Use of snake venom proteins in medicine

Snakes feed exclusively on freshly killed prey animals which, following the ir immobilization, have to be swallowed whole. Venomous snakes effect prey immobilization by injection of their venom. Snake venoms are highly concent rated, complex mixtures of individual proteins which, either as enzymes, en zyme effecters or blocking ligands, acting as single agents or in synergist ic conjunction with other venom components, modify vital structures of the prey organism to destroy their biological function. Predominantly neurotoxi c venoms paralyze respiratory activity by pre- or postsynaptic blockade of neuromuscular transmission. Predominantly haemocytotoxic snake venoms conta in components which interact with proteins of the haemostasis, kallikrein o r complement system, causing blood volume loss, hypotension or intravascula r coagulation which finally lead to circulatory failure. Several isolated s nake venom proteins with a known mode of action have found practical applic ation as pharmaceutical agents, diagnostic reagents or preparative tools in the field of haemostaseology, neurobiology and complement research.