Gating gramicidin channels in lipid bilayers: reaction coordinates and the mechanism of dissociation.

ABSTRACT: The dissociation of gramicidin A (gA) channels into monomers is the simplest example of a channel gating process. The initial steps in this process are studied via a computational model that simulates the reaction coordinate for dimer-monomer dissociation. The nonbonded interaction energy between the monomers is determined, allowing for their free relative translational and rotational motion. Lowest energy pathways and reaction coordinates of the gating process are determined. Partial rupture of the six hydrogen bonds (6HB) at the dimer junction takes place by coupling monomer rotation and lateral displacement. Coupling rotation with axial separation is far more expensive energetically. The transition state for channel dissociation occurs when monomers are displaced laterally by approximat

SUBMITTER: Miloshevsky GV 

PROVIDER: S-EPMC1303840 | biostudies-literature | 2004 Jan

REPOSITORIES: biostudies-literature