| Abstract: | Thirty-nine venoms from various vertebrate and invertebrate species were tested for their ability to consume haemolytic complement (C) activity upon incubation in fresh guinea-pig serum. Nineteen had `anti-complementary' activity, and these were provisionally sorted into the following groups: Pattern I—exemplified by the Naja haje (Egyptian cobra) and six other Elapidae species (all cobras), which induced selective consumption of C3—C9, and led to formation of a stable C3—C9-consuming intermediate; Pattern II—exemplified by the Agkistrodon rhodostoma (Malayan pit viper), Bitis arietans (puff adder), Bothrops jararaca (South American pit viper), Bothrops atrox (Fer de Lance) and three other species, which induced marked consumption of C4 and C2, as well as C3—C9, but did not form a stable C3—C9-consuming intermediate; and individual animals, e.g. the Lachesis muta (bushmaster), which induced other patterns (III—VI) of complement component consumption. Active fractions of representative venoms were partially purified by ion exchange and gel filtration chromatography and their interactions with the complement system characterized further. It is anticipated that these enzymes, with a capacity to activate the complement system in unique ways, will prove to be of further experimental usefulness. |
