title: Opportunities for mesoporous nanocrystalline SnO2 electrodes in kinetic and catalytic analyses of redox proteins.
abstract: PFV (protein film voltammetry) allows kinetic analysis of redox and coupled-chemical events. However, the voltammograms report on the electron transfer through a flow of electrical current such that simultaneous spectroscopy is required for chemical insights into the species involved. Mesoporous nanocrystalline SnO(2) electrodes provide opportunities for such 'spectroelectrochemical' analyses through their high surface area and optical transparency at visible wavelengths. Here, we illustrate kinetic and mechanistic insights that may be afforded by working with such electrodes through studies of Escherichia coli NrfA, a pentahaem cytochrome with nitrite and nitric oxide reductase activities. In addition, we demonstrate that the ability to characterize electrocatalytically active protein films by MCD (magnetic circular dichroism) spectroscopy is an advance that should ultimately assist our efforts to resolve catalytic intermediates in many redox enzymes.
authors.affiliation: Centre for Molecular and Structural Biochemistry, School of Chemical Sciences and Pharmacy, University of East Anglia, Norwich Research Park, Norwich, UK.
authors.forename: Gemma L
authors.initials: GL
authors.lastname: Kemp
authors.forename: Sophie J
authors.initials: SJ
authors.lastname: Marritt
authors.forename: Li
authors.initials: L
authors.lastname: Xiaoe
authors.forename: James R
authors.initials: JR
authors.lastname: Durrant
authors.forename: Myles R
authors.initials: MR
authors.lastname: Cheesman
authors.forename: Julea N
authors.initials: JN
authors.lastname: Butt
mesh_terms: D002384:Catalysis; D002942:Circular Dichroism; D003574:Cytochrome c Group / Q000032:analysis*; D004566:Electrodes; D004926:Escherichia coli / Q000201:enzymology; D007700:Kinetics; D008280:Magnetics; D053758:Nanoparticles / Q000737:chemistry*; D010084:Oxidation-Reduction; D016062:Porosity; D013499:Surface Properties; D017971:Tin Compounds / Q000737:chemistry*
chemical_list: D003574:Cytochrome c Group; D017971:Tin Compounds; C022302:cytochrome C-552; C045358:stannic oxide