Harada I, Noguchi T, Kido R
Hoppe Seylers Z Physiol Chem. 1978 Apr;359(4):481-8. doi: 10.1515/bchm.1978.359.1.481.
Aromatic-amino-acid-glyoxylate aminotransferase was highly purified from the mitochondrial fraction of livers from monkey and glucagon-injected rats. The two enzyme preparations showed physical and enzymic properties different from a kynurenine aminotransferase previously described. The two enzymes had nearly identical molecular weights (approximate 80 000), isoelectric points (pH 8.0) and pH optima (pH 8.0 - 8.5). However, a difference in substrate specificity was observed between the two enzymes. Both enzymes utilized glyoxylate, pyruvate, hydroxypyruvate and 2-oxo-4-methyl-thiobutyrate as effective amino acceptors. 2-Oxoglutarate was active for rat enzyme but not for monkey enzyme. With glyoxylate, amino donors were effective in the following order of activity; phenylalanine greater than histidine greater than tyrosine greater than tryptophan greater than 5-hydroxytrypotphan greater than kynurenine for the rat enzyme, and phenylalanine greater than kynurenine greater than histidine greater than tryptophan greater than 5-hydroxy-tryptophan for the monkey enzyme.
从猴子和注射胰高血糖素的大鼠肝脏的线粒体部分中高度纯化了芳香族氨基酸乙醛酸转氨酶。这两种酶制剂表现出与先前描述的犬尿氨酸转氨酶不同的物理和酶学性质。这两种酶的分子量（约80000）、等电点（pH 8.0）和最适pH（pH 8.0 - 8.5）几乎相同。然而，观察到这两种酶在底物特异性上存在差异。两种酶都利用乙醛酸、丙酮酸、羟基丙酮酸和2-氧代-4-甲基硫代丁酸作为有效的氨基受体。2-氧代戊二酸对大鼠酶有活性，但对猴子酶无活性。对于乙醛酸，氨基供体的活性顺序如下：对于大鼠酶，苯丙氨酸＞组氨酸＞酪氨酸＞色氨酸＞5-羟基色氨酸＞犬尿氨酸；对于猴子酶，苯丙氨酸＞犬尿氨酸＞组氨酸＞色氨酸＞5-羟基色氨酸。
