Presence of a lipophosphoglycan in two variants of Trypanosoma brucei brucei.

For the family of Trypanosomatidae (Trypanosoma and Leishmania) the organization of the glycoproteins on the cell surface is a well documented structural feature, because their plasma membranes are potential target for chemotherapy. By using metabolic labeling ( [32P] phosphate, [3H]-myristic acid, [3H]-galactose) and by appropriate fractionated extraction, we have found a trypanosomal molecule which has electrophoretic and chromatographic properties consistent with the lipophosphoglycan of Leishmania donovani defined by Turco et al (1987) Biochemistry 26, 6233-6238 (1). In addition, the trypanosomal lipophosphoglycan, appears to have chromatographic behaviour similar to the glycolipid C of Trypanosoma brucei brucei described by Krakow et al (1986) J. Biol. Chem. 261, 12147-12153 (2). Our results suggest that the role of the trypanosomal lipophosphoglycan may take place in the orientation of the glycoproteins in the surface coat and/or corresponds to the glycolipid precursor for the anchor of variant surface glycoprotein.