Influence of ionizing radiation on crotoxin: biochemical and immunological aspects.

Irradiation of crotoxin and its subunits with 2000 Gy of gamma-rays from 60Co source leads to aggregation and generation of lower mol. wt breakdown products. Aggregates separated by gel filtration retain at least part of their higher-ordered structure, based on their reactivity with monoclonal antibodies known to react with conformational epitopes in native crotoxin. These same aggregates can serve as antigens to raise antisera that cross-react and neutralize crotoxin. Compared with native crotoxin, aggregates appear less myotoxic, are largely devoid of phospholipase activity, and are virtually non-toxic in mice. These results indicate that irradiation of toxic proteins can promote significant detoxification, but still retain many of the original antigenic and immunological properties of native crotoxin.