HIV-1 entry inhibitors targeting Phe43 cavity in gp120

描述（由申请人提供）：最近发现的两个HIV-1 gp120与CD4络合的x射线晶体结构和人类中和抗体17b的Fab片段提供了CD4与gp120相互作用的结构细节，并揭示了gp120中存在一个大的疏水腔，其中CD4的Phe43结合（Phe43腔）。该项目的目标是使用基于结构的方法来鉴定小分子先导化合物，这些先导化合物将结合到该空腔以阻断CD4-gp120相互作用并阻止HIV-1进入宿主细胞。本提案的具体目的如下：(1)通过大型数据库的虚拟筛选，识别停靠在gp120中CD4结合腔（Phe43腔）的小分子。自动分子对接技术将作为一种虚拟筛选工具，只选择那些适合进入空腔并与gp120中CD4结合位点相互作用的化合物。(2)通过免疫学和病毒学筛选试验，鉴定阻断gp120与CD4结合的HIV-1进入抑制剂。潜在的先导化合物将通过两个步骤进行选择，以进行进一步的研究：(a)从虚拟筛选中选择的化合物将通过高通量酶联免疫吸附试验（ELISA）进行分析，以确定与gp120结合并阻断gp120与CD4结合的抑制剂，(b)从(a)中选择的抑制剂将进一步筛选对HIV-1介导的细胞融合和细胞病变效应（CPE）的抑制活性，以及体外细胞毒性。(3)优化制备抗hiv -1药物的先导化合物。通过重点文库设计和结构活性分析进一步优化最佳先导化合物。总的来说，这个项目将产生新的先导化合物，作为潜在的HIV-1进入抑制剂。本课题的长期目标是通过化学合成和结构活性分析对先导化合物进行优化，并筛选出3-4个最佳化合物作为新型抗hiv -1化疗药物进行临床前研究。

DESCRIPTION (provided by applicant): Two recently solved x-ray crystal structures of HIV-1 gp120 complexed with CD4 and the Fab fragment of a human neutralizing antibody 17b provided structural details of the interactions between CD4 and gp120 and revealed the presence of a large hydrophobic cavity in gp120 where Phe43 of CD4 binds (Phe43 cavity). The objective of this project is to use a structure-based approach to identify small molecular lead compounds that will bind to this cavity to block the CD4-gp120 interaction and prevent HIV-1 entry to host cells. The specific aims of this proposal are as follows: (1) To identify, by virtual screening of large databases, small molecules that dock into the CD4 binding cavity (Phe43 cavity) in gp120. The automated molecular docking technique will be used as a virtual screening tool to select only those compounds that fit into the cavity and interact with the CD4 binding site in gp120. (2) To identify, by immunological and virological screening assays, lead HIV-1 entry inhibitors that block gp120 binding to CD4. The potential lead compounds will be selected by a two-step process for further studies: (a) the selected compounds from virtual screening will be assayed by high throughput enzyme-linked immunosorbent assays (ELISA) to identify inhibitors that bind to gp120 and block gp120 binding to CD4, and (b) the selected inhibitors from (a) will be further screened for inhibitory activity against HIV-1 mediated cell fusion and cytopathic effects (CPE), and for in vitro cytotoxicity. (3) To optimize lead compounds for generating potent anti-HIV-1 agents. The best lead compounds will be optimized further through design of focused libraries and structure-activity analysis (SAR). Overall, this project will yield new lead compounds acting as potential HIV-1 entry inhibitors. The long-term goal of this proposal is to optimize the lead compounds through chemical synthesis and structure activity analyses and select 3-4 best compounds for further preclinical studies as novel ianti-HIV-1 chemotherapeutic agents.