HIV-1 entry inhibitors targeting Phe43 cavity in gp120

描述(申请人提供)：两个最近解决的HIV-1gp120与CD4络合的X射线晶体结构和一个人中和抗体17b的Fab片段提供了CD4和gp120之间相互作用的结构细节，并揭示了在gp120中存在一个巨大的疏水空腔，其中CD4的Phe43结合(Phe43空腔)。该项目的目标是使用基于结构的方法来确定将结合到这个空腔的小分子先导化合物，以阻止CD4-gp120相互作用并防止HIV-1进入宿主细胞。这项建议的具体目标如下：(1)通过对大型数据库的虚拟筛选，识别对接到gp120中的CD4结合腔(Phe43腔)中的小分子。自动分子对接技术将被用作一种虚拟筛选工具，只选择那些适合进入空腔并与gp120中的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结合的先导HIV-1进入抑制剂。潜在的先导化合物将通过两步法选出供进一步研究：(A)从虚拟筛选中选出的化合物将通过高通量酶联免疫吸附试验(ELISA)进行检测，以确定与gp120结合并阻断gp120与CD4结合的抑制剂，以及(B)从(A)中选出的抑制剂将进一步筛选出对HIV-1介导的细胞融合和细胞病变(CPE)的抑制活性以及体外细胞毒性。(3)优化先导化合物以产生有效的抗HIV-1药物。最好的先导化合物将通过重点文库的设计和构效分析(SAR)进一步优化。总体而言，该项目将产生新的先导化合物，作为潜在的艾滋病毒-1进入抑制剂。这项建议的长期目标是通过化学合成和结构活性分析来优化先导化合物，并选择3-4个最佳化合物作为新型i抗HIV-1化疗药物进行进一步的临床前研究。

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.