in highly oriented, solid supported lipid bilayers to prove the feasibility of performing incoherent NSE on biological samples. Lateral lipid diffusion was measured in a fluid phase model membrane system at a length scale of 12 Å. Using the high-energy resolution of the NSE technique, we find evidence for two dynamic processes.
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Lado-Touriño, Isabel, and Arisbel Cerpa-Naranjo. "Coarse-Grained Molecular Dynamics of pH-Sensitive Lipids." International Journal of Molecular Sciences 24, no. 5 (February 27, 2023): 4632. http://dx.doi.org/10.3390/ijms24054632.

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pH-sensitive lipids represent a class of lipids that can be protonated and destabilized in acidic environments, as they become positively charged in response to low-pH conditions. They can be incorporated into lipidic nanoparticles such as liposomes, which are able to change their properties and allow specific drug delivery at the acidic conditions encountered in some pathological microenvironments. In this work, we used coarse-grained molecular-dynamic simulations to study the stability of neutral and charged lipid bilayers containing POPC (1-palmitoyl-2-oleoyl-sn-glycero-3-phosphocholine) and various kinds of ISUCA ((F)2-(imidazol-1-yl)succinic acid)-derived lipids, which can act as pH-sensitive molecules. In order to explore such systems, we used a MARTINI-derived forcefield, previously parameterized using all-atom simulation results. We calculated the average area per lipid, the second-rank order parameter and the lipid diffusion coefficient of both lipid bilayers made of pure components and mixtures of lipids in different proportions, under neutral or acidic conditions. The results show that the use of ISUCA-derived lipids disturbs the lipid bilayer structure, with the effect being particularly marked under acidic conditions. Although more-in depth studies on these systems must be carried out, these initial results are encouraging and the lipids designed in this research could be a good basis for developing new pH-sensitive liposomes.
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Zorilă, Bogdan, George Necula, Mihai Radu, and Mihaela Bacalum. "Melittin Induces Local Order Changes in Artificial and Biological Membranes as Revealed by Spectral Analysis of Laurdan Fluorescence." Toxins 12, no. 11 (November 8, 2020): 705. http://dx.doi.org/10.3390/toxins12110705.

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Antimicrobial peptides (AMPs) are a class of molecules widely used in applications on eukaryotic and prokaryotic cells. Independent of the peptide target, all of them need to first pass or interact with the plasma membrane of the cells. In order to have a better image of the peptide action mechanism with respect to the particular features of the membrane it is necessary to better understand the changes induced by AMPs in the membranes. Laurdan, a lipid membrane probe sensitive to polarity changes in the environment, is used in this study for assessing changes induced by melittin, a well-known peptide, both in model and natural lipid membranes. More importantly, we showed that generalized polarization (GP) values are not always efficient or sufficient to properly characterize the changes in the membrane. We proved that a better method to investigate these changes is to use the previously described log-normal deconvolution allowing us to infer other parameters: the difference between the relative areas of elementary peak (ΔSr), and the ratio of elementary peaks areas (Rs). Melittin induced a slight decrease in local membrane fluidity in homogeneous lipid membranes. The addition of cholesterol stabilizes the membrane more in the presence of melittin. An opposite response was observed in the case of heterogeneous lipid membranes in cells, the local order of lipids being diminished. RS proved to be the most sensitive parameter characterizing the local membrane order, allowing us to distinguish among the responses to melittin of both classes of membrane we investigated (liposomes and cellular membranes). Molecular simulation of the melittin pore in homogeneous lipid bilayer suggests that lipids are more closely packed in the proximity of the melittin pore (a smaller area per lipid), supporting the experimental observation.
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23

Bamezai, Anil K., and Walter Bakun. "ROLE OF LIPID RAFT-BASED MEMBRANE ORDER IN SIGNALING THROUGH THE ANTIGEN RECEPTOR IN CD4+ T CELLS: INVESTIGATING THE MECHANISM." Journal of Immunology 196, no. 1_Supplement (May 1, 2016): 128.1. http://dx.doi.org/10.4049/jimmunol.196.supp.128.1.

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Abstract Plasma membrane of all animal cells are highly organized into liquid ordered (Io) and liquid disordered (Id) phases. While Io phase is enriched in saturated lipids, cholesterol and lapidated proteins, the unsaturated lipids and some proteins are the major constituents of the Id phase. Lipid rafts nano-domains on the membrane that are enriched in cholesterol and saturated lipids, constitute, in-part, the ordered phase of the membrane. We have previously reported the role of membrane order in spatiotemporal signaling in primary CD4+ T lymphocytes expressing αβ T cell receptor with specificity to chicken ovalbumin323–339 peptide (cOva323-339) (Schieffer et. al., 2014, BMC Immunology 15:58). Primary DO11 CD4+ T cells with disrupted lipid raft-based membrane order lose their proliferative capacity to clonally expand in response to cOva323-339. Moreover, integrity of membrane order within 120 minutes of antigen exposure is critical for antigen-specific clonal expansion of CD4+ T cells. Since early events of T cell activation are initiated at the plasma membrane we examined the effect of membrane disorder on key signaling proteins participating in early CD4+ T cell signaling, such as, p56lck, Zap70, LAT, PLC-γ1, and Akt. We show that disruption of lipid raft-based membrane order does not inhibit the early phosphorylation events associated with aforementioned signaling proteins after engaging the TCRαβ/CD3 complex on primary CD4+ T cells. We are currently assessing the contribution of accessory molecules/adhesion proteins expressed on CD4+ T cells whose biological function may depend on integrity of lipid raft-based membrane order.
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24

