Characterization of YqjM, an old yellow enzyme homolog from Bacillus subtilis involved in the oxidative stress response
Characterization of YqjM, an old yellow enzyme homolog from Bacillus subtilis involved in the oxidative stress response
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DOI：
10.1074/jbc.m211778200
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发表时间：
2003-05-30
影响因子：
4.8
通讯作者：
Macheroux, P
中科院分区：
文献类型：
--
作者：
Fitzpatrick, TB;Amrhein, N;Macheroux, P
在本文中，我们证明了来自枯草杆菌的蛋白质（YqjM）与同源酵母老黄酶（OYE）具有许多特征性生化性质;该酶与FMN紧密但非共价结合，优先使用NADPH作为还原当量的来源，并与酚类化合物形成电荷转移复合物，例如对羟基苯甲醛。与酵母OYE和该家族的其他成员一样，YqjM催化一系列α，β-不饱和醛和酮（包括硝基酯和硝基芳族化合物）的双键还原。虽然酵母OYE是1933年发现的该家族的第一个成员，并且是第一个分离的黄素酶，但该家族的生理作用仍然不清楚。α，β-不饱和化合物是底物的发现引起了OYE家族可能参与外源性物质或脂质过氧化产物的还原降解的猜测。在这里，我们第一次在蛋白质水平上证明，而YqjM在B中显示基础水平的表达。在枯草杆菌中，加入有毒的异生物质，三硝基甲苯，导致蛋白质在体内的快速诱导，表明在解毒中的作用。此外，我们表明，YqjM是快速诱导的氧化应激所施加的过氧化氢，表现出潜在的生理作用，这类神秘的蛋白质。
In this paper, we demonstrate that a protein from Bacillus subtilis (YqjM) shares many characteristic biochemical properties with the homologous yeast Old Yellow Enzyme (OYE); the enzyme binds FMN tightly but noncovalently, preferentially uses NADPH as a source of reducing equivalents, and forms charge transfer complexes with phenolic compounds such as p-hydroxybenzaldehyde. Like yeast OYE and other members of the family, YqjM catalyzes the reduction of the double bond of an array of alpha,beta-unsaturated aldehydes and ketones including nitroester and nitroaromatic compounds. Although yeast OYE was the first member of this family to be discovered in 1933 and was the first flavoenzyme ever to be isolated, the physiological role of the family still remains obscure. The finding that alpha, beta-unsaturated compounds are substrates provoked speculation that the OYE family might be involved in reductive degradation of xenobiotics or lipid peroxidation products. Here, for the first time, we demonstrate on the protein level that whereas YqjM shows a basal level of expression in B. subtilis, the addition of the toxic xenobiotic, trinitrotoluene, leads to a rapid induction of the protein in vivo denoting a role in detoxification. Moreover, we show that YqjM is rapidly induced in response to oxidative stress as exerted by hydrogen peroxide, demonstrating a potential physiological role for this enigmatic class of proteins.