The organ distribution of human alanine-2-oxoglutarate aminotransferase and alanine-glyoxylate aminotransferase

• Published in: Biochemical medicine Vol. 23; no. 1; pp. 25 - 34
• Main Authors: Kamoda, Naoki, Minatogawa, Yohsuke, Nakamura, Masayuki, Nakanishi, Junko, Okuno, Etsuo, Kido, Ryo
• Format: Journal Article
• Language: English
• Published: United States Elsevier Inc 01.02.1980
• Subjects: Aged; Alanine Transaminase - metabolism; Chemical Phenomena; Chemistry; Humans; Kidney - enzymology; Liver - enzymology; Male; Middle Aged; Organ Specificity; Transaminases
• ISSN: 0006-2944; 1557-7996
• DOI: 10.1016/0006-2944(80)90051-4

The organ distribution of human alanine-2-oxoglutarate aminotransferase and alanine-glyoxylate aminotransferase was investigated. Alanine-2-oxoglutarate aminotransferase was present in all tissues tested (liver, kidney, adrenal gland, brain, pancreas, spleen, jejunum mucosa, testis, lung, heart, and skeletal muscle), and was particularly high in the liver, skeletal muscle, heart, kidney, and pancreas. The aminotransferase of liver and kidney was predominantly present in the 10,000 g supernatant fraction. The concentration of alanine-glyoxylate aminotransferase is much higher in liver. Kidney contains the enzyme at 1 50 – 1 70 activity of that of the liver per gram wet weight of tissue and other organs tested show far less activity. The liver particulate fraction contained most of the alanine-glyoxylate aminotransferase activity, which was different from that of alanine-2-oxoglutarate aminotransferase. Isoelectric focusing profiles of liver and kidney extract showed the presence of two types of alanine-glyoxylate aminotransferase, having isoelectric points of pH 8.0 and 5.8, respectively. Liver extract possesses a high amount of p I 8.0 isoenzyme (98%), and kidney extract contained nearly an identical amount of p I 8.0 isoenzyme (41%) and p I 5.8 isoenzyme (59%). The p I 5.8 isoenzyme coincided with alanine-2-oxoglutarate aminotransferase on isoelectric focusing. Apparent K m values of liver alanine-2-oxoglutarate aminotransferase were 21, 0.8, 3.1, and 0.36 m m for alanine, pyruvate, glutamate, and 2-oxoglutarate, in the order mentioned, and those of alanine-glyoxylate aminotransferase were 7.7 and 0.21 m m for alanine and glyoxylate, respectively.