METABOLISM OF THE BRANCHED-CHAIN AMINO ACIDS

支链氨基酸的代谢

• 批准号: 4694454
• 负责人: J M POSTON
• 金额: --
• 依托单位: NATIONAL HEART, LUNG, AND BLOOD INSTITUTE
• 依托单位国家: 美国
• 资助国家: 美国
• 起止时间: 至
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/4694454
• 关键词: Clostridium; aminoacid analyzer; aminoacid metabolism; aminohydrolases; branched chain aminoacid; cobalamin; enzyme structure; fermentation; gas chromatography; isomerase; leucine; lipid metabolism; liver cells; maple syrup urine disease; megaloblastic anemia; microorganism metabolism; nutrition related tag; plant growth /development; racemization; tissue /cell culture; vitamin B12 coenzyme; yeasts

A study of the metabolism of the branched-chain amino acids has revealed a pathway of metabolism of leucine that is catabolic in bacteria and appears to be synthetic in humans. The pathway depends upon the activity of the enzyme, leucine 2, 3-aminomutase, an enzyme dependent upon adenosylcobalamin as a cofactor. Other enzymes which function in the pathway are Beta-leucine transaminase/deaminase, coenzyme A transferase, and thiolase. The relative carbon flux through this pathway and the pathway which is independent of cobalamin greatly favors the independent pathway in brain, heart, kidney, and liver. In the testis, however, the cobalamin-dependent pathway accounts for over forty percent of the carbon flux. This suggests that the metabolism of leucine may play an important role in this organ. The nature of the transaminase/deaminase will be examined and purification of the enzyme will be attempted. The relationship between enzyme activity and various disease states such as pernicious anemia and inborn errors of metabolism will be examined.

对支链氨基酸代谢的研究表明， 亮氨酸的代谢途径，在细菌中分解代谢， 在人体内合成。 该途径取决于细胞的活性， 亮氨酸2，3-氨基变位酶，一种依赖于 腺苷钴胺素作为辅助因子。 其他酶的功能， 途径是β-亮氨酸转氨酶/脱氨酶、辅酶A转移酶， 和硫解酶。 通过这一途径的相对碳通量和 不依赖于钴胺素的途径非常有利于独立的 脑、心脏、肾脏和肝脏中的通路。 然而，在睾丸中， 钴胺素依赖性途径占碳的百分之四十以上 通量 这表明，亮氨酸的代谢可能发挥重要作用， 在这个机构中的作用。 转氨酶/脱氨酶的性质将是 将尝试检测和纯化该酶。 的 酶活性与各种疾病状态之间的关系， 检查恶性贫血和先天性代谢缺陷。