期刊名称:Proceedings of the National Academy of Sciences
印刷版ISSN:0027-8424
电子版ISSN:1091-6490
出版年度:1981
卷号:78
期号:10
页码:6201-6205
DOI:10.1073/pnas.78.10.6201
语种:English
出版社:The National Academy of Sciences of the United States of America
摘要:Cells of the insect parasite Crithidia fasciculata incubated with [14C]glucose were found to possess only one lipid-bound oligosaccharide with solubility in chloroform/methanol/water mixtures and net charge similar to the charges of dolichol pyrophosphate derivatives. The saccharide moiety could be released from lipid by mild acid hydrolysis. Several enzymatic and chemical treatments of the oligosaccharide indicated that the latter had the structure Man alpha leads to Man alpha leads to Man alpha leads to [Man alpha leads to Man alpha leads to Man (alpha 1 leads to 6)]Man leads to GlcNAc(beta 1 leads to 4)GlcNAc. Two labeled oligosaccharides were liberated from proteins by a sequential treatment with a protease and endo-beta-N-acetylglucosamindase H. One of the protein-bound oligosaccharides had the same structure as the lipid-linked compound, whereas in the second oligosaccharide some mannose residues had been replaced by galactose units, but both compounds migrated as did a Man7GlcNAc standard. These were the largest oligosaccharides obtained even after short labeling periods. It is suggested that glycosylation of proteins in the protozoan Crithidia fasciculata does not involved glucosylated lipid-bound oligosaccharides as intermediates.