MECHANISTIC PROBES FOR ENZYME CATALYZED OXIDATIONS

研究的总体目标是阐明作用机制 催化碳氢化合物和胺氧化的酶。前 组包括血红素-硫醇盐细胞色素P450酶和二铁酶 如甲烷单加氧酶和硬脂酰去饱和酶。后一组 包括单胺氧化酶（MAO）酶以及P450酶。一个 对这些酶的作用机制的了解， 有利于治疗进展，例如，MAO是靶点， 酶的药物，用于治疗抑郁症和帕金森病。 研究方法包括使用“超敏感”的自由基探针 可以用作氧化反应的底物， 非常短命的激进分子设计了探针基片， 测定了自由基反应速率常数。来自产品分销 在酶氧化反应中，自由基的中间性是确定的，如果 自由基是中间体，自由基的寿命被测量。 对于含铁酶的烃氧化的研究，一些 现在已经有了超灵敏的探针，其他探针的开发也在进行中。 计划好了特别值得注意的是一个家庭的探针，区分 在自由基和阳离子中间体之间， 自由基反应中的反应性。酶催化氧化 PI的实验室正在使用酶进行校准探针 由其他团体纯化，并在其他团体的实验室中，使用 由PI集团提供的探针。预计结果将描绘出 反应机制的共同和不同特征， 看似不同的酶 对于酶催化胺氧化反应的研究， 基础阶段各种氮反应的动力学标度 含有自由基的物质通过直接激光 闪光光解方法和间接动力学竞争技术。当 含氮自由基的反应是可以理解的， 合理设计的机械探针将被开发和应用于 P450和MAO酶的氧化反应。

The overall goal of the research is to elucidate the mechanisms of action of enzymes that catalyze oxidations of hydrocarbons and amines. The former group includes the heme-thiolate cytochrome P450 enzymes and diiron enzymes such as methane monooxygenase and stearoyl desaturase. The latter group includes the monoamine oxidase (MAO) enzymes as well as P450 enzymes. An understanding of the mechanisms of actions of these enzymes is expected to be beneficial for therapeutic advances, for example, MAO is the target enzyme of drugs for treatment of depression and Parkinson's Disease. The method of study involves the use of "hypersensitive" radical probes that can be employed as substrates in oxidations to reveal the intermediacy of very short-lived radicals. The probe substrates are designed, and the radical reaction rate constants are determined. From product distributions in enzyme oxidations, the intermediacy of a radical is determined, and, if a radical is an intermediate, the lifetime of the radical is measured. For studies of hydrocarbon oxidations by iron-containing enzymes, some hypersensitive probes now exist, and the development of other probes is planned. Especially noteworthy is a family of probes that distinguish between radical and cationic intermediates while maintaining hypersensitive reactivity in the radical reaction. Enzyme catalyzed oxidations of calibrated probes are in progress in the PI's laboratory, using enzymes purified by other groups, and in the laboratories of other groups, using probes supplied by the PI's group. The results are expected to delineate common and dissimilar features in the mechanisms of reactions of the seemingly distinct enzymes. For studies of enzyme catalyzed amine oxidations, the work is at a more fundamental stage. Kinetic scales for reactions of a wide range of nitrogen containing radicals are being measured by a combination of direct, laser flash photolysis methods and indirect kinetic competition techniques. When the reactions of the nitrogen containing radicals are understood, rationally designed mechanistic probes will be developed and applied in oxidation reactions by P450 and MAO enzymes.