Electrochemical studies of heme proteins. Coulometric, polarographic, and combined spectroelectrochemical methods for reduction of the heme prosthetic group in cytochrome c

Betso, Stephen R.; Klapper, Michael H.; Anderson, Larry B.

doi:10.1021/ja00778a042

Cited by 147 publications

(25 citation statements)

References 1 publication

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Polarography applied to the metalloporphyrin group of proteins was started by study of hemin [52,53], but it was concluded that natural hemoproteins due to their high molecular weight are not amenable to polarographic investigation [54]. However, other authors could obtain 2 well-defined polarographic reduction waves with human methemoglobin [55], and a 1-electron reduction wave of heme iron in cytochrome c [56]. From polarographic behavior of cytochrome c 3 it was concluded that the 4 hemes per molecule accept stepwise 4 electrons in course of reduction [57].…”

Section: Activity Of Prosthetic Groupsmentioning

confidence: 99%

Early Polarographic Studies on Proteins

Heyrovský

2004

Electroanalysis

View full text Add to dashboard Cite

The first effects of proteins observed with the dropping mercury electrode were catalytic, due to evolution of hydrogen in weakly alkaline solutions. Catalytic lowering of hydrogen overvoltage in presence of cobalt ions, the socalled Brdicka reaction, became the main means for polarographic study of proteins. Apart from that, polarography has been used for following proteins in their adsorption on the electrode surface, in their anodic reaction with mercury at positive potentials, in reduction of the disulfidic bonds of their components, in their complexation with metallic ions in the solution, in electrode reactions of their prosthetic groups and in antigen-antibody interactions. Our review is limited to applications of the dropping mercury electrode.

show abstract

Section: Activity Of Prosthetic Groupsmentioning

confidence: 99%

Early Polarographic Studies on Proteins

Heyrovský

2004

Electroanalysis

View full text Add to dashboard Cite

show abstract

“…It is not surprising then that the mercury-water interface was the first to be used for the electrochemical investigation of electron-transfer reactions of redox proteins. Cytochrome c has been studied extensively (see, for example Betso et al 1972;Scheller et al 1976a, b) at the mercury electrode and, in summary, found to adsorb increasingly strongly at higher protein concentrations. In the same way, although there were early reports of rapid electron transfer from the mercury electrode to ferredoxins, more recent work (Kakutani et al 1980) has again suggested that very strong adsorption of these proteins takes place at the electrode surface.…”

Section: (E) Rubredoxinmentioning

confidence: 99%

Reactions of electron-transfer proteins at electrodes

Allen

Hill

et al. 1985

Quart. Rev. Biophys.

148

View full text Add to dashboard Cite

Studies of electron-transfer reactions of redox proteins have, in recent years, attracted widespread interest and attention. Progress has been evident from both physical and biological standpoints, with the increasing availability of three-dimensional structural data for many small electron-transfer proteins prompting a variety of systematic investigations (Isied, 1985). Most recently, attention has been directed towards questions concerning the elementary transfer of electrons between spatially remote redox sites, and the nature of protein–protein interactions which, for intermolecular processes, stabilize specific precursor complexes which may be optimally juxtaposed for electron-transfer. These and other issues, including the necessary reversibility of protein interfacial interactions and the dynamic properties of proteins as carriers of electrons in biological electron-transport systems, are now being addressed in the rapidly emerging field of direct (unmediated) protein electrochemistry. It is our intention in this article to discuss developments made in this area and highlight points which we believe to have the most bearing on our current understanding of diffusion-dominated, protein-mediated electron transport at electrode surfaces. First we shall outline some basic considerations which are best considered with reference to homogeneous systems.

show abstract

“…Also, thermodynamically, cytochrome cox should be more readily reduced at the electrode than any of the bipyridylium dications. Although cytochrome c has been reported to be electrochemically reduced [22], the rate of the heterogeneous electron transfer is exceedingly slow at the O T E s employed in this work. Thus, when the electrode potential is stepped to a value at which a dication is reduced at diffusion controlled rates, the electron transfer to oxidized cytochrome c proceeds essentially quantitatively through reactions (7)-(8), particularly if the total step time is kept short.…”

Section: Rates Of Electron Transfer From Radical Cations To Oxidized mentioning

confidence: 89%

Spectroelectrochemical Study of Mediators I. Bipyridylium Salts and Their Electron Transfer Rates to Cytochrome c

Steckhan

Kuwana

1974

Ber Bunsenges Phys Chem

151

View full text Add to dashboard Cite

In many potentiometric titrations of biological electron transfer components, mediators are often employed to act as electron transfer mediators between the components and the potentiometric electrode. Certain mediators have been employed recently as electrogenerated titrants of components in coulometric titrations, particularly in some spectroelectrochemical studies. In this paper, the optical and electrochemical characteristics of some bipyridylium salts are examined as mediator‐titrants. These salts (dications) undergo a reversible one electron reduction to the radical cation which can be a good reductant. Spectroelectrochemistry has also been applied to the evaluation of the rate of electron transfer from the radical to oxidized cytochrome c. The results reported herein are a part of our interest in evaluating the electron transfer properties of heme proteins found in the mammalian respiratory system.

show abstract

Electrochemical studies of heme proteins. Coulometric, polarographic, and combined spectroelectrochemical methods for reduction of the heme prosthetic group in cytochrome c

Cited by 147 publications

References 1 publication

Early Polarographic Studies on Proteins

Early Polarographic Studies on Proteins

Reactions of electron-transfer proteins at electrodes

Spectroelectrochemical Study of Mediators I. Bipyridylium Salts and Their Electron Transfer Rates to Cytochrome c

Contact Info

Product

Resources

About