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Title: Cholesterol Promotes Protein Binding by Affecting Membrane Electrostatics and Solvation Properties

Abstract

Binding of the retroviral structural protein Gag to the cellular plasma membrane is mediated by the protein’s matrix (MA) domain. Prominent among MA-PM interactions is electrostatic attraction between the positively charged MA domain and the negatively charged plasma membrane inner leaflet. Previously, we reported that membrane association of HIV-1 Gag, as well as purified Rous sarcoma virus (RSV) MA and Gag, depends strongly on the presence of acidic lipids and is enhanced by cholesterol (Chol). The mechanism underlying this enhancement was unclear. Here in this paper, using a broad set of in vitro and in silico techniques we addressed molecular mechanisms of association between RSV MA and model membranes, and investigated how Chol enhances this association. In neutron scattering experiments with liposomes in the presence or absence of Chol, MA preferentially interacted with preexisting POPS-rich clusters formed by nonideal lipid mixing, binding peripherally to the lipid headgroups with minimal perturbation to the bilayer structure. Molecular dynamics simulations showed a stronger MA-bilayer interaction in the presence of Chol, and a large Chol-driven increase in lipid packing and membrane surface charge density. Although in vitro MA-liposome association is influenced by disparate variables, including ionic strength and concentrations of Chol and charged lipids,more » continuum electrostatic theory revealed an underlying dependence on membrane surface potential. Together, these results conclusively show that Chol affects RSV MA-membrane association by making the electrostatic potential at the membrane surface more negative, while decreasing the penalty for lipid headgroup desolvation. The presented approach can be applied to other viral and nonviral proteins.« less

Authors:
 [1];  [2];  [3];  [4];  [4];  [5]; ORCiD logo [6];  [5];  [5];  [5]
  1. Weill Cornell Medical College, New York, NY (United States). Tri-Institutional PhD Program in Computational Biology and Medicine
  2. Univ. of Tennessee, Knoxville, TN (United States). Bredesen Center for Interdisciplinary Research and Graduate Education; Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States). Joint Inst. for Biological Sciences; Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States). Biology and Soft Matter Division
  3. Univ. of Auckland (New Zealand). School of Biological Sciences
  4. Weill Cornell Medical College, New York, NY (United States). Dept. of Physiology and Biophysics
  5. Cornell Univ., Ithaca, NY (United States). Dept. of Biochemistry and Molecular Cell Biology
  6. Univ. of Tennessee, Knoxville, TN (United States). Bredesen Center for Interdisciplinary Research and Graduate Education; Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States). Biology and Soft Matter Division; Univ. of Tennessee, Knoxville, TN (United States). Dept. of Physics and Astronomy; Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States). Shull Wollan Center
Publication Date:
Research Org.:
Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)
Sponsoring Org.:
USDOE Office of Science (SC), Basic Energy Sciences (BES) (SC-22); National Institutes of Health (NIH)
OSTI Identifier:
1408574
Grant/Contract Number:  
AC05-00OR22725; R01GM107013; R01GM105684; PO1DA012408
Resource Type:
Journal Article: Accepted Manuscript
Journal Name:
Biophysical Journal
Additional Journal Information:
Journal Volume: 113; Journal Issue: 9; Journal ID: ISSN 0006-3495
Publisher:
Elsevier
Country of Publication:
United States
Language:
English
Subject:
59 BASIC BIOLOGICAL SCIENCES

Citation Formats

Doktorova, Milka, Heberle, Frederick A., Kingston, Richard L., Khelashvili, George, Cuendet, Michel A., Wen, Yi, Katsaras, John, Feigenson, Gerald W., Vogt, Volker M., and Dick, Robert A.. Cholesterol Promotes Protein Binding by Affecting Membrane Electrostatics and Solvation Properties. United States: N. p., 2017. Web. doi:10.1016/j.bpj.2017.08.055.
Doktorova, Milka, Heberle, Frederick A., Kingston, Richard L., Khelashvili, George, Cuendet, Michel A., Wen, Yi, Katsaras, John, Feigenson, Gerald W., Vogt, Volker M., & Dick, Robert A.. Cholesterol Promotes Protein Binding by Affecting Membrane Electrostatics and Solvation Properties. United States. doi:10.1016/j.bpj.2017.08.055.
Doktorova, Milka, Heberle, Frederick A., Kingston, Richard L., Khelashvili, George, Cuendet, Michel A., Wen, Yi, Katsaras, John, Feigenson, Gerald W., Vogt, Volker M., and Dick, Robert A.. Tue . "Cholesterol Promotes Protein Binding by Affecting Membrane Electrostatics and Solvation Properties". United States. doi:10.1016/j.bpj.2017.08.055.
@article{osti_1408574,
title = {Cholesterol Promotes Protein Binding by Affecting Membrane Electrostatics and Solvation Properties},
author = {Doktorova, Milka and Heberle, Frederick A. and Kingston, Richard L. and Khelashvili, George and Cuendet, Michel A. and Wen, Yi and Katsaras, John and Feigenson, Gerald W. and Vogt, Volker M. and Dick, Robert A.},
abstractNote = {Binding of the retroviral structural protein Gag to the cellular plasma membrane is mediated by the protein’s matrix (MA) domain. Prominent among MA-PM interactions is electrostatic attraction between the positively charged MA domain and the negatively charged plasma membrane inner leaflet. Previously, we reported that membrane association of HIV-1 Gag, as well as purified Rous sarcoma virus (RSV) MA and Gag, depends strongly on the presence of acidic lipids and is enhanced by cholesterol (Chol). The mechanism underlying this enhancement was unclear. Here in this paper, using a broad set of in vitro and in silico techniques we addressed molecular mechanisms of association between RSV MA and model membranes, and investigated how Chol enhances this association. In neutron scattering experiments with liposomes in the presence or absence of Chol, MA preferentially interacted with preexisting POPS-rich clusters formed by nonideal lipid mixing, binding peripherally to the lipid headgroups with minimal perturbation to the bilayer structure. Molecular dynamics simulations showed a stronger MA-bilayer interaction in the presence of Chol, and a large Chol-driven increase in lipid packing and membrane surface charge density. Although in vitro MA-liposome association is influenced by disparate variables, including ionic strength and concentrations of Chol and charged lipids, continuum electrostatic theory revealed an underlying dependence on membrane surface potential. Together, these results conclusively show that Chol affects RSV MA-membrane association by making the electrostatic potential at the membrane surface more negative, while decreasing the penalty for lipid headgroup desolvation. The presented approach can be applied to other viral and nonviral proteins.},
doi = {10.1016/j.bpj.2017.08.055},
journal = {Biophysical Journal},
number = 9,
volume = 113,
place = {United States},
year = {Tue Nov 07 00:00:00 EST 2017},
month = {Tue Nov 07 00:00:00 EST 2017}
}

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