Purification of the lipophosphoglycan from two Leishmania mexicana strains by lectin affinity chromatography

Two lipophosphoglycans (LPG) from two Leishmania mexicana (Soberano and Yucatan) strains, isolated in Mexico, were purified by affinity chromatography with the Con A lectin. The LPG from each strain, with a 10 kDa molecular weight, possesses two fractions: one with high mannose concentrations and the other with a more heterogeneous saccharidic composition; the mannose-rich fraction and the heterogeneous fraction from the Yucatan strain show a single band of identity with rabbit IgG against promastigotes from L. mexicana Yucatan. Antigen recognition was abolished by treating the high mannose LPGs with alpha-mannosidase. The presence of non reductor alpha-mannose sequences, as determinant epitopes in L. mexicana Soberano and Yucatan strains, was determined by mass spectrometry analysis and enzymatic cleavage.