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Di Rocco G, Ranieri A, Borsari M, Sola M, Bortolotti CA, Battistuzzi G. Assessing the Functional and Structural Stability of the Met80Ala Mutant of Cytochrome c in Dimethylsulfoxide. Molecules 2022; 27:molecules27175630. [PMID: 36080396 PMCID: PMC9458088 DOI: 10.3390/molecules27175630] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2022] [Revised: 08/24/2022] [Accepted: 08/26/2022] [Indexed: 12/02/2022] Open
Abstract
The Met80Ala variant of yeast cytochrome c is known to possess electrocatalytic properties that are absent in the wild type form and that make it a promising candidate for biocatalysis and biosensing. The versatility of an enzyme is enhanced by the stability in mixed aqueous/organic solvents that would allow poorly water-soluble substrates to be targeted. In this work, we have evaluated the effect of dimethylsulfoxide (DMSO) on the functionality of the Met80Ala cytochrome c mutant, by investigating the thermodynamics and kinetics of electron transfer in mixed water/DMSO solutions up to 50% DMSO v/v. In parallel, we have monitored spectroscopically the retention of the main structural features in the same medium, focusing on both the overall protein structure and the heme center. We found that the organic solvent exerts only minor effects on the redox and structural properties of the mutant mostly as a result of the modification of the dielectric constant of the solvent. This would warrant proper functionality of this variant also under these potentially hostile experimental conditions, that differ from the physiological milieu of cytochrome c.
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Affiliation(s)
- Giulia Di Rocco
- Department of Life Sciences, University of Modena and Reggio Emilia, Via Campi 103, 41125 Modena, Italy
| | - Antonio Ranieri
- Department of Life Sciences, University of Modena and Reggio Emilia, Via Campi 103, 41125 Modena, Italy
| | - Marco Borsari
- Department of Chemical and Geological Sciences, University of Modena and Reggio Emilia, Via Campi 103, 41125 Modena, Italy
| | - Marco Sola
- Department of Life Sciences, University of Modena and Reggio Emilia, Via Campi 103, 41125 Modena, Italy
| | - Carlo Augusto Bortolotti
- Department of Life Sciences, University of Modena and Reggio Emilia, Via Campi 103, 41125 Modena, Italy
- Correspondence: (C.A.B.); (G.B.); Tel.: +39-0592058608 (C.A.B.); +39-059208639 (G.B.)
| | - Gianantonio Battistuzzi
- Department of Chemical and Geological Sciences, University of Modena and Reggio Emilia, Via Campi 103, 41125 Modena, Italy
- Correspondence: (C.A.B.); (G.B.); Tel.: +39-0592058608 (C.A.B.); +39-059208639 (G.B.)
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Di Rocco G, Battistuzzi G, Borsari M, Bortolotti CA, Ranieri A, Sola M. The enthalpic and entropic terms of the reduction potential of metalloproteins: Determinants and interplay. Coord Chem Rev 2021. [DOI: 10.1016/j.ccr.2021.214071] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
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Lancellotti L, Borsari M, Bellei M, Bonifacio A, Bortolotti CA, Di Rocco G, Ranieri A, Sola M, Battistuzzi G. Urea-induced denaturation of immobilized yeast iso-1 cytochrome c: Role of Met80 and Tyr67 in the thermodynamics of unfolding and promotion of pseudoperoxidase and nitrite reductase activities. Electrochim Acta 2020. [DOI: 10.1016/j.electacta.2020.137237] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
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Adsorbing surface strongly influences the pseudoperoxidase and nitrite reductase activity of electrode-bound yeast cytochrome c. The effect of hydrophobic immobilization. Bioelectrochemistry 2020; 136:107628. [PMID: 32795942 DOI: 10.1016/j.bioelechem.2020.107628] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2020] [Revised: 07/31/2020] [Accepted: 07/31/2020] [Indexed: 02/02/2023]
Abstract
The Met80Ala and Met80Ala/Tyr67Ala variants of S. cerevisiae iso-1 cytochrome c (ycc) and their adducts with cardiolipin immobilized onto a gold electrode coated with a hydrophobic self-assembled monolayer (SAM) of decane-1-thiol were studied through cyclic voltammetry and surface-enhanced resonance Raman spectroscopy (SERRS). The electroactive species - containing a six-coordinate His/His axially ligated heme and a five-coordinate His/- heme stable in the oxidized and reduced state, respectively - and the pseudoperoxidase activity match those found previously for the wt species and are only slightly affected by CL binding. Most importantly, the reduced His/- ligated form of these variants is able to catalytically reduce the nitrite ion, while electrode-immobilized wt ycc and other His/Met heme ligated variants under a variety of conditions are not. Besides the pseudoperoxidase and nitrite reductase functions, which are the most physiologically relevant abilities of these constructs, also axial heme ligation and the equilibria between conformers are strongly affected by the nature - hydrophobic vs. electrostatic - of the non-covalent interactions determining protein immobilization. Also affected are the catalytic activity changes induced by a given mutation as well as those due to partial unfolding due to CL binding. It follows that under the same solution conditions the structural and functional properties of immobilized ycc are surface-specific and therefore cannot be transferred from an immobilized system to another involving different interfacial protein-SAM interactions.
