Structure of the murine leukemia virus envelope glycoprotein precursor
Structure of the murine leukemia virus envelope glycoprotein precursor
复制标题
鼠白血病病毒包膜糖蛋白前体的结构
作者：
O. Witte;D. Wirth
用选择性免疫沉淀法分离到Moloney鼠白血病病毒糖基化的env基因前体（Pr 80 env）。使用药物衣霉素来抑制新生糖基化或内切糖苷酶H的特异性切割，证明前体含有分子量为60，000的脱辅基蛋白。最终的病毒粒子糖蛋白（gp 70）对内切糖苷酶H的作用有很大的抗性。结合内切糖苷酶H消化研究的Pr 80 env的糖肽的色谱法表明，前体含有两个不同的主要糖基化位点。分析内切糖苷酶H处理前后Pr 80 env的部分蛋白水解切割片段，将两个糖基化位点置于脱辅基蛋白序列的30，000-道尔顿区域内。动力学实验表明，碳水化合物加工以及蛋白水解裂解的后期步骤的成熟Pr 80 env。
The glycosylated env gene precurosr (Pr80env) of Moloney murine leukemia virus has been isolated by selective immunoprecipitation. Use of the drug tunicamycin to inhibit nascent glycosylation or specific cleavage with endoglycosidase H demonstrated that the precursor contained an apoprotein with a molecular weight of 60,000. The finished virion glycoprotein (gp70) was largely resistant to the action of endoglycosidase H. Chromatography of the glycopeptides of Pr80env in conjunction with endoglycosidase H digestion studies suggested that the precursor contained two distinct major glycosylation sites. Analysis of partial proteolytic cleavage fragments of Pr80env before and after endoglycosidase H treatment placed the two glycosylation sites within a 30,000-dalton region of the apoprotein sequence. Kinetic experiments showed that carbohydrate processing as well as proteolytic cleavage are late steps in the maturation of Pr80env.