High-throughput Computational Docking Screen for Small-molecule Inhibitors of HIV

描述（由申请人提供）：尽管抗HIV治疗最近取得了进展，但在HIV感染患者的长期治疗期间，药物毒性和耐药分离株的出现使寻找可用于开发新型抗病毒剂的新靶点成为必要。HIV-1基质蛋白（MA）是一种结构蛋白，参与逆转录病毒生命周期的几个阶段。虽然MA长期以来一直被认为是病毒体组装的关键，但有关这一功能的细节以及负责介导它的结构域仍在不断涌现。MA还参与了HIV-1 cDNA的核输入，最近还参与了感染过程中的新作用，包括病毒进入/脱壳，细胞内介导的运输，以及靶向病毒组装到脂筏。MA在HIV-1感染中的重要性及其作为抗病毒靶点的潜力已经通过两种旨在阻断其功能的策略的成功证明，一种是基于胞内抗体的方法，另一种是使用小分子的较新方法。鉴于这些研究的成功和HIV-1 MA功能的广泛性，我们使用了高通量计算对接（HTCD）方法来鉴定可能与HIV-1 MA结合并破坏其功能的小分子。从这个HTCD筛选，我们已经确定了19个小分子，预计结合HIV-1 MA的结构和功能的重要区域。从这19种化合物中，我们确定了8种具有抗病毒活性。重要的是，显示抗病毒活性的化合物可以分为三类：早期抑制剂，晚期抑制剂和两种似乎破坏早期和晚期事件的化合物。据我们所知，这些化合物代表了第一个可以破坏HIV-1复制周期早期和晚期过程的小分子抑制剂。在该提案中，我们希望通过研究MA上的结合亲和力、化学计量和结合位点（具体目标1）以及确定其范围、特异性和作用机制（具体目标2），建立适合通过药物化学进一步优化的MA靶向化合物。我们相信，这种跨学科策略的执行将成功地确定可用于深入了解HIV-1 MA蛋白的生物学功能，特别是其在HIV-1生命周期早期整合前阶段的作用的非常有用的试剂。此外，从这项研究中鉴定出的小分子有望成为一类新抗病毒剂的先导化合物。 公共卫生相关性：尽管抗逆转录病毒药物疗法取得了成功，但抑制HIV-1复制的新目标是非常可取的，需要新的药物来解决日益严重的耐药性问题。本申请中提出的研究将表征一类靶向HIV-1基质（MA）蛋白的化合物，这些化合物通过一种新的机制在HIV-1生命周期的多个阶段发挥作用。该提案中确定的化合物有可能作为新型抗HIV药物的模板，同时也提供了剖析HIV-1基本生物学的试剂。

DESCRIPTION (provided by applicant): Despite recent progress in anti-HIV therapy, drug toxicity and the emergence of drug-resistant isolates during long-term treatment of HIV-infected patients necessitate the search for new targets that can be used to develop novel antiviral agents. The HIV-1 matrix protein (MA) is a structural protein involved in several stages in the life cycle of the retrovirus. Although MA has long been known to be crucial for virion assembly, details regarding this function, and the domains responsible for mediating it, are still emerging. MA has also been implicated in nuclear import of HIV-1 cDNA and has recently been implicated in novel roles during infection including viral entry/uncoating, cytoskeletal-mediated transport, and targeting viral assembly to lipid rafts. The importance of MA in HIV-1 infection and its potential as an antiviral target have been demonstrated by the success of two strategies designed to block its function, one intrabody-based and another, more recent approach using small molecules. Given the success of these studies and the breadth of functions of HIV-1 MA, we have used a high-throughput computational docking (HTCD) approach to identify small molecules that may potentially bind to and disrupt the functions of HIV-1 MA. From this HTCD screen, we have identified 19 small molecules that are predicted to bind to HIV-1 MA in a structurally and functionally important region. From these 19 compounds, we have determined that eight possess antiviral activity. Importantly, the compounds that display antiviral activity can be grouped into three classes: early-stage inhibitors, late-stage inhibitors, and two compounds that appear to disrupt both early and late events. To our knowledge, these compounds represent the first small-molecule inhibitors that can disrupt both early- and late-stage processes in the replication cycle of HIV-1. In this proposal, we wish to establish the MA-targeted compounds that are suitable for further optimization via medicinal chemistry by investigating their binding affinity, stoichiometry, and binding site on MA (Specific Aim 1) in addition to determining their range, specificity, and mechanism of action (Specific Aim 2). We believe that execution of this cross-disciplinary strategy will successfully identify pharmacologically useful reagents that can be used to gain insight into the biological functions of HIV-1 MA protein, especially its role(s) in the early, pre-integration stage of the HIV-1 life cycle. Moreover, small molecules identified from this study hold promise as lead compounds for a new class of antiviral agent. PUBLIC HEALTH RELEVANCE: Despite the success of antiretroviral drug regimens, new targets for inhibition of HIV-1 replication are highly desirable, and new drugs are needed to combat the rising problem of drug resistance. The studies proposed in this application will characterize a class of compounds targeted at the HIV-1 matrix (MA) protein and that act via a novel mechanism at multiple stages in the HIV-1 life cycle. The compounds identified within this proposal have the potential to serve as templates for novel anti-HIV agents while also providing reagents with which to dissect the basic biology of HIV-1.