دورية أكاديمية
Crystallization and characterization of human liver kynurenine–glyoxylate aminotransferase. Identity with alanine–glyoxylate aminotransferase and serine–pyruvate aminotransferase
| العنوان: | Crystallization and characterization of human liver kynurenine–glyoxylate aminotransferase. Identity with alanine–glyoxylate aminotransferase and serine–pyruvate aminotransferase |
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| المؤلفون: | Okuno, Etsuo, Minatogawa, Yohsuke, Nakamura, Masayuki, Kamoda, Naoki, Nakanishi, Junko, Makino, Minoru, Kido, Ryo |
| المصدر: | Biochemical Journal ; volume 189, issue 3, page 581-590 ; ISSN 0264-6021 |
| بيانات النشر: | Portland Press Ltd. |
| سنة النشر: | 1980 |
| مصطلحات موضوعية: | Cell Biology, Molecular Biology, Biochemistry |
| الوصف: | Kynurenine–glyoxylate aminotransferase, alanine–glyoxylate aminotransferase and serine–pyruvate aminotransferase were co-purified and crystallized as yellow cubes from human liver particulate fraction. The crystalline enzyme was homogeneous by the criteria of electrophoresis, isoelectric focusing, gel filtration, sucrose-density-gradient centrifugation and analytical ultracentrifugation. The molecular weight of the enzyme was calculated as approx. 90000, 89000 and 99000 by the use of gel filtration, analytical ultracentrifugation and sucrose-density-gradient centrifugation respectively, with two identical subunits. The enzyme has a s20,w value of 5.23S, an isoelectric point of 8.3 and a pH optimum between 9.0 and 9.5. The enzyme solution showed absorption maxima at 280 and 420nm. The enzyme catalysed transamination between several l-amino acids and pyruvate or glyoxylate. The order of effectiveness of amino acids was alanine>serine>glutamine>glutamate>methionine>kynurenine = phenylalanine = asparagine>valine>histidine>lysine>leucine>isoleucine>arginine>tyrosine = threonine>aspartate, with glyoxylate as amino acceptor. The enzyme was active with glyoxylate, oxaloacetate, hydroxypyruvate, pyruvate, 4-methylthio-2-oxobutyrate and 2-oxobutyrate, but showed little activity with phenylpyruvate, 2-oxoglutarate and 2-oxoadipate, with kynurenine as amino donor. Kynurenine–glyoxylate aminotransferase activity was competitively inhibited by the addition of l-alanine or l-serine. From these results we conclude that kynurenine–glyoxylate aminotransferase, alanine–glyoxylate aminotransferase and serine–pyruvate aminotransferase activities of human liver are catalysed by a single protein. Kinetic parameters for the kynurenine–glyoxylate aminotransferase, alanine–glyoxylate aminotransferase, serine–pyruvate aminotransferase and alanine–hydroxypyruvate aminotransferase reactions of the enzyme are presented. |
| نوع الوثيقة: | article in journal/newspaper |
| اللغة: | English |
| DOI: | 10.1042/bj1890581 |
| الإتاحة: | https://doi.org/10.1042/bj1890581Test https://portlandpress.com/biochemj/article-pdf/189/3/581/574516/bj1890581.pdfTest |
| رقم الانضمام: | edsbas.F2DB7558 |
| قاعدة البيانات: | BASE |
| DOI: | 10.1042/bj1890581 |
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