Howe, Alaina, and Stavroula Sofou. "Daptomycin-Induced Lipid Phases on Model Lipid Bilayers: Effect of Lipid Type and of Lipid Leaflet Order on Membrane Permeability." Journal of Physical Chemistry B 125, no. 22 (May 26, 2021): 5775–85. http://dx.doi.org/10.1021/acs.jpcb.1c02047.

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25

Baykal-Caglar, Eda, Ebrahim Hassanzadeh, Mohammad Alwarawrah, and Juyang Huang. "The Unique Roles of Hybrid Lipids in Lipid Membrane Domain Size and Order." Biophysical Journal 106, no. 2 (January 2014): 95a. http://dx.doi.org/10.1016/j.bpj.2013.11.595.

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26

Lai, Alex L., Lukas K. Tamm, Jeffrey F. Ellena, and David S. Cafiso. "Synaptotagmin 1 Modulates Lipid Acyl Chain Order in Lipid Bilayers by Demixing Phosphatidylserine." Journal of Biological Chemistry 286, no. 28 (May 24, 2011): 25291–300. http://dx.doi.org/10.1074/jbc.m111.258848.

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27

Cho, Seok-Cheol, Woon-Yong Choi, Sung-Ho Oh, Choon-Geun Lee, Yong-Chang Seo, Ji-Seon Kim, Chi-Ho Song, et al. "Enhancement of Lipid Extraction from Marine Microalga,ScenedesmusAssociated with High-Pressure Homogenization Process." Journal of Biomedicine and Biotechnology 2012 (2012): 1–6. http://dx.doi.org/10.1155/2012/359432.

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Marine microalga,Scenedesmussp., which is known to be suitable for biodiesel production because of its high lipid content, was subjected to the conventional Folch method of lipid extraction combined with high-pressure homogenization pretreatment process at 1200 psi and 35°C. Algal lipid yield was about 24.9% through this process, whereas only 19.8% lipid can be obtained by following a conventional lipid extraction procedure using the solvent, chloroform : methanol (2 : 1, v/v). Present approach requires 30 min process time and a moderate working temperature of 35°C as compared to the conventional extraction method which usually requires >5 hrs and 65°C temperature. It was found that this combined extraction process followed second-order reaction kinetics, which means most of the cellular lipids were extracted during initial periods of extraction, mostly within 30 min. In contrast, during the conventional extraction process, the cellular lipids were slowly and continuously extracted for >5 hrs by following first-order kinetics. Confocal and scanning electron microscopy revealed altered texture of algal biomass pretreated with high-pressure homogenization. These results clearly demonstrate that the Folch method coupled with high-pressure homogenization pretreatment can easily destruct the rigid cell walls of microalgae and release the intact lipids, with minimized extraction time and temperature, both of which are essential for maintaining good quality of the lipids for biodiesel production.
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Türker-Kaya, Sevgi, Aygül Kına, and Selen Alın. "Divergent interaction profiles of gabapentin and levetiracetam with dipalmitoylphosphatidylcholine lipids." International Journal of Epilepsy 04, no. 02 (December 2017): 150–58. http://dx.doi.org/10.1016/j.ijep.2017.09.001.

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Abstract Background/Objectives The lipid solubility of antiepileptic drugs directly affects central nervous system availability. In relation to this, the interactions of gabapentin and levetiracetam with dipalmitoylphosphatidylcholine lipids depending on concentrations were comparatively investigated in the present study. Methods The effects of gabapentin and levetricetam as a function of concentration (1–5–10–20 mol%) on biophysical parameters of dipalmitoylphosphatidylcholine multilammelar vesicles were studied by differential scanning calorimetry and fourier transform infrared spectroscopy. Results The data revealed that gabapentin at all concentrations and levetiracetam at 1–5 mol% lowered main transition temperature, enthalpy, cooperativity, lipid fluidity, lipid order, and increased hydrogen binding capacity of glycerol and phosphate groups. However, 10–20 mol% of levetiracetam tend to show different effect on transition temperature, which could also reflect its opposing effect on lipid order and glycerol and phosphate group’s hydrations. Conclusions According to the corresponding findings depending on concentrations both drugs incorporate into phosphatidylcholines, perturbing the packing of lipids and affecting their thermotropic properties. Their binding affinity to acyl chains and hydrophilic parts of lipids was found to highly correlate with lipid-water partition and their solubility degree in water. Hence, the obtained results may offer evaluation of partition profile of the drugs into biological membranes depending on concentration.
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Tejada, Luis, Eva Salazar, Adela Abellán, Begoña Peinado, Juana Mulero, and Jose M. Cayuela. "A comparison of fatty acid profiles and lipolysis during ripening of dry-cured loins obtained from a native pig breed (ChatoMurciano) and from a modern crossbreed pig." Animal Production Science 56, no. 11 (2016): 1928. http://dx.doi.org/10.1071/an15033.

