Two subtypes of acetylcholinesterase isoenzymes distinguishable by Angusticeps-type toxin F 7

Abstract

1. Toxin F 7, a toxin isolated from Dendroaspis angusticeps (green mamba) venom, exhibited a potent inhibition on the acetylcholinesterase of Bungarus snake venoms and homogenized brains and muscles of Bungarus and Trimeresurus snakes as well as that of mammalian tissues. 2. The acetylcholinesterase in the venoms and tissues of Naja (cobra) species as well as that in avian tissues, however, was found to be about 1000 times less susceptible towards inhibition by toxin F 7. 3. It is concluded that there exist at least two subtypes of acetylcholinesterase isoenzymes distinguishable by an angnsliceps-type toxin F 7.