REACTIVITY OF THE IMINO ACIDS FORMED IN THE AMINO-ACID OXIDASE REACTION
REACTIVITY OF THE IMINO ACIDS FORMED IN THE AMINO-ACID OXIDASE REACTION
复制标题
DOI：
10.1021/bi00570a004
复制
发表时间：
1979-01-01
期刊：
影响因子：
2.9
通讯作者：
WELLNER, D
中科院分区：
文献类型：
--
作者：
HAFNER, EW;WELLNER, D
研究了D或L-氨基酸氧化酶[分别来自响尾蛇毒和猪肾]反应中形成的亚氨基酸的反应性。当亚氨基酸与α-氨基甲酸反应时，甘氨酸或其它氨基酸的氨基，转移产生的衍生物比母体亚氨基酸对水解的稳定性差。当亚氨基酸与ε反应时，通过将赖氨酸或其它伯胺的氨基转移，产生比母体亚氨基酸更稳定的水解衍生物。亚氨酸与肼和氨基脲迅速反应，形成稳定的腙和氨基脲。在pH7.7时，亮氨酸的亚氨基酸类似物与氨基脲的反应速率是相应酮酸的104倍。亚氨基酸与这些试剂的反应足够快，以允许人们以化学计量法跟踪氨基酸氧化酶反应。亚氨基酸也与氰化物反应产生稳定的加合物。亮氨酸的氨基酸类似物的水解速率与pH 8.5以上的pH无关。在较低的pH值下，水解速率随着pH值的降低而增加。在25 °在不添加氨基化合物的情况下，该亚氨基酸在pH 8.5下的半衰期为22秒。在pH 7.9时，其半衰期为9.9 s。
The reactivity of the imino acids formed in the D or L-amino acid oxidase [from Crotalus adamanteus venom and hog kidney, respectively] reaction was studied. When imino acids reacted with the .alpha.-amino group of glycine or other amino acids, transmination yielded derivatives less stable to hydrolysis than the parent imino acids. When imino acids reacted with the .epsilon.-amino group of lysine or other primary amines, transimination yielded derivatives more stable to hydrolysis than the parent imino acids. Imino acids react rapidly with hydrazine and semicarbazide, forming stable hydrazones and semicarbazones. At pH 7.7, the rate of reaction of the imino acid analog of leucine with semicarbazide was 104 times greater than that of the corresponding keto acid. The reaction of imino acids with these reagents is rapid enough to permit one to follow spectrophotometrically the amino acid oxidase reaction. Imino acids also reacted with cyanide to yield stable adducts. The rate of hydrolysis of the amino acid analog of leucine was independent of pH above pH 8.5. At lower pH values, the rate of hydrolysis increased with decreasing pH. At 25 .degree. C and in the absence of added amino compounds, this imino acid had a half-life of 22 s at pH 8.5. Its half-life was 9.9 s at pH 7.9.