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The fatty acid composition of neutral lipids (NL), polar lipids (PL) and free fatty acids (FFA) was analysed in dry-cured loins obtained from the native pig breed Chato Murciano (CM) and from a modern crossbreed pig genotype (CG) during the ripening stage (between the 30 and 60 days of processing). Fatty acid concentrations from neutral lipids, polar lipids and free fatty acid fractions were affected by breed. With respect to ripening time, lipolysis was more intense in the CG than in CM product, resulting in a decrease in the concentrations of fatty acids in the NL and PL fractions, accompanied by a corresponding increase in FFA. Results for lipid determination provided evidence that the concentrations of the different groups of fatty acids within the lipid fractions depend on the breed. In order of abundance, the groups of fatty acids in the neutral lipid fraction were monounsaturated fatty acids (MUFA) > saturated fatty acids (SFA) > polyunsaturated fatty acids (PUFA) (59%, 37% and 4% in CM; 58%, 35% and 6% in CG) at 60 days of processing. In the polar lipid fraction, the order was SFA > PUFA > MUFA (44%, 29% and 27% in CM; 42%, 38% and 20% in CG), and in free fatty acid fraction, the order was MUFA > PUFA > SFA (40%, 30%, and 30% in CM; 39%, 32%, and 29% in CG) at 60 days of processing.
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Korolev, Kirill Sergeevich, and David R. Nelson. "Orientational Order and Raft Interactions in Lipid Bilayers." Biophysical Journal 96, no. 3 (February 2009): 607a. http://dx.doi.org/10.1016/j.bpj.2008.12.3210.

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Svensson, Frida R., Per Lincoln, Bengt Nordén, and Elin K. Esbjörner. "Retinoid Chromophores as Probes of Membrane Lipid Order." Journal of Physical Chemistry B 111, no. 36 (September 2007): 10839–48. http://dx.doi.org/10.1021/jp072890b.

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Overbeck, Gernot A., Dirk Hönig, and Dietmar Möbius. "Long-range order and textures in lipid monolayers." Biosensors and Bioelectronics 10, no. 1-2 (January 1995): 99–103. http://dx.doi.org/10.1016/0956-5663(95)96798-4.

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Virani, Salim S., Christie M. Ballantyne, and Laura A. Petersen. "Decrease the Incentives to Order Lipid Panels—Reply." JAMA Internal Medicine 174, no. 3 (March 1, 2014): 473. http://dx.doi.org/10.1001/jamainternmed.2013.12842.

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34

Raghunath, Gokul, Yen-Cheng Chen, Mariana Marin, Hui Wu, and Gregory B. Melikyan. "SERINC5-Mediated Restriction of HIV-1 Infectivity Correlates with Resistance to Cholesterol Extraction but Not with Lipid Order of Viral Membrane." Viruses 14, no. 8 (July 27, 2022): 1636. http://dx.doi.org/10.3390/v14081636.

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Serine incorporator 5 (SER5) is a protein that upon incorporation into virions inhibits HIV-1 infectivity by interfering with the ability of the Env glycoprotein to promote viral fusion. The mechanisms by which SER5 antagonizes HIV-1 fusion are not well understood. A recent study of SER5’s structure revealed a lipid-binding pocket, suggesting the ability to sequester lipids. This finding, along with the well-documented modulation of HIV-1 infectivity by viral lipids, especially cholesterol, prompted our examination of SER5′s effect on the general lipid order of the HIV-1 membrane. Pseudoviruses bearing the SER5-sensitive HXB2-Env and containing SER5 or SER2, a control protein that lacks antiviral activity, were analyzed using two distinct lipid-order probes. We show that SER5 incorporation does not noticeably affect the lipid order of pseudoviruses. Although viral cholesterol extraction reduces HIV-1 infectivity, SER5+ viruses are less sensitive to cholesterol extraction than the control samples. In contrast, the virus’ sensitivity to cholesterol oxidation was not affected by SER5 incorporation. The hydrolytic release of sphingomyelin-sequestered cholesterol had a minimal impact on the apparent resistance to cholesterol extraction. Based on these results, we propose that a subpopulation of more stable Env glycoproteins responsible for the residual infectivity of SER5+ viruses is less sensitive to the cholesterol content of the viral membrane.
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Chime, Salome A., Paul A. Akpa, and Anthony A. Attama. "The Utility of Lipids as Nanocarriers and Suitable Vehicle in Pharmaceutical Drug Delivery." Current Nanomaterials 4, no. 3 (November 11, 2019): 160–75. http://dx.doi.org/10.2174/2405461504666191016091827.

