Interaction of batrachotoxinin-A benzoate with voltage-sensitive sodium channels: The effects of pH

Publisher Website
Google Scholar
Abstract
The binding of labeled batrachotoxinin-A benzoate (BTX-B) to voltage-sensitive sodium channels in broken membrane preparations of mouse cerebral cortex has been measured as a function of the pH. Specific binding is negligible at pH K a of batrachotoxinin-A, an analogue of BTX-B, was found by titrimetric methods to be ≥8.2. Analysis of the data shows that at least part of the pH dependence of BTX-B binding is due to the titration of a sodium channel residue(s) associated in some way with the BTX-B recognition site. The possible involvement of a histidine residue is suggested.