METABOLISM OF THE BRANCHED-CHAIN AMINO ACIDS

一项对支链氨基酸新陈代谢的研究揭示了 亮氨酸在细菌中分解代谢的代谢途径 在人类身上是合成的。这条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 腺苷钴胺作为辅因子。其他在人体内起作用的酶 途径有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 不依赖钴胺的途径非常有利于独立的 大脑、心脏、肾脏和肝脏的通路。然而，在睾丸中， 依赖钴胺的途径占碳的40%以上 流量。这表明亮氨酸的代谢可能起着重要的作用。 在这个器官中扮演的角色。转氨酶/脱氨酶的性质是 将尝试对该酶进行检测和纯化。这个 酶活性与各种疾病状态的关系，如 将检查恶性贫血和先天新陈代谢障碍。

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.