Dehydration of solute–lipid systems: hydration forces analysis

Bryant, Gary; Koster, Karen L.

doi:10.1016/j.colsurfb.2004.02.001

Cited by 14 publications

(29 citation statements)

References 32 publications

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“…The substrate-supported oriented POPC bilayers studied here provide a simple model of the stacking and close approach that cellular membranes may undergo upon dehydration, e.g., during extracellular freezing. The RHs of 97 and 75% RH used in this study are equivalent to equilibrium freezing to À3 and À33 C, respectively (34). These temperatures are well in the range of freezing temperatures that herbaceous plants may encounter and survive in temperate climate regions of the Earth (see (33) for a review).…”

Section: Discussionmentioning

confidence: 96%

Intrinsically Disordered Stress Protein COR15A Resides at the Membrane Surface during Dehydration

Bremer

Kent

Hauß

et al. 2017

Biophysical Journal

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Plants from temperate climate zones are able to increase their freezing tolerance during exposure to low, above-zero temperatures in a process termed cold acclimation. During this process, several cold-regulated (COR) proteins are accumulated in the cells. One of them is COR15A, a small, intrinsically disordered protein that contributes to leaf freezing tolerance by stabilizing cellular membranes. The isolated protein folds into amphipathic α-helices in response to increased crowding conditions, such as high concentrations of glycerol. Although there is evidence for direct COR15A-membrane interactions, the orientation and depth of protein insertion were unknown. In addition, although folding due to high osmolyte concentrations had been established, the folding response of the protein under conditions of gradual dehydration had not been investigated. Here we show, using Fourier transform infrared spectroscopy, that COR15A starts to fold into α-helices already under mild dehydration conditions (97% relative humidity (RH), corresponding to freezing at -3°C) and that folding gradually increases with decreasing RH. Neutron diffraction experiments at 97 and 75% RH established that the presence of COR15A had no significant influence on the structure of 1-palmitoyl-2-oleoyl-sn-glycero-3-phosphocholine (POPC) membranes. However, using deuterated POPC we could clearly establish that COR15A interacts with the membranes and penetrates below the headgroup region into the upper part of the fatty acyl chain region. This localization is in agreement with our hypothesis that COR15A-membrane interaction is at least, in part, driven by a hydrophobic interaction between the lipids and the hydrophobic face of the amphipathic protein α-helix.

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Section: Discussionmentioning

confidence: 96%

Intrinsically Disordered Stress Protein COR15A Resides at the Membrane Surface during Dehydration

Bremer

Kent

Hauß

et al. 2017

Biophysical Journal

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“…At low sugar/lipid ratios, the hydration (osmotic) effect of the sugar dominates -the presence of the sugar helps retain more water in the system at fixed RH 51 , increasing the number of waters per lipid and water distribution width but having little effect on the bilayer repeat spacing. This hydrating effect appears to be constant within the range of sugar/lipid ratios studied here.…”

Section: Resultsmentioning

confidence: 99%

Direct Comparison of Disaccharide Interaction with Lipid Membranes at Reduced Hydrations

et al. 2015

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Abstract:Understanding sugar-lipid interactions during desiccation and freezing is an important step in the elucidation of cryo-and anhydro-protection mechanisms. We determine sucrose, trehalose and water concentration distributions in intra-bilayer volumes between opposing dioleoylphosphatidylcholine bilayers over a range of reduced hydrations and sugar concentrations. Stacked lipid bilayers at reduced hydration provide a suitable system to mimic environmental dehydration effects, as well as a suitable system for direct probing of sugar locations by neutron membrane diffraction. Sugar distributions show that sucrose and trehalose both behave as typical uncharged solutes, largely excluded from the lipid bilayers regardless of sugar identity, and with no correlation between sugar distribution and the lipid headgroup position as the hydration is changed. These results are discussed in terms of current opinions about cryo-and anhydro-protection mechanisms.2

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“…Low molecular weight hydrophilic substances, as simple as sugars, can significantly disturb the hydration efficiency of the glycerol head groups of liquid crystalline lipids (or the area of lipid–water contact) . In the case of MO (at 30% water content, 20 °C), the addition of sucrose from 1 to 30% (w/v) was found to induce a phase transition toward more negative curvature in the order of cubic Ia3d (<2% sucrose) → cubic Pn3m (≥5% sucrose) → H 2 phases (≥10% sucrose) .…”

Section: Interactions Of Llcs With Biological Componentsmentioning

confidence: 99%

Self‐Assembled Nanostructured Lipid Systems: Is There a Link between Structure and Cytotoxicity?

Tan

Hong

et al. 2018

Advanced Science

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Self‐assembly of lipid‐based liquid crystalline (LLC) nanoparticles is a formulation art arising from the hydrophilic–lipophilic qualities and the geometric packing of amphiphilic lipid molecules in an aqueous environment. The diversity of commercialized amphiphilic lipids and an increased understanding of the physicochemical factors dictating their membrane curvature has enabled versatile architectural design and engineering of LLC nanoparticles. While these exotic nanostructured materials are hypothesized to form the next generation of smart therapeutics for a broad field of biomedical applications, biological knowledge particularly on the systemic biocompatibility or cytotoxicity of LLC materials remains unclear. Here, an overview on the interactions between LLCs of different internal nanostructures and biological components (including soluble plasma constituents, blood cells, and isolated tissue cell lines) is provided. Factors affecting cell–nanoparticle tolerability such as the type of lipids, type of steric stabilizers, nanoparticle surface charges, and internal nanostructures (or lipid phase behaviors) are elucidated. The mechanisms of cellular uptake and lipid transfer between neighboring membrane domains are also reviewed. A critical analysis of these studies sheds light on future strategies to transform LLC materials into a viable therapeutic entity ideal for internal applications.

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Dehydration of solute–lipid systems: hydration forces analysis

Cited by 14 publications

References 32 publications

Intrinsically Disordered Stress Protein COR15A Resides at the Membrane Surface during Dehydration

Intrinsically Disordered Stress Protein COR15A Resides at the Membrane Surface during Dehydration

Direct Comparison of Disaccharide Interaction with Lipid Membranes at Reduced Hydrations

Self‐Assembled Nanostructured Lipid Systems: Is There a Link between Structure and Cytotoxicity?

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