Four glycoproteins of apparent molecular weights 300,000, 140,000, 125,000, and 36,000 (gp300, gp140, gp125, and gp36) are detectable in human immunodeficiency virus type 2 (HIV-2) infected cells. The gp125 and gp36 are the external and transmembrane components, respectively, of the envelope glycoproteins of HIV-2 mature virions. The gp300, which is a dimeric form of gp14O, the precursor of HIV-2 envelope glycoprotein, is probably formed by a pH dependent fusion in the endoplasmic reticulum. Such a doublet is also observed in cells infected with simian immunodeficiency virus (SIV), a virus closely related to HIV-2. On the other hand, the envelope glycoprotein precursor of HIV-1 does not form a dimer during its processing. Experiments carried out with various inhibitors of oligosaccharide trimming enzymes suggest that transient dimerization of the glycoprotein precursor is required for its efficient transport to the Golgi apparatus and for its processing. The gp300 is useful for detecting antibodies to HIV-2 antigens in human body fluids and for raising antibodies to gp300.
在人类免疫缺陷病毒 2 型(HIV-2)感染细胞中可检测到表观分子量分别为 300,000、140,000、125,000 和 36,000 的四种糖蛋白(gp300、gp140、gp125 和 gp36)。gp125 和 gp36 分别是 HIV-2 成熟病毒包膜糖蛋白的外膜和跨膜成分。gp300 是 gp14O 的二聚体形式,是 HIV-2 包膜糖蛋白的前体,可能是在内质网中通过 pH 依赖性融合形成的。在感染猿猴免疫缺陷病毒(SIV)(一种与 HIV-2 密切相关的病毒)的细胞中也能观察到这种双聚体。另一方面,HIV-1 的包膜糖蛋白前体在加工过程中不会形成二聚体。使用各种
寡糖修饰酶抑制剂进行的实验表明,糖蛋白前体的短暂二聚化是其有效运输到高尔基体并进行加工所必需的。gp300 可用于检测人体液中的 HIV-2 抗原
抗体,也可用于培养 gp300
抗体。