Alanine scanning mutagenesis of HIV-1 gp41 heptad repeat 1: insight into the gp120-gp41 interaction.
Alanine scanning mutagenesis of HIV-1 gp41 heptad repeat 1: insight into the gp120-gp41 interaction.
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DOI：
10.1021/bi1005267
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发表时间：
2010-06
期刊：
影响因子：
2.9
通讯作者：
J. Sen;Tianran Yan;Jizhen Wang;Lijun Rong;Lin Tao;M. Caffrey
中科院分区：
文献类型：
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作者：
J. Sen;Tianran Yan;Jizhen Wang;Lijun Rong;Lin Tao;M. Caffrey
在诱变、生物化学和结构研究的基础上，HIV gp 41的七肽重复序列1（HR 1）已被证明在HIV进入中起许多关键作用，包括在融合前状态下与gp 120相互作用和在融合状态下与gp 41七肽重复序列2（HR 2）相互作用。此外，HR 1是恩夫韦肽（一种HR 2的肽类似物）的治疗干预部位。在这项研究中，每个氨基酸残基在gp 41 HR 1的功能的重要性已被系统地检查丙氨酸扫描诱变，随后表征的诱变效果折叠（通过掺入到病毒粒子），协会与gp 120，和膜融合。对进入的突变效应可以分为三类：（1）野生型（定义为>野生型进入的40%），（2）受损的（定义为野生型进入的5-40%），和（3）无功能的（定义为<野生型进入的5%）。有趣的是，大多数HR 1突变（77%）表现出受损或无功能进入。令人惊讶的是，突变对折叠、缔合或融合的影响与七肽位置无关;然而，折叠缺陷最常发现于HR 1的N-末端区域。此外，gp 41-gp 120相互作用的破坏与HR 1的C-末端区域相关，表明该区域与gp 120相互作用最密切。总之，gp 41 HR 1对丙氨酸取代的敏感性表明，即使局部环境的微小变化也可能严重影响包膜功能，从而加强了HR 1是治疗干预的有吸引力的位点的概念。
On the basis of mutagenesis, biochemical, and structural studies, heptad repeat 1 of HIV gp41 (HR1) has been shown to play numerous critical roles in HIV entry, including interacting with gp120 in prefusion states and interacting with gp41 heptad repeat 2 (HR2) in the fusion state. Moreover, HR1 is the site of therapeutic intervention by enfuviritide, a peptide analogue of HR2. In this study, the functional importance of each amino acid residue in gp41 HR1 has been systematically examined by alanine scanning mutagenesis, with subsequent characterization of the mutagenic effects on folding (as measured by incorporation into virions), association with gp120, and membrane fusion. The mutational effects on entry can be grouped into three classes: (1) wild type (defined as >40% of wild-type entry), (2) impaired (defined as 5-40% of wild-type entry), and (3) nonfunctional (defined as <5% of wild-type entry). Interestingly, the majority of HR1 mutations (77%) exhibit impaired or nonfunctional entry. Surprisingly, effects of mutations on folding, association, or fusion are not correlated to heptad position; however, folding defects are most often found in the N-terminal region of HR1. Moreover, disruption of the gp41-gp120 interaction is correlated to the C-terminal region of HR1, suggesting that this region interacts most closely with gp120. In summary, the sensitivity of gp41 HR1 to alanine substitutions suggests that even subtle changes in the local environment may severely affect envelope function, thereby strengthening the notion that HR1 is an attractive site for therapeutic intervention.