The presence of galactofuranose and ribose units in asparagine-linked oligosaccharides of the digenetic trypanosomatid Endotrypanum schaudinni.

It was found that the digenetic trypanosomatid Endotrypanum schaudinni transferred Man7GlcNAc2 in protein N-glycosylation. Endo-beta-N-acetylglucosaminidase H-sensitive oligosaccharides were identified as Man7GlcNAc2, Man6GlcNAc2, Rib1Man6GlcNAc2 and/or Gal1Man6GlcNAc2, Man5GlcNAc containing two galactose or ribose units or one of each residues, Rib1Man5GlcNAc2 and Gal1Man5GlcNAc2. The galactoses were in the furanose configuration. Endo-beta-N-acetylglucosaminidase H-resistant glycopeptides that were retained by concanavalin A-Sepharose and eluted with alpha-methylmannoside were found to contain mannose, galactofuranose and ribose units. The presence of galactofuranoses in N-glycoproteins has been reported previously in several monogenetic trypanosomatids but only in one digenetic parasite (Trypanosoma cruzi). This and a recent publication on the structure of Blastocrithidia culicis N-linked oligosaccharides are the first reports on the presence of ribose in eukaryotic glycoconjugates.