HIV Protease Activation and Viral Replication

描述（由申请方提供）：HIV-1蛋白酶的激活是病毒复制的重要步骤。与所有逆转录病毒蛋白酶的情况一样，酶活性需要蛋白酶同源二聚体的形成。阻止二聚化的突变会干扰蛋白酶功能;编码无功能酶的病毒变体组装异常且无感染性。对抑制酶二聚化的化合物的体外研究产生了类似的结果。尽管蛋白酶二聚化在所有逆转录病毒系统中具有不变的性质，但重要的生物学和结构问题仍未得到解答。首先，虽然结构研究已经确定了参与二聚体界面的残基，但尚未研究特定氨基酸在促进和维持二聚体形成中的作用。其次，大量的结构和生物学信息表明，有序的蛋白酶介导的前体加工，颗粒组装和感染性之间存在密切联系。然而，蛋白酶二聚化和随后的酶活化对颗粒组装和感染性的确切影响尚不清楚。最后，尽管临床上可用的基于底物的HIV蛋白酶抑制剂对疾病进展产生了巨大影响，但在用这些活性位点定向化合物治疗的患者中经常出现耐药变体。迫切需要抑制剂设计的新方法来开发其他有效的治疗剂。在下面描述的研究中，我们将确定维持HIV蛋白酶二聚体的关键相互作用以及最终结构在病毒复制中的作用。此外，我们将探索通过破坏二聚体形成来抑制病毒蛋白酶的新策略。总的来说，我们的研究将为蛋白酶结构，酶功能和逆转录病毒生物学提供重要的见解。具体而言，我们将： I. 定义单个氨基酸在二聚体形成中的作用。 二.表征F-IIV蛋白酶二聚体界面中的取代对病毒复制的影响。 伊利。将GagPol中的HIV蛋白酶活化表征为潜在的抑制靶标。

DESCRIPTION (provided by applicant): Activation of the HIV-1 protease is an essential step in viral replication. As is the case for all retroviral proteases, enzyme activity requires the formation of protease homodimers. Mutations that block dimerization interfere with the protease function; viral variants encoding non-functional enzymes are aberrantly assembled and non-infectious. In vitro studies of compounds that inhibit the enzyme from dimerizing produce similar results. Despite the invariant nature of protease dimerization across all retroviral systems, important biological and structural questions remain unanswered. First, although structural studies have identified the residues involved in the dimer interface, the role of specific amino acids in promoting and maintaining dimer formation has not been examined. Second, a wealth of structural and biological information suggests that there is a close association between ordered, protease-mediated precursor processing, particle assembly and infectivity. However, the precise effect of protease dimerization and subsequent enzyme activation on particle assembly and infectivity is unclear. Finally, although clinically available substrate-based inhibitors of the HIV protease have made a dramatic impact on disease progression, resistant variants frequently arise in patients treated with these active site-directed compounds. Novel approaches to inhibitor design are urgently needed to develop additional effective therapeutic agents. In the studies described below, we will define the interactions critical for maintenance of the HIV protease dimer and the role that the final structure plays in viral replication. Further, we will explore novel strategies for inhibition of the viral protease through disrupting dimer formation. Overall, our studies will provide important insights into protease structure, enzyme function and retroviral biology. Specifically, we will: I. Define the role of individual amino acids in dimer formation. II. Characterize the effect of substitutions in the F-IIV protease dimer interface on viral replication. IlI. Characterize HIV protease activation within GagPol as a potential target for inhibition.