SYNTHESIS OF ACTIVE SITE-DIRECTED SRC INHIBITORS

Pp60c-src(Src)是一种蛋白酪氨酸激酶(PTK)，已被证明 在几种癌症中活跃度升高，包括乳腺癌， 结肠、肺和其他组织，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，特别是 靶向pp60c-src，用于治疗具有 这种PTK的活性升高。由于活动性的差异 在肿瘤和正常组织之间，我们认为pp60c-src的抑制剂将 一般毒性低，具有很大的治疗潜力。自.以来 PTKs的天然底物是蛋白质，我们的工作旨在 多肽类抑制剂的研究进展。需要检验的主要假设 在这个建议中，通过了解多肽的结合模式 我们的目标酶的抑制剂，我们可以开发活性部位定向的，小的 与酶结合的分子肽链抑制剂增加 亲和力和增强的生物利用度。我们的战略是紧凑发展 结合多肽，确定它们在溶液中的自由构象和 当结合到酶上时，并从这个信息设计模拟多肽 抑制剂。我们已经开发出一种环十肽，它可以作为一种 是pp60c-src的竞争性抑制物，Kii+640 nM， 与其他PTKs和对照相比，该酶对该酶具有很强的选择性 酵素。在这项建议中，我们的努力将分为两大部分 区域，(1)进一步了解或的相互作用的性质 具有酶活性部位的多肽，使用附加类似物作为 以及核磁共振和分子建模，以及(2)使用这些信息来 设计非肽类抑制剂。从迄今进行的核磁共振研究和 关于胰岛素受体激酶的结构，我们提出了假说 多肽的结合方式，并设计了化合物的测试 这个假说。进一步的核磁共振研究将提供更详细的结构 这些信息将用于模拟肽类抑制剂的设计。 此外，我们正在开发基于机制的(自杀)抑制剂组 加入我们的多肽模拟物中。来自生物界的反馈 测试和结构研究将使继续改进成为可能 我们的抑制剂。这些化合物被带到临床前动物试验中 将在我们的实验室中以多克的数量合成。

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.