Crude
venom of Bothrops jararacussu and isolated
phospholipases A2 (PLA2) of this toxin (
BthTX-I and
BthTX-II) were chemically modified (alkylation) by
p-bromophenacyl bromide (BPB) in order to study antibody production capacity in function of the structure-function relationship of these substances (crude
venom and PLA2 native and alkylated).
BthTX-II showed enzymatic activity, while
BthTX-I did not. Alkylation reduced
BthTX-II activity by 50% while this process abolished the catalytic and myotoxic activities of
BthTX-I, while reducing its
edema-inducing activity by about 50%. Antibody production against the native and alkylated forms of
BthTX-I and -II and the cross-reactivity of
antibodies to native and alkylated toxins did not show any apparent differences and these observations were reinforced by surface plasmon resonance (SPR) data. Histopathological analysis of mouse gastrocnemius muscle sections after injection of PBS,
BthTX-I,
BthTX-II, or both
myotoxins previously incubated with
neutralizing antibody showed inhibition of the toxin-induced
myotoxicity. These results reveal that the chemical modification of the
phospholipases A2 (PLA2) diminished their toxicity but did not alter their antigenicity. This observation indicates that the modified PLA2 may provide a biotechnological tool to attenuate the toxicity of the crude
venom, by improving the production of
antibodies and decreasing the local toxic effects of this poisonous substance in animals used to produce
antivenom.