对型肝炎病毒受体结合和进入的结构洞察
Ashish Kumar1, Reafa A Hossain1, Samantha A Yost2
1Structural Virology Section, Laboratory of Infectious Diseases, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD, USA.
Nature
|September 16, 2021
概括
肝炎C病毒 (HCV) 的进入涉及E2糖蛋白与CD81受体的结合. 低pH和CD81结合诱导E2的结构变化,促进病毒膜融合.
科学领域:
- 病毒学
- 结构生物学
- 细胞生物学
背景情况:
- 肝炎C病毒导致慢性肝病,肝硬化和肝癌, 影响全球超过7000万.
- HCV包膜糖蛋白E1和E2通过病毒进入,但确切的机制尚不清楚.
- 中和抗体通常针对E2糖蛋白与CD81受体的大细胞外环 (CD81-LEL) 的相互作用.
研究的目的:
- 阐明HCV进入的结构和分子机制.
- 研究pH和CD81结合在HCV E2和CD81-LEL之间的相互作用中的作用.
- 确定E2介导膜融合的结构基础.
主要方法:
- 使用X射线结晶学来确定E2复合物的结构.
- 对关键E2残留物进行了变异性研究.
- 脂质体漂浮试验评估了E2与膜的相互作用.
主要成果:
- 低pH增强了CD81-LEL与E2糖蛋白的结合.
- 在CD81-LEL结合时,晶体结构显示了E2的形状变化,将残留物418-422位移,并扩展了内部循环 (520-539).
- 特定的E2残留物 (Tyr529,Trp531,Ile422) 对于膜相互作用至关重要,低pH和CD81-LEL促进这种相互作用.
结论:
- 酸化和CD81-LEL结合导致了E2的构造变化.
- 这种形状变化为膜融合的E2原始化,代表了HCV进入的关键步骤.
- 这些发现提供了HCV与宿主细胞膜相互作用的分子模型.
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