scholarly journals Relative Affinities of Protein-Cholesterol Interactions from Equilibrium Molecular Dynamics Simulations

2021 ◽  
Author(s):  
T. Bertie Ansell ◽  
Luke Curran ◽  
Michael R Horrell ◽  
Tanadet Pipatpolkai ◽  
Suzanne C Letham ◽  
...  
Keyword(s):  
Molecular Dynamics ◽  
Membrane Proteins ◽  
Membrane Protein ◽  
Specific Interaction ◽  
Protein Structures ◽  
Md Simulations ◽  
Lipid Binding ◽  
Coarse Grained ◽  
Binding Affinities ◽  
Interaction Sites

Specific interactions of lipids with membrane proteins contribute to protein stability and function. Multiple lipid interactions surrounding a membrane protein are often identified in molecular dynamics (MD) simulations and are, increasingly, resolved in cryo-EM densities. Determining the relative importance of specific interaction sites is aided by determination of lipid binding affinities by experimental or simulation methods. Here, we develop a method for determining protein-lipid binding affinities from equilibrium coarse-grained MD simulations using binding saturation curves, designed to mimic experimental protocols. We apply this method to directly obtain affinities for cholesterol binding to multiple sites on a range of membrane proteins and compare our results with free energies obtained from density-based equilibrium methods and with potential of mean force calculations, getting good agreement with respect to the ranking of affinities for different sites. Thus, our binding saturation method provides a robust, high-throughput alternative for determining the relative consequence of individual sites seen in e.g. cryo-EM derived membrane protein structures surrounded by a plethora of ancillary lipid densities.

scholarly journals MERMAID: dedicated web server to prepare and run coarse-grained membrane protein dynamics

2019 ◽  
Vol 47 (W1) ◽  
pp. W456-W461 ◽  
Author(s):  
Mangesh Damre ◽  
Alessandro Marchetto ◽  
Alejandro Giorgetti
Keyword(s):  
Molecular Dynamics ◽  
Membrane Proteins ◽  
Membrane Protein ◽  
Protein Dynamics ◽  
Conformational Changes ◽  
Coarse Grained ◽  
Computational Power ◽  
Molecular Features ◽  
Molecular Events ◽  
Membrane Protein Dynamics

Abstract Atomistic molecular dynamics simulations of membrane proteins have been shown to be extremely useful for characterizing the molecular features underlying their function, but require high computational power, limiting the understanding of complex events in membrane proteins, e.g. ion channels gating, GPCRs activation. To overcome this issue, it has been shown that coarse-grained approaches, although requiring less computational power, are still capable of correctly describing molecular events underlying big conformational changes in biological systems. Here, we present the Martini coarse-grained membrane protein dynamics (MERMAID), a publicly available web interface that allows the user to prepare and run coarse-grained molecular dynamics (CGMD) simulations and to analyse the trajectories.

scholarly journals Lipid binding attenuates channel closure of the outer membrane protein OmpF

2018 ◽  
Vol 115 (26) ◽  
pp. 6691-6696 ◽  
Author(s):  
Idlir Liko ◽  
Matteo T. Degiacomi ◽  
Sejeong Lee ◽  
Thomas D. Newport ◽  
Joseph Gault ◽  
...  
Keyword(s):  
Mass Spectrometry ◽  
Membrane Protein ◽  
Outer Membrane ◽  
Lipid Bilayers ◽  
Protein Structures ◽  
Anion Channel ◽  
Lipid Binding ◽  
Coarse Grained ◽  
Strong Interactions ◽  
Voltage Dependent Anion Channel

Strong interactions between lipids and proteins occur primarily through association of charged headgroups and amino acid side chains, rendering the protonation status of both partners important. Here we use native mass spectrometry to explore lipid binding as a function of charge of the outer membrane porin F (OmpF). We find that binding of anionic phosphatidylglycerol (POPG) or zwitterionic phosphatidylcholine (POPC) to OmpF is sensitive to electrospray polarity while the effects of charge are less pronounced for other proteins in outer or mitochondrial membranes: the ferripyoverdine receptor (FpvA) or the voltage-dependent anion channel (VDAC). Only marginal charge-induced differences were observed for inner membrane proteins: the ammonia channel (AmtB) or the mechanosensitive channel. To understand these different sensitivities, we performed an extensive bioinformatics analysis of membrane protein structures and found that OmpF, and to a lesser extent FpvA and VDAC, have atypically high local densities of basic and acidic residues in their lipid headgroup-binding regions. Coarse-grained molecular dynamics simulations, in mixed lipid bilayers, further implicate changes in charge by demonstrating preferential binding of anionic POPG over zwitterionic POPC to protonated OmpF, an effect not observed to the same extent for AmtB. Moreover, electrophysiology and mass-spectrometry–based ligand-binding experiments, at low pH, show that POPG can maintain OmpF channels in open conformations for extended time periods. Since the outer membrane is composed almost entirely of anionic lipopolysaccharide, with similar headgroup properties to POPG, such anionic lipid binding could prevent closure of OmpF channels, thereby increasing access of antibiotics that use porin-mediated pathways.