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Paradisi A, Lancellotti L, Borsari M, Bellei M, Bortolotti CA, Di Rocco G, Ranieri A, Sola M, Battistuzzi G. Met80 and Tyr67 affect the chemical unfolding of yeast cytochrome c: comparing the solution vs.immobilized state. RSC Chem Biol 2020. [DOI: 10.1039/d0cb00115e] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
Abstract
The motional regime affects the unfolding propensity and axial heme coordination of the Met80Ala and Met80Ala/Tyr67Ala variants of yeast iso-1 cytochromec.
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Affiliation(s)
| | - Lidia Lancellotti
- Department of Chemistry and Geology
- University of Modena and Reggio Emilia
- 41126 Modena
- Italy
| | - Marco Borsari
- Department of Chemistry and Geology
- University of Modena and Reggio Emilia
- 41126 Modena
- Italy
| | - Marzia Bellei
- Department of Life Sciences
- University of Modena and Reggio Emilia
- 41126 Modena
- Italy
| | | | - Giulia Di Rocco
- Department of Life Sciences
- University of Modena and Reggio Emilia
- 41126 Modena
- Italy
| | - Antonio Ranieri
- Department of Life Sciences
- University of Modena and Reggio Emilia
- 41126 Modena
- Italy
| | - Marco Sola
- Department of Life Sciences
- University of Modena and Reggio Emilia
- 41126 Modena
- Italy
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Sepasi Tehrani H, Moosavi-Movahedi AA. Catalase and its mysteries. PROGRESS IN BIOPHYSICS AND MOLECULAR BIOLOGY 2018. [PMID: 29530789 DOI: 10.1016/j.pbiomolbio.2018.03.001] [Citation(s) in RCA: 147] [Impact Index Per Article: 24.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Catalase is one of the firsts in every realm of biological sciences. At the same time it also has a number of unusual features. It has one of the highest turnover numbers of all enzymes. It is essential for neutralizing the noxious hydrogen peroxide both in the nature and the various industries such as dairy, textile and pharmaceutics. It also has the merit of being one of the first protein crystals to be isolated. Ironically its three-dimensional structure was discerned some forty years later. However through the times this senile enzyme has continued to intrigue the scientists by surprising facts and phenomena, such as peculiar interweaving of subunits and remarkable thermal stability. It is also known for suicide inactivation by its own substrate. Catalase is known to be implicated in various medical scenarios and its levels have served as a marker in that capacity. It has even been incorporated into several pharmaceuticals. This review strives to clarify these perspectives. It also draws attention to the biophysical contributions offered by thermodynamics and kinetics in these discoveries. The ultimate aim of this review, however, is to state that the venerable catalase will continue to bewilder us with its mysteries well into the twenty-first century.
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Affiliation(s)
- Hessam Sepasi Tehrani
- Department of Biology, Islamic Azad University, Science and Research Branch, Tehran, Iran.
