SYNTHESIS OF ACTIVE SITE-DIRECTED SRC INHIBITORS

pp 60 c-src（Src）是一种蛋白酪氨酸激酶（PTK），已被证明 在几种癌症中具有升高的活性，包括乳腺癌， 结肠、肺和其他组织中，与正常组织相比。 的总体目的 我们的研究是开发新的化疗药物， 靶向pp 60 c-src，用于治疗具有 这种PTK的活性升高。 由于活动差异 在肿瘤和正常组织之间，我们认为pp 60 c-src的抑制剂将 全身毒性低，治疗潜力大。 以来 PTK的天然底物是蛋白质，我们的工作旨在 肽基抑制剂的开发。 待检验的主要假设 通过了解肽的结合模式 我们的目标酶的抑制剂，我们可以开发活性位点定向，小 分子肽模拟物抑制剂，其与酶结合， 亲和性和增强的生物利用度。 我们的战略是发展紧密的 结合肽，确定它们在溶液中游离的构象， 当与酶结合时，并根据此信息设计肽模拟物 抑制剂的 我们开发了一种环状十肽，可以作为 “前导”肽，其是pp 60 c-src的竞争性抑制剂，Kii+640 nM， 相对于其他PTK和对照， 内切酶 在这一建议中，我们的努力将分为两大部分。 （1）进一步了解相互作用的性质， 使用另外的类似物， 以及NMR和分子建模，和（2）使用这些信息， 设计非肽类抑制剂。 根据迄今为止进行的NMR研究， 胰岛素受体激酶的结构，我们提出了假设 的肽的结合模式，并已设计的化合物进行测试 这个假设。 进一步的NMR研究将提供更详细的结构 这些信息将用于肽模拟物抑制剂的设计。 此外，我们正在开发基于机制的（自杀）抑制剂组 被整合到我们的肽模拟物中。 生物学的反馈 测试以及结构研究将使不断完善 我们的抑制剂。 这些化合物用于临床前动物试验 将在我们的实验室里以数克的数量合成。

pp60c-src (Src) is a protein tyrosine kinase (PTK) that has been shown to have elevated activity in several cancers, including cancers of the breast, colon, lung and others, compared to normal tissues. The overall purpose of our research is to develop new chemotherapeutic agents, specifically targeted to pp60c-src, to be used in the treatment of tumors that possess elevated activity of this PTK. Because of the activity differential between tumor and normal tissue, we feel that inhibitors of pp60c-src will have low general toxicity and great therapeutic potential. Since the natural substrates of PTKs are proteins our work is aimed at the development of peptide-based inhibitors. The major hypothesis to be tested in this proposal is that by understanding the modes of binding of peptide inhibitors of our target enzyme, we can develop active-site directed, small molecule peptidomimetic inhibitors that bind to the enzyme with increased affinity and enhanced bioavailability. Our strategy is to develop tight binding peptides, determine their conformations both free in solution and when bound to the enzyme, and from this information design peptidomimetic inhibitors. We have developed a cyclic decapeptide which serves as a "lead" peptide which is a competitive inhibitor of pp60c-src, Kii+640 nM, and which is very selective for this enzyme versus other PTKs and control enzymes. In this proposal our efforts will be divided into two major areas, (1) further understanding the nature of the interactions of or peptides with the active site of the enzyme using additional analogues as well as NMR and molecular modeling, and (2) usage of this information to design non-peptidic inhibitors. From NMR studies carried out to date and the structure of the insulin receptor kinase, we have developed hypotheses of the modes of binding of the peptide and have designed compounds o test this hypothesis. Further NMR studies will provide more detailed structural information that will be used in the design of peptidomimetic inhibitors. Additionally, we are developing mechanism-based (suicide) inhibitor groups to be incorporated into our peptide mimetics. Feedback from the biological testing as well as the structural studies will enable continuing refinement of our inhibitors. Those compounds taken to pre-clinical animal testing will be synthesized in multi-gram quantities in our laboratories.