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Peroxide-dependent analyte conversion by the heme prosthetic group, the heme Peptide "microperoxidase-11" and cytochrome C on chitosan capped gold nanoparticles modified electrodes.

Yarman A, Neumann B, Bosserdt M, Gajovic-Eichelmann N, Scheller FW - Biosensors (Basel) (2012)

Bottom Line: In view of the role ascribed to the peroxidatic activity of degradation products of cytochrome c (cyt c) in the processes of apoptosis, we investigate the catalytic potential of heme and of the cyt c derived heme peptide MP-11 to catalyse the cathodic reduction of hydrogen peroxide and to oxidize aromatic compounds.The electrochemical signal for the peroxide reduction is generated by the redox conversion of the heme group, whilst a reaction product of the substrate oxidation is cathodically reduced in the substrate indication.The peroxidatic activity of cyt c immobilized in the chitosan layer for catechol was found to be below 1 per mill and for p-aminophenol about 3% as compared with that of heme or MP-11.

View Article: PubMed Central - PubMed

Affiliation: Fraunhofer Institute for Biomedical Engineering, IBMT, D-14476 Potsdam, Germany. aysu.yarman@yahoo.de.

ABSTRACT
In view of the role ascribed to the peroxidatic activity of degradation products of cytochrome c (cyt c) in the processes of apoptosis, we investigate the catalytic potential of heme and of the cyt c derived heme peptide MP-11 to catalyse the cathodic reduction of hydrogen peroxide and to oxidize aromatic compounds. In order to check whether cyt c has an enzymatic activity in the native state where the protein matrix should suppress the inherent peroxidatic activity of its heme prosthetic group, we applied a biocompatible immobilization matrix and very low concentrations of the co-substrate H2O2. The biocatalysts were entrapped on the surface of a glassy carbon electrode in a biocompatible chitosan layer which contained gold nanoparticles. The electrochemical signal for the peroxide reduction is generated by the redox conversion of the heme group, whilst a reaction product of the substrate oxidation is cathodically reduced in the substrate indication. The catalytic efficiency of microperoxidase-11 is sufficient for sensors indicating HRP substrates, e.g., p-aminophenol, paracetamol and catechol, but also the hydroxylation of aniline and dehalogenation of 4-fluoroaniline. The lower limit of detection for p-aminophenol is comparable to previously published papers with different enzyme systems. The peroxidatic activity of cyt c immobilized in the chitosan layer for catechol was found to be below 1 per mill and for p-aminophenol about 3% as compared with that of heme or MP-11.

No MeSH data available.


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Concentration dependence for aniline at 0 V of the Hemin-AuNP-CH/GCE.
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biosensors-02-00189-f006: Concentration dependence for aniline at 0 V of the Hemin-AuNP-CH/GCE.

Mentions: In contrast to catechol and paracetamol with hemin based sensor, for aniline no response was obtained in the lower micromolar range, but the current increased linearly between 124.9 and 871 µM on stepwise addition of aniline in the presence of 10 µM peroxide (Figure 6).


Peroxide-dependent analyte conversion by the heme prosthetic group, the heme Peptide "microperoxidase-11" and cytochrome C on chitosan capped gold nanoparticles modified electrodes.

Yarman A, Neumann B, Bosserdt M, Gajovic-Eichelmann N, Scheller FW - Biosensors (Basel) (2012)

Concentration dependence for aniline at 0 V of the Hemin-AuNP-CH/GCE.
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4263574&req=5

biosensors-02-00189-f006: Concentration dependence for aniline at 0 V of the Hemin-AuNP-CH/GCE.
Mentions: In contrast to catechol and paracetamol with hemin based sensor, for aniline no response was obtained in the lower micromolar range, but the current increased linearly between 124.9 and 871 µM on stepwise addition of aniline in the presence of 10 µM peroxide (Figure 6).

Bottom Line: In view of the role ascribed to the peroxidatic activity of degradation products of cytochrome c (cyt c) in the processes of apoptosis, we investigate the catalytic potential of heme and of the cyt c derived heme peptide MP-11 to catalyse the cathodic reduction of hydrogen peroxide and to oxidize aromatic compounds.The electrochemical signal for the peroxide reduction is generated by the redox conversion of the heme group, whilst a reaction product of the substrate oxidation is cathodically reduced in the substrate indication.The peroxidatic activity of cyt c immobilized in the chitosan layer for catechol was found to be below 1 per mill and for p-aminophenol about 3% as compared with that of heme or MP-11.

View Article: PubMed Central - PubMed

Affiliation: Fraunhofer Institute for Biomedical Engineering, IBMT, D-14476 Potsdam, Germany. aysu.yarman@yahoo.de.

ABSTRACT
In view of the role ascribed to the peroxidatic activity of degradation products of cytochrome c (cyt c) in the processes of apoptosis, we investigate the catalytic potential of heme and of the cyt c derived heme peptide MP-11 to catalyse the cathodic reduction of hydrogen peroxide and to oxidize aromatic compounds. In order to check whether cyt c has an enzymatic activity in the native state where the protein matrix should suppress the inherent peroxidatic activity of its heme prosthetic group, we applied a biocompatible immobilization matrix and very low concentrations of the co-substrate H2O2. The biocatalysts were entrapped on the surface of a glassy carbon electrode in a biocompatible chitosan layer which contained gold nanoparticles. The electrochemical signal for the peroxide reduction is generated by the redox conversion of the heme group, whilst a reaction product of the substrate oxidation is cathodically reduced in the substrate indication. The catalytic efficiency of microperoxidase-11 is sufficient for sensors indicating HRP substrates, e.g., p-aminophenol, paracetamol and catechol, but also the hydroxylation of aniline and dehalogenation of 4-fluoroaniline. The lower limit of detection for p-aminophenol is comparable to previously published papers with different enzyme systems. The peroxidatic activity of cyt c immobilized in the chitosan layer for catechol was found to be below 1 per mill and for p-aminophenol about 3% as compared with that of heme or MP-11.

No MeSH data available.


Related in: MedlinePlus