Design of inhibitors targeted to the CD4 binding site on HIV-1 gp120

针对 HIV-1 gp120 上 CD4 结合位点的抑制剂的设计

• 批准号: 8988530
• 负责人: Asim K Debnath
• 金额: $ 76.84万
• 依托单位: NEW YORK BLOOD CENTER
• 依托单位国家: 美国
• 财政年份: 2013
• 资助国家: 美国
• 起止时间: 2013-02-15 至 2018-01-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8988530
• 关键词: AIDS prevention; AIDS therapy; Acids; Affinity; Agonist; Antibodies; Antiviral Agents; Arginine; Aspartic Acid; Binding; Binding Sites; CD4 Antigens; Cell surface; Cells; Clinical Research; Collaborations; Complex; Computer Simulation; Data; Databases; Dissociation; Docking; Drug Design; Drug resistance; Electrostatics; Entropy; Evaluation; Glycoproteins; Goals; HIV Envelope Protein gp120; HIV-1; Half-Life; Health; Immunoglobulin Fragments; Infection; Intervention; Kinetics; Lead; Measures; Mediating; Nature; Pharmaceutical Chemistry; Pharmaceutical Preparations; Phenylalanine; Positioning Attribute; Property; Receptor Cell; Reporting; Research; Resistance; Role; Site; Sodium Chloride; Structure; Thermodynamics; Toxic effect; United States National Institutes of Health; Virus; base; clinically relevant; design; enthalpy; flexibility; glycosylation; improved; inhibitor/antagonist; innovation; interfacial; microbicide; mimicry; mutant; neutralizing antibody; next generation; novel; piperidine; pre-clinical; prevent; prophylactic; scaffold; screening; small molecule inhibitor; targeted treatment; virtual

DESCRIPTION (provided by applicant): The entry of HIV-1 into host cells is mediated by the binding of the envelope glycoprotein gp120 to the host cell receptor CD4. The structures of the gp120-CD4-17b complex indicate that the CD4 binding site (CD4BS) on gp120 is located in a hydrophobic cavity, termed "Phe43 cavity" where Phe43CD4 makes critical hydrophobic contacts. Studies of these structures also confirmed an important electrostatic interaction between Arg59CD4 and Asp368gp120. Similar structural mimicry of several potent broad neutralizing antibodies (bNAbs) has recently been reported. The highly conserved nature of the residues in the CD4BS of gp120 and their role in binding to CD4 and CD4BS targeted bNAbs validates this site as a promising target for therapeutic and prophylactic intervention. Despite th remarkable diversity of the HIV-1 envelope glycoprotein sequence, glycosylation and conformational flexibility, gp120 must retain conserved domains required for binding to CD4. However, the well-conserved CD4 binding site has yet to be exploited to its full potential as a target in designing drugs to prevent HIV-1 entry, which will be the focus of our research. We were the first to identify two small molecule inhibitors, NBD-556 and NBD-557, which target the CD4BS on gp120. These molecules show unprecedented ability to induce conformational changes in gp120 similar to that of CD4; thereby, acting as agonists. Recently, we solved the structure of NBD-556 in complex with the gp120 coree, confirming that NBD-556 binds to the cavity of gp120. We used this structure to design new leads with improved anti-HIV-1 activity. However, these lead compounds showed CD4 agonist properties. In additional studies, we confirmed that a newly designed lead, NBD-11021, is a CD4 antagonist. Moreover, a recent report showed that the bNAb PGV04 targets the CD4BS but induces distinct conformational changes in gp120 that are not recognized by the 17b antibody. PGV04 thus does not induce exposure of the coreceptor binding site, suggesting that it is a CD4 antagonist not an agonist. We hypothesize that lead compounds, including NBD-11021, can be optimized by incorporating the distinct binding features of PGV04 with gp120 to produce a more potent and selective new class of HIV-1 entry inhibitors with CD4 antagonist properties. The goals of the proposed studies will be accomplished by three highly integrated specific aims. In Aim-1, the leads will be optimized through structure-guided design and medicinal chemistry. In Aim-2, thermodynamic and kinetic properties such as enthalpy, entropy, on- and off-rates and binding affinity (KD) will be measured as well as their antiviral potency and toxicity. The x-ray structures of new inhibitors in complex with gp120 will be determined. In Aim-3, mechanism of action will be studied and the resistant mutants of the inhibitors will be selected. The data from these studies will be used in designing potent next-generation entry inhibitors that will potentially escape resistance and be clinically relevant. The long-term goal is to develop a new class of HIV-1 entry inhibitors for pre clinical and clinical studies.

描述（由申请人提供）：HIV-1进入宿主细胞的介导是由包膜糖蛋白GP120与宿主细胞受体CD4的结合介导的。 GP120-CD4-17B复合物的结构表明，GP120上的CD4结合位点（CD4B）位于疏水腔中，称为“ Phe43腔”，其中Phe43cd4与关键的疏水接触。对这些结构的研究还证实了ARG59CD4和ASP368GP120之间的重要静电相互作用。最近报道了几种有效的广泛中和抗体（BNAB）的类似结构模仿。 GP120 CD4B中残基的高度保守性质及其在与CD4和CD4B的靶向BNAB结合中的作用验证该部位是治疗和预防性干预的有希望的目标。尽管HIV-1包膜糖蛋白序列，糖基化和构象柔韧性的显着多样性，但GP120必须保留与CD4结合所需的保守域。但是，保存良好的CD4结合位点尚未被利用其全部潜力作为设计药物以防止HIV-1进入的目标，这将是我们研究的重点。我们是第一个识别两个小分子抑制剂NBD-556和NBD-557，它们靶向GP120上的CD4B。这些分子表现出了前所未有的诱导gp120中构象变化的能力，类似于CD4的构象变化。因此，充当激动剂。最近，我们解决了与GP120 Coree复合物中NBD-556的结构，证实NBD-556与GP120的腔结合。我们使用这种结构来设计具有改进的抗HIV-1活性的新导线。但是，这些铅化合物显示CD4激动剂特性。在其他研究中，我们证实了新设计的铅NBD-111021是CD4拮抗剂。此外，最近的一份报告表明，BNAB PGV04靶向CD4B，但诱导GP120中的明显构象变化，而17B抗体未识别。因此，PGV04不会诱导共感受器结合位点的暴露，这表明它是CD4拮抗剂而不是激动剂。我们假设可以通过将PGV04与GP120的独特结合特征合并到GP120中，以生成具有CD4拮抗剂CD4拮抗剂的更有效和选择性的新型HIV-1进入抑制剂，从而优化铅化合物，包括NBD-11121。拟议研究的目标将由三个高度综合的特定目标实现。在AIM-1中，将通过结构引导的设计和药物化学来优化铅。在AIM-2中，将测量热力学和动力学特性，例如焓，熵，偏置和离子和结合亲和力（KD），以及它们的抗病毒效能和毒性。新抑制剂的X射线结构 将确定与GP120的复杂性。在AIM-3中，将研究作用机理，并将选择抑制剂的抗性突变体。这些研究的数据将用于设计有效的下一代进入抑制剂，这些抑制剂可能会避免抵抗力并在临床上具有相关性。长期目标是为PRE开发新的HIV-1进入抑制剂 临床和临床研究。