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Substrate specificity of human glutamine transaminase K as an aminotransferase and as a cysteine S-conjugate beta-lyaseстатья
Информация о цитировании статьи получена из
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Статья опубликована в журнале из списка Web of Science и/или Scopus
Дата последнего поиска статьи во внешних источниках: 14 февраля 2019 г.
- Авторы: Cooper Arthur J.L., Pinto John T., Krasnikov Boris F., Niatsetskaya Zoya V., Han Qian, Jianyong Li, Vauzour David, Spencer Jeremy P.E.
- Журнал: Archives of Biochemistry and Biophysics
- Том: 474
- Номер: 1
- Год издания: 2008
- Издательство: Academic Press
- Местоположение издательства: United States
- Первая страница: 72
- Последняя страница: 81
- DOI: 10.1016/j.abb.2008.02.038
- Аннотация: Rat kidney glutamine transaminase K (GTK) exhibits broad specificity both as an aminotransferase and as a cysteine S-conjugate beta-lyase. The beta-lyase reaction products are pyruvate, ammonium and a sulfhydryl-containing fragment. We show here that recombinant human GTK (rhGTK) also exhibits broad specificity both as an aminotransferase and as a cysteine S-conjugate beta-lyase. S-(1,1,2,2-Tetrafluoroethyl)-l-cysteine is an excellent aminotransferase and beta-lyase substrate of rhGTK. Moderate aminotransferase and beta-lyase activities occur with the chemopreventive agent Se-methyl-l-selenocysteine. l-3-(2-Naphthyl)alanine, l-3-(1-naphthyl)alanine, 5-S-l-cysteinyldopamine and 5-S-l-cysteinyl-l-DOPA are measurable aminotransferase substrates, indicating that the active site can accommodate large aromatic amino acids. The alpha-keto acids generated by transamination/l-amino acid oxidase activity of the two catechol cysteine S-conjugates are unstable. A slow rhGTK-catalyzed beta-elimination reaction, as measured by pyruvate formation, was demonstrated with 5-S-l-cysteinyldopamine, but not with 5-S-l-cysteinyl-l-DOPA. The importance of transamination, oxidation and beta-elimination reactions involving 5-S-l-cysteinyldopamine, 5-S-l-cysteinyl-l-DOPA and Se-methyl-l-selenocysteine in human tissues and their biological relevance are discussed.
- Добавил в систему: Красников Борис Фёдорович