Evidence for the plasma membrane localization of carbohydrate‐containing macromolecules from epimastigote forms of Trypanosoma cruzi

The existence of carbohydrate-containing substances on the surface of Tryp~~oso~a cmzi was demonstrated by cell ag~utination with Con A [l] and by cytochemical studies in tissue culture forms [2]. A sugar-containing macromolecular complex has been extracted from T. cruzi epimastigote whole cells, This complex consists of 4 PAS-positive bands as judged from SDS-polyac~lamide gel electrophoresis -(bands A-D) f3]. The electrophoretic pattern of bands A, B and C can be altered by pretreatment of the complex with a proteolytic enzyme, pointing to a glycoprotein nature. Band D, however, is a carbohydrateand lipid-rich substance which has tentatively been named LPPG [4-6] _ Although both the complex and pure LPPG are effective in the inhibition of Con A-induced agglutination of epimastigotes, non-circumstantial evidence for the plasma membrane localization of these substances was lacking. Such evidence and the antigenic nature of part of the complex are presented in this communication.