Weissenhorn W, Wharton S A, Calder L J, Earl P L, Moss B, Aliprandis E, Skehel J J, Wiley D C
Laboratory of Molecular Medicine, Howard Hughes Medical Institute, Children's Hospital, Boston, MA 02215, USA.
EMBO J. 1996 Apr 1;15(7):1507-14.
The human immunodeficiency virus-1 (HIV-1) envelope glycoprotein is composed of a soluble glycopolypeptide gp120 and a transmembrane glycopolypeptide gp41. These subunits form non-covalently linked oligomers on the surface of infected cells, virions and cells transfected with the complete env gene. Two length variants of the extracellular domain of gp41 (aa 21-166 and aa 39-166), that both lack the N-terminal fusion peptide and the C-terminal membrane anchor and cytoplasmic domain, have been expressed in insect cells to yield soluble oligomeric gp41 proteins. Oligomerization was confirmed by chemical cross-linking and gel filtration. Electron microscopy and circular dichroism measurements indicate a rod-like molecule with a high alpha-helical content and a high melting temperature (78 degrees C). The binding of monoclonal antibody Fab fragments dramatically increased the solubility of both gp41 constructs. We propose that gp41 folds into its membrane fusion-active conformation, when expressed alone.
人类免疫缺陷病毒1型（HIV-1）包膜糖蛋白由可溶性糖多肽gp120和跨膜糖多肽gp41组成。这些亚基在受感染细胞、病毒粒子以及用完整env基因转染的细胞表面形成非共价连接的寡聚体。gp41细胞外结构域的两种长度变体（氨基酸21-166和氨基酸39-166），均缺乏N端融合肽以及C端膜锚定和胞质结构域，已在昆虫细胞中表达，以产生可溶性寡聚gp41蛋白。通过化学交联和凝胶过滤证实了寡聚化。电子显微镜和圆二色性测量表明，该分子呈棒状，具有高α-螺旋含量和高熔点（78摄氏度）。单克隆抗体Fab片段的结合显著增加了两种gp41构建体的溶解度。我们提出，当单独表达时，gp41会折叠成其膜融合活性构象。
