MECHANISM-BASED ENZYME INHIBITORS: NOVEL ANTIFOLATES

拟议中的项目是旨在进行长期研究的一部分。 在开发新的化疗方法时 增殖性疾病。这项研究的主要目的是 将机械方面的考虑应用于设计和后续工作 新型抗叶酸的研究。这项研究的重点是 叶酸和抗叶酸的聚γ-谷氨酸链 辅因子活性和/或细胞毒性，作为药物设计的基础。 作为特定的靶点，酶的两个代谢周期，一个 负责聚古胺盐的形成和分解 另一种是叶酸多聚谷氨酸依赖 胸腺嘧啶酸的生物合成已经被选择。 该项目的化学部分涉及到合理的设计， 新型抗叶酸酯的合成与表征。对.的使用 计算机化的分子建模技术计划获得 洞察靶标酶的活性部位及其 利用过去和未来与候选药物的互动 结构-活性关联和X射线结晶学 结构信息。这些化学研究是与 涉及代谢和酶学的生化研究 叶基和反叶基聚谷氨酸酯以及对 新合成化合物的酶抑制活性 化合物。这些研究使用完整和可逆的 通透性L1210小鼠白血病细胞及其分离的酶 系统。透气性细胞系统可直接研究 叶酸和叶酸多聚谷氨酸的细胞代谢 类似物及其与完整代谢酶的相互作用 小路。化合物的细胞毒性在 体外测定L1210细胞的生长抑制程度 悬浮培养中的白血病细胞。这是一个重要的目标 将细胞和游离酶抑制联系起来的项目 体外细胞毒性数据的活性，并使用这些 预测体内生物活性的相关性。结果是 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。 除了它们潜在的治疗作用外，拟议的 类似物可以作为研究本质的有用工具。 多聚谷氨酰化在癌细胞中的作用。药物研究-- 酶的相互作用可能会加深我们对催化作用的了解 叶酸依赖酶的作用机制及提供新的 抑制剂设计的基本原理。因为叶酸代谢是 与核酸生物合成和细胞密切相关 ，这项研究可能会导致重要的观察结果 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.