Degradation of lysine in chicks.
Degradation of lysine in chicks.
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雏鸡中赖氨酸的降解。
DOI：
10.1093/jn/102.5.583
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发表时间：
1972
期刊：
影响因子：
--
通讯作者：
M. Nesheim
中科院分区：
文献类型：
--
作者：
S. H. Wang;M. Nesheim
研究了针对日粮精氨酸高 (HA) 或低 (LA) 需求而选择的两种雏鸡的赖氨酸降解情况。这些研究表明，L-氨基酸氧化酶和赖氨酸酮戊二酸还原酶在鸡肝脏中对L-赖氨酸的初始降解具有活性，分别导致哌啶酸和糖苷的形成。 L-赖氨酸-U-14C 与肝匀浆或线粒体的有氧孵育导致 14COz 产生，并受到 Oi 和 α-酮戊二酸的刺激。在这些条件下，哌可酸作为主要代谢物积累，并很容易被鸡肝匀浆氧化成 14COz。当 L-赖氨酸-U-14C 与肝匀浆或线粒体以及邻酮戊二酸和 NADPH 一起厌氧培养时，“C-糖苷作为主要代谢物积累。在这些研究中，L-氨基酸氧化酶和赖氨酸-酮戊二酸还原酶均受到饮食处理的影响。HA 菌株中肝脏赖氨酸-酮戊二酸还原酶的活性始终较低与饲喂不同种类的昼夜菌的 LA 品系相比，在 HA 和 LA 雏鸡中未检测到肝脏 L-氨基酸氧化酶活性的差异。这些数据提供了额外的证据，表明糖苷途径可能是雏鸡体内 L-赖氨酸降解的主要途径。观察到的肝脏赖氨酸-酮戊二酸还原酶活性的差异可能解释了赖氨酸代谢的变化。部分是因为两种菌株对精氨酸的不同饮食需求。 J. Nutr. 102: 583-596, 1972。
Lysine degradation in two strains of chicks selected for a high (HA) or low (LA) requirement of dietary arginine was investigated. These studies suggest that both an L-amino acid oxidase and lysine-ketoglutarate reduc Aaseare active in chick liver for the initial degradation of L-lysine, leading to the formation of pipecolic acid and saccharopine, respectively. Aerobic incubation of L-lysine-U-14C with liver homogenates or mitochondria led to 14COzproduc tion which was stimulated by Oi and a-ketoglutarate. Under these conditions, pipecolic acid accumulated as the major metabolite and was readily oxidized to 14COzby chick liver homogenates. When L-lysine-U-14C was incubated anaerobi- cally with liver homogenates or mitochondria along with o-ketoglutarate and NADPH, "C-saccharopine accumulated as the major metabolite. Both L-amino acid oxidase and lysine-ketoglutarate reducAase were affected by dietary treat ments in these studies. The activity of liver lysine-ketoglutarate reducAase was consistently lower in the HA strain than in the LA strain fed various lypes of diels, bui no difference in Ihe activities of liver L-amino acid oxidase could be detected in the HA and LA chicks. These data provide additional evidence thai Ihe saccharopine palhway may be Ihe major palhway for L-lysine degradation in vivo in chicks. The slrain differences in liver lysine-keloglutarate reducAase activity observed may account for variation in lysine metabolism and in part for the different dietary requirements of arginine of the two strains. J. Nutr. 102: 583-596, 1972.