Properties of proteinaceous toxins in the salivary gland of the marine gastropod (Monoplex echo).

Three proteinaceous toxins (named echotoxins 1, 2, and 3) with both lethal and hemolytic activities were purified from the salivary gland of the marine gastropod (Monoplex echo) by gel filtration on Sephadex G-75 and cation-exchange FPLC on Mono S, although marked reduction in toxicity was observed in the latter chromatography. When subjected to reverse-phase HPLC on TSKgel Phenyl-5PW RP, echotoxin 2 afforded a single peak, while both echotoxins 1 and 3 were further separated into two components, respectively. All echotoxins are monomeric simple proteins with a molecular mass of about 25kDa and their N-termini are blocked.