STRUCTURAL MODELS FOR MOLYBDOENZYMES

钼是参与嘌呤代谢的酶中的一种必需元素， 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 土壤中的水平影响硝酸盐和亚硝酸盐的水平，并干扰 铜代谢正常。目前的证据表明，钼酶下降 分成两个班。这项研究是与钼酶类有关的 包括黄嘌呤氧化酶、亚硫酸盐氧化酶和硝酸还原酶。 这些酶含有一种常见的钼辅助因子，它被认为是一种 具有连接硫原子的单体钼中心。这样做的目的是 研究是为了研究钼中心的结构模型。 这些酶通过一个综合的合成程序和化学、光谱 以及定义明确的钼化合物的X射线结构研究。特价 重点将放在单体钼(V)化合物上，这些化合物 含有附着在钼上的硫化或氢化硫化基团，以及 金属的配位环境是由空间位阻控制的 限制配基。化合物将通过电子顺磁进行表征 波谱(EPR)、95Mo核磁共振波谱(核磁共振)，以及 X射线结晶学。

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.