GLYCOPROTEINS AS COMPONENTS OF THE LETHAL FACTORS IN COBRA VENOM (NAJA NAJA)

Abstract

A number of protein fractions (eight) have been separated from crude cobra venom (Naja naja) by agar electrophoresis on slides. A study of the lethal effect of the various fractions has demonstrated that there are two fractions which are lethal to mice when injected individually. The most potent of the lethal factors (MLD = 6 μg) contained a glycoprotein. Treatment of crude venom and the lethal fraction (eluted from the electrophoretic pattern) with periodate under mild conditions in which only the C—C linkages of the carbohydrates are believed to be oxidized resulted in about 50% loss of toxicity. These results suggest that the carbohydrate moiety of the glycoprotein is required for its lethal effect. Sialic acid has been detected in crude venom, but treatment of venom with the specific enzyme neuraminidase did not affect the toxicity of venom.