Todeschini A R, da Silveira E X, Jones C, Wait R, Previato J O, Mendonça-Previato L
Instituto de Microbiologia, CCS-Bloco I, Universidade Federal do Rio de Janeiro, 21944-970-Cidade Universitária, Rio de Janeiro-RJ, Brasil.
Glycobiology. 2001 Jan;11(1):47-55. doi: 10.1093/glycob/11.1.47.
Glycoproteins on the cell surface of Trypanosoma cruzi are known to play important roles in the interaction of the parasite with the host cells. We previously determined the structures of the O-glycan chains from the sialoglycoproteins (mucin-like molecules) of the G- and Y-strains and observed significant differences between them. We now report the structures of the sialylated and nonsialylated O-linked oligosaccharides isolated from the cell surface glycoproteins of the myotropic CL-Brener strain grown in the presence of fetal calf serum. The structures of the O-linked oligosaccharide alditols obtained by reductive beta-elimination of the sialoglycoprotein were determined by a combination of methylation analysis, fast atom bombardment-mass spectrometry and nuclear magnetic resonance spectroscopy. The presence of a beta-galactopyranose substituent on the N-acetylglucosamine O-4 position shows that these O-linked oligosaccharides from CL-Brener strain belong to the same family as those isolated from mucins expressed by T. cruzi Y strain, a reticulotropic strain. In addition, novel O-glycans, including alpha2-3 mono-sialylated species are described.
已知克氏锥虫细胞表面的糖蛋白在该寄生虫与宿主细胞的相互作用中发挥重要作用。我们之前确定了G株和Y株唾液酸糖蛋白（黏蛋白样分子）的O-聚糖链结构，并观察到它们之间存在显著差异。我们现在报告从在胎牛血清存在下培养的亲肌CL-Brener株细胞表面糖蛋白中分离出的唾液酸化和非唾液酸化O-连接寡糖的结构。通过对唾液酸糖蛋白进行还原性β-消除得到的O-连接寡糖糖醇的结构，是通过甲基化分析、快原子轰击质谱和核磁共振光谱相结合的方法确定的。在N-乙酰葡糖胺的O-4位上存在β-吡喃半乳糖取代基，表明CL-Brener株的这些O-连接寡糖与从网状亲嗜性Y株克氏锥虫表达的黏蛋白中分离出的寡糖属于同一家族。此外，还描述了新型O-聚糖，包括α2-3单唾液酸化种类。
