Nyame K, Cummings R D, Damian R T
Department of Zoology, University of Georgia, Athens 30602.
Mol Biochem Parasitol. 1988 Apr;28(3):265-74. doi: 10.1016/0166-6851(88)90011-4.
This report describes the structures of the high-mannose-type N-linked oligosaccharides in glycoproteins synthesized by Schistosoma mansoni adult male worms. Adult male schistosomes were incubated in vitro in media containing either [2-3H]mannose, [6-3H]glucosamine or [6-3H]galactose to allow metabolic radiolabeling of the oligosaccharide moieties of newly synthesized glycoproteins. Glycopeptides were prepared from the radiolabeled glycoproteins by digestion with Pronase and fractionation by chromatography on concanavalin A-Sepharose. Eleven percent of [3H]mannose incorporated into the schistosome glycopeptides was recovered in high mannose-type Asn-linked oligosaccharides which bound to the immobilized lectin. Upon treatment of [3H]mannose-labeled glycopeptide with endo-beta-N-acetylglucosaminidase H, the high mannose-type chains were released and their structures were determined by high performance liquid chromatography, methylation analysis, acetolysis and exoglycosidase digestion. The major species of high mannose-type chains synthesized by S. mansoni adult males have the composition Man7GlcNAc2, Man8GlcNac2 and Man9GlcNA2. Structural analyses indicate that these oligosaccharides are similar to high mannose-type chains synthesized by mammalian cells.
本报告描述了曼氏血吸虫成年雄虫合成的糖蛋白中高甘露糖型N - 连接寡糖的结构。成年雄血吸虫在含有[2 - 3H]甘露糖、[6 - 3H]葡糖胺或[6 - 3H]半乳糖的培养基中进行体外培养，以使新合成糖蛋白的寡糖部分进行代谢性放射性标记。通过用链霉蛋白酶消化并在伴刀豆球蛋白A - 琼脂糖上进行色谱分离，从放射性标记的糖蛋白中制备糖肽。掺入血吸虫糖肽中的[3H]甘露糖有11%在与固定化凝集素结合的高甘露糖型天冬酰胺连接寡糖中回收。用内切β - N - 乙酰葡糖胺糖苷酶H处理[3H]甘露糖标记的糖肽后，高甘露糖型链被释放，其结构通过高效液相色谱、甲基化分析、乙酰解和外切糖苷酶消化来确定。曼氏血吸虫成年雄虫合成的高甘露糖型链的主要种类具有Man7GlcNAc2、Man8GlcNac2和Man9GlcNA2的组成。结构分析表明，这些寡糖与哺乳动物细胞合成的高甘露糖型链相似。
