CYCLOPROPYL METABOLITES, ENZYMATIC INHIBITION/FORMATION

已发现环丙基是重要的结构基团。 在各种各样的天然产品中。最近，许多小说 酶抑制剂和机械探针的设计是基于 该部分的固有环应变和相关性质。 对环丙基代谢物的独特生物活性感兴趣 以及它们作为治疗剂的潜在用途，我们已经进行了一项 研究环丙烷诱导的 酶失活 在过去几年里，我们集中精力 研究酰基辅酶A脱氢酶的失活机制 （亚甲基环丙基）乙酰辅酶A（MCPA-CoA）， 牙买加呕吐病我们的初步结果似乎支持 激进的机制，我们最近开始探索是否有一个 强氢键参与α-H（pKa）的活化 约16）的抑制剂。 我们还将继续 研究了（亚甲基环丙基）对巴豆酸酶的失活作用 甲酰辅酶A（MCPF-CoA）。 这两项研究都与 类选择性抑制剂作为可能的治疗药物的发展 调节脂肪酸代谢的元素来治疗 高血糖症 我们正在研究的另一个系统是1-氨基环丙烷-1-， 羧酸（ACC）脱氨酶，其是一种PLP依赖性酶，催化 各种环丙基氨基酸的开环，反应 维生素B6催化剂的独特之处 以增进我们对 环丙基代谢物的生物处理，我们已经开始了一个 CFA生物合成环丙烷脂肪酸的研究 合成酶 这种酶催化顺式双 磷脂侧链中的化学键， 反应，它可能是抗生素治疗的一个可能的目标 抗药性细菌感染的风险 总的来说，我们的努力将 需要一个多方面的方法，包括表达和 所需酶的纯化，底物类似物的合成， 抑制剂和辅因子，分离产物的表征 从与这些化合物的酶孵育，以及使用物理 和光谱方法来评估的过程和动力学的 反应. 这些机制研究不仅将提供有价值的 用于设计策略以控制和/或模仿 目标酶的催化作用，但也将使我们能够完善 我们对环丙基作为 机械探测器因此，我们的预期结果应该是一个 对酶学机械学的广阔领域做出了重大贡献。

The cyclopropyl groups has been found to be an important structural feature in a wide variety of natural products. Recently, many novel enzyme inhibitors and mechanistic probes have been designed based upon the intrinsic ring strain and associated properties of this moiety. Intrigued by the unique biological activity of cyclopropyl metabolites and their potential use as therapeutic agents, we have undertaken an investigation into the mechanistic details of cyclopropanoid-induced enzyme inactivation. In the past few years we have focused our efforts on studying the inactivation mechanism of acyl-CoA dehydrogenases by (methylenecyclo-propyl) acetyl-CoA (MCPA-CoA), the causative agent of Jamaican vomiting sickness. Our initial results appear to support a radical mechanism, and we have recently begun to explore whether a strong hydrogen bond is involved in the activation of the alpha-H (pKa approximately 16) of the inhibitor. We will also continue to investigate the inactivation of crotonase by (methylenecyclopropyl) formyl-CoA (MCPF-CoA). Both studies are particularly relevant towards the development of class-selective inhibitors as possible therapeutic elements in the regulation of fatty acid metabolism to treat hyperglycemia. Another system we are studying is 1-aminocyclopropane-1- carboxylate (ACC) deaminase, which is a PLP-dependent enzyme catalyzing the ring cleavage of a variety of cyclopropyl amino acids, a reaction unique to vitamin B6 catalysts. To enhance our overall understanding of the bioprocessing of cyclopropyl metabolites, we have initiated a study of the biosynthesis of cyclopropane fatty acids (CFAs) by CFA synthase. This enzyme catalyzes a the cyclopropanation of cis-double bonds in phospholipid side chains which is a mechanistically intriguing reaction, and it may be a possible target for the antibiotic treatment of drug-resistant bacterial infections. Overall, our efforts will require a multi-faceted approach including the expression and purification of the desired enzymes, the synthesis of substrate analogs, inhibitors, and cofactors, the characterization of products isolated from enzymatic incubations with these compounds, and the use of physical and spectroscopic methods for assessing the course and kinetics of the reactions. These mechanistic studies will not only provide valuable information for designing strategies to control and/or mimic the catalytic roles of the target enzymes, but will also enable us to refine our assessment concerning the potential use of the cyclopropyl group as a mechanistic probe. Thus, our anticipated results should make a significant contribution to the broad field of mechanistic enzymology.