Tsai P K, Ballou L, Esmon B, Schekman R, Ballou C E
Proc Natl Acad Sci U S A. 1984 Oct;81(20):6340-3. doi: 10.1073/pnas.81.20.6340.
The total cell wall mannoprotein has been isolated from a mutant of Saccharomyces cerevisiae that fails to remove the glucose units of the dolichol-linked precursor after transfer of the oligosaccharide to asparagine units in the protein. The oligosaccharides released from this mannoprotein by endoglucosaminidase H digestion show 1H NMR signals assignable to three alpha-linked glucose units as delta 5.52, 5.27, and 5.17, and a comparison with the chemical shifts of reference compounds shows that these signals are consistent with the structure alpha Glc----2 alpha Glc----3 alpha Man----2. This provides a direct confirmation for the structure previously assigned to the lipid-linked precursor. Analysis of the larger oligosaccharides confirms that the presence of the glucose units does not prevent elongation of the alpha 1----6-linked polymannose backbone or addition of alpha 1----3-linked mannose to the core.
已从酿酒酵母的一个突变体中分离出总细胞壁甘露糖蛋白，该突变体在将寡糖转移至蛋白质中的天冬酰胺单元后，无法去除多萜醇连接前体的葡萄糖单元。通过内切葡糖胺聚糖酶H消化从该甘露糖蛋白释放的寡糖显示出可归属于三个α-连接葡萄糖单元的1H NMR信号，其化学位移为δ5.52、5.27和5.17，与参考化合物的化学位移比较表明，这些信号与结构αGlc----2αGlc----3αMan----2一致。这为先前赋予脂质连接前体的结构提供了直接证实。对较大寡糖的分析证实，葡萄糖单元的存在并不妨碍α1----6连接的多聚甘露糖主链的延长或α1----3连接的甘露糖添加到核心中。
