Biomaterial Database

Mediated electrochemistry of dimethyl sulfoxide reductase from Rhodobacter capsulatus. 2009

Kuan-I Chen, and Alastair G McEwan, and Paul V Bernhardt

Centre for Metals in Biology, School of Chemistry and Molecular Biosciences, University of Queensland, Brisbane, QLD, 4072, Australia.

Electrochemically driven catalysis of the bacterial enzyme dimethyl sulfoxide (DMSO) reductase (Rhodobacter capsulatus) has been studied using the macrocyclic complex (trans-6,13-dimethyl-1,4,8,11-tetraazacyclotetradecane-6,13-diamine)cobalt(III) as a mediator. In the presence of both DMSO and DMSO reductase, the normal transient Co(III/II) voltammetric response of the complex is transformed into an amplified and sigmoidal (steady-state) waveform characteristic of a catalytic EC' mechanism. At low concentrations of DMSO (approximately K (M)) or high mediator concentrations (more than the concentration of DMSO reductase), the steady-state character of the voltammetric response disappears and is replaced by more complicated waveforms that are a convolution of transient and steady-state behavior as different steps within the catalytic cycle become rate limiting. Through digital simulation of cyclic voltammetry performed under conditions where the sweep rate, DMSO concentration, DMSO reductase concentration and mediator concentration were varied systematically, we were able to model all voltammograms with a single set of rate and equilibrium constants which provide new insights into the kinetics of the DMSO reductase catalytic mechanism that have hitherto been inaccessible from steady state or stopped flow kinetic studies.

UI	MeSH Term	Description	Entries
D007506	Iron-Sulfur Proteins	A group of proteins possessing only the iron-sulfur complex as the prosthetic group. These proteins participate in all major pathways of electron transport: photosynthesis, respiration, hydroxylation and bacterial hydrogen and nitrogen fixation.	Iron-Sulfur Protein,Iron Sulfur Proteins,Iron Sulfur Protein,Protein, Iron-Sulfur,Proteins, Iron Sulfur,Proteins, Iron-Sulfur,Sulfur Proteins, Iron
D007700	Kinetics	The rate dynamics in chemical or physical systems.
D009942	Organometallic Compounds	A class of compounds of the type R-M, where a C atom is joined directly to any other element except H, C, N, O, F, Cl, Br, I, or At. (Grant & Hackh's Chemical Dictionary, 5th ed)	Metallo-Organic Compound,Metallo-Organic Compounds,Metalloorganic Compound,Organometallic Compound,Metalloorganic Compounds,Compound, Metallo-Organic,Compound, Metalloorganic,Compound, Organometallic,Compounds, Metallo-Organic,Compounds, Metalloorganic,Compounds, Organometallic,Metallo Organic Compound,Metallo Organic Compounds
D010088	Oxidoreductases	The class of all enzymes catalyzing oxidoreduction reactions. The substrate that is oxidized is regarded as a hydrogen donor. The systematic name is based on donor:acceptor oxidoreductase. The recommended name will be dehydrogenase, wherever this is possible; as an alternative, reductase can be used. Oxidase is only used in cases where O2 is the acceptor. (Enzyme Nomenclature, 1992, p9)	Dehydrogenases,Oxidases,Oxidoreductase,Reductases,Dehydrogenase,Oxidase,Reductase
D002384	Catalysis	The facilitation of a chemical reaction by material (catalyst) that is not consumed by the reaction.	Catalyses
D003198	Computer Simulation	Computer-based representation of physical systems and phenomena such as chemical processes.	Computational Modeling,Computational Modelling,Computer Models,In silico Modeling,In silico Models,In silico Simulation,Models, Computer,Computerized Models,Computer Model,Computer Simulations,Computerized Model,In silico Model,Model, Computer,Model, Computerized,Model, In silico,Modeling, Computational,Modeling, In silico,Modelling, Computational,Simulation, Computer,Simulation, In silico,Simulations, Computer
D004058	Diffusion	The tendency of a gas or solute to pass from a point of higher pressure or concentration to a point of lower pressure or concentration and to distribute itself throughout the available space. Diffusion, especially FACILITATED DIFFUSION, is a major mechanism of BIOLOGICAL TRANSPORT.	Diffusions
D004121	Dimethyl Sulfoxide	A highly polar organic liquid, that is used widely as a chemical solvent. Because of its ability to penetrate biological membranes, it is used as a vehicle for topical application of pharmaceuticals. It is also used to protect tissue during CRYOPRESERVATION. Dimethyl sulfoxide shows a range of pharmacological activity including analgesia and anti-inflammation.	DMSO,Dimethyl Sulphoxide,Dimethylsulfoxide,Dimethylsulphinyl,Dimethylsulphoxide,Dimexide,Rheumabene,Rimso,Rimso 100,Rimso-50,Sclerosol,Sulfinylbis(methane),Rimso 50,Rimso50,Sulfoxide, Dimethyl,Sulphoxide, Dimethyl
D004563	Electrochemistry	The study of chemical changes resulting from electrical action and electrical activity resulting from chemical changes.	Electrochemistries
D004566	Electrodes	Electric conductors through which electric currents enter or leave a medium, whether it be an electrolytic solution, solid, molten mass, gas, or vacuum.	Anode,Anode Materials,Cathode,Cathode Materials,Anode Material,Anodes,Cathode Material,Cathodes,Electrode,Material, Anode,Material, Cathode