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Lipid based excipients have gained popularity recently in the formulation of drugs in order to improve their pharmacokinetic profiles. For drugs belonging to the Biopharmaceutics Classification System (BCS) class II and IV, lipid excipients play vital roles in improving their pharmacokinetics properties. Various nanocarriers viz: Solid lipid nanoparticles, nanostructured lipid carriers, selfnanoemulsifying drug delivery systems (SNEDDS), nanoliposomes and liquid crystal nanoparticles have been employed as delivery systems for such drugs with evident successes. Lipid-based nanotechnology have been used to control the release of drugs and have utility for drug targeting and hence, have been used for the delivery of various anticancer drugs and for colon targeting. Drugs encapsulated in lipids have enhanced stability due to the protection they enjoy in the lipid core of these nanoformulations. However, lipid excipients could be influenced by factors which could affect the physicochemical properties of lipid-based drug delivery systems (LBDDS). These factors include the liquid crystalline phase transition, lipid crystallization and polymorphism amongst others. However, some of the physicochemical properties of lipids made them useful as nanocarriers in the formulation of various nanoformulations. Lipids form vesicles of bilayer which have been used to deliver drugs and are often referred to as liposomes and nanoliposomes. This work aims at reviewing the different classes of lipid excipients used in formulating LBDDS and nanoformulations. Also, some factors that influence the properties of lipids, different polymorphic forms in lipid excipients that made them effective nanocarriers in nano-drug delivery would be discussed. Special considerations in selecting lipid excipients used in formulating various forms of nanoformulations would be discussed.
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Nichols, Frank C., Bekim Bajrami, Robert B. Clark, William Housley, and Xudong Yao. "Free Lipid A Isolated from Porphyromonas gingivalis Lipopolysaccharide Is Contaminated with Phosphorylated Dihydroceramide Lipids: Recovery in Diseased Dental Samples." Infection and Immunity 80, no. 2 (December 5, 2011): 860–74. http://dx.doi.org/10.1128/iai.06180-11.

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ABSTRACTRecent reports indicate thatPorphyromonas gingivalismediates alveolar bone loss or osteoclast modulation through engagement of Toll-like receptor 2 (TLR2), though the factors responsible for TLR2 engagement have yet to be determined. Lipopolysaccharide (LPS) and lipid A, lipoprotein, fimbriae, and phosphorylated dihydroceramides ofP. gingivalishave been reported to activate host cell responses through engagement of TLR2. LPS and lipid A are the most controversial in this regard because conflicting evidence has been reported concerning the capacity ofP. gingivalisLPS or lipid A to engage TLR2 versus TLR4. In the present study, we first preparedP. gingivalisLPS by the Tri-Reagent method and evaluated this isolate for contamination with phosphorylated dihydroceramide lipids. Next, the lipid A prepared from this LPS was evaluated for the presence of phosphorylated dihydroceramide lipids. Finally, we characterized the lipid A by the matrix-assisted laser desorption ionization mass spectrometry (MALDI-MS) and electrospray-MS methods in order to quantify recovery of lipid A in lipid extracts from diseased teeth or subgingival plaque samples. Our results demonstrate that both the LPS and lipid A derived fromP. gingivalisare contaminated with phosphorylated dihydroceramide lipids. Furthermore, the lipid extracts derived from diseased teeth or subgingival plaque do not contain free lipid A constituents ofP. gingivalisbut contain substantial amounts of phosphorylated dihydroceramide lipids. Therefore, the free lipid A ofP. gingivalisis not present in measurable levels at periodontal disease sites. Our results also suggest that the TLR2 activation of host tissues attributed to LPS and lipid A ofP. gingivaliscould actually be mediated by phosphorylated dihydroceramides.
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Matas, C., F. Garcia-Vazquez,, M. Sansegundo, S. Ruiz, and J. Gadea. "326 COMPARING CHANGES IN MEMBRANE LIPID ORDER IN EPIDIDYMAL AND EJACULATED BOAR SPERMATOZOA." Reproduction, Fertility and Development 19, no. 1 (2007): 277. http://dx.doi.org/10.1071/rdv19n1ab326.

