title: Electron transfer between the hydrogenase from Desulfovibrio vulgaris (Hildenborough) and viologens. 2. Investigations by chronoamperometry.
abstract: The electron transfer kinetics between the hydrogenase from Desulfovibrio vulgaris (strain Hildenborough) and the mediators methyl viologen, di-(n-aminopropyl) viologen and propyl viologen sulfonate have been investigated by chronoamperometry. Second-order rate constants were calculated on basis of the theory for a simple catalytic mechanism and are compared with the results obtained before by cyclic voltammetry (preceding paper in this journal). From the ionic-strength dependence and the observed differences in the rate constants for the differently charged viologens, the existence of an electrostatic interaction between mediator and a negatively charged part of the protein is confirmed. Chronoamperometry (computer-controlled) was found to possess advantages over cyclic voltammetry in the determination of homogeneous rate constants (faster, more accurate, and better reproducibility).
authors.affiliation: Laboratory of Biochemistry, Agricultural University, Wageningen, The Netherlands.
authors.forename: J C
authors.initials: JC
authors.lastname: Hoogvliet
authors.forename: L C
authors.initials: LC
authors.lastname: Lievense
authors.forename: C
authors.initials: C
authors.lastname: van Dijk
authors.forename: C
authors.initials: C
authors.lastname: Veeger
mesh_terms: D002384:Catalysis; D003201:Computers; D003901:Desulfovibrio / Q000201:enzymology*; D004563:Electrochemistry; D004579:Electron Transport; D006864:Hydrogenase / Q000378:metabolism*; D007700:Kinetics; D011726:Pyridinium Compounds / Q000378:metabolism*; D014755:Viologens / Q000378:metabolism*
chemical_list: D011726:Pyridinium Compounds; D014755:Viologens; D006864:Hydrogenase