PRODUCTION OF ANTIPEPTIDE ANTIBODIES AGAINST TRYPANOPAIN-TB FROM TRYPANOSOMA-BRUCEI-BRUCEI - EFFECTS OF ANTIBODIES ON ENZYME-ACTIVITY AGAINST Z-PHE-ARG-AMC

Anti-peptide antibodies were produced against the cysteine proteinase trypanopain-Tb from Trypanosoma brucei brucei and the effects of these antibodies on enzyme activity against carboxybenzoyl (Z)-Phe-Arg-amin omethylcoumarin (AMC) investigated. A peptide was synthesised correspo nding to a region of the trypanopain-Tb active site around the active site histidine so that the resulting anti-peptide antibodies specifica lly targeted the active site of the enzyme. Such antibodies were consi dered more likely to modulate enzyme activity compared with antibodies directed against other regions of the enzyme. Trypanopain-Tb activity was modulated by rabbit and chicken antibodies produced against both the free and conjugated peptide. Rabbit anti-peptide antibodies enhanc ed trypanopain-Tb activity by up to 64% at 500 mu g/ml relative to non -immune antibodies. Chicken antibodies on the other hand, both enhance d (by up to 176% at 500 mg/ml) and inhibited (by up to 85% at 250 mg/m l) trypanopain-Tb activity against Z-Phe-Arg-AMC. The nature of the an tibody effect depended on the stage during the immunisation protocol a t which the antibodies were produced. Chicken antibodies also modulate d trypanopain-Tb activity in lysates of T.b. brucei, while rabbit anti bodies were only effective against the purified enzyme. Anti-trypanopa in-Tb peptide antibodies were thus shown to have the potential to affe ct trypanopain-Tb activity.