Variable-Temperature Spectroelectrochemical Study of Horseradish Peroxidase

Farhangrazi, Z. Shadi; Fossett, Martin E.; Powers, Linda S.; Ellis, Walther R.

doi:10.1021/bi00009a017

Cited by 92 publications

(64 citation statements)

References 28 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Reduction potentials for the E1/E2 and E2/HRP(Fe(III)) redox couples determined by spectroelectrochemical titration with mediators have very similar values in acid and neutral solutions and approach 700 and 680 mV (Ag/AgCl) at pH 7.0 and ionic strength of 0.1, respectively [27,28]. These redox potentials are pHdependent and shift to more positive values with decreasing pH, correspondingly to 790 and 770 mV at pH 6.0 [29].…”

Section: Peroxidase Bioelectrocatalytic Cyclesmentioning

confidence: 99%

Direct Peroxidase Bioelectrocatalysis on a Variety of Electrode Materials

Ferapontova¹

2004

Electroanalysis

117

101

View full text Add to dashboard Cite

The role of the electrode material in the efficiency of direct (non-mediated) bioelectrocatalytic reduction of H 2 O 2 catalyzed by horseradish peroxidase (HRP) is studied and discussed. The variations in direct peroxidase bioelectrocatalysis when coming from carbon/graphite to metal electrodes and oxides, as well as modified electrodes, are analyzed regarding the variations in adsorption/orientation of peroxidase at the electrodes, interfacial electron transfer rates and mechanism of catalysis.

show abstract

Section: Peroxidase Bioelectrocatalytic Cyclesmentioning

confidence: 99%

Direct Peroxidase Bioelectrocatalysis on a Variety of Electrode Materials

Ferapontova¹

2004

Electroanalysis

117

101

View full text Add to dashboard Cite

show abstract

“…Redox Potential of Fe 2ϩ /Fe 3ϩ Couple-Redox potential of Fe 2ϩ /Fe 3ϩ couple is also one of the factors reflecting the formation of compounds I and II in the peroxidases (40). The monitored electrode potentials against the ratio of the reduced form to the total amount of enzyme were fitted well by the theoretical Nernst equation (Equation 1) (data not shown).…”

mentioning

confidence: 93%

Detection of a Tryptophan Radical as an Intermediate Species in the Reaction of Horseradish Peroxidase Mutant (Phe-221 → Trp) and Hydrogen Peroxide

Morimoto¹,

Tanaka²,

Takahashi³

et al. 1998

Journal of Biological Chemistry

View full text Add to dashboard Cite

The crucial reaction intermediate in the reaction of peroxidase with hydrogen peroxide (H 2 O 2 ), compound I, contains a porphyrin -cation radical in horseradish peroxidase (HRP), which catalyzes oxidation of small organic and inorganic compounds, whereas cytochrome c peroxidase (CcP) has a radical center on the tryptophan residue (Trp-191) and oxidizes the redox partner, cytochrome c. To investigate the roles of the amino acid residue near the heme active center in discriminating the function of the peroxidases in these two enzymes, we prepared a CcP-like HRP mutant, F221W (Phe-221 3 Trp). Although the rapid spectral scanning and stoppedflow experiments confirmed that the F221W mutant reacts with H 2 O 2 to form the porphyrin -cation radical at the same rate as for the wild-type enzyme, the characteristic spectral features of the porphyrin -cation radical disappeared rapidly, and were converted to the compound II-type spectrum. The EPR spectrum of the resultant species produced by reduction of the porphyrin -cation radical, however, was quite different from that of compound II in HRP, showing typical signals from a Trp radical as found for CcP. The sequential radical formation from the porphyrin ring to the Trp residue implies that the proximal Trp is a key residue in the process of the radical transfer from the porphyrin ring, which differentiates the function of peroxidases.

show abstract

“…An obvious pair of peaks corresponding to the reversible oxidation of the intact active enzyme was obtained (Fig. 4a) [22]. A control experiment with the electrode modified with heme-DSPG-CaCO 3 microparticles under the same conditions was carried out as well, and no response was found.…”

Section: Resultsmentioning

confidence: 94%

Direct Electrochemistry of Horseradish Peroxidase Immobilized in Calcium Carbonate Microsphere Doped with Phospholipids

Liu

et al. 2008

Electroanalysis

View full text Add to dashboard Cite

Protein electrochemistry affords a direct method to study the biological electron transfer processes. However, supplying a biocompatible environment to maintain the native state of protein is all-important and challengeable. Here, we chose vaterite, one of the crystalline polymorphs of calcium carbonate, with highly porous nature and large specific surface area, which was doped with phospholipids, as the matrix to immobilize horseradish peroxidase (HRP). The integrity of HRP was kept during the simple immobilization procedure. By virtue of this organic/inorganic complex matrix, the direct electrochemistry of HRP was realized, and the activity of HRP for catalyzing reduction of O 2 and H 2 O 2 was preserved.

show abstract

Variable-Temperature Spectroelectrochemical Study of Horseradish Peroxidase

Cited by 92 publications

References 28 publications

Direct Peroxidase Bioelectrocatalysis on a Variety of Electrode Materials

Direct Peroxidase Bioelectrocatalysis on a Variety of Electrode Materials

Detection of a Tryptophan Radical as an Intermediate Species in the Reaction of Horseradish Peroxidase Mutant (Phe-221 → Trp) and Hydrogen Peroxide

Direct Electrochemistry of Horseradish Peroxidase Immobilized in Calcium Carbonate Microsphere Doped with Phospholipids

Contact Info

Product

Resources

About