STRUCTURAL MODELS FOR MOLYBDOENZYMES

钼是一种必需的微量元素，是第二种元素中唯一的金属。 以及第三个过渡系列，对所有形式的生命都是必不可少的。在……里面 人类，钼酶参与亚硫酸盐氧化(亚硫酸盐氧化酶) 和嘌呤代谢(黄嘌呤氧化酶)。致命的同时缺陷 这两种酶的活性都是由于先天缺乏 一种常见的钼辅助因子(MOCO)现在在儿童中得到了很好的证明。 接触过多的钼与痛风有关，而钼 缺乏可能会加重对亚硫酸盐的敏感性。这个项目的总体目标是 研究是为了了解它的结构、功能和反应性 生理活性蝶呤钼酶的研究 模型化合物和酶本身。亚硫酸盐氧化物酶是 生物无机、生化和生物物理化学家的基本兴趣 因为它提供了调查 钼辅助因子、氧原子转移化学和分子内 单个分子系统内的电子转移反应。这项研究 在此建议通过集成的 合成、结构、光谱和反应性研究计划 模型化合物和亚硫酸盐氧化酶本身。重点将放在 钼铁模型的合成与表征 亚硫酸盐氧化酶中的相互作用对电子自旋回波的发展 包络调制(ESEEM)光谱作为钼的探针 模型化合物和酶中的环境；研究分子内 亚硫酸盐钼和铁中心之间的电子转移 以及启动亚硫酸盐结构的测定 X-射线结晶学分析氧化物酶。

Molybdenum, an essential trace element, is the only metal in the second and third transition series that is essential for all forms of life. In humans, molybdoenzymes are involved in sulfite oxidation (sulfite oxidase) and purine metabolism (xanthine oxidase). Fatal simultaneous deficiencies in the activities of both of these enzymes due to an inborn deficiency of a common 'molybdenum cofactor' (Moco) are now well documented in children. Exposure to excess molybdenum has been linked with gout, and molybdenum deficiency may aggravate sensitivity to sulfite. The overall goal of this research is to understand the structure, function, and reactivity of this physiologically vital pterin-containing molybdenum enzyme through studies of model compounds and the enzyme itself. Sulfite oxidase is of fundamental interest to bioinorganic, biochemical and biophysical chemists because it provides opportunities to investigate the structure of the molybdenum cofactor, oxygen atom transfer chemistry, and intramolecular electron transfer reactions within a single molecular system. The research proposed here addresses these fundamental issues through an integrated program of synthetic, structural, spectroscopic and reactivity studies of model compounds and of sulfite oxidase itself. Emphasis will be given to the synthesis and characterization of models for the molybdenum-iron interaction in sulfite oxidase; to the development of electron spin echo envelope modulation (ESEEM) spectroscopy as a probe of the molybdenum environment in model compounds and enzymes; to studying intramolecular electron transfer between the molybdenum and iron centers of sulfite oxidase; and to initiating the determination of the structure of sulfite oxidase by X-ray crystallography.