Open AccessState-dependent protein-lipid interactions of a pentameric ligand-gated ion channel in a neuronal membrane
Author(s) -
Marc A. Dämgen,
Philip C. Biggin
Publication year - 2021
Publication title -
plos computational biology/plos computational biology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.628
H-Index - 182
eISSN - 1553-7358
pISSN - 1553-734X
DOI - 10.1371/journal.pcbi.1007856
Subject(s) - allosteric regulation , ion channel , ligand gated ion channel , biophysics , glycine receptor , chemistry , transmembrane domain , membrane protein , membrane lipids , lipid bilayer , peripheral membrane protein , transmembrane protein , allosteric enzyme , plasma protein binding , receptor , biochemistry , membrane , biology , integral membrane protein , glycine , amino acid
Pentameric ligand-gated ion channels (pLGICs) are receptor proteins that are sensitive to their membrane environment, but the mechanism for how lipids modulate function under physiological conditions in a state dependent manner is not known. The glycine receptor is a pLGIC whose structure has been resolved in different functional states. Using a realistic model of a neuronal membrane coupled with coarse-grained molecular dynamics simulations, we demonstrate that some key lipid-protein interactions are dependent on the receptor state, suggesting that lipids may regulate the receptor’s conformational dynamics. Comparison with existing structural data confirms known lipid binding sites, but we also predict further protein-lipid interactions including a site at the communication interface between the extracellular and transmembrane domain. Moreover, in the active state, cholesterol can bind to the binding site of the positive allosteric modulator ivermectin. These protein-lipid interaction sites could in future be exploited for the rational design of lipid-like allosteric drugs.