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Topic: Cytochrome c peroxidase


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In the News (Fri 17 Feb 12)

  
  Cytochrome c peroxidase
Cytochrome c peroxidase (CcP) is one member of a huge family of heme peroxidases.
The reaction with peroxide is quite similar for all of the heme peroxidases, and the heme binding pocket is highly conserved among heme peroxidases.
CcP does not have a well defined metabolic role, but seems to be designed to detoxify hydrogen peroxide formed in the intermembrane space of mitochrondria during aerobic metabolism.
chem-faculty.ucsd.edu /kraut/projects.html   (680 words)

  
  Cytochrome c peroxidase   (Site not responding. Last check: )
Cytochrome c peroxidase, or CCP,(PDB 2CYP, EC 1.11.1.5) is a water soluble ferric heme containing enzyme in the peroxidase family of enzymes that takes reducing equivalents from cytochrome c and reduces hydrogen peroxide to water.
Cytochrome c peroxidase can react with hydroperoxides other than hydrogen peroxide, but the reaction rate is much slower than with hydrogen peroxide.
Unlike most peroxidases, CCP compound I is fairly long lived, decaying to CCP compound II with a half life at room temperature of 40 minutes to a couple hours.
www.icyclopedia.com /encyclopedia/c/cy/cytochrome_c_peroxidase.html   (284 words)

  
 [No title]
a.3.1.1 (A:) Cytochrome c6 (synonym: cytochrome c553) {Green alga (Cladophora glomerata)}
a.3.1.1 (B:) Mono-heme c-type cytochrome SoxX {Rhodovulum sulfidophilum}
a.3.1.4 (C:1-80) Flavocytochrome c sulfide dehydrogenase, FCSD, cytochrome subunit {Purple phototrophic bacterium (Chromatium vinosum)}
www.sbc.su.se /~erik/cbop/map/cluster_1668.html   (73 words)

  
 Peroxidase - InformationBlast
For a compound such as cytochrome c peroxidase, the compounds that donate electrons are very specific, because there is a very closed active site.
Cytochrome c peroxidase is used as a soluble, easily purified model for cytochrome c oxidase.
Glutathione peroxidase is a peroxidase found in humans containing selenocysteine.
www.informationblast.com /Peroxidase.html   (151 words)

  
 A peroxidase is an enzyme enzyme usually containing heme heme that...   (Site not responding. Last check: )
A "peroxidase" is an enzyme enzyme, usually containing heme heme, that catalyzes a reaction of the form: :ROOR' + electron donor (2 e-) + 2H+ → ROH + R'OH Many of these compounds are optimally designed to process hydrogen peroxide peroxide.
For a compound such as cytochrome c peroxidase cytochrome c peroxidase, the compounds that donate electrons are very specific, because there is a very closed active site.
Cytochrome c peroxidase Cytochrome c peroxidase is used as a soluble, easily purified model for cytochrome c oxidase cytochrome c oxidase.
www.biodatabase.de /Peroxidase   (220 words)

  
 Replacement of the Axial Histidine Ligand with Imidazole in Cytochrome c Peroxidase. 2. Effects on Heme Coordination ...
The inability of imidazole to complement function in the axial histidine deletion mutant, H175G, of yeast cytochrome c peroxidase has been an intriguing but unresolved issue that impacts our understanding of the role of axial ligands in heme catalysis.
However, the overall rate of enzyme turnover using cytochrome c as a substrate is <5% of WT and is unaffected by Im coordination.
However, while this form is fully reactive with peroxide, the reaction with cytochrome c remains inefficient, perhaps implicating the altered Trp-191 radical species.
pubs.acs.org /cgi-bin/abstract.cgi/bichaw/2001/40/i05/abs/bi002090q.html   (468 words)

