Logo of Science Foundation Ireland  Logo of the Higher Education Authority, Ireland7 Capacities
Ireland's High-Performance Computing Centre | ICHEC
Home | News | Infrastructure | Outreach | Services | Research | Support | Education & Training | Consultancy | About Us | Login


Title:Human aquaporin 4 gating dynamics in dc and ac electric fields: A molecular dynamics study
Authors:J.-A. Garate, Niall J. English, J. M. D. MacElroy, 2011
Abstract: Water self-diffusion within human aquaporin 4 has been studied using molecular dynamics (MD) simulations in the absence and presence of external ac and dc electric fields. The computed diffusive (pd) and osmotic (pf) permeabilities under zero-field conditions are (0.718 ± 0.24) × 10−14 cm3 s−1 and (2.94 ± 0.47) × 10−14 cm3 s−1, respectively; our pf agrees with the experimental value of (1.50 ± 0.6) × 10−14 cm3 s−1. A gating mechanism has been proposed in which side-chain dynamics of residue H201, located in the selectivity filter, play an essential role. In addition, for nonequilibrium MD in external fields, it was found that water dipole orientation within the constriction region of the channel is affected by electric fields (e-fields) and that this governs the permeability. It was also found that the rate of side-chain flipping motion of residue H201 is increased in the presence of e-fields, which influences water conductivity further.
ICHEC Project:Electric and electromagnetic field effects on nanomaterial-protein systems
Publication:Journal of Chemical Physics 134 (5), 055110, February 2011
URL: http://dx.doi.org/10.1063/1.3529428
Keywords: biochemistry; biodiffusion; biomembrane transport; molecular biophysics; molecular dynamics method; osmosis; permeability; proteins; self-diffusion; water
Status: Published

return to publications list