Biochemical characterization of the HpxO enzyme from Klebsiella pneumoniae, a novel FAD-dependent urate oxidase.
Biochemical characterization of the HpxO enzyme from Klebsiella pneumoniae, a novel FAD-dependent urate oxidase.
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肺炎克雷伯菌 HPxO 酶（一种新型 FAD 依赖性尿酸氧化酶）的生化特征。
DOI：
10.1021/bi900160b
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发表时间：
2009
期刊：
影响因子：
2.9
通讯作者：
Begley,TadhgP
中科院分区：
文献类型：
--
作者：
O'Leary,SeánE;Hicks,KatherineA;Ealick,StevenE;Begley,TadhgP
肺炎克雷伯氏菌的HpxO酶最近被提出，在遗传研究的基础上，催化尿酸羟基化为5-羟基异尿酸作为嘌呤分解代谢途径的一部分。其一级序列表明HpxO催化活性取决于黄素辅因子（FAD），这与之前研究的所有不需要辅因子的尿酸氧化酶形成鲜明对比。在这里，我们证明了生化HpxO是一种FAD依赖性尿酸氧化酶。我们的数据是一致的建议，HpxO结合的黄素氢过氧化物是羟基化物种。这些结果证实了嘌呤catastrophic存在一种新的机制范式。
The HpxO enzyme fromKlebsiella pneumoniaewas recently proposed, on the basis of genetic studies, to catalyze the hydroxylation of uric acid to 5-hydroxyisourate as part of the purine catabolic pathway. Its primary sequence suggests that the HpxO catalytic activity depends on a flavin cofactor (FAD), contrasting with all previously studied urate oxidase enzymes, which have no cofactor requirement. Here we demonstrate biochemically that HpxO is an FAD-dependent urate oxidase. Our data are consistent with the proposal that HpxO-bound flavin hydroperoxide is the hydroxylating species. These results confirm the existence of a novel mechanistic paradigm in purine catabolism.