MECHANISM-BASED ENZYME INHIBITORS: NOVEL ANTIFOLATES

拟议的项目是长期研究工作的一部分， 新的化疗方法的发展， 增殖性疾病 本研究的主要目的是 在设计中考虑机械因素， 新型抗叶酸剂研究。 本研究着重于 叶酸和抗叶酸剂的聚-γ-谷氨酰链 辅因子活性和/或细胞毒性，作为药物设计的基础。 作为特异性靶标，两个代谢循环的酶，一个 负责多谷氨酸盐的形成和分解 另一种是叶酸聚谷氨酸依赖型 选择了胸苷酸的生物合成。 化工部分工程涉及合理设计， 新型叶酸拮抗剂合成与表征 使用 计算机化分子模拟技术计划获得 深入了解目标酶的活性位点及其 利用过去和未来与候选药物的相互作用 构效关系和X射线晶体学 结构信息。 化学研究与 涉及代谢和酶学的生物化学研究 Folyl和antifolyl聚谷氨酸盐的研究以及对Folyl聚谷氨酸盐的评价 新合成的酶抑制活性 化合物. 这些研究采用了完整的和可逆的 透化的L1210小鼠白血病细胞和分离的酶 系统. 透化细胞系统使得直接研究成为可能 多聚谷氨酸盐的细胞代谢 类似物及其与完整代谢酶的相互作用 途径。 化合物的细胞毒性是在 通过测量L1210的生长抑制程度体外 悬浮培养的白血病细胞。 这是一个重要的目标， 将细胞和无细胞酶抑制剂 活性与体外细胞毒性数据，并使用这些 相关性来预测体内生物活性。 的结果 这项研究将有助于制定未来的研究计划，包括 治疗应用的可能性。 除了潜在的治疗效用外， 类似物可以作为有用的工具，在研究的基本 多聚谷氨酰化在癌细胞中的作用。 药物的研究- 酶的相互作用可能会进一步我们的知识的催化 叶酸依赖性酶的作用机制并提供新的 抑制剂设计的基本原理。 由于叶酸代谢是 与核酸生物合成和细胞生物学密切相关 扩散，这项研究可能会导致重要的观察， 肿瘤生物学

The proposed project is part of a long range research effort aimed at the development of new approaches to the chemotherapy of proliferative diseases. The main objective of this research is to apply mechanistic considerations to the design and subsquent study of novel antifolates. The study focuses on the role of the poly-gamma-glutamyl chain of folates and antifolates in their cofactor activity and/or cytotoxicity, as a basis for drug design. As specific targets, enzymes of two metabolic cycles, one responsible for the formation and breakdown of polygultamates and the other for the folate polyglutatmate dependent biosynthesis of thymidylate have been chosen. The chemical part of the project involves the rational design, synthesis and characterization of new antifolates. The use of computerized molecular modelling techniques is planned to gain insight into the active sites of target enzymes and their interaction with drug candidates utilizing past and future structure-activity correlations and x-ray crystallographic structural information. The chemical studies are coordinated with the biochemical studies involving the metabolism and enzymology of folyl and antifolyl polyglutamates as well as the evaluation of the enzyme inhibitory activities of the newly synthesized compounds. These studies employ intact and reversibly permeabilized L1210 murine leukemia cells and isolated enzyme systems. The permeabilized cell system premits the direct study of the cellular metabolism of polyglutamates of folates and folate analogues and their interaction with enzymes of intact metabolic pathways. The cytotocicity of the compounds is determined in vitro by measuring the extent of growth inhibition of L1210 leukemia cells in suspension cultures. It is an important goal of the project to correlate cellular and cell-free enzyme inhibitory activity with in vitro cytotoxicity data and to use these correlations to predict in vivo biological activity. The results of this study will help to formulate future research plans including the possibility of therapeutic applications. In addition to their potential therapeutic utility, the proposed analogues may serve as useful tools in the study of the essential role of polyglutamylation in cancer cells. The study of drug- enzyme interactions may further our knowledge of the catalytic mechansms of folate dependent enzymes and furnish new rationales for inhibitor design. Since folate metabolism is intimately linked to nucleic acid biosynthesis and Cellular proliferation, this research may lead to important observations in tumor biology.