1. Reductive activation of nitrate reductases
- Author
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Brian J. N. Jepson, Lee J. Anderson, Myles R. Cheesman, David J. Richardson, Julea N. Butt, Sarah J. Field, Simon J. George, Ann Reilly, Andrew J. Gates, and Nicholas P. Thornton
- Subjects
Synechococcus ,chemistry.chemical_classification ,Paracoccus pantotrophus ,Binding Sites ,Synechococcus elongatus ,Inorganic chemistry ,Electron Spin Resonance Spectroscopy ,Activation energy ,Photochemistry ,Catalysis ,Enzyme Activation ,Inorganic Chemistry ,chemistry.chemical_compound ,Enzyme ,Nitrate ,chemistry ,Nitrate Reductases ,Respiratory nitrate reductase ,Spectroscopy, Fourier Transform Infrared ,Steady state (chemistry) ,Oxidation-Reduction - Abstract
Protein film voltammetry of Paracoccus pantotrophus respiratory nitrate reductase (NarGH) and Synechococcus elongatus assimilatory nitrate reductase (NarB) shows that reductive activation of these enzymes may be required before steady state catalysis is observed. For NarGH complementary spectroscopic studies suggest a structural context for the activation. Catalytic protein film voltammetry at a range of temperatures has allowed quantitation of the activation energies for nitrate reduction. For NarGH with an operating potential of ca. 0.05 V the activation energy of ca. 35 kJ mol-1 is over twice that measured for NarB whose operating potential is ca. -0.35 V.
- Published
- 2005
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