STRUCTURAL MODELS FOR MOLYBDOENZYMES

钼酶的结构模型

• 批准号: 3293467
• 负责人: JOHN H ENEMARK
• 金额: $ 18.25万
• 依托单位: UNIVERSITY OF ARIZONA
• 依托单位国家: 美国
• 财政年份: 1986
• 资助国家: 美国
• 起止时间: 1986-06-01 至 1991-05-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/3293467
• 关键词: X ray crystallography; aminoacid; arthritis; atherosclerosis; chemical models; chemical structure function; copper; cysteine; electron spin resonance spectroscopy; environmental toxicology; enzyme structure; glycine; gout; histidine; ligands; metal poisoning; methionine; molybdenum; nitrate reductases; nuclear magnetic resonance spectroscopy; purine /pyrimidine metabolism; stereochemistry; sulfites; xanthine oxidase

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.

钼是参与嘌呤代谢的酶的必需元素， 硫代谢和无机氮的同化。 接触 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含量会影响硝酸盐和亚硝酸盐的含量，并干扰 铜代谢正常。 目前的证据表明钼酶下降 分为两个班级。 这项研究与钼酶类别相关， 包括黄嘌呤氧化酶、亚硫酸盐氧化酶和硝酸盐还原酶。 这些酶含有一种常见的钼辅助因子，被认为是 具有配位硫原子的单体钼中心。 本次活动的目标 研究目的是调查钼中心的结构模型 这些酶通过合成和化学、光谱的综合程序 以及明确钼化合物的 X 射线结构研究。 特别的 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基或氢硫基，以及以下化合物 金属的配位环境受空间控制 约束配体。 化合物将通过电子顺磁性来表征 光谱 (EPR)、95Mo 核磁共振光谱 (NMR) 和 X 射线晶体学。