Design of SMAC Peptidomimetics and Nonpeptidic Mimetics

SMAC 肽模拟物和非肽模拟物的设计

• 批准号: 6908072
• 负责人: SHAOMENG WANG
• 金额: $ 28.23万
• 依托单位: UNIVERSITY OF MICHIGAN AT ANN ARBOR
• 依托单位国家: 美国
• 财政年份: 2004
• 资助国家: 美国
• 起止时间: 2004-07-01 至 2008-04-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6908072
• 关键词: X ray crystallography; antineoplastics; apoptosis; binding proteins; biomimetics; biotechnology; biotherapeutic agent; cysteine endopeptidases; drug design /synthesis /production; enzyme activity; fluorescence polarization; membrane permeability; mitochondria; neoplastic cell; nuclear magnetic resonance spectroscopy; peptide chemical synthesis; pharmacokinetics; protein binding; protein protein interaction; protein structure function

DESCRIPTION (provided by applicant): Smac/DIABLO was recently discovered as a potent pro-apoptotic protein released from mitochondria. Smac functions as an endogenous antagonist for the Inhibitors of Apoptosis Proteins (lAPs) by binding to the BIR3 domain of X-linked lAP (XIAP) and other lAP proteins and displace caspase-9 from this site. High resolution 3D structures of Smac in complex with the BIR3 domain of XIAP showed that the interaction between them is mediated by only four Smac residues at its N-terminus and a small but well-defined binding groove in the XIAP BIR3 domain, which is suitable for designing small molecule inhibitors. Several recent studies have shown that short Smac peptides (4-8 residues) tethered to a carrier peptide for intra-cellular delivery are effective to overcome apoptosis-resistance of cancer cells in vitro and in vivo by directing targeting lAP proteins, while having no toxicity to normal tissues or to animals. Hence, Smac mimetics that bind to the BIR3 domain in XlAP where Smac and caspase-9 bind may have great therapeutic potential to be developed as an entirely new class of anticancer drugs through overcoming apoptosis-resistance of cancer cells as mediated by lAP protein overexpression. In this project, we propose to design, synthesize and characterize highly potent Smac peptido-mimetics and nonpeptidic mimetics with much improved cell permeability over Smac peptides through the following Specific Aims: Aim 1. (a). Structure-based design of Smac peptido-mimetics and nonpeptidic mimetics based upon the published high-resolution experimental structures of Smac in complex with XlAP BIR3. (b). Determination of high-resolution structures of several most potent Smac mimetics through X-ray crystallography. Aim 2. Chemical synthesis of these Smac mimetics designed in Aim 1. Aim 3. (a). Determination of the binding affinities of these Smac mimetics to the BIR3 domain of XIAP by the fluorescence polarization-based method; (b). Conclusive confirmation of the binding of the most potent Smac mimetics to the XlAP BIR3 protein by NMR methods. Aim 4. Investigation of the activity, specificity and molecular mechanisms of action of the most potent Smac mimetics. Designing highly potent and cell-permeable Smac mimetics is a new and exciting area of research. Our current proposed research represents the first but an essential step toward our long-term goal of developing a novel anticancer drug through targeting apoptosis-resistance in cancer cells mediated by lAP proteins.

描述（由申请人提供）：Smac/DIABLO 最近被发现是一种从线粒体释放的有效促凋亡蛋白。 Smac 通过与 X-连锁 lAP (XIAP) 和其他 lAP 蛋白的 BIR3 结构域结合，并从该位点取代 caspase-9，充当凋亡蛋白抑制剂 (lAP) 的内源性拮抗剂。 Smac 与 XIAP BIR3 结构域复合物的高分辨率 3D 结构表明，它们之间的相互作用仅由其 N 末端的 4 个 Smac 残基以及 XIAP BIR3 结构域中的小但明确的结合槽介导，这是合适的用于设计小分子抑制剂。最近的几项研究表明，与载体肽连接用于细胞内递送的短 Smac 肽（4-8 个残基）可通过直接靶向 lAP 蛋白，有效克服体外和体内癌细胞的凋亡抗性，同时无毒性对正常组织或动物。因此，与 XlAP 中 Smac 和 caspase-9 结合的 BIR3 结构域结合的 Smac 模拟物可能具有巨大的治疗潜力，可以通过克服 lAP 蛋白过度表达介导的癌细胞凋亡抵抗来开发为全新一类抗癌药物。在这个项目中，我们建议通过以下具体目标设计、合成和表征高效的 Smac 肽模拟物和非肽模拟物，其细胞渗透性比 Smac 肽大大提高： 目标 1.(a)。基于已发表的 Smac 与 XlAP BIR3 复合物的高分辨率实验结构的 Smac 肽模拟物和非肽模拟物的结构设计。 （二）。通过 X 射线晶体学测定几种最有效的 Smac 模拟物的高分辨率结构。 目标 2. 目标 1. 目标 3. (a) 中设计的这些 Smac 模拟物的化学合成。通过基于荧光偏振的方法测定这些 Smac 模拟物与 XIAP BIR3 结构域的结合亲和力； （二）。通过 NMR 方法最终确认最有效的 Smac 模拟物与 XlAP BIR3 蛋白的结合。目标 4. 研究最有效的 Smac 模拟物的活性、特异性和分子作用机制。 设计高效且具有细胞渗透性的 Smac 模拟物是一个令人兴奋的新研究领域。我们目前提出的研究代表了我们通过靶向 lAP 蛋白介导的癌细胞的凋亡抗性来开发新型抗癌药物的长期目标的第一步，也是至关重要的一步。