CYCLOPROPYL METABOLITES, ENZYMATIC INHIBITION/FORMATION

环丙基已被发现是一个重要的结构 在各种各样的天然产品中都有特色。最近，很多小说 酶抑制剂和机械探针的设计是基于 这一部分的固有环应变和相关的性质。 对环丙基代谢物独特的生物活性感兴趣 以及它们作为治疗剂的潜在用途，我们已经进行了一项 环丙烷诱导的机理细节研究 酶失活。在过去的几年里，我们集中力量 关于酰辅酶A脱氢酶失活机理的研究 (亚甲基环丙基)乙酰辅酶A(MCPA-CoA) 牙买加人的呕吐症。我们的初步结果似乎支持 激进的机制，我们最近开始探索一个 强氢键参与了α-H(PKA)的活化 约16)的缓蚀剂。我们还将继续 亚甲基环丙基对巴豆酶失活作用的研究 甲酰辅酶A(MCPF-CoA)这两项研究都特别与 类选择性抑制剂作为可能的治疗药物的开发 元素在脂肪酸代谢中的调节作用 高血糖症。我们正在研究的另一个体系是1-氨基环丙烷-1- 羧酸(ACC)脱氨酶，是一种依赖PLP的酶，催化 多种环丙基氨基酸的环状裂解反应 维生素B6催化剂所独有的。提高我们的整体认识 关于环丙基代谢物的生物处理，我们已经启动了一项 循环伏安法生物合成环丙烷脂肪酸的研究 合成酶。该酶催化顺式双环丙烷化反应。 磷脂侧链中的键是一个耐人寻味的力学问题 反应，可能是抗生素治疗的一个可能的靶点 耐药细菌感染。总体而言，我们的努力将 需要多方面的方法，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 从酶与这些化合物的孵化，并使用物理 和光谱方法来评估过程和动力学 反应。这些机械论研究不仅将提供有价值的 有关设计策略以控制和/或模仿 目标酶的催化作用，但也将使我们能够提炼 我们对环丙基潜在用途的评估 机械探头。因此，我们的预期结果应该会使 对机械酶学的广泛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.