Different pattern of glycoproteins with unusual O-linked oligosaccharides in two strains of Trypanosoma cruzi epimastigotes

ABSTRACT

The glycoconjugate profiles of epimastigotes of the Y strain and of two stocks of the tulahuen strain which differ in their infectivity have been compared. The surface location of the glycoconjugates was evidenced by labelling with glactose oxidase/NaB3H4. Fluorography of SDS-polyacrylamide gel electrophoresis showed a different pattern in the glycoprotein range for both strains and also for two lines (T0 and T2) of the Tulahuen strain. While T0 showed only one glycoprotein with Mr 45 kDa, T2 revealed three glycoproteins in the range of 25-57 kDa. Two fast components, corresponding to glycolipids were also shown. The glycoproteins were isolated with 44 percent phenol and they were purified from the aqueous phase. Alkaline borohydride treatment of the labelled glycoproteins under the conditions of beta-elimination released strongly labelled O-glycosidically linked oligosaccharides. These O-linked glycans are not of the usual type found in glycoproteins. N-acetylgalactosamine which links O-glycans to the protein in the known mucin type glycoproteins has not been detected in the T. cruzi glycoproteins (1).