Britt W J, Vugler L G
Department of Pediatrics and Microbiology, University of Alabama, Birmingham 35294.
J Virol. 1989 Jan;63(1):403-10. doi: 10.1128/JVI.63.1.403-410.1989.
The processing pathway of the major envelope glycoprotein complex, gp55-116 (gB), of human cytomegalovirus was studied using inhibitors of glycosylation and endoglycosidases. The results of these studies indicated that the mature gp55-116 is synthesized by the addition of both simple and complex N-linked sugars to a nonglycosylated precursor of estimated Mr 105,000. In a rapid processing step, the Mr 105,000 precursor is glycosylated to a protein of Mr 150,000 (gp150) which contains only endoglycosidase H-sensitive sugar linkages. The gp150 is then processed relatively slowly to a Mr 165,000 to 170,000 species (gp165-170), which is then cleaved to yield the mature gp55-116. Monensin prevented the final processing steps of the gp150, including cleavage, suggesting that transport through the Golgi apparatus is required for complete processing. Digestion of the intracellular forms of this complex as well as the virion forms confirmed the above findings and indicated that the mature virion form of gp55 contains 8,000 daltons of N-linked sugars. The virion gp116 contains some 52,000 to 57,000 daltons of N-linked carbohydrates and approximately 5,000 daltons of O-linked sugars.
利用糖基化抑制剂和内切糖苷酶研究了人巨细胞病毒主要包膜糖蛋白复合物gp55 - 116（gB）的加工途径。这些研究结果表明，成熟的gp55 - 116是通过将简单型和复合型N - 连接糖添加到估计分子量为105,000的非糖基化前体上合成的。在一个快速加工步骤中，分子量为105,000的前体被糖基化为分子量为150,000的蛋白质（gp150），该蛋白质仅含有对内切糖苷酶H敏感的糖连接。然后，gp150相对缓慢地加工为分子量为165,000至170,000的物质（gp165 - 170），随后被切割产生成熟的gp55 - 116。莫能菌素阻止了gp150的最终加工步骤，包括切割，这表明通过高尔基体的运输是完全加工所必需的。对该复合物的细胞内形式以及病毒体形式的消化证实了上述发现，并表明gp55的成熟病毒体形式含有8,000道尔顿的N - 连接糖。病毒体gp116含有约52,000至57,000道尔顿的N - 连接碳水化合物和约5,000道尔顿的O - 连接糖。
