Exploring ion permeation energetics in gramicidin A using polarizable charge equilibration force fields.

ABSTRACT: All-atom molecular dynamics simulations have been applied in the recent past to explore the free energetics underlying ion transport processes in biological ion channels. Roux and co-workers, Kuyucak and co-workers, Busath and co-workers, and others have performed rather elegant and extended time scale molecular dynamics simulations using current state-of-the-art fixed-charge (nonpolarizable) force fields to calculate the potential of mean force defining the equilibrium flux of ions through prototypical channels such as gramicidin A. An inescapable conclusion of such studies has been the gross overestimation of the equilibrium free energy barrier, generally predicted to be from 10 to 20 kcal/mol depending on the force field and simulation protocol used in the calculation; this translates t

SUBMITTER: Patel S 

PROVIDER: S-EPMC2818143 | biostudies-literature | 2009 Oct

REPOSITORIES: biostudies-literature