Structure and Function of Cobrotoxin

Cobrotoxin, a neurotoxic crystalline protein, was isolated from the venom of Taiwan cobra Naja naja atra and was proved to be the main toxic protein in cobra venom. Cobrotoxin was successfully immobilized on Sepharose through its free amino groups without altering the antigenic activity. Rabbits hyperimmunized with cobrotoxin in Freunds complete adjuvant do produce non- precipitating as well as precipitating antibodies. By affinity chromatography of supernatants obtained from precipitin reaction at the maximum precipitation on a column of cobrotoxin-Sepharose, the non-precipitating antibodies were separated from the antisera. Specific neutralizing capacity of the antibody preparations obtained from affinity chromatography was much higher than those isolated by precipitin reactions. Both precipitating and non-precipitating antibodies were proved to be similar with regard to molecular size and elution appearing on cobrotoxin-Sepharose column.