Cooperative gating and spatial organization of membrane proteins through elastic interactions.
Biological membranes are elastic media in which the presence of a transmembrane protein leads to local bilayer deformation. The energetics of deformation allow two membrane proteins in close proximity to influence each other's equilibrium conformation via their local deformations, and spatially organize the proteins based on their geometry. We use the mechanosensitive channel of large conductance (MscL) as a case study to examine the implications of bilayer-mediated elastic interactions on protein conformational statistics and clustering. The deformations around MscL cost energy on the order of 10 kBT and extend approximately 3 nm from the protein edge, as such elastic forces induce cooperative gating, and we propose experiments to measure these effects. Additionally, since elastic interactions are coupled to protein conformation, we find that conformational changes can severely alter the average separation between two proteins. This has important implications for how conformational changes organize membrane proteins into functional groups within membranes.
Ursell
Tristan
T
Department of Applied Physics, California Institute of Technology, Pasadena, California, United States of America.
Huang
Kerwyn Casey
KC
Peterson
Eric
E
Phillips
Rob
R
D002462:Cell Membrane / Q000737:chemistry*; D003198:Computer Simulation; D019281:Dimerization; D004548:Elasticity; D029968:Escherichia coli Proteins / Q000737:chemistry* / Q000648:ultrastructure*; D007473:Ion Channels / Q000737:chemistry* / Q000648:ultrastructure*; D008051:Lipid Bilayers / Q000737:chemistry*; D008565:Membrane Proteins / Q000737:chemistry* / Q000648:ultrastructure*; D008956:Models, Chemical; D008958:Models, Molecular; D011487:Protein Conformation
D029968:Escherichia coli Proteins; D007473:Ion Channels; D008051:Lipid Bilayers; D008565:Membrane Proteins; C086596:MscL protein, E coli