Isolation and partial characterization of a toxin from the venom of the East African orthognath spider Pterinochilus spec.

A minor basic polypeptide in the venom of the East African orthognath spider Pterinochilus spec. was the most toxic of 16 basic components in this venom. This toxin A4/4 was purified by gel permeation on Sephadex G-50 and ion exchange chromatography on CM-Sephadex C-25 with a yield of 1.3% of the total protein content of the crude venom. The polypeptide has an isoelectric point of 9.39 and molecular weight of 10,500. The s.c. LD50 in mice is 0.1 mg/kg. Death occurred due to respiratory paralysis. After administration of sublethal doses rapid reversibility of the symptoms and total recovery of the animals was observed.