COFACTOR DEPENDENT AMINE OXIDATIONS

描述：阐明生物氧化的机制 各种胺氧化酶产生的胺将提供有关活性的信息 站点结构并允许高效和选择性的合理设计 具有治疗潜力的基于机制的（自杀）抑制剂。 的 当前拨款期的主要重点将是依赖黄素的 线粒体单胺氧化酶（MAO）（项目 I）和醌- 含有胺氧化酶（项目 II），其中一个家族含有 铜和另一个似乎不含铜的家族 （称为氨基脲敏感胺氧化酶）。 醌- 含有酶的酶似乎利用转氨基机制 伯胺的脱氨基作用，而电子转移、氢原子 转移、氢化物转移和加成-消除机制全部 仍然是 MAO 的争夺者。 这笔赠款的目的之一是解决 通过进行模型研究来解决机械问题，并 设计和评估可能区分候选者的新探针 机制。 模拟感兴趣的酶化学的模型可以 然后用于（i）“筛选”抑制剂设计的新颖想法，以及（ii） 为理解光谱特征提供参考导数 由酶显示。 设计抑制剂的初步筛选 将在 PI 的实验室中进行，而纯定向研究 酶制剂将与教授合作进行 格林纳威（克拉克大学）、卡根（波士顿大学）、杜利（蒙大拿州） 州立大学）、帕尔西奇（阿尔伯塔大学）和埃德蒙森（埃默里大学） 大学）。 对铜胺氧化酶的相关兴趣 是三羟基苯丙氨酸醌的生物发生机制 来自活性位点酪氨酸残基的辅因子。 铜的机制- 介导的苯酚氧化和可能的铜催化 随后的氧化/水合步骤将在模型研究中进行评估。

DESCRIPTION: Elucidation of the mechanisms of biological oxidation of amines by the various amine oxidases will provide information on active site structure and permit the rational design of efficient and selective mechanism-based (suicide) inhibitors with therapeutic potential. The major focus of the current grant period will be on the flavin-dependent mitochondrial monoamine oxidases (MAO) (Project I) and on the quinone- containing amine oxidases (Project II), one family of which contains copper and the another family of which appears not to contain copper (known as semicarbazide-sensitive amine oxidases). The quinone- containing enzymes appear to utilize a transamination mechanism for deamination of primary amines, whereas electron-transfer, hydrogen-atom- transfer, hydride-transfer, and addition-elimination mechanisms all remain in contention for MAO. One aim of this grant is to address mechanistic questions through the conduct of model studies, and to design and evaluate new probes which might distinguish among candidate mechanisms. Models which mimic the enzyme chemistry of interest can then be used (i) to "screen" novel ideas for inhibitor design, and (ii) to provide reference derivatives for understanding spectral features displayed by the enzymes. Preliminary screening of designed inhibitors will be carried out in the PI's lab, whereas directed studies with pure enzyme preparations will be carried out in collaboration with Professors Greenaway (Clark University), Kagan (Boston University), Dooley (Montana State University), Palcic (University of Alberta), and Edmondson (Emory University). A related interest in regard to the copper amine oxidases is the mechanism of biogenesis of the trihydroxyphenylalanine quinone cofactor from the active-site tyrosine residue. Mechanisms for copper- mediated phenol oxygenation and possibly copper catalysis of the subsequent oxidation/hydration steps will be assessed in model studies.