Lipid-Protein Interactions Modulate the Conformational Equilibrium of a Potassium Channel

Membranes do not only provide a matrix for variety of chemical reactions mediated by membrane proteins, but also actively participate in the regulation protein structure and function. We conducted molecular dynamics simulations to investigate how lipid-protein interactions affect function case MthK, potassium channel. constructed different bilayers test effects thickness, cholesterol content, unsaturation degree lipid tails. observed ion permeation rates MthK membranes, ascribed them shift conformational equilibrium between two states channel that differ according whether inner transmembrane helix has kink. Two key residues kink region modulate opening selectivity filter hydration central cavity, respectively, which serve as gates MthK. The crosstalk these our implies model one gate eventually leads closure other. In summary, work reveals (1) environments conformation MthK; (2) their explain channels conformations.