MEVALONATED METABOLIZING ENZYMES & THEIR INBORN DEFECTS

甲羟酸化代谢酶

• 批准号: 6523701
• 负责人: HENRY M MIZIORKO
• 金额: $ 24.39万
• 依托单位: MEDICAL COLLEGE OF WISCONSIN
• 依托单位国家: 美国
• 财政年份: 1998
• 资助国家: 美国
• 起止时间: 1998-09-01 至 2004-08-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6523701
• 关键词: X ray crystallography; active sites; affinity labeling; alcohol phosphotransferase; enzyme activity; enzyme deficiency; enzyme feedback; enzyme mechanism; enzyme model; enzyme structure; fatty acid metabolism; gene mutation; isoprenoid; mevalonate; posttranslational modifications; protein sequence; recombinant proteins; site directed mutagenesis

DESCRIPTION: Mevalonic acid is a key intermediate in the biosynthesis of cellular isoprenoids and sterols. Three enzymes, mevalonate kinase, phosphomevalonate kinase, and mevalonate 5-pyrophosphate decarboxylase, are required to metabolize mevalonate to the biosynthetically active isoprenoid, isopentenyl pyrophosphate. Initial work outlined for the enzymes of mevalonate metabolism focuses on mevalonate kinase, which can modulate production of isoprenoids and sterols. Perturbation of mevalonate kinase activity from its normal physiological range has been correlated with disease. In particular, mevalonic aciduria results from inherited mevalonate kinase deficiency. The proposed studies will result in the elucidation of structure/function correlations that account for mevalonate kinase catalysis and feedback regulation. This information will be useful for prediction of the consequences of mutations in the human gene that encodes this enzyme. Additionally, such data will facilitate the design of therapeutic strategies aimed at attenuating enzyme activity and potentially diminishing prenylation of cellular targets. Progress toward these long-term objectives will be generated by initial pursuit of four specific aims. (1) Recombinant forms of human and rat mevalonate kinase will be developed and characterized. The purified enzymes will be kinetically and structurally characterized and the mechanism of feedback inhibition established. (2) Using affinity labeling and sited-directed mutagenesis techniques, mevalonate kinase's active site will be identified and the function of active site amino acids assigned. (3) High resolution structures of rat and human mevalonate kinases will be determined by X-ray crystallography. (4) Human mevalonate kinase mutants will be modeled to determine the molecular basis for mevalonic aciduria.

描述：甲羟戊酸是生物合成的关键中间体 细胞类异戊二烯和甾醇。 三种酶，甲羟戊酸激酶， 磷酸甲羟戊酸激酶和甲羟戊酸 5-焦磷酸脱羧酶 将甲羟戊酸代谢为具有生物合成活性的类异戊二烯所需的， 异戊烯焦磷酸。 酶的初步工作概述 甲羟戊酸代谢集中于甲羟戊酸激酶，它可以调节 类异戊二烯和甾醇的生产。 甲羟戊酸激酶的干扰 其正常生理范围的活动与 疾病。 特别是，甲羟戊酸尿症是由遗传引起的 甲羟戊酸激酶缺乏。 拟议的研究将导致 阐明甲羟戊酸的结构/功能相关性 激酶催化和反馈调节。 这些信息将会有用 预测人类基因突变的后果 编码这种酶。 此外，这些数据将有助于设计 旨在减弱酶活性的治疗策略，并可能 减少细胞靶标的异戊二烯化。 这些方面的进展 长期目标将通过初步追求四个具体目标而产生 目标。 (1) 人和大鼠甲羟戊酸激酶的重组形式将是 开发和表征。 纯化的酶将在动力学上和 结构特征和反馈抑制机制 已确立的。 (2)利用亲和标记和定点诱变 技术，甲羟戊酸激酶的活性位点将被识别，并且 指定的活性位点氨基酸的功能。 (3) 高分辨率 大鼠和人甲羟戊酸激酶的结构将通过 X 射线确定 晶体学。 (4) 人类甲羟戊酸激酶突变体将被建模为 确定甲羟戊酸尿症的分子基础。