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7
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Bellei M, Bortolotti CA, Di Rocco G, Borsari M, Lancellotti L, Ranieri A, Sola M, Battistuzzi G. The influence of the Cys46/Cys55 disulfide bond on the redox and spectroscopic properties of human neuroglobin. J Inorg Biochem 2018; 178:70-86. [DOI: 10.1016/j.jinorgbio.2017.10.005] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2017] [Revised: 09/21/2017] [Accepted: 10/09/2017] [Indexed: 12/21/2022]
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Gasselhuber B, Carpena X, Graf MMH, Pirker KF, Nicolussi A, Sündermann A, Hofbauer S, Zamocky M, Furtmüller PG, Jakopitsch C, Oostenbrink C, Fita I, Obinger C. Eukaryotic Catalase-Peroxidase: The Role of the Trp-Tyr-Met Adduct in Protein Stability, Substrate Accessibility, and Catalysis of Hydrogen Peroxide Dismutation. Biochemistry 2015; 54:5425-38. [DOI: 10.1021/acs.biochem.5b00831] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Bernhard Gasselhuber
- Department
of Chemistry, Division of Biochemistry, BOKU-University of Natural Resources and Life Sciences, Muthgasse 18, A-1190 Vienna, Austria
| | - Xavi Carpena
- Institut de Biologia Molecular (IBMB-CSIC), Parc Cientific de Barcelona, Baldiri Reixac 10-12, 08028 Barcelona, Spain
| | - Michael M. H. Graf
- Department
of Material Sciences and Process Engineering, Institute for Molecular
Modeling and Simulation, BOKU-University of Natural Resources and Life Sciences, Muthgasse 18, A-1190 Vienna, Austria
| | - Katharina F. Pirker
- Department
of Chemistry, Division of Biochemistry, BOKU-University of Natural Resources and Life Sciences, Muthgasse 18, A-1190 Vienna, Austria
| | - Andrea Nicolussi
- Department
of Chemistry, Division of Biochemistry, BOKU-University of Natural Resources and Life Sciences, Muthgasse 18, A-1190 Vienna, Austria
| | - Axel Sündermann
- Department
of Material Sciences and Process Engineering, Institute for Molecular
Modeling and Simulation, BOKU-University of Natural Resources and Life Sciences, Muthgasse 18, A-1190 Vienna, Austria
| | - Stefan Hofbauer
- Department
for Structural and Computational Biology, Max F. Perutz Laboratories, University of Vienna, Campus Biocenter 5, A-1030 Vienna, Austria
| | - Marcel Zamocky
- Department
of Chemistry, Division of Biochemistry, BOKU-University of Natural Resources and Life Sciences, Muthgasse 18, A-1190 Vienna, Austria
- Institute
of Molecular Biology, Slovak Academy of Sciences, Dubravska cesta
21, SK-84551 Bratislava, Slovakia
| | - Paul G. Furtmüller
- Department
of Chemistry, Division of Biochemistry, BOKU-University of Natural Resources and Life Sciences, Muthgasse 18, A-1190 Vienna, Austria
| | - Christa Jakopitsch
- Department
of Chemistry, Division of Biochemistry, BOKU-University of Natural Resources and Life Sciences, Muthgasse 18, A-1190 Vienna, Austria
| | - Chris Oostenbrink
- Department
of Material Sciences and Process Engineering, Institute for Molecular
Modeling and Simulation, BOKU-University of Natural Resources and Life Sciences, Muthgasse 18, A-1190 Vienna, Austria
| | - Ignacio Fita
- Institut de Biologia Molecular (IBMB-CSIC), Parc Cientific de Barcelona, Baldiri Reixac 10-12, 08028 Barcelona, Spain
| | - Christian Obinger
- Department
of Chemistry, Division of Biochemistry, BOKU-University of Natural Resources and Life Sciences, Muthgasse 18, A-1190 Vienna, Austria
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Kudalkar SN, Njuma OJ, Li Y, Muldowney M, Fuanta NR, Goodwin DC. A role for catalase-peroxidase large loop 2 revealed by deletion mutagenesis: control of active site water and ferric enzyme reactivity. Biochemistry 2015; 54:1648-62. [PMID: 25674665 DOI: 10.1021/bi501221a] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Catalase-peroxidases (KatGs), the only catalase-active members of their superfamily, all possess a 35-residue interhelical loop called large loop 2 (LL2). It is essential for catalase activity, but little is known about its contribution to KatG function. LL2 shows weak sequence conservation; however, its length is nearly identical across KatGs, and its apex invariably makes contact with the KatG-unique C-terminal domain. We used site-directed and deletion mutagenesis to interrogate the role of LL2 and its interaction