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Web interface for Brownian dynamics simulation of ion transport and its applications to beta-barrel pores.

ABSTRACT: Brownian dynamics (BD) based on accurate potential of mean force is an efficient and accurate method for simulating ion transport through wide ion channels. Here, a web-based graphical user interface (GUI) is presented for carrying out grand canonical Monte Carlo (GCMC) BD simulations of channel proteins: http://www.charmm-gui.org/input/gcmcbd. The webserver is designed to help users avoid most of the technical difficulties and issues encountered in setting up and simulating complex pore systems. GCMC/BD simulation results for three proteins, the voltage dependent anion channel (VDAC), ?-Hemolysin (?-HL), and the protective antigen pore of the anthrax toxin (PA), are presented to illustrate the system setup, input preparation, and typical output (conductance, ion density profile, ion selectivity, and ion asymmetry). Two models for the input diffusion constants for potassium and chloride ions in the pore are compared: scaling of the bulk diffusion constants by 0.5, as deduced from previous all-atom molecular dynamics simulations of VDAC, and a hydrodynamics based model (HD) of diffusion through a tube. The HD model yields excellent agreement with experimental conductances for VDAC and ?-HL, while scaling bulk diffusion constants by 0.5 leads to underestimates of 10-20%. For PA, simulated ion conduction values overestimate experimental values by a factor of 1.5-7 (depending on His protonation state and the transmembrane potential), implying that the currently available computational model of this protein requires further structural refinement.

SUBMITTER: Lee KI

PROVIDER: S-EPMC3240732 | biostudies-literature | 2012 Jan

REPOSITORIES: biostudies-literature

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Web interface for Brownian dynamics simulation of ion transport and its applications to beta-barrel pores.

Lee Kyu Il KI Jo Sunhwan S Rui Huan H Egwolf Bernhard B Roux Benoît B Pastor Richard W RW Im Wonpil W

Journal of computational chemistry 20111121 3

Brownian dynamics (BD) based on accurate potential of mean force is an efficient and accurate method for simulating ion transport through wide ion channels. Here, a web-based graphical user interface (GUI) is presented for carrying out grand canonical Monte Carlo (GCMC) BD simulations of channel proteins: http://www.charmm-gui.org/input/gcmcbd. The webserver is designed to help users avoid most of the technical difficulties and issues encountered in setting up and simulating complex pore systems ...[more]

PMID: 22102176

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Dataset Information

Web interface for Brownian dynamics simulation of ion transport and its applications to beta-barrel pores.

Publications

Web interface for Brownian dynamics simulation of ion transport and its applications to beta-barrel pores.

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