Presence of glycerol and fatty acids in the C-terminal end of a variant surface glycoprotein from Trypanosoma equiperdum.

The composition of the C-terminal end of a variant surface glycoprotein from Trypanosoma equiperdum (BoTat-1 VSG) has been examined. It has been reported for two Trypanosoma brucei VSGs (Holder, A.A., Biochem. J. (1983), 209, 261-262) that ethanolamine was involved in binding the C-terminal amino acid to an oligosaccharide side chain. Tryptic glycopeptides were prepared from BoTat-1 VSG and analyzed. One of them was found to contain ethanolamine and consequently was assumed to be C-terminal. It was shown that the glycopeptide also included phosphate, glycerol and fatty acids. The fatty acid composition was representative of that of glycerolipids. All the results suggest that the end of the molecule is a core of phosphatidylethanolamine.