Isolation of a cardiotonic glycoprotein,striatoxin, from the venom of the marine snail Conus striatus

Striatoxin, a powerful cardiotonic glycoprotein has been isolated from the venom of the marine snail Conus striatus, monitored by the inotropic action on the guinea-pig left atria. The molecular weight was estimated to be 25,000 by gel filtration. The purified glycoprotein is electrophoretically homogeneous. The toxin at concentrations above 10^?7 g/ml has a long-lasting inotropic action, which was abolished by tetrodotoxin (10^?6 M). The minimum lethal dose in the fish Rhodeus ocellatus smithi was 1 μg/g body weight. A possible biological role of striatoxin in C. striatus is briefly discussed.