Related Experiment Video
Updated: May 19, 2026
![Protein Film Infrared Electrochemistry Demonstrated for Study of H2 Oxidation by a [NiFe] Hydrogenase](/_next/image?url=https%3A%2F%2Fcloudfront.jove.com%2FCDNSource%2Fteasers%2F55858.jpg&w=3840&q=50)
Protein Film Infrared Electrochemistry Demonstrated for Study of H2 Oxidation by a [NiFe] Hydrogenase
Published on: December 4, 2017
Catalytic electrochemistry of xanthine dehydrogenase
Palraj Kalimuthu1, Silke Leimkühler, Paul V Bernhardt
1School of Chemistry and Molecular Biosciences, University of Queensland, Brisbane 4072, Australia.
Abstract:
We report the mediated electrocatalytic voltammetry of the molybdoenzyme xanthine dehydrogenase (XDH) from Rhodobacter capsulatus at a thiol-modified Au electrode. The 2-electron acceptor N-methylphenazinium methanesulfonate (phenazine methosulfate, PMS) is an effective artificial electron transfer partner for XDH instead of its native electron acceptor NAD(+). XDH catalyzes the oxidative hydroxylation of hypoxanthine to xanthine and xanthine to uric acid. Cyclic voltammetry was used to generate the active (oxidized) form of the mediator. Simulation of the catalytic voltammetry across a broad range of substrate and PMS concentrations at different sweep rates was achieved with the program DigiSim to yield a set of consistent rate and equilibrium constants that describe the catalytic system. This provides the first example of the mediated electrochemistry of a xanthine dehydrogenase (or oxidase) that is uncomplicated by interference from product oxidation. A remarkable two-step, sequential oxidation of hypoxanthine to uric acid via xanthine by XDH is observed.
More Related Videos
10:21Developing Photosensitizer-Cobaloxime Hybrids for Solar-Driven H2 Production in Aqueous Aerobic Conditions
Published on: October 5, 2019
08:57Simultaneous Measurement of Superoxide/Hydrogen Peroxide and NADH Production by Flavin-containing Mitochondrial Dehydrogenases
Published on: February 24, 2018
Related Concept Videos
Electron Transport Chain: Complex III and IV
Catalysis
Catalysis
Heterogeneous Catalysis
Pyruvate Oxidation
First, the enzyme pyruvate dehydrogenase removes the carboxyl group from pyruvate and releases it as carbon dioxide. The stripped molecule is then oxidized and releases electrons, which are then picked up by NAD+...
Thermal and Photochemical Electrocyclic Reactions: Overview