Superoxide reductase from the hyperthermophilic anaerobe
Pyrococcus furiosus
uses electrons from reduced nicotinamide adenine dinucleotide phosphate, by way of rubredoxin and an oxidoreductase, to reduce superoxide to hydrogen peroxide, which is then reduced to water by peroxidases. Unlike superoxide dismutase, the enzyme that protects aerobes from the toxic effects of oxygen, SOR does not catalyze the production of oxygen from superoxide and therefore confers a selective advantage on anaerobes. Superoxide reductase and associated proteins are catalytically active 80°C below the optimum growth temperature (100°C) of
P. furiosus
, conditions under which the organism is likely to be exposed to oxygen.
超氧化物还原酶来自于超热嗜厌氧菌Pyrococcus furiosus,通过利用还原型烟酰胺腺嘌呤二核苷酸磷酸盐、红蛋白和氧化还原酶所提供的电子,将超氧化物还原为过氧化氢,然后过氧化氢再被过氧化酶还原为水。与保护好氧生物免受氧气毒性影响的超氧化物歧化酶不同,超氧化物还原酶不催化超氧化物向氧气的转化,因此为厌氧菌提供了选择性优势。超氧化物还原酶和相关蛋白质在比P. furiosus最适生长温度(100°C)低80°C的条件下仍具有催化活性,这种条件下该生物可能会暴露在氧气中。