Sakuraba H, Fujiwara S, Noguchi T
Department of Biochemistry, Kyushu Dental College, Kitakyushu, Japan.
Biochem Biophys Res Commun. 1996 Dec 13;229(2):603-6. doi: 10.1006/bbrc.1996.1850.
In marine fish liver, degradative enzymes able to convert purines to urate have been shown to be located in the cytosol and degradative enzymes able to convert urate to urea and glyoxylate in the peroxisomes. The end products of purine degradation are urea and glyoxylate in fish. Glyoxylate may be converted to glycine by alanine:glyoxylate aminotransferase for the reutilization of purine carbons. The present report describes that hepatic alanine:glyoxylate aminotransferase is located both in the peroxisomes and in the mitochondria in fresh water fish, showing that the intracellular localization of the enzyme differs between fresh water fish and marine fish. This is the first report on the presence of alanine:glyoxylate aminotransferase in fish peroxisomes.
在海鱼肝脏中，能够将嘌呤转化为尿酸盐的降解酶已被证明位于胞质溶胶中，而能够将尿酸盐转化为尿素和乙醛酸的降解酶位于过氧化物酶体中。鱼类嘌呤降解的终产物是尿素和乙醛酸。乙醛酸可通过丙氨酸：乙醛酸氨基转移酶转化为甘氨酸，以实现嘌呤碳的再利用。本报告描述了淡水鱼肝脏中的丙氨酸：乙醛酸氨基转移酶既存在于过氧化物酶体中，也存在于线粒体中，这表明该酶在淡水鱼和海鱼中的细胞内定位有所不同。这是关于鱼类过氧化物酶体中存在丙氨酸：乙醛酸氨基转移酶的首次报道。
