Covalently reactive CD4 mimetics for inhibition of HIV

抑制 HIV 的共价反应性 CD4 模拟物

• 批准号: 6745369
• 负责人: Carl Veith Hanson
• 金额: $ 10.7万
• 依托单位: PUBLIC HEALTH FOUNDATION ENTERPRISES
• 依托单位国家: 美国
• 财政年份: 2004
• 资助国家: 美国
• 起止时间: 2004-02-01 至 2006-01-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6745369
• 关键词: CD4 molecule; HIV envelope protein gp120; SDS polyacrylamide gel electrophoresis; antiAIDS agent; biomimetics; biotechnology; biotin; cell fusion; covalent bond; human immunodeficiency virus; human tissue; immunoprecipitation; peptide structure; virion

DESCRIPTION (provided by applicant): Therapeutic administration of soluble CD4 is theoretically an attractive means of competitively inhibiting the binding of HIV to its primary cellular receptor, but was a failure in clinical trials more than a decade ago. We propose the creation of novel CD4 analogs to overcome the stoichiometric and affinity limitations of that initial approach. Using electrophilic phosphonate ester probes, we recently discovered that HIV gp120 contains activated nucleophilic amino acids. In the proposed studies, CD4 (and CD4 peptide mimetic, s) will be modified by the addition of activated electrophilic phosphonates, which will result in specific covalent bonding of these constructs to nucleophilic sites on gp120 on the surface of HIV virions. Such an "infinite" affinity interaction will result in irreversible blocking of HIV infectivity. The concept is based on our successful analogous work on catalytic antibodies, in which nucleophilic immunoglobulin sites bind to electrophiles in the substrate ligand. Thus the Specific Aims of this proposed Innovation Grant are (1) to create covalently reactive CD4 and CD4 peptide mimetics; (2) to determine the potency, intra- and intersubtype breadth and irreversibility of HIV neutralization and inhibition of cell-to-cell spread of HIV infection via cell fusion by these covalently reactive CD4 analogues; (3) to demonstrate the irreversibility of binding of the constructs to gp120 and to intact virions; and (4) to determine the role in the virus neutralization that isplayed by the covalency (vs. conventional noncovalent antibody binding). Successful results should lead tofollow-up testing in primate models and human clinical trials. The proposed studies may also help to definecovalent and pseudocovalent forces as a novel mechanism of protein-ligand interactions.

描述（由申请人提供）：可溶性 CD4 的治疗性施用理论上是竞争性抑制 HIV 与其主要细胞受体结合的一种有吸引力的方法，但在十多年前的临床试验中失败了。我们建议创建新型 CD4 类似物，以克服该初始方法的化学计量和亲和力限制。使用亲电膦酸酯探针，我们最近发现 HIV gp120 含有活化的亲核氨基酸。在拟议的研究中，CD4（和 CD4 肽模拟物，s）将通过添加活化的亲电子膦酸盐进行修饰，这将导致这些构建体与 HIV 病毒颗粒表面 gp120 上的亲核位点形成特异性共价键合。这种“无限”的亲和力相互作用将导致不可逆地阻断HIV感染性。该概念基于我们在催化抗体方面成功的类似工作，其中亲核免疫球蛋白位点与底物配体中的亲电子试剂结合。因此，本次创新资助计划的具体目标是 (1) 创建共价反应性 CD4 和 CD4 肽模拟物； (2) 确定这些共价反应性 CD4 类似物通过细胞融合实现 HIV 中和和抑制 HIV 感染的细胞间传播的效力、亚型内和亚型间广度以及不可逆性； (3) 证明构建体与 gp120 和完整病毒体结合的不可逆性； (4)确定共价键在病毒中和中的作用（相对于传统的非共价抗体结合）。成功的结果应该会导致灵长类动物模型和人体临床试验的后续测试。拟议的研究还可能有助于将共价和伪共价力定义为蛋白质-配体相互作用的新机制。