Hydrogen peroxide-forming NADH oxidase belonging to the peroxiredoxin oxidoreductase family: Existence and physiological role in bacteria
Hydrogen peroxide-forming NADH oxidase belonging to the peroxiredoxin oxidoreductase family: Existence and physiological role in bacteria
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DOI：
10.1128/jb.183.8.2431-2438.2001
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发表时间：
2001-04-01
影响因子：
3.2
通讯作者：
Niimura, Y
中科院分区：
文献类型：
--
作者：
Nishiyama, Y;Massey, V;Niimura, Y
属于过氧化还原酶氧化还原酶家族的木两杆菌和菊粉乳杆菌 NADH 氧化酶在小二硫键氧化还原蛋白 AhpC（过氧化还原蛋白）存在的情况下对过氧化氢和烷基氢过氧化物表现出极高的过氧化还原酶活性。在厌氧和厌氧细菌中，大多数测试菌株都检测到了 AhpC 连接的烷基氢过氧化物还原酶活性，特别是在需氧条件下生长良好的 6 种细菌中表现出特别高的活性，包括需氧细菌（粪产碱菌和地衣芽孢杆菌）和兼性厌氧细菌（木两杆菌、菊粉乳杆菌、大肠杆菌和鼠伤寒沙门氏菌血清型）。在没有 AhpC 的情况下，来自 A. xylanus 和 S. inulinus 的纯化酶催化 NADH 连接的氧还原成过氧化氢。在这六种菌株的细胞提取物中观察到类似的活性。地衣芽孢杆菌的细胞提取物显示四种菌株中 AhpC 连接的烷基氢过氧化物还原酶活性最高，过氧化氢和烷基氢过氧化物的 V-max 值与来自 A. xylanus 和 S. inulinus 的酶的 V-max 值相似，用 A. xylanus 过氧化还原酶基因探测的三个菌株的 Southern 印迹分析显示单个强条带，这些条带可能源自单个过氧化还原蛋白在其他具有高 AhpC 还原酶活性的菌株中也发现了单条带，这表明属于过氧化还原酶氧化还原酶家族的 NADH 氧化酶分布广泛，并且可能在需氧生长细菌的过氧化物清除系统和 NAD 有效再生系统中发挥重要作用。
Amphibacillus xylanus and Sporolactobacillus inulinus NADH oxidases belonging to the peroxiredoxin oxidoreductase family show extremely high peroxide reductase activity for hydrogen peroxide and alkyl hydroperoxides in the presence of the small disulfide redox protein, AhpC (peroxiredoxin), In order to investigate the distribution of this enzyme system in bacteria, 15 bacterial strains were selected from typical aerobic, facultatively anaerobic, and anaerobic bacteria, AhpC-linked alkyl hydroperoxide reductase activities were detected in most of the tested strains, and especially high activities were shown in six bacterial species that grow well under aerobic conditions, including aerobic bacteria (Alcaligenes faecalis and Bacillus licheniformis) and facultatively anaerobic bacteria (Amphibacillus xylanus, Sporolactobacillus inulinus, Escherichia coli, and Salmonella enterica serovar Typhimurium). In the absence of AhpC, the purified enzymes from A. xylanus and S. inulinus catalyze the NADH-linked reduction of oxygen to hydrogen peroxide. Similar activities were observed in the cell extracts from each of these six strains. The cell extract of B. licheniformis revealed the highest AhpC-linked alkyl hydroperoxide reductase activity in the four strains, with V-max values for hydrogen peroxide and alkyl hydroperoxides being similar to those for the enzymes from A. xylanus and S. inulinus, Southern blot analysis of the three strains probed with the A. xylanus peroxiredoxin reductase gene revealed single strong bands, which are presumably derived from the individual peroxiredoxin reductase genes, Single bands were also revealed in other strains which show high AhpC-linked reductase activities, suggesting that the NADH oxidases belonging to the peroxiredoxin oxidoreductase family are widely distributed and possibly play an important role both in the peroxide scavenging systems and in an effective regeneration system for NAD in aerobically growing bacteria.