Biochemical evidence of the antigenic cell surface heterogeneity of Leishmania mexicana.

In the present study, an enzymatical and structural analysis of Leishmania mexicana cell-surface components was carried out, demonstrating that protease and acid phosphatase activities were present at the L. mexicana cell surface. These findings correlate with the expression of the main components detected on the surface of L. mexicana promastigotes: the 50-kDa component is responsible for the acid phosphatase activity, whereas glycoprotein 65 (gp65) was characterized as the structural polypeptide of the surface protease. Furthermore, the 50- and 65-kDa antigens were found to be structurally different, inasmuch as no homology was observed in their peptide digestion profiles. The results presented in this communication confirm heterogeneity in the expression of the surface components of L. mexicana promastigotes at both the structural and the biochemical level.