METABOLISM OF THE BRANCHED-CHAIN AMINO ACIDS

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，一种依赖腺苷钴胺素的酶 作为辅助因子。 在该途径中起作用的其他酶是 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，非常有利于脑中的独立通路， 心脏肾脏和肝脏 然而，在睾丸中， 这条路径占碳通量的40%以上。 这表明 亮氨酸的代谢可能在这个器官中起重要作用。 将检查转氨酶/脱氨酶的性质并纯化 将尝试使用酶。 酶活性之间的关系 和各种疾病状态，如恶性贫血和先天性缺陷， 将检查代谢。

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 cobalamindependent 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.