with the C-terminal domain in KatG structure and catalysis. Single and double substitutions of the LL2 apex had little impact on the active site heme [by magnetic circular dichroism or electron paramagnetic resonance (EPR)] and activity (catalase or peroxidase). Conversely, deletion of a single amino acid from the LL2 apex reduced catalase activity by 80%. Deletion of two or more apex amino acids or all of LL2 diminished catalase activity by 300-fold. Peroxide-dependent but not electron donor-dependent kcat/KM values for deletion variant peroxidase activity were reduced 20-200-fold, and kon for cyanide binding diminished by 3 orders of magnitude. EPR spectra for deletion variants were all consistent with an increase in the level of pentacoordinate high-spin heme at the expense of hexacoordinate high-spin states. Together, these data suggest a shift in the distribution of active site waters, altering the reactivity of the ferric state, toward, among other things, compound I formation. These results identify the importance of LL2 length conservation for maintaining an intersubunit interaction that is essential for an active site water distribution that facilitates KatG catalytic activity.
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Affiliation(s)
- Shalley N Kudalkar
- Department of Chemistry and Biochemistry, Auburn University , Auburn, Alabama 36849-5312, United States
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Njuma OJ, Ndontsa EN, Goodwin DC. Catalase in peroxidase clothing: Interdependent cooperation of two cofactors in the catalytic versatility of KatG. Arch Biochem Biophys 2013; 544:27-39. [PMID: 24280274 DOI: 10.1016/j.abb.2013.11.007] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2013] [Revised: 11/11/2013] [Accepted: 11/15/2013] [Indexed: 11/26/2022]
Abstract
Catalase-peroxidase (KatG) is found in eubacteria, archaea, and lower eukaryotae. The enzyme from Mycobacterium tuberculosis has received the greatest attention because of its role in activation of the antitubercular pro-drug isoniazid, and the high frequency with which drug resistance stems from mutations to the katG gene. Generally, the catalase activity of KatGs is striking. It rivals that of typical catalases, enzymes with which KatGs share no structural similarity. Instead, catalatic turnover is accomplished with an active site that bears a strong resemblance to a typical peroxidase (e.g., cytochrome c peroxidase). Yet, KatG is the only member of its superfamily with such capability. It does so using two mutually dependent cofactors: a heme and an entirely unique Met-Tyr-Trp (MYW) covalent adduct. Heme is required to generate the MYW cofactor. The MYW cofactor allows KatG to leverage heme intermediates toward a unique mechanism for H2O2 oxidation. This review evaluates the range of intermediates identified and their connection to the diverse catalytic processes KatG facilitates, including mechanisms of isoniazid activation.
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Affiliation(s)
- Olive J Njuma
- Department of Chemistry and Biochemistry, Auburn University, Auburn, AL 36849-5312, USA
| | - Elizabeth N Ndontsa
- Department of Chemistry and Biochemistry, Auburn University, Auburn, AL 36849-5312, USA
| | - Douglas C Goodwin
- Department of Chemistry and Biochemistry, Auburn University, Auburn, AL 36849-5312, USA.
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Hofbauer S, Bellei M, Sündermann A, Pirker KF, Hagmüller A, Mlynek G, Kostan J, Daims H, Furtmüller PG, Djinović-Carugo K, Oostenbrink C, Battistuzzi G, Obinger C. Redox thermodynamics of high-spin and low-spin forms of chlorite dismutases with diverse subunit and oligomeric structures. Biochemistry 2012; 51:9501-12. [PMID: 23126649 PMCID: PMC3557923 DOI: 10.1021/bi3013033] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
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Chlorite dismutases (Clds) are heme b-containing
oxidoreductases that convert chlorite to chloride and dioxygen. In
this work, the thermodynamics of the one-electron reduction of the
ferric high-spin forms and of the six-coordinate low-spin cyanide
adducts of the enzymes from Nitrobacter winogradskyi (NwCld) and Candidatus “Nitrospira defluvii”
(NdCld) were determined through spectroelectrochemical experiments.
