Enfuvirtide (T20)-Based Lipopeptide Is a Potent HIV-1 Cell Fusion Inhibitor: Implications for Viral Entry and Inhibition
Enfuvirtide (T20)-Based Lipopeptide Is a Potent HIV-1 Cell Fusion Inhibitor: Implications for Viral Entry and Inhibition
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基于恩夫韦肽 (T20) 的脂肽是一种有效的 HIV-1 细胞融合抑制剂：对病毒进入和抑制的影响
DOI：
10.1128/jvi.00831-17
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发表时间：
2017-09-01
影响因子：
5.4
通讯作者：
He, Yuxian
中科院分区：
文献类型：
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作者：
Ding, Xiaohui;Zhang, Xiujuan;He, Yuxian
肽药物恩福韦肽（T20）是目前唯一用于HIV-1感染联合治疗的病毒融合抑制剂，但其抗病毒活性相对较低，且易诱导耐药。新兴研究表明，基于脂肽的融合抑制剂，如LP-11和LP-19，主要靶向gp41口袋位点，大大提高了抗病毒效力和体内稳定性。在这项研究中，我们专注于开发一种基于t20的脂肽抑制剂，该抑制剂缺乏口袋结合序列，靶向不同的位点。首先，T20的c端富含色氨酸基序（TRM）被证实是其结合和抑制靶标所必需的；然后，一种新的脂肽，称为LP-40，是通过用脂肪酸基团取代TRM而产生的。LP-40对靶位点的结合亲和力显著增强，对HIV-1膜融合、进入和感染的抑制活性显著增强。与LP-11和LP-19不同，LP-40在肽序列和脂质部分之间需要一个灵活的连接体，而在LP-40上添加一个连接体会大大降低其效力，这意味着与gp41的延长n端螺旋的结合模式不同。此外，有趣的是，LP-40在抑制HIV-1 env介导的细胞-细胞融合方面比LP-11表现出更强的活性，而在抑制假病毒进入方面比LP-11表现出更弱的活性，这两种抑制剂表现出协同抗病毒作用。LP-40与目标肽复合物的晶体结构揭示了它们的关键结合残基和基序。总之，我们的研究不仅提供了一种有效的HIV-1融合抑制剂，而且还揭示了病毒抑制机制的新见解。T20是唯一可用于治疗病毒感染的膜融合抑制剂；然而，T20需要高剂量，耐药遗传屏障低，其抑制机制和结构基础尚不清楚。在这里，我们报道了LP-40的设计，这是一种基于t20的脂肽抑制剂，它大大提高了抗hiv活性，是一种比无细胞病毒感染更有效的细胞-细胞融合抑制剂。两类膜锚定脂肽（LP-40和LP-11）的结合模式验证了当前的融合模型，其中扩展的预发夹结构桥接病毒和细胞膜，它们的互补作用提示了HIV-1感染联合治疗的重要策略。此外，我们对T20及其衍生物的作用机制的理解得益于LP-40的晶体结构。
ABSTRACT The peptide drug enfuvirtide (T20) is the only viral fusion inhibitor used in combination therapy for HIV-1 infection, but it has relatively low antiviral activity and easily induces drug resistance. Emerging studies demonstrate that lipopeptide-based fusion inhibitors, such as LP-11 and LP-19, which mainly target the gp41 pocket site, have greatly improved antiviral potency and in vivo stability. In this study, we focused on developing a T20-based lipopeptide inhibitor that lacks pocket-binding sequence and targets a different site. First, the C-terminal tryptophan-rich motif (TRM) of T20 was verified to be essential for its target binding and inhibition; then, a novel lipopeptide, termed LP-40, was created by replacing the TRM with a fatty acid group. LP-40 showed markedly enhanced binding affinity for the target site and dramatically increased inhibitory activity on HIV-1 membrane fusion, entry, and infection. Unlike LP-11 and LP-19, which required a flexible linker between the peptide sequence and the lipid moiety, addition of a linker to LP-40 sharply reduced its potency, implying different binding modes with the extended N-terminal helices of gp41. Also, interestingly, LP-40 showed more potent activity than LP-11 in inhibiting HIV-1 Env-mediated cell-cell fusion while it was less active than LP-11 in inhibiting pseudovirus entry, and the two inhibitors displayed synergistic antiviral effects. The crystal structure of LP-40 in complex with a target peptide revealed their key binding residues and motifs. Combined, our studies have not only provided a potent HIV-1 fusion inhibitor, but also revealed new insights into the mechanisms of viral inhibition. IMPORTANCE T20 is the only membrane fusion inhibitor available for treatment of viral infection; however, T20 requires high doses and has a low genetic barrier for resistance, and its inhibitory mechanism and structural basis remain unclear. Here, we report the design of LP-40, a T20-based lipopeptide inhibitor that has greatly improved anti-HIV activity and is a more potent inhibitor of cell-cell fusion than of cell-free virus infection. The binding modes of two classes of membrane-anchoring lipopeptides (LP-40 and LP-11) verify the current fusion model in which an extended prehairpin structure bridges the viral and cellular membranes, and their complementary effects suggest a vital strategy for combination therapy of HIV-1 infection. Moreover, our understanding of the mechanism of action of T20 and its derivatives benefits from the crystal structure of LP-40.