THE ROLE OF INDIVIDUAL OLIGOSACCHARIDE CHAINS IN THE ACTIVITIES OF THE HN GLYCOPROTEIN OF NEWCASTLE-DISEASE VIRUS
THE ROLE OF INDIVIDUAL OLIGOSACCHARIDE CHAINS IN THE ACTIVITIES OF THE HN GLYCOPROTEIN OF NEWCASTLE-DISEASE VIRUS
复制标题
DOI：
10.1006/viro.1995.1497
复制
发表时间：
1995-10-01
期刊：
影响因子：
3.7
通讯作者：
MORRISON, TG
中科院分区：
文献类型：
--
作者：
MCGINNES, LW;MORRISON, TG
为了探讨N-连接碳水化合物在新城疫病毒(NDV)血凝素神经氨酸酶(HN)糖蛋白活性中的作用，对新城疫病毒(NDV)株HN序列的6个糖基化加成点(G1-G6)进行了突变。突变蛋白在聚丙烯酰胺凝胶上的迁移以及对突变蛋白的内切糖苷酶H的消化表明，有四个添加位点(分别位于119、341、433和481位氨基酸的G1、G2、G3和G4)被使用，而两个(分别位于508和538位氨基酸的G5和G6)未被使用。从单个和所有可能的双突变和三重突变DNA组合以及未糖基化的分子中表达的蛋白质的特征包括：特定抗原位点的存在、二硫键连接二聚体的形成、稳定性、向细胞表面的运输和生物活性。结果表明，糖基化A1位置G1和G2在分子的折叠、稳定性或转运中几乎没有可检测到的作用，无论是单独的还是与其他突变一起。然而，这些片段的突变显著增加了细胞附着和蛋白质的融合促进活性，特别是在组合中。G4糖基化位点的突变单独或与其他位点消除突变一起抑制成熟蛋白的形成，而消除G3添加位点的突变对折叠效率有轻微的影响，特别是与G4位点的突变相结合。当归一化到表面表达时，G3和G4上的碳水化合物添加位点的单独消除或与其他突变结合在一起会抑制蛋白质的神经氨酸酶活性，但不会抑制融合促进活性。因此，两种寡糖在成熟过程中没有可检测到的作用，但确实调节了蛋白质的生物学活性。另外两种寡糖同时影响蛋白质的折叠和活性。(C)1995年学术出版社。
To explore the role of N-linked carbohydrate in the activities of the hemagglutinin-neuraminidase (HN) glycoprotein of Newcastle disease virus (NDV), the six glycosylation addition sites (G1-G6) in the HN sequence of the AV strain of NDV were mutated. Migration of mutant protein on polyacrylamide gels as well as endoglycosidase H digestion of mutant protein showed that four of the addition sites (G1, G2, G3, and G4 at amino acids 119, 341, 433, and 481, respectively) are used while two (G5 and G6 at amino acids 508 and 538, respectively) are not used. Proteins expressed from single and all possible combinations of double and triple mutant DNAs as well as the unglycosylated molecule were characterized for the presence of specific antigenic sites, formation of disulfide-linked dimers, stability, transport to the cell surface, and biological activity. Results showed that glycosylation al positions G1 and G2 play little detectable role in the folding, stability, or transport of the molecule either singly or in combination with other mutations. Mutation of these sequons, however, significantly increased the cell attachment and fusion promotion activities of the protein, particularly in combination. Mutation of the glycosylation site at G4 either singly or in combination with other site-eliminating mutants inhibited the formation of the mature protein, while a mutation eliminating the addition site at G3 had a slight effect on the efficiency of folding, particularly in combination with mutation of the site G4. When normalized to surface expression, elimination of carbohydrate addition sites at G3 and G4 singly or in combination with other mutations depressed in particular the neuraminidase activity of the protein but not the fusion promotion activity. Thus two oligosaccharides do not have a detectable role in maturation but do modulate the biological activities of the protein. The other two oligosaccharides influence both folding and activity Of the protein. (C) 1995 Academic Press, Inc.