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The diffusion of lipids in the plasma membrane of ejaculated spermatozoa is influenced by seminal plasma proteins and the composition of the suspending medium (Wolfe et al. 2001 Mol. Reprod. Dev. 59, 306–313). Merocyanine 540 (M540) is a hydrophobic dye that has been shown to stain cell membranes more intensely if their lipid components are in a higher state of disorder, as is the case of capacitated spermatozoa. It is believed that the membrane fluidity changes detected by M540 precede the calcium influx, making M540 a method for evaluating the early events of capacitation. The aim of this study was to determine if there are differences in the dynamics of lipid disorder in the plasma membrane of ejaculated and epididymal boar spermatozoa under different conditions of capacitation. The sperm capacitation treatments were: washed in Delbucco's PBS supplemented with 0.1 % BSA (PBS-BSA), washed on a Percoll gradient (PG), and unwashed (UW: Control). During measurement, the samples were kept at 38�C and 5 % CO2 to maintain constant incubation conditions. Membrane lipid order and sperm viability were determined by flow cytometry with M540 (2.7 �M) and Yo-Pro-1 (25 nM), respectively. Samples were analyzed on a Coulter Epics XL flow cytometer (Beckman Coulter Co., Inc., Fullerton, CA, USA). A total of 10 000 gated events were collected per sample, with sample running rates of approximately 600 events/s. Data were analyzed by analysis of variance (ANOVA). For the epidydimal vs. ejaculated results, the percentage of low lipid disorder spermatozoa was higher in the epididymal (19.23%) than in the ejaculated (5.84%) groups, and the proportion of high disorder (42.85%) and dead cells (48.59%) was higher in the ejaculated group. In relation to sperm treatment (UW, PBS-BSA, and PG), the percentage of high disorder was similar in all of the treatment groups (UW: 44.62 %; PBS-BSA: 43.08%; PG: 43.41%). Finally, the percentage of low disorder was lower in the PBS-BSA and PERCOLL (10.68% and 12.83%, respectively) groups, and the highest was obtained for the UW group (14.09%). In conclusion, the staining with M540 revealed that the lipid disorder was affected by the source of the sperm and the sperm treatment. A significant increase in membrane lipid low disorder and decrease in high disorder and dead cells were detected when epididymal sperm were compared with ejaculated sperm, so the seminal plasma and the sperm treatment to eliminate disorder have an important effect in the lipid membrane order. Supported by MEC (AGL2006-03495/GAN) and Fundaci�n S�neca (03018/PI/05).
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Paolorossi, Mariana, and Guillermo G. Montich. "Conformational changes of β2-human glycoprotein I and lipid order in lipid–protein complexes." Biochimica et Biophysica Acta (BBA) - Biomembranes 1808, no. 9 (September 2011): 2167–77. http://dx.doi.org/10.1016/j.bbamem.2011.05.007.

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Georgiev, Georgi As, Douglas Borchman, Petar Eftimov, and Norihiko Yokoi. "Lipid Saturation and the Rheology of Human Tear Lipids." International Journal of Molecular Sciences 20, no. 14 (July 12, 2019): 3431. http://dx.doi.org/10.3390/ijms20143431.

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Elevated levels of acyl chain saturation of meibomian lipids are associated with enhanced tear film (TF) stability in infants to shortened TF breakup time with meibomian gland dysfunction. Thus, the effect of saturation on the surface properties of human TF lipids (TFLs) using a Langmuir surface balance and Brewster angle microscopy was studied. Lipid phase transitions were measured using infrared spectroscopy. The raise in the % of saturation resulted in thicker, and more elastic films at π = 12 mN/m, with the effects being proportional to the saturation level. At the same time, at lower (≤10 mN/m) π, the raise in saturation resulted in an altered spreading and modified structure of TFL layers. The strong impact of saturation on TFL surface properties correlated with a saturation induced increase of the TFL acyl chain order, phase transition temperature, and lipid–lipid interactions. The native TFL order and πmax were significantly greater, compared with native meibum collected from the same individual. Aggregation of lipids on the tear surface due to saturation was not as significant as it was for meibum. Although the surface pressure/area isotherms for TFL were similar for meibum, differences in rheology and phase transition parameters warrant the study of both.
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Wang, Yixiang, Xiao Si, Yi Feng, Dan Feng, Xiaoyu Xu, and Yan Zhang. "Ionizable Lipids with Triazole Moiety from Click Reaction for LNP-Based mRNA Delivery." Molecules 28, no. 10 (May 12, 2023): 4046. http://dx.doi.org/10.3390/molecules28104046.

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Ionizable lipid-containing lipid nanoparticles (LNPs) as a non-viral vector with good safety and potency have been considered as an ideal delivery system for gene therapy. The screening of ionizable lipid libraries with common features but diverse structures holds the promise of finding new candidates for LNPs to deliver different nucleic acid drugs such as messenger RNAs (mRNAs). Chemical strategies for the facile construction of ionizable lipid libraries with diverse structure are in high demand. Here, we report on the ionizable lipids containing the triazole moiety prepared by the copper-catalyzed alkyne–azide click reaction (CuAAC). We demonstrated that these lipids served well as the major component of LNPs, in order to encapsulate mRNA using luciferase mRNA as the model system. Thus, this study shows the potential of click chemistry in the preparation of lipid libraries for LNP assembly and mRNA delivery.
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Yarovoy, Yury, Dane M. Drutis, Thomas M. Hancewicz, Ursula Garczarek, K. P. Ananthapadmanabhan, and Manoj Misra. "Quantification of Lipid Phase Order of In Vivo Human Skin Using Attenuated Total Reflection Fourier Transform Infrared (ATR FT-IR) Spectroscopy and Multivariate Curve Resolution Analysis." Applied Spectroscopy 73, no. 2 (November 16, 2018): 182–94. http://dx.doi.org/10.1177/0003702818812738.

