Cross-neutralizations of phospholipase A2 neurotoxins from snake venoms.

Rabbit antisera were produced against several purified phospholipase A2 neurotoxins from snake venoms. The neutralizing and cross-neutralizing capacities of these antisera were evaluated using mice. In all except one case, homologous antisera neutralized the lethal effects of the neurotoxins. In several instances, antisera that exhibited strong ELISA cross-reactivity (MIDDLEBROOK and KAISER, Toxicon, 27, 965-977, 1989) were also capable of cross-neutralizations. Homologous antisera neutralized elapid neurotoxins much more effectively than did heterologous antisera. With the crotalid neurotoxins, homologous and heterologous antisera had similar neutralization potentials. These observations further define the immunological relatedness of the phospholipase A2 neurotoxins and suggest that common neutralizing epitopes exist within subgroups of these toxins.