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.