Protein glycosylation in Trypanosoma cruzi. I. Characterization of dolichol-bound monosaccharides and oligosaccharides synthesized "in vivo".

Trypanosoma cruzi cells, the causative agent of Chagas disease, incubated with [U-14C]glucose in the presence of 5 mM sodium pyruvate or 5.5 mM glucose, were found to synthesize Man9GlcNAc2-P-P-dolichol as the main and largest dolichol disphosphate derivative. No traces of glucosylated derivatives or of dolichol-bound oligosaccharides with a size larger than that of a Man9GlcNAc2 standard could be detected in any case. The synthesis of mannose-P-dolichol but not that of glucose-P-dolichol was found to occur in vivo in these cells. The inability to synthesize glucose-P-dolichol may explain the absence of glucosylated dolichol diphosphate derivatives. The lipid moiety of the dolichol derivatives appeared to have about 13 isoprene residues, the first of which was saturated.