Spectroscopic studies of PhTX facilitated cation movement across membranes

Philanthotoxins, noncompetitive inhibitors of the nicotinic acetylcholine r eceptor and various glutamate receptors, were found to be capable of mediat ing cation transport across lipid bilayers. With respect to the relatively weak binding constants of these amphiphilic polyamines to neuronal receptor proteins, this finding implies that their interaction with cell membranes might have to be considered in addition to that with protein receptors to f ully understand the molecular mechanism of these neurotoxins. (C) 1999 Else vier Science Ltd. All rights reserved.