The cytochrome cbb(3) is an isoenzyme in the family of cytochrome c oxidases. This protein purified from Pseudomonas stutzeri displays a cyanide-sensitive nitric oxide reductase activity (V-max=100 +/-9 mol NO.mol cbb(3)(-1).min(-1) and K-m=12 +/-2.5 mum), which is lost upon denaturation. This enzyme is only partially reduced by ascorbate, and readily re-oxidized by NO under anaerobic conditions at a rate consistent with the turnover number for NO consumption. As shown by transient spectroscopy experiments and singular value decomposition (SVD) analysis, these results suggest that the cbb(3)-type cytochromes, sharing structural features with bacterial nitric oxide reductases, are the enzymes retaining the highest NO reductase activity within the heme-copper oxidase superfamily.
The cytochrome cbb3 from Pseudomonas stutzeri displays nitric oxide reductase activity / Forte, Elena; Urbani, Andrea; Saraste, Matti; Sarti, Paolo; Brunori, Maurizio; Giuffre', Alessandro. - In: EUROPEAN JOURNAL OF BIOCHEMISTRY. - ISSN 0014-2956. - 268:(2001), pp. 6486-6491. [10.1046/j.0014-2956.2001.02597.x]
The cytochrome cbb3 from Pseudomonas stutzeri displays nitric oxide reductase activity
FORTE, Elena;SARTI, Paolo;BRUNORI, Maurizio;GIUFFRE', ALESSANDRO
2001
Abstract
The cytochrome cbb(3) is an isoenzyme in the family of cytochrome c oxidases. This protein purified from Pseudomonas stutzeri displays a cyanide-sensitive nitric oxide reductase activity (V-max=100 +/-9 mol NO.mol cbb(3)(-1).min(-1) and K-m=12 +/-2.5 mum), which is lost upon denaturation. This enzyme is only partially reduced by ascorbate, and readily re-oxidized by NO under anaerobic conditions at a rate consistent with the turnover number for NO consumption. As shown by transient spectroscopy experiments and singular value decomposition (SVD) analysis, these results suggest that the cbb(3)-type cytochromes, sharing structural features with bacterial nitric oxide reductases, are the enzymes retaining the highest NO reductase activity within the heme-copper oxidase superfamily.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.