Inhibitors Targeting HIV Integrase Multimers

描述（由申请人提供）：对当前抗HIV药物具有耐药性的HIV表型的不断出现表明需要开发具有替代抑制机制的新疗法。HIV整合酶（IN）通常被认为是一个重要的抗病毒靶点，原因如下：它的催化活性是病毒复制所必需的，没有与IN密切相关的细胞等价物，特异性的IN抑制剂可能对目前可用疗法耐药的病毒株有效。本研究的重点是开发HIV IN多聚体作为新的治疗靶点。我的方法的主要新颖之处在于稳定而不是破坏非活性构象中的IN多聚体。我最近的发现证明了这一点的基本原理，该发现表明，为了在病毒DNA存在下形成功能性多聚体，未配体的IN亚基必须具有高度的动态和灵活性。限制IN的柔韧性会对其催化活性产生不利影响。作为原理证明，我已经报道了一种小分子抑制剂（化合物1），它有效地结合在IN二聚体界面上，并将相互作用的亚基稳定为非活性构象。这些发现使我提出了以下假设：HIV IN具有独特的结构口袋，可以被小分子选择性地靶向，通过将IN锁定在非生产性多聚体状态来抑制病毒整合。为了解决这一假设，我的初步研究已经在IN二聚体界面上确定了两个适合结合小变容抑制剂的单独位点（这里称为“底部”和“侧面”口袋）。目的1将侧重于增加化合物1对“底部”口袋的结合特异性和亲和力；目标2将合理设计新的变构分子，选择性地结合“侧”口袋。

DESCRIPTION (provided by applicant): The continuous emergence of HIV phenotypes resistant to the current anti-HIV drugs dictates a need to develop new therapies with alternative mechanisms of inhibition. HIV integrase (IN) is commonly viewed as an important antiviral target for the following reasons: its catalytic activities are required for viral replication, there is no closely related cellular equivalent of IN, and specific IN inhibitors are likely to be effective against viral strains resistant to currently available therapies. The present proposal focuses on exploiting HIV IN multimers as a new therapeutic target. The main novelty of my approach is to stabilize rather than destabilize IN multimers in the inactive conformation. The rationale for this has been provided by my recent findings which demonstrated that unliganded IN subunits have to be highly dynamic and flexible in order to form functional multimers in the presence of viral DNA. Restricting IN flexibility adversely affects its catalytic activities. As a proof of principle I have reported a small molecule inhibitor (compound 1) that effectively binds at the IN dimer interface and stabilizes interacting subunits into an inactive conformation. These findings led me to the following hypothesis: HIV IN possesses unique structural pockets that can be selectively targeted by small molecules to inhibit viral integration by locking IN into an unproductive multimeric state. To address this hypothesis, my preliminary studies have identified two separate sites (which are termed here as "bottom" and "side" pockets) at the IN dimer interface suitable for binding of small allosteric inhibitors. Aim 1 will focus to increase the binding specificity and affinity of compound 1 for the "bottom" pocket; aim 2 will rationally design new allosteric molecules selectively binding the "side" pocket. PUBLIC HEALTH RELEVANCE: Emergence of HIV-1 strains resistant to the current antiretroviral therapies is a serious clinical problem. Therefore, there is an urgent need to identify and validate new viral targets for drug discovery. One such target investigated in the present proposal is a multimeric structure of a key HIV-1 enzyme integrase.