A theoretical analysis of pH dependence of sodium channel conductance.
A new theory termed tunnel-acid-group-potential (TAGPT), which explains the effects of pHo and pHi on the ion conductance through different membrane channels, is presented. It is suggested that shifts in pHo and pHi change the values of negative charges generated by acid groups of side chains of some polar (Glu, Asp) amino acid residues lining the tunnel part of the channel. The resulting electrostatic field modification affects the heights of rate-limiting energy barriers (for ion transport) in the transition zones between the tunnel and the vestibules, which changes the channel conductance.
Veresov
V G
VG
Institute of Photobiology, Academy of Sciences of Belarus, Minsk, Republic of Belarus. volot@bas31.basnet.minsk.by
D004553:Electric Conductivity; D006863:Hydrogen-Ion Concentration; D008954:Models, Biological; D015222:Sodium Channels / Q000502:physiology*
D015222:Sodium Channels