Electrochemical and spectroreflectance studies of the adsorbed horse heart cytochrome c and cytochrome c3 from D. Vulgaris, miyazaki strain, at gold electrode

Hinnen, C.; Parsons, Roger; Niki, Katsumi

doi:10.1016/s0022-0728(83)80079-5

Cited by 121 publications

(49 citation statements)

References 33 publications

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“…Intensive research has shown it is not easy to achieve DET to cyt c at solid electrode surfaces, since the redox-active heme centre is wrapped by the peptide chain and protected from the solvent 15,16 . It is known that Cyt c adsorbs strongly on conventional metal electrodes like Pt, Hg, Au or Ag 17 and conformational changes suffered by the protein (unfolding and/or denaturation) lead to slow electrontransfer kinetics 18,19 . This difficulty has been overcome by using electrode modifiers such as metal oxides, advanced carbon materials, DNA or lipid membranes [20][21][22][23][24][25][26] .…”

Section: Introductionmentioning

confidence: 99%

Direct Electron Transfer to Cytochrome c Induced by a Conducting Polymer

et al. 2017

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The direct electron transfer (DET) to redox proteins has become a central topic in the development of biotechnological devices. The present work explores the mechanisms of the direct electrochemistry between cytochrome c and a conducting polymer, PEDOT-PSS. This polymer has been electrosynthesized from its monomers in aqueous solution on gold electrodes and its capabilities for DET to cyt c have been examined by electrochemical and spectroelectrochemical methods. The polymer was electrodeposited with controlled thickness and we determined the electron transfer rate constant for cyt c oxidation was about 2 orders of magnitude higher than those obtained at conventional electrodes. Spectroelectrochemical measurements allowed to evaluate the redox state of the polymer as a function of the potential and, in addition, the observation of intrinsic cyt c redox activity upon electron transfer from the conducting polymer. During the oxidation process of this protein, lysine residues placed near the heme crevice interact electrostatically with the anionic polyelectrolyte PSS. This interaction favors the orientation of the heme group towards the chains of PEDOT backbone, which is the eventual responsible for the electron transfer to the protein.3

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Section: Introductionmentioning

confidence: 99%

Direct Electron Transfer to Cytochrome c Induced by a Conducting Polymer

et al. 2017

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“…In like manner, polishing of an edge-plane pyrolytic graphite (EPG) electrode in air produces [5] One of the roles the electrode surface functionalities may play in promoting protein electrochemistry is to prevent degradative adsorption. It is a well accepted fact that, at Hg [7] or untreated metal electrodes [8], cyt c usually undergoes irreversible adsorption accompanied by loss of activity, as illustrated by the shifted redox potential (z -0.5 V). Nevertheless, if the metal electrode is preconditioned by some special treatments and thus transformed from a hydrophobic to a hydrophilic surface, quasi-reversible cyclic voltammetric response with a mid-point potential consistent with the redox potential of native cyt c (+ 0.02 V) was [9] observed.…”

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confidence: 99%

Direct electrochemistry of proteins

Burrows¹,

Guo²,

Hill³

et al. 1991

European Journal of Biochemistry

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Direct electrochemistry of site-specific mutants of yeast iso-I-cytochrome c (cyt c) and their complexes with bovine cytochrome b5 (cyt b5) has been investigated at edge-plane pyrolytic graphite (EPG) and bis(4-pyridy1)-disulphide-modified gold electrodes. Structure/function relationships have been investigated with the particular aim of clarifying the factors controlling the interactions of proteins at electrode/electrolyte interfaces and the determinants for direct electrochemistry in ternary protein/protein/electrode adducts, e.g. cyt c/cyt bs/EPG. Investigations of the cyt c mutants alone revealed a variety of electrochemical responses: all the mutants show similar voltammetric reversibility at modified gold electrodes, whereas at EPG electrodes the reversibility follows the order: Asn5211e -Cysl02Thr > Cysl02Thr > Asn52Ala -Cysl02Thr. Mid-point potentials follow the order:The structural basis for these differences is briefly discussed. When these mutants are bound to cyt bs, the differences in electrochemical response are greatly enhanced in the ternary cyt clcyt b5/EPG adducts. A minimal analysis of these differences supports a model of multiple overlapping binding and recognition domains on cyt c which may be finely tuned to allow ternary complex formation so that a single-site variation could modify or abolish direct electrochemistry in the ternary adduct.Although a relatively new technique, direct bioelectrochemistry can provide [I -31 novel insights into structure/ function relationships in redox proteins. It appears that some of the same features control protein -protein recognition as well as protein -electrode surface recognition. However, both types of interactions remain incompletely defined.In general, it is known that, in order to achieve efficiently fast electron transfer to a protein, the electrode must be functionalised to provide a relatively specific surface for the protein to bind reversibly. For example, modification of a gold electrode by pyridine derivatives [4] provides a polar hydrogen bonding surface which appears to recognize and bind proteins like horse heart cytochrome c (cyt c), thereby promoting electrochemical reaction exemplified by quasi-reversible cyclic voltammograms. In the absence of such modification, nonspecific protein adsorption may readily occur leading to an electrochemically insulating surface layer. In like manner, polishing of an edge-plane pyrolytic graphite (EPG) electrode in air produces [5] One of the roles the electrode surface functionalities may play in promoting protein electrochemistry is to prevent degradative adsorption. It is a well accepted fact that, at Hg [7] or untreated metal electrodes [8], cyt c usually undergoes irreversible adsorption accompanied by loss of activity, as illustrated by the shifted redox potential (z -0.5 V). Nevertheless, if the metal electrode is preconditioned by some special treatments and thus transformed from a hydrophobic to a hydrophilic surface, quasi-reversible cyclic voltammetric response with a mid-point potential ...

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“…5, 11,17,8,14, [4]arene-monocrown-3 (7). 0.24 g (0.24 mmol) of thiacalixcrown 3 and 0.11 g (0.96 mmol) of potassium thioacetate were stirred in 10 mL of DMF for 3 h at 90 0 С.…”

Section: ⋅Minmentioning

confidence: 99%

“…[1][2][3] However, electrostatic physisorption of biomolecules (for example, cytochrome c ) onto planar gold surface is not effective and has been shown to result in drastic changes in its conformation and often in denaturation of protein. [4,5] Surface functionalization using a self-assembled monolayer (SAM) is of great importance for engineering biosensor devices, which use electrical current or UV-Vis absorption involving protein mediation. [6] It plays a key role because of shedding absorbed biomolecules from the excessive electron density of the metal and binds targeting proteins through the establishment of complementary intermolecular interactions.…”

Section: Introductionmentioning

confidence: 99%