Polyclonal antibodies against native weak toxin Naja kaouthia discriminate native weak toxins and some other three-fingered toxins against their denaturated forms

Abstract

Polyclonal antibodies obtained by immunization of rabbits with native form of weak toxin (WTX) from cobra Naja kaouthia venom efficiently interacted with WTX and a weak toxin from Naja oxiana venom, but not so with their denaturated forms. These antibodies could also bind with lower affinity other groups of three-fingered toxins: long-chain α-neurotoxins, muscarinic toxins and cytotoxins, but practically did not bind short-chain α-neurotoxins. The efficiency of toxin–antibody interaction depends on the group (weak toxins, long or short α-neurotoxins, cytotoxins etc.) to which the toxin belongs, but not on species of snake from which the toxin originates. There is a correlation between the results obtained and phylogenetic analysis of the three-fingered toxins which revealed that WTX is very close to other weak toxins, relatively close to long α-neurotoxins, cytotoxins and muscarinic toxins, but is distant from the short α-neurotoxins.