Specific protein–lipid interactions in membrane proteins

2005 ◽  
Vol 33 (5) ◽  
pp. 938-942 ◽  
Author(s):  
C. Hunte
Keyword(s):  
Membrane Proteins ◽  
Membrane Protein ◽  
Structural Integrity ◽  
Protein Structures ◽  
Specific Protein ◽  
Lipid Binding ◽  
Functional Roles ◽  
Lipid Interactions ◽  
Head Groups ◽  
Lipid Species

Many membrane proteins selectively bind defined lipid species. This specificity has an impact on correct insertion, folding, structural integrity and full functionality of the protein. How are these different tasks achieved? Recent advances in structural research of membrane proteins provide new information about specific protein–lipid interactions. Tightly bound lipids in membrane protein structures are described and general principles of the binding interactions are deduced. Lipid binding is stabilized by multiple non-covalent interactions from protein residues to lipid head groups and hydrophobic tails. Distinct lipid-binding motifs have been identified for lipids with defined head groups in membrane protein structures. The stabilizing interactions differ between the electropositive and electronegative membrane sides. The importance of lipid binding for vertical positioning and tight integration of proteins in the membrane, for assembly and stabilization of oligomeric and multisubunit complexes, for supercomplexes, as well as for functional roles are pointed out.

scholarly journals Production of Monoclonal Antibodies against Outer Membrane Proteins of Burkholderia pseudomallei, Strain C-141

2008 ◽  
pp. 54-57
Author(s):  
S. S. Vetchinin ◽  
P. C. Kopylov ◽  
N. V. Kiseleva ◽  
A. M. Baranov ◽  
E. V. Baranova ◽  
...  
Keyword(s):  
Monoclonal Antibodies ◽  
Membrane Proteins ◽  
Membrane Protein ◽  
Burkholderia Pseudomallei ◽  
Culture Supernatant ◽  
Outer Membrane Proteins ◽  
Specific Interaction ◽  
Protein Structures ◽  
High Specificity ◽  
Protein Moiety

Monoclonal antibodies (MAb) were produced against two B. pseudomallei high-purified membrane proteins with Mr 29 kDa (p29) and 45 kDa (p45). Monoclonal antibodies from culture supernatant fluids of 4F2 and 1G11 clones showed specific interaction with protein moiety of p29 both Burkholderia pseudomallei and Burkholderia mallei in ELISA and Western blotting. However, MAb of 3G4 clone were bound to the LPS-protein structures of these microbial cells. Analysis of interaction of Mabs from 4F2 and 1G11 clones with antigens of different lysates of pathogenic cells confirmed high specificity of these antibodies to p29 membrane protein of B. pseudomallei and B. mallei.

scholarly journals Lipid-Uptake Pathways and Lipid-Protein interactions in P-glycoprotein Revealed by Coarse-Grained Molecular Dynamics Simulations

2017 ◽  
Author(s):  
E. Barreto-Ojeda ◽  
V. Corradi ◽  
R.-X. Gu ◽  
D.P. Tieleman
Keyword(s):  
Molecular Dynamics ◽  
Protein Interactions ◽  
Experimental Studies ◽  
Md Simulations ◽  
Lipid Binding ◽  
Coarse Grained ◽  
Substrate Uptake ◽  
Lipid Uptake ◽  
P Glycoprotein ◽  
Dynamics Simulations

AbstractP-glycoprotein (P-gp) exports a broad range of dissimilar compounds, including drugs, lipids and lipid-like molecules. Due to its substrate promiscuity, P-gp is a key player in the development of cancer multidrug resistance (MDR). Although P-gp is one of the most studied members of ABC-transporters, the mechanism of how its substrates access the cavity remains unclear. In this work, we performed coarse-grained (CG) molecular dynamics (MD) simulations to explore possible pathways of lipid-uptake in the inward-facing conformation of P-gp embedded in bilayers with different PC:PE lipid ratios. Our results show that in the inward facing orientation only lipids from the lower leaflet are taken up by the transporter. We identify positively charged residues at the portals of P-gp that favor lipid entrance to the cavity, as well as lipid binding sites, in good agreement with previous experimental studies. Our results show no selectivity for PC vs. PE lipids. We offer several examples of lipid uptake-pathways for PC and PE lipids that help to elucidate the molecular mechanism of substrate-uptake in P-gp.