These proteins belong to two phylogenetically separated lineages that
differ in subunit (21.5 and 26 kDa, respectively) and oligomeric (dimeric
and pentameric, respectively) structure but exhibit similar chlorite
degradation activity. The E°′ values
for free and cyanide-bound proteins were determined to be −119
and −397 mV for NwCld and −113 and −404 mV for
NdCld, respectively (pH 7.0, 25 °C). Variable-temperature spectroelectrochemical
experiments revealed that the oxidized state of both proteins is enthalpically
stabilized. Molecular dynamics simulations suggest that changes in
the protein structure are negligible, whereas solvent reorganization
is mainly responsible for the increase in entropy during the redox
reaction. Obtained data are discussed with respect to the known structures
of the two Clds and the proposed reaction mechanism.
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Affiliation(s)
- Stefan Hofbauer
- Department of Chemistry, Division of Biochemistry, VIBT-Vienna Institute of BioTechnology, BOKU-University of Natural Resources and Life Sciences, A-1190 Vienna, Austria
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12
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Cheng W, Harper WF. Chemical kinetics and interactions involved in horseradish peroxidase-mediated oxidative polymerization of phenolic compounds. Enzyme Microb Technol 2012; 50:204-8. [DOI: 10.1016/j.enzmictec.2011.12.005] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2011] [Revised: 12/01/2011] [Accepted: 12/22/2011] [Indexed: 11/30/2022]
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Zámocký M, Droghetti E, Bellei M, Gasselhuber B, Pabst M, Furtmüller PG, Battistuzzi G, Smulevich G, Obinger C. Eukaryotic extracellular catalase-peroxidase from Magnaporthe grisea - Biophysical/chemical characterization of the first representative from a novel phytopathogenic KatG group. Biochimie 2012; 94:673-83. [PMID: 21971530 PMCID: PMC3317519 DOI: 10.1016/j.biochi.2011.09.020] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2011] [Accepted: 09/21/2011] [Indexed: 12/04/2022]
Abstract
All phytopathogenic fungi have two catalase-peroxidase paralogues located either intracellularly (KatG1) or extracellularly (KatG2). Here, for the first time a secreted bifunctional, homodimeric catalase-peroxidase (KatG2 from the rice blast fungus Magnaporthe grisea) has been produced heterologously with almost 100% heme occupancy and comprehensively investigated by using a broad set of methods including UV-Vis, ECD and resonance Raman spectroscopy (RR), thin-layer spectroelectrochemistry, mass spectrometry, steady-state & presteady-state spectroscopy. RR spectroscopy reveals that MagKatG2 shows a unique mixed-spin state, non-planar heme b, and a proximal histidine with pronounced imidazolate character. At pH 7.0 and 25 °C, the standard reduction potential E°' of the Fe(III)/Fe(II) couple for the high-spin native protein was found to fall in the range typical for the KatG family. Binding of cyanide was relatively slow at pH 7.0 and 25 °C and with a K(d) value significantly higher than for the intracellular counterpart. Demonstrated by mass spectrometry MagKatG2 has the typical Trp118-Tyr251-Met277 adduct that is essential for its predominantly catalase activity at the unique acidic pH optimum. In addition, MagKatG2 acts as a versatile peroxidase using both one- and two-electron donors. Based on these data, structure-function relationships of extracellular eukaryotic KatGs are discussed with respect to intracellular KatGs and possible role(s) in host-pathogen interaction.
