Fry D W, Richardson K E
Biochim Biophys Acta. 1979 Apr 12;567(2):482-91. doi: 10.1016/0005-2744(79)90134-7.
Glycolic acid dehydrogenase has been purified over 800-fold from human liver by (NH4)2SO4 fractionation and column chromatography with DEAE-cellulose and hydroxyapatite. The enzyme catalyzes the direct oxidation of glycolate to oxalate without forming glyoxylate as a free intermediate. Activity is found only in the liver in the soluble fraction. The enzyme is specific for glycolate and inhibits no activity towards glycine or glyoxylate. Glyoxylate and DL-phenyllactate exhibit the enzyme. Optimum activity occurs sharply at pH 6.1 and the Michaelis constant for glycolate was 6.3.10(-5)M. Molecular oxygen does not appear to be the electron acceptor and no requirement for cofactors has been demonstrated, althoug flavin mononucleotide, ascorbate and cytochrome c stimulate activity. The isolation of this enzyme which may account for a significant part of the normal oxalate excretion in man, provides a more complete understanding of the pathways of oxalate biosynthesis and must be taken into account when considering possible methods for controlling disorders of oxalate metabolism.
通过硫酸铵分级分离以及使用二乙氨基乙基纤维素（DEAE - 纤维素）和羟基磷灰石进行柱色谱法，已从人肝脏中纯化出乙醇酸脱氢酶，纯化倍数超过800倍。该酶催化乙醇酸直接氧化为草酸盐，不会形成游离的乙醛酸中间体。活性仅在肝脏的可溶部分中被发现。该酶对乙醇酸具有特异性，对甘氨酸或乙醛酸没有抑制活性。乙醛酸和DL - 苯乳酸可使该酶表现出活性。最佳活性在pH 6.1时急剧出现，乙醇酸的米氏常数为6.3×10⁻⁵M。分子氧似乎不是电子受体，并且尚未证明对辅因子有需求，尽管黄素单核苷酸、抗坏血酸和细胞色素c可刺激活性。这种酶的分离可能解释了人体正常草酸盐排泄的很大一部分，这有助于更全面地了解草酸盐生物合成途径，并且在考虑控制草酸盐代谢紊乱的可能方法时必须予以考虑。
