Insights into the molecular mechanism of inhibition and drug resistance for HIV-1 RT with carbovir triphosphate.
Insights into the molecular mechanism of inhibition and drug resistance for HIV-1 RT with carbovir triphosphate.
复制标题
深入了解三磷酸卡波韦对 HIV-1 RT 的抑制和耐药性的分子机制。
DOI：
10.1021/bi0121858
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发表时间：
2002
期刊：
影响因子：
2.9
通讯作者：
Anderson,KarenS
中科院分区：
文献类型：
--
作者：
Ray,AdrianS;Yang,Zhenjun;Shi,Junxing;Hobbs,Ann;Schinazi,RaymondF;Chu,ChungK;Anderson,KarenS
Abacavir （1592U89，或Ziagen）是一种强大的选择性HIV-1病毒复制抑制剂，已被FDA批准用于治疗获得性免疫缺陷综合征。阿巴卡韦被代谢成活性化合物三磷酸碳韦（CBVTP）。该化合物是鸟苷类似物，在其平面碳环脱氧核糖环上含有2 ',3 ' -不饱和，作为分子靶标作用于HIV-1逆转录酶（RTWT），导致DNA合成链终止。HIV-1 RT （RTM184V）在阿巴卡韦治疗后，临床观察到一个氨基酸从蛋氨酸184转变为缬氨酸。天然底物dGTP或CBVTP在RTWTand rtm184v的DNA和rna定向聚合过程中被利用的能力由预稳态动力学参数定义。在RTWT的情况下，发现CBVTP相对于dGTP是一个令人惊讶的差底物。在DNA和rna定向聚合中，RTM184V对CBVTP的利用效率都低于dGTP，这表明这种突变在CBVMP掺入水平上赋予了抗性。考虑到早期的研究表明，与天然底物dTTP相比，含有平面2 ',3 ' -不饱和核糖环的胸腺嘧啶核苷类似物D4TTP的三磷酸形式的掺入效率更高，rtwt相对较低的掺入效率是出乎意料的。这种差异可能与脱氧核糖环上的氧被碳等构取代有关。通过合成和评价D4GTP（与D4TTP互补的平面2 ',3 ' -不饱和脱氧核糖鸟苷类似物）来验证这一假设。与CBVTP相比，D4GTP被发现是rtwt的优良底物，并且M184V突变不会产生抗性，从而为核苷类抑制剂的结构-活性关系提供了新的见解。在这项工作中，我们阐明了对抑制和耐药的分子机制的理解如何导致发现一种新的D4G前药。这种化合物有望成为一种有效的抗病毒药物，特别是在临床环境中经常遇到的耐药M184V HIV-1 RT。
Abacavir (1592U89, or Ziagen) is a powerful and selective inhibitor of HIV-1 viral replication that has been approved by the FDA for treatment of acquired immunodeficiency syndrome. Abacavir is metabolized to the active compound carbovir triphosphate (CBVTP). This compound is a guanosine analogue containing a 2‘,3‘-unsaturation in its planar carbocyclic deoxyribose ring that acts on HIV-1 reverse transcriptase (RTWT) as a molecular target, resulting in chain termination of DNA synthesis. A single amino acid change from methionine 184 to valine in HIV-1 RT (RTM184V) has been observed clinically in response to abacavir treatment. The ability of the natural substrate, dGTP, or CBVTP to be utilized during DNA- and RNA-directed polymerization by RTWTand RTM184Vwas defined by pre-steady-state kinetic parameters. In the case of RTWT, CBVTP was found to be a surprisingly poor substrate relative to dGTP. In both DNA- and RNA-directed polymerization, a decrease in the efficiency of CBVTP utilization with respect to dGTP was found with RTM184V, suggesting that this mutation confers resistance at the level of CBVMP incorporation. The relatively low incorporation efficiency for RTWTwas unanticipated considering earlier studies showing that the triphosphate form of a thymidine nucleoside analogue containing a planar 2‘,3‘-unsaturated ribose ring, D4TTP, was incorporated with high efficiency relative to the natural substrate, dTTP. The difference may be related to the isosteric replacement of oxygen in the deoxyribose ring with carbon. This hypothesis was tested by synthesizing and evaluating D4GTP (the planar 2‘,3‘-unsaturated deoxyribose guanosine analogue that is complementary to D4TTP). In contrast to CBVTP, D4GTP was found to be an excellent substrate for RTWTand no resistance was conferred by the M184V mutation, thus providing novel insight into structure−activity relationships for nucleoside-based inhibitors. In this work, we illustrate how an understanding of the molecular mechanism of inhibition and drug resistance led to the discovery of a novel prodrug of D4G. This compound shows promise as a potent antiviral especially with the drug resistant M184V HIV-1 RT that is so often encountered in a clinical setting.