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A new analysis methodology utilizing multivariate curve resolution (MCR) has been successfully combined with Fourier transform infrared (FT-IR) measurement of in vivo human skin to resolve lipid phase constituents in the spectra relative to high and low chain ordering. A clinical study was performed to measure lipid order through different depths of stratum corneum of human subjects. Fourier transform IR spectra were collected through the top 10 layers of the skin on four sites on the left and right forearm of 12 individuals. Depth profiling was achieved by tape stripping to remove layers of skin with 10 successive tapes from each site. In vivo ATR FT-IR spectra were collected after removing each tape. Three isolated spectral regions were analyzed, centered around 2850 cm−1, 1460–1480 cm−1, and 730 cm−1, corresponding to stretching, scissoring, and rocking –CH2 vibrational modes, respectively. Both traditional lipid conformation analysis and MCR analysis were performed on the same spectral data. The lipid order ratio, expressed as the fraction of highly ordered orthorhombic (OR) lipids to the total lipids content (orthorhombic + hexagonal [HEX] + liquid crystal [LC]), was assessed as function of depth. Lipid order depth profiles (LODP) show an increase in order with the stratum corneum depth which can be adequately described by an exponential function for the data obtained in this study. The LODP derived from the three vibrational modes show very similar trends, although the absolute order ratios are somewhat different. The variance of the skin LODP across individuals is much greater than between sites within the same individual. The higher arm sites closer to the elbow on the left and right arm show no statistically significant difference and are recommended for use in comparative studies. The scissoring mode shows the highest sensitivity for determination of LODP value.
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42

Sarwal, Rashmi, S. N. Sanyal, and S. Khera. "Lipid metabolism inTrichuris globulosa(Nematoda)." Journal of Helminthology 63, no. 4 (December 1989): 287–97. http://dx.doi.org/10.1017/s0022149x00009160.

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ABSTRACTAdult males and females ofTrichuris globulosa, an intestinal nematode parasite of goats, were studied for their lipid composition, capability of incorporation of (Na)-1-14C-acetate into different lipid classes and the activity of certain key enzymes of lipid metabolism. The parasite possesses a large variety of lipids including certain complex lipids. These are phosphatidylcholine (PC), diphosphatidylglycerol (cardiolipin), lysophosphatidylcholine (LPC), lysophosphatidylethanolamine (LPE), phosphatidylserine (PS), phosphatidylinositol (PI), plasmalogens (choline+ethanolamine), mono-, di- and triacylglycerols, free and esterified cholesterol, non-esterified fatty acids (NEFA), gangliosides, cerebrosides (glycosyl ceramide) and sulphuric acid esters of cerebrosides (sulphatides). The females contain more lipids than males, particularly the acylglycerols and phospholipids, possibly to meet the energy requirement and structural entities for the daily production of large numbers of eggs. Incorporation studies of labelled substrate, sodium-1-14C acetate demonstrate that the adult female has extremely active mechanisms for biosynthesizing these lipids. Most of the labels are found in PC, PE, SM, acylglycerols, NEFA, gangliosides, cerebrosides and sulphatides. Cholesterol, although a minor component of the parasitic lipids, incorporates large amount of label and also undergoes fast turnover. Kinetic analysis of the incorporation by measuring the rate constant (k) and half life (t½) reveals that gangliosides are the fastest biosynthesizing and turning over lipids, although they constitute only 0·1% of the total lipids. The presence of important enzymes of lipid biosynthesis, glucose-6-phosphate dehydrogenase, malate dehydrogenase and hydroxymethyl glutaryl-CoA reductase and an enzyme of lipid ester hydrolysis, triacylglycerol lipase, is also established inT. globulosa. Michaelis-Menten kinetic characteristics of the parasitic enzymes (Km, Vmax, v and the first order rate constant, k) are comparable with those of rat liver homogenates.
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Doroudgar, Mahmoudreza, Johannes Morstein, Johanna Becker-Baldus, Dirk Trauner, and Clemens Glaubitz. "How Photoswitchable Lipids Affect the Order and Dynamics of Lipid Bilayers and Embedded Proteins." Journal of the American Chemical Society 143, no. 25 (June 16, 2021): 9515–28. http://dx.doi.org/10.1021/jacs.1c03524.

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44

Tzoneva, Rumiana, Tihomira Stoyanova, Annett Petrich, Desislava Popova, Veselina Uzunova, Albena Momchilova, and Salvatore Chiantia. "Effect of Erufosine on Membrane Lipid Order in Breast Cancer Cell Models." Biomolecules 10, no. 5 (May 22, 2020): 802. http://dx.doi.org/10.3390/biom10050802.

