Reconstitution of lipoproteins. II. Lipid–protein interaction between dimyristoyl-lecithin and dimyristoyl-lecithin:cholesterol vesicles and purified apolipoprotein C-I and C-III2 studied by isomeric spin-labelled lecithins

1980 ◽  
Vol 58 (7) ◽  
pp. 592-598 ◽  
Author(s):  
D. J. Vaughan ◽  
W. C. Breckenridge ◽  
N. Z. Stanacev
Keyword(s):  
Protein Interactions ◽  
Phase Changes ◽  
Phospholipid Bilayer ◽  
Head Group ◽  
Lipid Phase ◽  
Resonance Spectroscopy ◽  
Apolipoprotein C ◽  
Lipid Protein Interaction ◽  
Lipid Protein Interactions ◽  
Induced Changes

The reconstitution of purified apolipoprotein C-I and C-III2 with sn-3-dimyristoyl-lecithin and sn-3-dimyristoyl-lecithin:cholesterol (10:1) vesicles was studied by electron spin resonance spectroscopy using isomeric 5′-, 12′-, and 16′-(N-oxyl-4″,4″-dimethyloxazolidine)stearoyl spin-labelled lecithin probes. Results obtained from the temperature-induced changes of lipoprotein recombinants showed the hydrophilic nature of the lipid–protein interactions. The temperature-induced phospholipid phase transition, as measured by 5′-(N-oxyl-4″,4″-dimethyloxazolidine)stearoyl spin-labelled lecithin probe in recombinants containing apoprotein C-1 or apoprotein C-III2, is very broad and has a small cooperative unit indicative of extensive lipid–protein interactions occurring at the head group region of the phospholipid bilayer. When 12′- and 16′-(N-oxyl-4″,4″-dimethyloxazolidine)stearoyl spin-labelled lecithins are used as probes in the same system, similar sharper and more cooperative lipid phase changes are detected. These results indicate a surface location for both apoprotein C-I and apoprotein C-III2 with respect to the phospholipid bilayer in lipoprotein recombinants with and without cholesterol.

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.

scholarly journals Interaction of soluble and membrane proteins with monolayers of glycosphingolipids

1982 ◽  
Vol 203 (3) ◽  
pp. 717-725 ◽  
Author(s):  
G D Fidelio ◽  
B Maggio ◽  
F A Cumar
Keyword(s):  
Membrane Proteins ◽  
Surface Potential ◽  
Protein Interactions ◽  
Lipid Monolayers ◽  
Anionic Phospholipids ◽  
Surface Potential Measurements ◽  
Lipid Protein Interaction ◽  
Lipid Protein Interactions ◽  
The Individual ◽  
Free Interfaces

1. The interactions of four proteins (albumin, myelin basic protein, melittin and glycophorin) with eight neutral or acidic glycosphingolipids, including sulphatides and gangliosides, five zwitterionic or anionic phospholipids and some of their mixtures, were studied in lipid monolayers at the air/145 mM-NaCl interface. 2. In lipid-free interfaces, the surface pressure and surface potential reached by either soluble or integral membrane proteins did not reveal marked differences. 3. All the proteins studied showed interactions with each of the lipids but the maximal interactions were found for basic proteins with acidic glycosphingolipids. 4. Surface-potential measurements indicated that different dipolar organizations at the interface can be adopted by lipid-protein interactions showing the same value for surface free energy. 5. The individual surface properties of either the lipid of protein component are modified as a consequence of the lipid-protein interaction. 6. In mixed-lipid monolayers, the composition of the interface may affect the lipid-protein interactions in a non-proportional manner with respect to the relative amount of the individual lipid components.

scholarly journals CG2AT2: An Enhanced Fragment-based approach for Serial Multi-scale Molecular Dynamics simulations

2021 ◽  
Author(s):  
Owen N. Vickery ◽  
Phillip J. Stansfeld
Keyword(s):  
Molecular Dynamics ◽  
Protein Interactions ◽  
Integral Membrane Protein ◽  
Phospholipid Bilayer ◽  
Coarse Grained ◽  
Macromolecular Complex ◽  
Macromolecular Complexes ◽  
Lipid Dynamics ◽  
Lipid Protein Interactions ◽  
Dynamics Simulations

AbstractCoarse-grained molecular dynamics provides a means for simulating the assembly and interactions of macromolecular complexes at a reduced level of representation, thereby allowing both longer timescale and larger sized simulations. Here, we describe an enhanced fragment-based protocol for converting macromolecular complexes from coarse-grained to atomistic resolution, for further refinement and analysis. While the focus is upon systems that comprise an integral membrane protein embedded in a phospholipid bilayer, the technique is also suitable for e.g. membrane-anchored and soluble protein/nucleotide complexes. Overall, this provides a method for generating an accurate and well equilibrated atomic-level description of a macromolecular complex. The approach is evaluated using a diverse test set of eleven system configurations of vary size and complexity. Simulations are assessed in terms of protein stereochemistry, conformational drift, lipid/protein interactions, and lipid dynamics.

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