STRUCTURE AND FUNCTION OF MYELOPEROXIDASE

髓过氧化物酶是多形核中性粒细胞的一种血红素酶， 纯化并通过各种光谱手段检查。 特别 髓过氧化物酶的特征是它能够催化 卤素离子如氯离子、溴离子和碘离子的氧化， 次卤酸盐通过过氧化氢杀死摄入的有机体。 以来 血红素基团是这种酶的活性中心， 血红素组的环境，以及 底物结合（特别是氯离子）对这些性能的影响将是 阐明，以获得有关机制的重要信息 酶的作用。 本提案的主要目标是：（1） 确定氯离子结合位点，（2）表征 血红素基团的结构，（3）确定的模式， 血红素基团和脱辅基蛋白部分之间的相互作用，以及（4） 系统评价血红素组之间的不等价性 利用光吸收，电子顺磁共振，质子， 和氯-核磁共振，共振拉曼散射，和 动力学光谱 阐明了其分子机制， 髓过氧化物酶的酶作用对于我们理解 多形核白细胞的杀菌功能，这对于 哺乳动物物种抵抗细菌感染的生存。

Myeloperoxidase, a heme enzyme of polymorphonuclear neutrophils, will be purified and examined by a variety of spectroscopic means. Special characteristics of myeloper-oxidase is its ability to catalyze the oxidation of halide ion, such as chloride, bromide, and iodide ions, to hypohalite by hydrogen peroxide to kill the ingested organism. Since the heme group is the active center of this enzyme, the electronic properties of the heme irom, the environment of the heme group, and the effect of substrate binding (particularly chloride ion) on these properties will be elucidated in order to obtain the vital informations about the mechanism of action of the enzyme. The primary goals of this proposal are: (1) determination of the chloride binding site, (2) characterization of the structure of the heme group, (3) determination of the mode of the interactions between the heme group and apo-protein moeity, and (4) evaluation of the inequivalence between the heme groups by systematic utilization of light absorption, electron paramagentic resonance, proton- and chlorine-nuclear magnetic resonance, resonance Raman scattering, and kinetic spectroscopies. Elucidation of the molecular mechanism of the enzyme action of myeloperoxidase is essential for our understanding the bacteriocidal function of polymophonuclear leukocytes, which is vital for survival of mammalian species against bacterial infections.