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BIOCHEMISTRY OF THE 3-METHYLGLUTACONIC ACIDURIAS

3-甲基戊二酸的生物化学

基本信息

批准号：
2144187
负责人：
RICHARD Ian KELLEY
金额：
$ 12.04万
依托单位：
HUGO W. MOSER RES INST KENNEDY KRIEGER
依托单位国家：
美国
项目类别：
财政年份：
1992
资助国家：
美国
起止时间：
1992-07-01 至 1995-06-30
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/2144187
关键词：
aminoacid metabolism animal tissue coenzyme A enzyme activity fatty acid metabolism human tissue hydro lyase inborn metabolism disorder intracellular transport isoprenoid isozymes leucine mevalonate molecular pathology tissue /cell culture

项目摘要

In recent years, our laboratory and other biochemical genetics units have identified a number of patients who have persistent 3-methylglutaconic aciduria but who do not have an identifiable disturbance in their metabolism of leucine, the presumed precursor of 3-methylglutaconic acid in man. Our further studies of these patients suggest instead that their urinary 3-methylglutaconate derives from the "trans-methyl-glutaconate (mevalonate) shunt, "a little known isoprenoid-related pathway that may be of fundamental importance to our understanding of not only these patients but also regulation of polyisoprenoid and cholesterol metabolism in man. This proposal addresses several questions we seek to answer to be able to understand better the different pathways of 3-methylglutaconic acid metabolism in man. 1) What is the activity of the mevalonate shunt in cultured human fibroblasts, lymphoblasts, and myoblasts? Methods will be developed for measuring overall flux through the shunt and then applied to the study of the activity of the methyl-glutaconate shunt in cultured cells. 2) What is the subcellular localization of the mevalonate shunt? Are there multiple enzymes with the ability to hydrate 3-methylglutaconate or 3- methylglutaconyl-CoA with different subcellular localizations? We will assay subcellular fractions (rat liver, muscle, and fibroblast) for hydratase activity and compare the activities in normal cells with those found in cells from patients with 3-methylglutaconic aciduria. 3) What is the metabolic pathway for the production of 3-methylglutaconate independent of leucine catabolism and the diversion of mevalonate carbon to the synthesis of n-fatty acids? The metabolism of leucine and mevalonate in cultured cells will be traced using various labelling strategies to identify the level(s), synthetic or catabolic, at which isoprenoid carbon is diverted to 3-methylglutaconate. Identified pathways will then be studied in cell lines from patients with leucine-independent 3- methylglutaconic aciduria.

近年来，我们的实验室和其他生化遗传学单位，确定了一些持续性3-甲基戊烯二酸酸尿症，但没有可识别的障碍，亮氨酸的代谢，3-甲基戊烯二酸的假定前体，伙计我们对这些患者的进一步研究表明，尿3-甲基戊烯二酸衍生自“反式-甲基戊烯二酸（甲羟戊酸）分流，“一个鲜为人知的类异戊二烯相关的途径，可能是对我们理解这些病人而且调节人的多聚类异戊二烯和胆固醇代谢。该提案涉及我们寻求回答的几个问题，以便能够更好地了解3-甲基戊烯二酸的不同途径人体新陈代谢 1)甲羟戊酸分流在培养的人中的活性是多少成纤维细胞成淋巴细胞成肌细胞将制定方法，测量通过分流器的总通量，然后应用于研究戊烯二酸甲酯分流在培养细胞中的活性。 2)甲羟戊酸分流的亚细胞定位是什么？有具有水合3-甲基戊烯二酸或3- 甲基戊烯二酰辅酶A与不同的亚细胞定位？我们将测定亚细胞组分（大鼠肝脏、肌肉和成纤维细胞）水合酶活性，并将正常细胞中的活性与在3-甲基戊烯二酸尿症患者的细胞中发现。 3)产生3-甲基戊烯二酸的代谢途径是什么独立于亮氨酸催化剂和甲羟戊酸碳转移到 N-脂肪酸的合成亮氨酸和甲羟戊酸的代谢将使用各种标记策略追踪培养细胞中的确定类异戊二烯碳的合成或分解代谢水平转化为戊烯二酸3-甲酯。确定的路径将在来自亮氨酸非依赖性3- 甲基戊烯二酸尿症。