Structure-Based CD-4-gp120 Antagonism

描述（由申请人提供）：本项目的中心目标是利用gp120/CD4/mAb17b复合体的结构和基于结构的模拟物来设计HIV-1与人类细胞相互作用的拮抗剂。HIV-1的t细胞对接和进入是艾滋病细胞感染的主要途径，它是由HIV包膜蛋白gp120特异性识别t细胞表面蛋白CD4和趋化因子辅助受体驱动的。CD4的晶体结构是已知的，它与gp120和辅助受体替代抗体17b的复合物也是已知的。揭示了gp120与CD4和辅助受体结合位点的结构性质和相互关系。对病毒细胞识别蛋白参与者的高分辨率结构理解和先进的模拟设计技术使得结合结构测定、建模、微小蛋白工程、有机合成和热力学分析设计新的HIV- 1感染拮抗剂以及阐明gp 120/CD4/辅助受体分子网络中的识别机制成为可能。本提案的具体目标是：(1)通过现有高分辨率结构的计算建模和蛋白质伴侣的结构预测来确定CD4-gp120和gp120共受体界面的结合位点；(2)通过化学和重组DNA方法将CD4、gp120和辅受体/l7b结合位点结构元件移植到构象受限的微型蛋白构建体中，获得微型蛋白模拟物，并利用这些结构元件定义驱动相互作用网络形成的最小结构元件；(3)通过结构驱动和多样性驱动的设计方案生成cd4 - gp120界面的肽基和非肽基探针；(4)表征gp 120/CD4/辅助受体网络中的识别热力学，并制定设计gp 120拮抗剂的热力学指南，以保持对自然发生的多态性和潜在的耐药HIV-1突变体的活性；(5)利用高分辨率结构、建模、热力学、微小蛋白和限制性拟肽等确定的关键结构元件，设计HIV感染和艾滋病发病机制的CD4小分子拮抗剂。HIV-1包膜与宿主细胞受体结合的结构驱动力和新的艾滋病候选药物。从长远来看，衍生的模拟策略将有助于设计其他相互作用的拮抗剂，如gp120- gp41和gp120- dc - sign，这些拮抗剂也与人类细胞- hiv -1附着和病毒进入有关。总体而言，本项目将为蛋白质模拟物的构建、先进的定义技术提供关键。

DESCRIPTION (provided by applicant): The central objective of this Program Project is to use the structure of the gp120/CD4/mAb17b complex and structure-based mimetics to design antagonists of the interaction of HIV-1 with human cells. T-cell docking and entry by HIV-1, a major route of cell infection in AIDS, is driven by specific recognition of T-cell surface protein CD4 and chemokine coreceptor by HIV envelope protein gp120. The crystallographic structure of CD4 is known, as is its complex with gp120 and the coreceptor surrogate antibody 17b. The structural nature and interrelationship of gp120 binding sites for CD4 and coreceptor have been revealed. The advancing high-resolution structural understanding of the protein participants in virus-cell recognition together with the advancing technology of mimetics design make it possible to combine structure determination, modeling, miniprotein engineering, organic synthesis and thermodynamics analysis to design new antagonists for HIV- 1 infection as well as to elucidate recognition mechanisms in the gp 120/CD4/coreceptor molecular network. The specific aims of this proposal are: (1) identify binding sites in the CD4-gp120 and gp120-coreceptor interfaces by computational modeling of existing high-resolution structures and structural predictions of the protein partners; (2) transplant CD4, gp120 and coreceptor/l7b binding site structural elements into conformationally constrained miniprotein constructs by chemical and recombinant DNA approaches to obtain miniprotein mimetics and use these to define the minimal structural elements driving formation of the interaction network; ( 3 ) generate peptidyl and nonpeptidyl probes of CD4-gp 120 interface via structure-driven and diversity- driven design schemes; (4) characterize the thermodynamics of recognition in the gp 120/CD4/coreceptor network and develop thermodynamic guidelines for design of gp 120 antagonists that maintain activity against naturally occurring polymorphisms and potential drug-resistant HIV-1 mutants; ( 5 ) utilize key structural elements as determined from high resolution structure, modeling, thermodynamics, miniproteins and constrained peptidomimetics to design small molecule CD4 antagonists for HIV infection and AIDS pathogenesis. structural driving forces of HIV-1 envelope attachment with host cell receptors and new drug candidates for AIDS. Long term, the mimetics strategies derived will be useful to design antagonists of other interactions, such as gp120- gp41 and gp120-DC-SIGN, that also are associated with human cell-HIV-1 attachment and viral entry. Overall, this project will yield technologies for protein mimetics construction, advanced definition of key.