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Key Words
- extracellular catalase–peroxidase
- peroxidases–catalase superfamily
- phytopathogen
- oxidative stress
- resonance raman spectroscopy
- reduction potential
- 5c, five-coordinated
- 6c, six-coordinated
- apx, ascorbate peroxidase
- arp, arthromyces ramosus peroxidase
- bp1, barley peroxidase type 1
- cai, codon adaptation index
- caps, 3-(cyclohexylamino)propane-1-sulfonic acid
- ccd, charge-coupled device
- ccp, cytochrome c peroxidase
- cip, coprinus cinereus peroxidase
- ct, charge transfer
- l-dopa, 3,4-dihydroxy-l-phenylalanine
- e°′, reduction potential, referred to the standard hydrogen electrode, measured at ph 7.0
- ecd, electronic cd
- esi, electrospray ionization
- ha, hydroxyapatite
- hgt, horizontal gene transfer
- hrp, horseradish peroxidase
- hs, high-spin
- katg, catalase–peroxidase
- iptg, isopropyl-β-thiogalactopyranoside
- katg1, intracellular eukaryotic catalase–peroxidase
- katg2, extracellular eukaryotic catalase–peroxidase
- lc, liquid chromatography
- lip, lignin peroxidase
- ls, low-spin
- magkatg2, catalase–peroxidase from magnaporthe grisea
- mcac, metal chelate affinity chromatography
- mcd, monochlorodimedone
- mops, 4-morpholinepropane sulfonic acid
- mnp, manganese peroxidase
- nj, neighbor-joining method
- ottle, optically transparent thin-layer electrochemistry
- qs, quantum mixed-spin
- rr, resonance raman
- rt-pcr, reverse-transcription pcr
- sbp, soybean peroxidase
- she, standard hydrogen electrode
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Affiliation(s)
- Marcel Zámocký
- Division of Biochemistry, Department of Chemistry, Vienna Institute of Biotechnology at BOKU - University of Natural Resources and Life Sciences, Muthgasse 18, A-1190 Vienna, Austria.
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Vlasits J, Jakopitsch C, Bernroitner M, Zamocky M, Furtmüller PG, Obinger C. Mechanisms of catalase activity of heme peroxidases. Arch Biochem Biophys 2010; 500:74-81. [DOI: 10.1016/j.abb.2010.04.018] [Citation(s) in RCA: 126] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2010] [Revised: 04/23/2010] [Accepted: 04/24/2010] [Indexed: 11/15/2022]
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Battistuzzi G, Bellei M, Bortolotti CA, Sola M. Redox properties of heme peroxidases. Arch Biochem Biophys 2010; 500:21-36. [PMID: 20211593 DOI: 10.1016/j.abb.2010.03.002] [Citation(s) in RCA: 155] [Impact Index Per Article: 11.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2010] [Revised: 03/01/2010] [Accepted: 03/02/2010] [Indexed: 10/19/2022]
Abstract
Peroxidases are heme enzymes found in bacteria, fungi, plants and animals, which exploit the reduction of hydrogen peroxide to catalyze a number of oxidative reactions, involving a wide variety of organic and inorganic substrates. The catalytic cycle of heme peroxidases is based on three consecutive redox steps, involving two high-valent intermediates (Compound I and Compound II), which perform the oxidation of the substrates. Therefore, the thermodynamics and the kinetics of the catalytic cycle are influenced by the reduction potentials of three redox couples, namely Compound I/Fe3+, Compound I/Compound II and Compound II/Fe3+. In particular, the oxidative power of heme peroxidases is controlled by the (high) reduction potential of the latter two couples. Moreover, the rapid H2O2-mediated two-electron oxidation of peroxidases to Compound I requires a stable ferric state in physiological conditions, which depends on the reduction potential of the Fe3+/Fe2+ couple. The understanding of the molecular determinants of the reduction potentials of the above redox couples is crucial for the comprehension of the molecular determinants of the catalytic properties of heme peroxidases. This review provides an overview of the data available on the redox properties of Fe3+/Fe2+, Compound I/Fe3+, Compound I/Compound II and Compound II/Fe3+ couples in native and mutated heme peroxidases. The influence of the electron donor properties of the axial histidine and of the polarity of the heme environment is analyzed and the correlation between the redox properties of the heme group with the catalytic activity of this important class of metallo-enzymes is discussed.
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Affiliation(s)
- Gianantonio Battistuzzi
- Department of Chemistry, University of Modena and Reggio Emilia, via Campi 183, 41100 Modena, Italy.
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