Nitric oxide dioxygenase: An enzymic function for flavohemoglobin
Nitric oxide dioxygenase: An enzymic function for flavohemoglobin
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DOI：
10.1073/pnas.95.18.10378
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发表时间：
1998-09-01
影响因子：
11.1
通讯作者：
Salzman, AL
中科院分区：
文献类型：
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作者：
Gardner, PR;Gardner, AM;Salzman, AL
氧化物（NO.）是一种毒素，各种生命形式似乎都进化出了解毒的策略。不知道。分离出快速消耗NO.的大肠杆菌的抗性突变体，一个不-转化活性在需要NADPH、FAD和O-2的提取物中重建，是氰化物敏感的，并产生NO3-。这种一氧化氮双加氧酶（NOD）的N端20个氨基酸中有19个与大肠杆菌的相同。大肠杆菌黄素血红蛋白。此外，NOD活性是由黄素血红蛋白基因产生的，并可被NO诱导。Flavohemoglobin/NOD缺陷型突变体也对气态NO的生长抑制敏感。结果确定了进化上保守的黄素血红蛋白的功能，而且，表明NO.解毒可能是一个更古老的功能，广泛分布的血红蛋白，相关的高铁血红蛋白还原酶，比双氧运输和存储。
oxide (NO.) is a toxin, and various life forms appear to have evolved strategies for its detoxification. NO.-resistant mutants of Escherichia coli were isolated that rapidly consumed NO., An NO.-converting activity was reconstituted in extracts that required NADPH, FAD, and O-2, was cyanide-sensitive, and produced NO3-. This nitric oxide dioxygenase (NOD) contained 19 of 20 N-terminal amino acids identical to those of the E. coli flavohemoglobin. Furthermore, NOD activity was produced by the flavohemoglobin gene and was inducible by NO.. Flavohemoglobin/NOD-deficient mutants were also sensitive to growth inhibition by gaseous NO.. The results identify a function for the evolutionarily conserved flavohemoglobins and, moreover, suggest that NO. detoxification may be a more ancient function for the widely distributed hemoglobins, and associated methemoglobin reductases, than dioxygen transport and storage.