Duncan J D, Wallis J O, Azari M R
Calbiochem, La Jolla, CA 92037.
Biochem Biophys Res Commun. 1989 Oct 31;164(2):919-26. doi: 10.1016/0006-291x(89)91546-5.
Lactate oxidase was purified from cells of Aerococcus viridans by a procedure which utilized ammonium sulfate fractionation, DEAE Sepharose CL-6B chromatography, and Sephadex G-100 chromatography. The final preparation was homogeneous by SDS-polyacrylamide gel electrophoresis. The enzyme appears to be a tetramer with a subunit molecular weight of 44,000 and utilizes FMN as a cofactor. The enzyme was highly specific for L-lactate. D-lactate, glycolate, and D,L-2-hydroxybutyrate were not oxidized by the enzyme but were competitive inhibitors. The enzyme could be irreversibly inactivated by incubation with bromopyruvate. This inactivation appears to involve a covalent modification near the active site of the enzyme; however, the flavin cofactor is not the site of this modification.
通过采用硫酸铵分级分离、DEAE琼脂糖CL-6B层析和葡聚糖G-100层析的方法，从绿色气球菌细胞中纯化出乳酸氧化酶。通过SDS-聚丙烯酰胺凝胶电泳分析，最终制备的酶呈现均一性。该酶似乎是一种四聚体，亚基分子量为44,000，以FMN作为辅因子。该酶对L-乳酸具有高度特异性。D-乳酸、乙醇酸和D,L-2-羟基丁酸不能被该酶氧化，但却是竞争性抑制剂。通过与溴丙酮酸孵育，该酶可被不可逆地失活。这种失活似乎涉及酶活性位点附近的共价修饰；然而，黄素辅因子并非此修饰的位点。
