Hunt L A, Etchison J R, Summers D F
Proc Natl Acad Sci U S A. 1978 Feb;75(2):754-8. doi: 10.1073/pnas.75.2.754.
The biosynthesis and maturation of the oligosaccharide moieties of the envelope glycoprotein of vesicular stomatitis virus were investigated in virus-infected HeLa and BHK21 cells after pulse labeling with [2-3H]mannose. Two major forms of the virus glycoprotein were detected by polyacrylamide gel electrophoresis, which appear to correspond to the viral glycoprotein with either "precursor" or "mature" oligosaccharide chains. The precursor chains in both HeLa and BHK21 cells infected with vesicular stomatitis virus obtained after a 30-min pulse were large oligomannose structures containing approximately 7--9 mannose residues as estimated by gel filtration analysis. The size of the oligomannose structures initially transferred to the protein may have been even larger. Mature, virus-size oligosaccharide chains, which could be detected after a 20- to 30-min delay, contained only three mannose residues and, in addition, contained branch structures terminating in sialic acid. A precursor--product relationship of these two forms of oligosaccharide chains was demonstrated by pulse--chase labeling of virus-infected HeLa cells. These studies indicated that the large oligomannosyl core structures initially added to the glycoprotein were being "trimmed" by the removal of mannose residues prior to (and/or during) the addition of the branch chains terminating in sialic acid.
在用[2-³H]甘露糖脉冲标记后，对水泡性口炎病毒包膜糖蛋白寡糖部分的生物合成和成熟过程在病毒感染的HeLa细胞和BHK21细胞中进行了研究。通过聚丙烯酰胺凝胶电泳检测到病毒糖蛋白的两种主要形式，它们似乎分别对应于带有“前体”或“成熟”寡糖链的病毒糖蛋白。经30分钟脉冲处理后，在感染水泡性口炎病毒的HeLa细胞和BHK21细胞中获得的前体链是大的寡甘露糖结构，通过凝胶过滤分析估计含有约7-9个甘露糖残基。最初转移到蛋白质上的寡甘露糖结构的大小可能更大。在延迟20至30分钟后可检测到的成熟的、病毒大小的寡糖链仅含有三个甘露糖残基，此外还含有以唾液酸结尾的分支结构。通过对病毒感染的HeLa细胞进行脉冲追踪标记，证明了这两种寡糖链形式之间的前体-产物关系。这些研究表明，最初添加到糖蛋白上的大的寡甘露糖核心结构在添加以唾液酸结尾的分支链之前（和/或期间）通过去除甘露糖残基而被“修剪”。
