Preparation and characterization of monoclonal antibodies against beta-bungarotoxin and its A- and B-chains

Splenocytes from Balb/c mice immunized with beta-bungarotoxin, a protein neurotoxin that exhibits phospholipase A2 activity, were fused with SP2/0 murine myeloma cells. Eighty-seven stable hybridoma cell lines were established which secrete monoclonal antibodies of the subclass IgG1 and K light chain and react with intact neurotoxin. Some antibodies were further analyzed. These recognize at least two immuno-dominant regions located on the A- and B-chains of the toxin, and the native toxin but show no crossreactivity with a protein homologous to chain A (porcine pancreas phospholipase A2) nor to chain B (toxin 1 from Dendroaspis polylepis). Two monoclonal antibodies inhibit phospholipase A2 activity of the neurotoxin but only one partially neutralizes its biological activity when injected together with the toxin, delaying the time of death.