Structure-Based Development of nonnucleoside anti-HIV-1 RT Drugs

描述(由申请人提供)：HIV-1RT是一种关键酶，负责病毒复制和随后的病毒感染。因此，它已成为针对HIV-1感染的治疗干预的主要靶点。然而，携带酶活性突变RT的耐药病毒株的快速出现降低了对药物的敏感性，这阻碍了控制HIV-1感染传播的所有努力。对核苷抑制剂的抗性机制似乎相当复杂，因为许多突变位点并不聚集在聚合酶裂解中假定的dNTP结合口袋周围。然而，对于非核苷类逆转录酶抑制剂(NNRTI)，在与其配基的RT的晶体结构中可以看到一个共同的疏水结合区。在p66亚基中，位于手指、手掌和拇指亚区的一些疏水残基的侧链聚集在一起，形成一个疏水的NNRTI结合口袋。由于NNRTI结合口袋的改变，这些疏水残基的任何突变都会降低药物敏感性。我们的建议旨在通过开发一组新的NNRTI来解决这个问题，这些NNRTI对HIV-1 RT的野生型和常见耐药变体都有效。利用基于结构的分子模拟和体外分析相结合的方法，我们从大量对野生型和突变型RT都具有抑制活性的化合物中选择了四个不同的先导化合物。我们计划通过基于结构的设计策略进一步修饰这些先导化合物，以提高它们的抑制潜力，然后进行合成和体外抗HIV-1 RT筛选。 公共卫生相关性：这项提案的主要重点是开发一种新的NNRTI，它对HIV-1 RT的野生型和耐药变种都同样有效。基于结构模拟和体外抗RT活性，我们从大量化合物中选择了四个非核苷先导化合物，对HIV-1RT野生型和耐药RT突变体都具有抗RT活性。这些最初的先导化合物将被修饰，以进一步增强它们的抗RT活性。

DESCRIPTION (provided by applicant): HIV-1 RT is a key enzyme responsible for viral replication and subsequent perpetuation of viral infection. Hence, it has been the primary target for therapeutic intervention against HIV-1 infection. However, rapid emergence of drug-resistant viral strains harboring enzymatically-active mutant RT with reduced drug-sensitivity has frustrated all efforts to control the spread of HIV-1 infection. The mechanism of resistance to nucleoside inhibitors seems to be quite complex since a number of mutational sites do not cluster around the putative dNTP-binding pocket in the polymerase cleft. However, for nonnucleoside RT inhibitors (NNRTIs), a common hydrophobic binding region is seen in the crystal structures of RT liganded with these inhibitors. The side chains of a number of hydrophobic residues located in the fingers, palm and thumb subdomains in the p66 subunit converge to form a hydrophobic NNRTI binding pocket. Any mutational change in these hydrophobic residues reduces the drug-sensitivity due to alteration in the NNRTI-binding pocket. Our proposal seeks to address this problem by developing a group of new NNRTIs which are effective against both the wild type and common drug-resistant variants of HIV-1 RT. Using a combination of structure-based molecular modeling and in vitro assays, we have selected four distinct lead compounds from a large repertoire of compounds displaying inhibitory activity against both wild type and mutant RT. We plan to further modify these lead compounds by a structure-based design strategy to improve their inhibitory potential followed by synthesis and in vitro anti-HIV-1 RT screening. PUBLIC HELATH RELEVANCE: The major focus of this proposal is to develop a new class of NNRTIs that is equally effective against both the wild type and drug-resistant variants of HIV-1 RT. We selected four nonnucleoside lead compounds from a large repertoire of compounds based on structure-based modeling and in vitro anti- RT activity against both the wild type HIV-1 RT and drug-resistant RT mutants. These initial lead compounds will be modified to further enhance their anti-RT activity.