The copper site in nitrous oxide reductase. Biol Met 1990;3(2):103-9
Date
01/01/1990Pubmed ID
1965779DOI
10.1007/BF01179514Scopus ID
2-s2.0-0025622656 (requires institutional sign-in at Scopus site) 31 CitationsAbstract
The properties of the novel copper enzyme nitrous oxide reductase from denitrifying Pseudomonas stutzeri are described. Multifrequency electron paramagnetic resonance spectroscopy is used to characterize the various forms of the enzyme. The features observed at 2.4, 3.4, 4.5, 9.31 and 35 GHz are explained by a mixed-valence [Cu(1.5)...Cu(1.5)] S = 1/2 species with the unpaired electron delocalized between the two Cu nuclei. This site is also present in the catalytically inactive derivative of nitrous oxide reductase which was obtained from a transposon Tn5-induced mutant with defective chromophore biosynthesis. The resemblance of the low-frequency electron paramagnetic resonance spectra to the spectra for the so-called CuA of cytochrome c oxidase can be taken as a first indication that the CuA may have a structural and electronic arrangement similar to the electron-paramagnetic-resonance-detectable copper in nitrous oxide reductase. Results from oxidation/reduction experiments, and from a quantitative determination of sulfhydryl and disulfide residues in the various forms of nitrous oxide reductase, suggest the involvement of the redox-couple cysteine/cystine in the structural organization of the active site of nitrous oxide reductase.
Author List
Kroneck PM, Riester J, Zumft WG, Antholine WEMESH terms used to index this publication - Major topics in bold
Binding SitesCopper
Electron Spin Resonance Spectroscopy
Electron Transport Complex IV
Models, Chemical
Oxidation-Reduction
Oxidoreductases
Pseudomonas
Sulfhydryl Compounds