Molecular Theory Applied to Lipid Bilayers and Lipid–Protein Interactions

2009 ◽  
pp. 1-39 ◽  
Author(s):  
Amalie L. Frischknecht ◽  
Laura J. D. Frink
Keyword(s):  
Lipid Bilayers ◽  
Protein Interactions ◽  
Molecular Theory ◽  
Lipid Protein Interactions

scholarly journals A molecular theory of lipid-protein interactions in the plasma lipoproteins

FEBS Letters ◽  
1974 ◽  
Vol 38 (3) ◽  
pp. 247-253 ◽  
Author(s):  
Jere P. Segrest ◽  
Richard L. Jackson ◽  
Joel D. Morrisett ◽  
Antonio M. Gotto
Keyword(s):  
Protein Interactions ◽  
Molecular Theory ◽  
Plasma Lipoproteins ◽  
Lipid Protein Interactions

scholarly journals Lateral electric field inhibits gel-to-fluid transition in lipid bilayers

2021 ◽  
Author(s):  
Nidhin Thomas ◽  
Ashutosh Agrawal
Keyword(s):  
Electric Field ◽  
Melting Temperature ◽  
Lipid Bilayers ◽  
Electric Fields ◽  
Protein Interactions ◽  
Atomic Scale ◽  
Lateral Electric Field ◽  
Lipid Protein Interactions ◽  
Dynamics Simulations ◽  
Induced Changes

We report evidence of lateral electric field-induced changes in the phase transition temperatures of lipid bilayers. Our atomic scale molecular dynamics simulations show that lateral electric field increases the melting temperature of DPPC, POPC and POPE bilayers. Remarkably, this shift in melting temperature is only induced by lateral electric field, and not normal electric field. This mechanism could provide new mechanistic insights into lipid-lipid and lipid-protein interactions in the presence of endogenous and exogenous electric fields.

Membrane Protein–Lipid Interactions Probed Using Mass Spectrometry

2019 ◽  
Vol 88 (1) ◽  
pp. 85-111 ◽  
Author(s):  
Jani Reddy Bolla ◽  
Mark T. Agasid ◽  
Shahid Mehmood ◽  
Carol V. Robinson
Keyword(s):  
Mass Spectrometry ◽  
Membrane Protein ◽  
Lipid Bilayers ◽  
Protein Interactions ◽  
Native Mass Spectrometry ◽  
Lipid Interactions ◽  
X Ray Crystallography ◽  
Native Ms ◽  
Molecular Aspects ◽  
Lipid Protein Interactions

Membrane proteins that exist in lipid bilayers are not isolated molecular entities. The lipid molecules that surround them play crucial roles in maintaining their full structural and functional integrity. Research directed at investigating these critical lipid–protein interactions is developing rapidly. Advancements in both instrumentation and software, as well as in key biophysical and biochemical techniques, are accelerating the field. In this review, we provide a brief outline of structural techniques used to probe protein–lipid interactions and focus on the molecular aspects of these interactions obtained from native mass spectrometry (native MS). We highlight examples in which lipids have been shown to modulate membrane protein structure and show how native MS has emerged as a complementary technique to X-ray crystallography and cryo–electron microscopy. We conclude with a short perspective on future developments that aim to better understand protein–lipid interactions in the native environment.

scholarly journals Membrane Constriction by ESCRT-III Proteins Induces Structural Lipid Bilayer Asymmetries

2021 ◽  
Author(s):  
Frank Russell Moss ◽  
James Lincoff ◽  
Maxwell Tucker ◽  
Arshad Mohammed ◽  
Michael Grabe ◽  
...  
Keyword(s):  
Lipid Bilayers ◽  
Protein Interactions ◽  
Electrostatic Interactions ◽  
Membrane Surface ◽  
Spontaneous Curvature ◽  
Membrane Mechanics ◽  
Vesicular Traffic ◽  
Outer Leaflet ◽  
Lipid Diffusion ◽  
Lipid Protein Interactions

Cells utilize molecular machines to form and remodel their membrane-defined compartments' compositions, shapes, and connections. The regulated activity of these membrane remodeling machines drives processes like vesicular traffic and organelle homeostasis. Although molecular patterning within membranes is essential to cellular life, characterizing the composition and structure of realistic biological membranes on the molecular length scale remains a challenge, particularly during membrane shape transformations. Here, we employed an ESCRT-III protein coating model system to investigate how membrane-binding proteins bind to and alter the structural patterns within lipid bilayers. We observe leaflet-level and localized lipid structures within a constricted and thinned membrane nanotube. To map the fine structure of these membranes, we compared simulated bilayer nanotubes with experimental cryo-EM reconstructions of native membranes and membranes containing halogenated lipid analogs. Halogenated lipids scatter electrons more strongly, and analysis of their surplus scattering enabled us to estimate the concentrations of lipids within each leaflet and to estimate lipid shape and sorting changes induced by high curvature and lipid-protein interactions. Specifically, we found that cholesterol enriched within the inner leaflet due to its spontaneous curvature, while acidic lipids enriched in the outer leaflet due to electrostatic interactions with the protein coat. The docosahexaenoyl (DHA) polyunsaturated chain-containing lipid SDPC enriched strongly at membrane-protein contact sites. Simulations and imaging of brominated SDPC showed how a pair of phenylalanine residues opens a hydrophobic defect in the outer leaflet and how DHA tails stabilize the defect and "snorkel" up to the membrane surface to interact with these side chains. This highly curved nanotube differs markedly from protein-free, flat bilayers in leaflet thickness, lipid diffusion, and other structural asymmetries with implications for our understanding of membrane mechanics.

scholarly journals Structure and activity of lipid bilayer within a membrane-protein transporter

2018 ◽  
Vol 115 (51) ◽  
pp. 12985-12990 ◽  
Author(s):  
Weihua Qiu ◽  
Ziao Fu ◽  
Guoyan G. Xu ◽  
Robert A. Grassucci ◽  
Yan Zhang ◽  
...  
Keyword(s):  
Lipid Bilayer ◽  
Lipid Bilayers ◽  
Protein Interactions ◽  
Extraction Methods ◽  
Free System ◽  
Outer Leaflet ◽  
Proton Relay ◽  
Native Cell ◽  
Lipid Protein Interactions ◽  
Structure And Activity

Membrane proteins function in native cell membranes, but extraction into isolated particles is needed for many biochemical and structural analyses. Commonly used detergent-extraction methods destroy naturally associated lipid bilayers. Here, we devised a detergent-free method for preparing cell-membrane nanoparticles to study the multidrug exporter AcrB, by cryo-EM at 3.2-Å resolution. We discovered a remarkably well-organized lipid-bilayer structure associated with transmembrane domains of the AcrB trimer. This bilayer patch comprises 24 lipid molecules; inner leaflet chains are packed in a hexagonal array, whereas the outer leaflet has highly irregular but ordered packing. Protein side chains interact with both leaflets and participate in the hexagonal pattern. We suggest that the lipid bilayer supports and harmonizes peristaltic motions through AcrB trimers. In AcrB D407A, a putative proton-relay mutant, lipid bilayer buttresses protein interactions lost in crystal structures after detergent-solubilization. Our detergent-free system preserves lipid–protein interactions for visualization and should be broadly applicable.

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