Gram G J, Hemming A, Bolmstedt A, Jansson B, Olofsson S, Akerblom L, Nielsen J O, Hansen J E
Laboratory for Infectious Diseases, Hvidovre Hospital, Denmark.
Arch Virol. 1994;139(3-4):253-61. doi: 10.1007/BF01310789.
Glycosylation is necessary for HIV-1 gp120 to attain a functional conformation, and individual N-linked glycans of gp120 are important, but not essential, for replication of HIV-1 in cell culture. We have constructed a mutant HIV-1 infectious clone lacking a signal for N-linked glycosylation in the V1-loop of HIV-1 gp120. Lack of an N-linked glycan was verified by a mobility enhancement of mutant gp120 in SDS-gel electrophoresis. The mutated virus showed no differences in either gp120 content per infectious unit or infectivity, indicating that the N-linked glycan was neither essential nor affecting viral infectivity in cell culture. We found that the mutated virus lacking an N-linked glycan in the V1-loop of gp120 was more resistant to neutralization by monoclonal antibodies to the V3-loop and neutralization by soluble recombinant CD4 (sCD4). Both viruses were equally well neutralized by ConA and a conformation dependent human antibody IAM-2G12. This suggests that the N-linked glycan in the V1-loop modulates the three-dimensional conformation of gp120, without changing the overall functional integrity of the molecule.
糖基化对于HIV-1 gp120获得功能性构象是必需的，并且gp120的单个N-连接聚糖对于HIV-1在细胞培养中的复制很重要，但并非必不可少。我们构建了一个突变的HIV-1感染性克隆，该克隆在HIV-1 gp120的V1环中缺乏N-连接糖基化信号。通过SDS凝胶电泳中突变型gp120的迁移率增强来验证N-连接聚糖的缺失。突变病毒在每个感染单位的gp120含量或感染性方面均无差异，这表明N-连接聚糖在细胞培养中既不是必需的，也不影响病毒感染性。我们发现，在gp120的V1环中缺乏N-连接聚糖的突变病毒对V3环单克隆抗体的中和作用以及可溶性重组CD4（sCD4）的中和作用更具抗性。两种病毒均被伴刀豆球蛋白A和构象依赖性人抗体IAM-2G12同样有效地中和。这表明V1环中的N-连接聚糖可调节gp120的三维构象，而不会改变分子的整体功能完整性。
