Allosteric suppression of HIV-1 reverse transcriptase structural dynamics upon inhibitor binding.
Allosteric suppression of HIV-1 reverse transcriptase structural dynamics upon inhibitor binding.
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DOI：
10.1016/j.bpj.2010.11.004
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发表时间：
2011-01
影响因子：
3.4
通讯作者：
James M. Seckler;M. Barkley;P. Wintrode
中科院分区：
文献类型：
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作者：
James M. Seckler;M. Barkley;P. Wintrode
Efavirenz是第二代非核苷类逆转录酶抑制剂（NNRTI），也是临床批准的抗艾滋病方案的常见组成部分。nnrti是一种非竞争性抑制剂，它结合在逆转录酶（RT）的p66亚基的疏水口袋中~ 10 Å，从聚合酶活性位点。氢交换质谱（HXMS）表明，除NNRTI结合位点外，efavirenz结合降低了RT异二聚体多个区域的分子柔韧性。在HXMS监测的47个消化酶片段中，有15个片段在使用依非韦伦时H/D交换率发生了显著变化。先前在未配体RT中观察到的NNRTI结合口袋中β-薄片缓慢的协同展开，被efavirenz显著抑制。HXMS还定义了一个广泛的变构偶联位点网络，包括四个不同的变构稳定区域和一个变构不稳定区域。efavirenz结合的效果从NNRTI结合口袋扩展到bbb60 Å。结构动力学的变构变化传播到p66亚基的拇指和连接子结构域、RNase H结构域以及p51亚基的拇指和手掌子结构域。这些变构区可能代表潜在的新药物靶点。
Efavirenz is a second-generation nonnucleoside reverse transcriptase inhibitor (NNRTI) and a common component of clinically approved anti-AIDS regimens. NNRTIs are noncompetitive inhibitors that bind in a hydrophobic pocket in the p66 subunit of reverse transcriptase (RT) ∼10 Å from the polymerase active site. Hydrogen exchange mass spectrometry (HXMS) shows that efavirenz binding reduces molecular flexibility in multiple regions of RT heterodimer in addition to the NNRTI binding site. Of the 47 peptic fragments monitored by HXMS, 15 showed significantly altered H/D exchange rates in the presence of efavirenz. The slow cooperative unfolding of aβ-sheet in the NNRTI binding pocket, which was previously observed in unliganded RT, is dramatically suppressed by efavirenz. HXMS also defines an extensive network of allosterically coupled sites, including four distinct regions of allosteric stabilization, and one region of allosteric destabilization. The effects of efavirenz binding extend >60 Å from the NNRTI binding pocket. Allosteric changes to the structural dynamics propagate to the thumb and connection subdomains and RNase H domain of the p66 subunit as well as the thumb and palm subdomains of the p51 subunit. These allosteric regions may represent potential new drug targets.