Characterization of human immunodeficiency virus type 1 gp120 binding to liposomes containing galactosylceramide.
Characterization of human immunodeficiency virus type 1 gp120 binding to liposomes containing galactosylceramide.
复制标题
人类免疫缺陷病毒 1 型 gp120 与含有半乳糖神经酰胺的脂质体结合的表征。
DOI：
10.1128/jvi.68.9.5890-5898.1994
复制
发表时间：
1994
影响因子：
5.4
通讯作者：
Doms,RW
中科院分区：
文献类型：
--
作者：
Long,D;Berson,JF;Cook,DG;Doms,RW
1 型人类免疫缺陷病毒 (HIV-1) 会感染一些缺乏 CD4 的细胞类型，这表明存在一种或多种替代病毒受体。其中一种受体是半乳糖神经酰胺（GalCer），一种广泛分布于神经系统和结肠上皮细胞中的鞘糖脂。使用脂质体浮选测定，我们发现 HIV-1 表面糖蛋白 gp120 与含有 GalCer 的脂质体定量结合，但不与仅含有磷脂和胆固醇的脂质体结合。结合是饱和的，并且通过将脂质体与抗GalCer抗体预温育来抑制结合。我们观察到 gp120 与含有乳糖神经酰胺、葡萄糖神经酰胺和半乳糖基硫酸盐的脂质体的结合效率较低，而未检测到与含有混合神经节苷脂、精神氨酸或鞘磷脂的脂质体的结合。与 GalCer 的结合速度很快，很大程度上与温度和 pH 无关，并且在去除大多数外周膜蛋白的条件下稳定。相比之下，与乳糖神经酰胺结合的 gp120 可以被 2 M 氯化钾或 3 M 硫氰酸钾去除，表明相互作用不太稳定。 gp120 上 N 连接寡糖的去除不会影响结合效率。然而，正如之前观察到的 CD4 结合一样，gp120 的热变性阻止了与 GalCer 的结合。最后，结合严重依赖于靶膜中 GalCer 的浓度，这表明与富含糖脂的结构域发生结合，并且 GalCer 构象对于 gp120 识别可能很重要。
Human immunodeficiency virus type 1 (HIV-1) infects some cell types which lack CD4, demonstrating that one or more alternative viral receptors exist. One such receptor is galactosylceramide (GalCer), a glycosphingolipid distributed widely in the nervous system and in colonic epithelial cells. Using a liposome flotation assay, we found that the HIV-1 surface glycoprotein, gp120, quantitatively bound to liposomes containing GalCer but not to liposomes containing phospholipids and cholesterol alone. Binding was saturable and was inhibited by preincubating liposomes with anti-GalCer antibodies. We observed less efficient binding of gp120 to liposomes containing lactosylceramide, glucosylceramide, and galactosylsulfate, whereas no binding to liposomes containing mixed gangliosides, psychosine, or sphingomyelin was detected. Binding to GalCer was rapid, largely independent of temperature and pH, and stable to conditions which remove most peripheral membrane proteins. By contrast, gp120 bound to lactosylceramide could be removed by 2 M potassium chloride or 3 M potassium thiocyanate, demonstrating a less stable interaction. Removal of N-linked oligosaccharides on gp120 did not affect binding efficiency. However, as previously observed for CD4 binding, heat denaturation of gp120 prevented binding to GalCer. Finally, binding was critically dependent on the concentration of GalCer in the target membrane, suggesting that binding to glycolipid-rich domains occurs and that GalCer conformation may be important for gp120 recognition.