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Alkylphospholipids are a novel class of antineoplastic drugs showing remarkable therapeutic potential. Among them, erufosine (EPC3) is a promising drug for the treatment of several types of tumors. While EPC3 is supposed to exert its function by interacting with lipid membranes, the exact molecular mechanisms involved are not known yet. In this work, we applied a combination of several fluorescence microscopy and analytical chemistry approaches (i.e., scanning fluorescence correlation spectroscopy, line-scan fluorescence correlation spectroscopy, generalized polarization imaging, as well as thin layer and gas chromatography) to quantify the effect of EPC3 in biophysical models of the plasma membrane, as well as in cancer cell lines. Our results indicate that EPC3 affects lipid–lipid interactions in cellular membranes by decreasing lipid packing and increasing membrane disorder and fluidity. As a consequence of these alterations in the lateral organization of lipid bilayers, the diffusive dynamics of membrane proteins are also significantly increased. Taken together, these findings suggest that the mechanism of action of EPC3 could be linked to its effects on fundamental biophysical properties of lipid membranes, as well as on lipid metabolism in cancer cells.
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Ardalić, Daniela, Aleksandra Stefanović, Jelena Kotur-Stevuljević, Ana Ninić, Slavica Spasić, Vesna Spasojević-Kalimanovska, Zorana Jelić-Ivanović, and Željko Miković. "Lipid indexes and parameters of lipid peroxidation during physiological pregnancy." Journal of Laboratory Medicine 43, no. 2 (April 24, 2019): 93–99. http://dx.doi.org/10.1515/labmed-2018-0026.

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Abstract Background Specific metabolic changes during physiological pregnancy are characterized by hyperlipidemia and increased oxidative stress. However, these specific changes raise the question of their pro-atherogenic potential during pregnancy and their influence on the risk of developing cardiovascular disease (CVD) in women later in life, as well as complications during pregnancy. The aim of this study was to investigate the changes in lipid indexes and parameters of lipid peroxidation in non-complicated pregnancy in order to estimate their course of change and potential relationship during non-complicated pregnancy. Methods The study included 43 healthy pregnant women and 38 non-pregnant healthy women, in appropriate ages, as the control group. Lipid parameters and oxidative stress parameters were monitored in a longitudinal study in the first, second and third trimesters, and before delivery during non-complicated pregnancy. Results Results have shown that lipid indexes rise during pregnancy. The values were significantly increased when compared to the first trimester in all lipid indices and in comparison with the control group. Thyobarbituric acid reactive substances (TBARS) and lipid hydroperoxides (LOOH) were not changed significantly during physiological pregnancy, but LOOH showed a significantly higher value in the first trimester compared with the control group. Prooxidative-antioxidative balance (PAB) significantly increases as pregnancy progresses. Conclusions We observed the changes in lipids, lipid indexes and parameters that indicate oxidative modification of lipids in physiological pregnancy that may lead to an atherogenic, prooxidant state.
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46

Choi, Jae Young, Qi Qiao, Se-Hoon Hong, Chang Min Kim, Jae-Hee Jeong, Yeon-Gil Kim, Yong-Keun Jung, Hao Wu, and Hyun Ho Park. "CIDE domains form functionally important higher-order assemblies for DNA fragmentation." Proceedings of the National Academy of Sciences 114, no. 28 (June 26, 2017): 7361–66. http://dx.doi.org/10.1073/pnas.1705949114.

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Cell death-inducing DFF45-like effector (CIDE) domains, initially identified in apoptotic nucleases, form a family with diverse functions ranging from cell death to lipid homeostasis. Here we show that the CIDE domains of Drosophila and human apoptotic nucleases Drep2, Drep4, and DFF40 all form head-to-tail helical filaments. Opposing positively and negatively charged interfaces mediate the helical structures, and mutations on these surfaces abolish nuclease activation for apoptotic DNA fragmentation. Conserved filamentous structures are observed in CIDE family members involved in lipid homeostasis, and mutations on the charged interfaces compromise lipid droplet fusion, suggesting that CIDE domains represent a scaffold for higher-order assembly in DNA fragmentation and other biological processes such as lipid homeostasis.
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Taylor, Andrew M., and Anthony Watts. "Spin-label studies of lipid-protein interactions with reconstituted band 3, the human erythrocyte chloride-bicarbonate exchanger." Biochemistry and Cell Biology 76, no. 5 (October 1, 1998): 815–22. http://dx.doi.org/10.1139/o98-097.

