Disulfide Sensitivity in the Env Protein Underlies Lytic Inactivation of HIV-1 by Peptide Triazole Thiols.
Disulfide Sensitivity in the Env Protein Underlies Lytic Inactivation of HIV-1 by Peptide Triazole Thiols.
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DOI：
10.1021/acschembio.5b00381
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发表时间：
2015-12-18
影响因子：
4
通讯作者：
Chaiken I
中科院分区：
文献类型：
--
作者：
Bailey LD;Kalyana Sundaram RV;Li H;Duffy C;Aneja R;Rosemary Bastian A;Holmes AP;Kamanna K;Rashad AA;Chaiken I
我们研究了肽三唑硫醇 (PTT) 裂解灭活 HIV-1 病毒粒子的作用模式，特别是 gp120 二硫化物与病毒裂解所需的 C 末端半胱氨酸-SH 之间的关系。合成了通过 PTT SH 交联获得的专性 PTT 二聚体，以及药效基团异亮氨酸-二茂铁三唑-脯氨酸-色氨酸和半胱氨酸-SH 之间具有连续截短接头的 PTT。 PTT 变体显示裂解活性丧失，但在 SH 阻断后没有结合和感染抑制。连接子截短时观察到裂解活性与结合和感染抑制不成比例的损失。 PTT 与 gp120 的分子对接表明，只要接头长度足够，肽 SH 就可以接近并破坏几种替代的 gp120 二硫化物。结合在 V3 环底部的 gp120 mAb 2G12 对裂解的抑制以及二硫键突变效应表明，PTT 诱导的 V3 环底部 gp120 二硫键簇的破坏是 HIV-1 裂解灭活的重要步骤。此外，用还原剂二硫苏糖醇和三(2-羧乙基)膦处理病毒后，PTT诱导的裂解得到增强。总体而言，结果与以下观点一致：PTT 的结合使肽 SH 基团干扰聚集在 gp120 中 CD4 结合位点附近的保守二硫键，导致 gp120 和可能的 gp41 中的二硫键交换，Env 尖峰重排，并最终破坏病毒膜。裂解活性对硫醇-二硫键相互作用的依赖性可能与 gp120 固有的二硫键交换敏感性有关，此前已报道 gp120 在 HIV-1 细胞感染中发挥作用。
We investigated the mode of action underlying lytic inactivation of HIV-1 virions by peptide triazole thiol (PTT), in particular the relationship between gp120 disulfides and the C-terminal cysteine-SH required for virolysis. Obligate PTT dimer obtained by PTT SH cross-linking and PTTs with serially truncated linkers between pharmacophore isoleucine–ferrocenyltriazole-proline–tryptophan and cysteine-SH were synthesized. PTT variants showed loss of lytic activity but not binding and infection inhibition upon SH blockade. A disproportionate loss of lysis activity vs binding and infection inhibition was observed upon linker truncation. Molecular docking of PTT onto gp120 argued that, with sufficient linker length, the peptide SH could approach and disrupt several alternative gp120 disulfides. Inhibition of lysis by gp120 mAb 2G12, which binds at the base of the V3 loop, as well as disulfide mutational effects, argued that PTT-induced disruption of the gp120 disulfide cluster at the base of the V3 loop is an important step in lytic inactivation of HIV-1. Further, PTT-induced lysis was enhanced after treating virus with reducing agents dithiothreitol and tris (2-carboxyethyl)phosphine. Overall, the results are consistent with the view that the binding of PTT positions the peptide SH group to interfere with conserved disulfides clustered proximal to the CD4 binding site in gp120, leading to disulfide exchange in gp120 and possibly gp41, rearrangement of the Env spike, and ultimately disruption of the viral membrane. The dependence of lysis activity on thiol–disulfide interaction may be related to intrinsic disulfide exchange susceptibility in gp120 that has been reported previously to play a role in HIV-1 cell infection.