ANALYSIS OF THE CYSTEINE PROTEINASES OF LEISHMANIA-MEXICANA AND TRYPANOSOMA-CRUZI USING SPECIFIC ANTISERA

Antisera raised against papain and cysteine proteinases (CPs) purified from Leishmania mexicana and Trypanosoma cruzi have been used to stud y the proteins in the two parasites. The antisera against the major CP of T. cruzi (cruzipain) not only cross-reacted with known CPs of L. m exicana but also detected stage-specific molecules that may represent previously unrecognised CPs. The binding of the same antisera to extra cts of different life cycle stages of T. cruzi suggested that the stag es possess different isoforms of cruzipain. The lack of cross-reactivi ty of anti-papain antiserum against cruzipain suggests that the major immunogenic epitopes of these CPs are different, whereas the detection of the major CPs of L. mexicana with both heterologous antisera shows that the parasite's enzymes share epitopes with the other CPs.