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Lipid-protein interactions in reconstituted band 3 preparations were investigated by using spin-labeled lipids in conjunction with electron paramagnetic resonance (EPR) spectroscopy. Purified erythrocyte band 3 was reconstituted into egg phosphatidylcholine liposomes at high protein density with preservation predominantly of the dimeric state. Lipid-protein associations were revealed by the presence of a component in the EPR spectra that, when compared to spectra obtained from protein-free bilayers, indicated that lipid chain motions are restricted by interactions with the protein. From the fraction of the motionally restricted component obtained from the phosphatidylcholine spin-label, a value of 64 ± 14 annular lipids per band 3 dimer was obtained. This agrees with a value of 62 for the number of lipids that may be accommodated around the electron density map of a band 3 dimer. Selectivity of various spin-labeled lipids for the protein revealed that androstanol had a lower affinity for the band 3 interface, whereas a distinct preference was observed for the negatively charged lipids phosphatidylglycerol and stearic acid over phosphatidylcholine. This preference for negatively charged lipids could not be screened by 1-M salt, indicating that electrostatic lipid-protein interactions are not dominant. Estimates of annular lipid exchange rates from measured acyl chain segmental motions suggested that the rate of exchange between bilayer and boundary lipids was ~106 s-1, at least an order of magnitude slower than the rate of lipid lateral diffusion in protein-free bilayers.Key words: band 3, reconstitution, electron paramagnetic resonance, lipid-protein interactions.
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Miura, Kentaro, H. Ueno, Yu Numa, S. Morita, and Makoto Nishimoto. "Effects of fatty acid from deep-sea microorganisms on lipid bilayer membrane fluidity under high pressure: comparison of branched-chain and polyunsaturated fatty acid." E3S Web of Conferences 322 (2021): 01019. http://dx.doi.org/10.1051/e3sconf/202132201019.

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In this study, the effects of unsaturated and saturated branchedchain fatty acids in biomembranes of microorganisms living under high temperature and high pressure on the fluidity of biomembranes were investigated by time-resolved fluorescence anisotropy measurements. First, the relationship between the order parameter S and the rotational diffusion coefficient Dw, which can be calculated from the fluorescence anisotropy measurements, and the motion of lipid molecules was investigated using lipids with three different structures, and it was found that the former was related to the spacing of lipid molecules and the latter to the motion of lipid molecules. Next, we investigated the S and Dw values of lipid bilayer membrane containing the saturated branched-chain fatty acid 12-methyltridecanoic acid (12-MTA) and the polyunsaturated fatty acid (PUFA) cis-4,7,10,13,16,19-docosahexaenoic acid (DHA). The results showed that 12-MTA increased the S value and decreased the Dw value. On the other hand, DHA tended to reduce the S value and increase the Dw value, albeit slightly. These results mean that 12-MTA narrows the molecular spacing of lipids and inhibits lipid molecular movement, while DHA tends to widen the molecular spacing of lipids and promote lipid molecular movement.
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Gonzalez-Delgado, Angel Dario, Andres Fernando Barajas-Solano, and Yeimmy Yolima Peralta-Ruiz. "Evaluation of in-situ transient simultaneous cell disruption and transesterification of microalgae." Contemporary Engineering Sciences 10, no. 27 (2017): 1319–27. http://dx.doi.org/10.12988/ces.2017.710143.

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Microalgae has recently been highlighted as source of valuable products including biofuel. The production process of biofuels from microalgae involves mass cultivation, harvesting, deep dewatering, lipid extraction and biofuel conversion. In this work, lipids from microalgae Navicula sp. were obtained using multifunctional process that consists of acid hydrolysis or cellular disruption, oil extraction and in situ transesterification. The effect of alcohol added to produce ethyl and methyl esters on lipid extraction efficiency was evaluated using methanol and ethanol in order to determine the most suitable route for obtaining the high values of lipids and total reducing sugar. The highest lipid extraction efficiency and total reducing sugar (7.72 % and 2.63 mg/ml, respectively) was obtained for methanol. The low lipid extraction efficiency of multifuctional process is due to transesterification of lipids that gradually released into the system. The formation of alkyl esters was confirmed by FTIR with an increase in carbonyl peak as the reaction progressed, thus muntifuctional process reduce cost of alkyl esters production by eliminating the step of lipid extraction by solvent.
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Khoury, Spiro, Jenny Colas, Véronique Breuil, Eva Kosek, Aisha S. Ahmed, Camilla I. Svensson, Fabien Marchand, Emmanuel Deval, and Thierry Ferreira. "Identification of Lipid Biomarkers for Chronic Joint Pain Associated with Different Joint Diseases." Biomolecules 13, no. 2 (February 9, 2023): 342. http://dx.doi.org/10.3390/biom13020342.

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Abstract:
Lipids, especially lysophosphatidylcholine LPC16:0, have been shown to be involved in chronic joint pain through the activation of acid-sensing ion channels (ASIC3). The aim of the present study was to investigate the lipid contents of the synovial fluids from controls and patients suffering from chronic joint pain in order to identify characteristic lipid signatures associated with specific joint diseases. For this purpose, lipids were extracted from the synovial fluids and analyzed by mass spectrometry. Lipidomic analyses identified certain choline-containing lipid classes and molecular species as biomarkers of chronic joint pain, regardless of the pathology, with significantly higher levels detected in the patient samples. Moreover, correlations were observed between certain lipid levels and the type of joint pathologies. Interestingly, LPC16:0 levels appeared to correlate with the metabolic status of patients while other choline-containing lipids were more specifically associated with the inflammatory state. Overall, these data point at selective lipid species in synovial fluid as being strong predictors of specific joint pathologies which could help in the selection of the most adapted treatment.
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