PURIFICATION AND PROPERTIES OF AEROCOCCUS-VIRIDANS LACTATE OXIDASE
PURIFICATION AND PROPERTIES OF AEROCOCCUS-VIRIDANS LACTATE OXIDASE
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DOI：
10.1016/0006-291x(89)91546-5
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发表时间：
1989-10-31
影响因子：
3.1
通讯作者：
AZARI, MR
中科院分区：
文献类型：
--
作者：
DUNCAN, JD;WALLIS, JO;AZARI, MR
采用硫酸铵分级沉淀、DEAE-SepharoseCL-6 B柱层析和SephadexG-100柱层析的方法，从草绿气球菌（Aerococcusviridans）细胞中分离纯化了乳酸氧化酶。最终制备物通过SDS-聚丙烯酰胺凝胶电泳是均匀的。该酶似乎是一个四聚体，亚基分子量为44，000，并利用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-羟基丁酸不氧化的酶，但竞争性抑制剂。该酶可通过与溴丙酮酸孵育而不可逆地失活。这种失活似乎涉及酶活性位点附近的共价修饰;然而，黄素辅因子不是这种修饰的位点。
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 wnzyme 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.