Open AccessNitrite reductase activity in Nitrobacter vulgaris
Author(s) -
Ahlers Beate,
König Wilfried,
Bock Eberhard
Publication year - 1990
Publication title -
fems microbiology letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.899
H-Index - 151
eISSN - 1574-6968
pISSN - 0378-1097
DOI - 10.1111/j.1574-6968.1990.tb13847.x
Subject(s) - nitrite , dithionite , nitrobacter , chemistry , nitrite reductase , sodium dithionite , enzyme , biochemistry , inorganic chemistry , nitrate , organic chemistry
In Nitrobacter vulgaris strain Ab 1 a membrane‐bound nitrite reductase was found to be co‐purified with the nitrite oxidoreductase, the key enzyme system of nitrite oxidizing cells. The relative molecular weight of the enzyme, estimated by SDS‐PAGE, was assumed to be 63 000. The pH optimum was shown to be 6.1 and the K m value for nitrite 263 μM. The IEP was calculated to be at pH 5.5–6.0. The enzyme was inhibited by N,N ‐diethyldithiocarbaminate (DDC), o ‐phenanthroline and ethylmaliendiimide. Dithionite‐reduced benzyl and methyl viologen, NADH/FMN, and dithionite‐reduced horse heart cytochrome c were suitable electron donors for nitrite reduction. The enriched enzyme produced NO as the only end product and showed weak cytochrome c oxidase activity.