Simulation studies of the interactions between membrane proteins and detergents

2005 ◽  
Vol 33 (5) ◽  
pp. 910-912 ◽  
Author(s):  
P.J. Bond ◽  
J. Cuthbertson ◽  
M.S.P. Sansom
Keyword(s):  
Membrane Proteins ◽  
Membrane Protein ◽  
Self Assembly ◽  
Kinetic Mechanism ◽  
Coarse Grained ◽  
Simulation Studies ◽  
High Resolution Data ◽  
Biologically Relevant ◽  
Structure And Dynamics ◽  
Detergent Interactions

Interactions between membrane proteins and detergents are important in biophysical and structural studies and are also biologically relevant in the context of folding and transport. Despite a paucity of high-resolution data on protein–detergent interactions, novel methods and increased computational power enable simulations to provide a means of understanding such interactions in detail. Simulations have been used to compare the effect of lipid or detergent on the structure and dynamics of membrane proteins. Moreover, some of the longest and most complex simulations to date have been used to observe the spontaneous formation of membrane protein–detergent micelles. Common mechanistic steps in the micelle self-assembly process were identified for both α-helical and β-barrel membrane proteins, and a simple kinetic mechanism was proposed. Recently, simplified (i.e. coarse-grained) models have been utilized to follow long timescale transitions in membrane protein–detergent assemblies.

scholarly journals Molecular Dynamics Scoring of Protein–Peptide Models Derived from Coarse-Grained Docking

Molecules ◽  
2021 ◽  
Vol 26 (11) ◽  
pp. 3293
Author(s):  
Mateusz Zalewski ◽  
Sebastian Kmiecik ◽  
Michał Koliński
Keyword(s):  
Molecular Dynamics ◽  
Geometry Optimization ◽  
Computational Prediction ◽  
Md Simulations ◽  
Coarse Grained ◽  
Ligand Interaction ◽  
Vast Number ◽  
Docking Simulations ◽  
Peptide Models ◽  
Peptide Complexes

One of the major challenges in the computational prediction of protein–peptide complexes is the scoring of predicted models. Usually, it is very difficult to find the most accurate solutions out of the vast number of sometimes very different and potentially plausible predictions. In this work, we tested the protocol for Molecular Dynamics (MD)-based scoring of protein–peptide complex models obtained from coarse-grained (CG) docking simulations. In the first step of the scoring procedure, all models generated by CABS-dock were reconstructed starting from their original C-alpha trace representations to all-atom (AA) structures. The second step included geometry optimization of the reconstructed complexes followed by model scoring based on receptor–ligand interaction energy estimated from short MD simulations in explicit water. We used two well-known AA MD force fields, CHARMM and AMBER, and a CG MARTINI force field. Scoring results for 66 different protein–peptide complexes show that the proposed MD-based scoring approach can be used to identify protein–peptide models of high accuracy. The results also indicate that the scoring accuracy may be significantly affected by the quality of the reconstructed protein receptor structures.

scholarly journals A Generic Force Field for Simulating Native Protein Structures Using Dissipative Particle Dynamics

Soft Matter ◽  
2021 ◽  
Author(s):  
Rakesh K Vaiwala ◽  
Ganapathy Ayappa
Keyword(s):  
Molecular Dynamics ◽  
Force Field ◽  
Molecular Dynamics Simulations ◽  
Dissipative Particle Dynamics ◽  
Protein Structures ◽  
Particle Dynamics ◽  
Coarse Grained ◽  
Native Protein ◽  
Dynamics Simulations

A coarse-grained force field for molecular dynamics simulations of native structures of proteins in a dissipative particle dynamics (DPD) framework is developed. The parameters for bonded interactions are derived by...

scholarly journals Antimicrobial action of the cationic peptide, chrysophsin-3: a coarse-grained molecular dynamics study

Soft Matter ◽  
2018 ◽  
Vol 14 (15) ◽  
pp. 2796-2807 ◽  
Author(s):  
Andrea Catte ◽  
Mark R. Wilson ◽  
Martin Walker ◽  
Vasily S. Oganesyan
Keyword(s):  
Molecular Dynamics ◽  
Large Scale ◽  
Md Simulations ◽  
Antimicrobial Action ◽  
Coarse Grained ◽  
Cationic Peptide ◽  
Coarse Grained Molecular Dynamics

Antimicrobial action of a cationic peptide is modelled by large scale MD simulations.

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