STRUCTURAL MODELS FOR MOLYBDOENZYMES

钼是参与嘌呤代谢的酶中的必需元素， 硫代谢和无机氮的同化。 暴露于 过量的钼与痛风和动脉粥样硬化有关。 钼 土壤中的硝酸盐和亚硝酸盐的水平， 正常的铜代谢。 目前的证据表明， 分成两个班。 这项研究涉及到的酶类， 包括黄嘌呤氧化酶、亚硫酸盐氧化酶和硝酸盐还原酶。 这些酶含有一个共同的钼辅因子，它被认为是一种 单体钼中心与连接硫原子。 这一目标 研究是调查钼中心的结构模型， 这些酶的合成和化学，光谱， 以及对明确定义的钼化合物的X射线结构研究。 特别 重点将是单体钼（V）化合物， 含有连接到钼上的硫基或氢硫基， 金属的配位环境受空间位阻的控制 约束配体。 化合物将通过电子顺磁 光谱（EPR）、95Mo核磁共振光谱（NMR）和 X射线晶体学

Molybdenum is an essential element in enzymes involved in purine metabolism, sulfur metabolism, and the assimilation of inorganic nitrogen. Exposure to excess molybdenum has been linked with gout and atherosclerosis. Molybdenum levels in the soil affect the levels of nitrate and nitrite and interfere with normal copper metabolism. Current evidence indicates that molybdoenzymes fall into two classes. This research is related to the class of molybdoenzymes which includes the xanthine oxidases, the sulfite oxidases and the nitrate reductases. These enzymes contain a common molybdenum cofactor which is thought to be a monomeric molybdenum center with ligating sulfur atoms. The objectives of this research are to investigate structural models for the molybdenum centers of these enzymes by an integrated program of synthesis and chemical, spectroscopic and x-ray structural studies on well-defined molybdenum compounds. Special emphasis will be given to monomeric molybdenum(V) compounds, compounds which contain sulfido or hydrosulfido groups attached to molybdenum, and compounds in which the coordination environment about the metal is controlled by sterically constraining ligands. Compounds will be characterized by electron paramagnetic spectroscopy (EPR), 95Mo nuclear magnetic resonance spectroscopy (NMR), and x-ray crystallography.