  
 Cytochrome
The fluorescence spectra of the molybdenum cofactor derivative prepared from cytochrome a1c1 were very similar to those of the cofactor derivative from xanthine oxidase, and the aponitrate reductase of nit-1 mutant of Neurospora crassa was complemented by addition of the molybdenum cofactor derived from the cytochrome.
Further, the ESR spectrum of cytochrome a1c1 was similar to that of liver sulfite oxidase.
The content of cytochrome a1 in the cells cultivated with the medium in which tungsten was substituted for molybdenum markedly decreased as compared with that in the cells cultivated in the molybdenum-supplemented medium.
www.ithyroid.com /cytochrome.htm   (1736 words)

  
 CcP
Cytochrome c peroxidase from Saccharomyces cerevisiae (E.C. 1.11.1.5, CcP 1) is one of the two most thoroughly studied of the heme peroxidases (1-6).
CcP is found in the mitochondrial intermembrane space of bakers’ yeast cells where it catalyzes the reduction of hydrogen peroxide to water using reducing equivalents supplied by two molecules of reduced cytochrome c, as represented by the overall reaction shown in Equation 1 (1-6).
In the CcP mechanism (2, 8, 28, 29) the initial oxidation is a bimolecular reaction of resting state CcP with H 2O 2 (Equation 2).
www.wsu.edu /~hemeteam/research/ccp.html   (9057 words)

  
 Department of Chemistry
Cytochromes are truly excellent electron transfer proteins for electrochemical and spectroscopic studies and they continue to be one of our favorite molecules.
Genetically engineered yeast cytochrome c mutants with single-site amino acid substitutions are being employed to address this objective.
Although much of our current work is focused on the cytochromes, we also remain very interested in the coupling of enzymes to electrodes.
www.ncsu.edu /ncsu/chemistry/facultyPages/efb.research.html   (684 words)

  
 Excision of a proposed electron transfer pathway in cytochrome c peroxidase and its replacement by a ligand-binding ...
CCP and yeast cyt c (Pelletier and Kraut 1992), the heme of
Shown in A (top) is the structure of wild-type cytochrome c peroxidase (gray) superimposed on the structure of the channel mutant in the absence (blue) and presence (red) of bound benzimidazole.
Zhou, J.S. and Hoffman, B.M. Stern-Volmer in reverse: 2:1 Stoichiometry of the cytochrome c cytochrome c peroxidase electron-transfer complex.
www.proteinscience.org /cgi/content/full/11/5/1251   (4363 words)

  
 Studies on Cytochrome c Peroxidase. III. KINETICS OF THE PEROXIDATIC OXIDATION OF FERROCYTOCHROME c CATALYZED BY ...
KINETICS OF THE PEROXIDATIC OXIDATION OF FERROCYTOCHROME c CATALYZED BY CYTOCHROME c PEROXIDASE -- Yonetani and Ray 241 (3): 700 -- Journal of Biological Chemistry
The peroxidatic oxidation of ferrocytochrome c catalyzed by
Stern-volmer in reverse: 2:1 stoichiometry of the cytochrome c-cytochrome c peroxidase electron-transfer complex
www.jbc.org /cgi/content/abstract/241/3/700   (247 words)

  
 Metals in Biology
Cytochrome C Peroxidase is an interesting case in that the radical does not stay on the porphyrin, but migrates to a close by tryptophan.
It's redox partner is cytochrome c, and its thought the trp radical holds the radical equivalent closer to the cytochrome c binding surface for more efficient electron transfer.
Cytochrome C Peroxidase is over twice the size of myglobin, ca 50 kD, and most peroxidases are similarly sized.
chem.ps.uci.edu /~pfarmer/127i/h2o2act.html   (193 words)

  
 Department of Biochemistry and Molecular Biology at UBC - Mauk
We have been studying the electron transfer kinetics and complex formation of three pairs of electron transfer proteins for which three-dimensional structures are available: cytochrome c and cytochrome b5, cytochrome c and cytochrome c peroxidase, and cytochrome b5 and methemoglobin.
Cytochrome c peroxidase is an unusual enzyme in that it forms a catalytic intermediate with a stable cationic radical center that resides on a tryptophanyl residue near the heme prosthetic group.
To help understand the basis by which the porphyrin-centered radical is stabilized, we are studying a variety of cytochrome c peroxidase variants in which the electrostatic properties of the active site have been modified by site-directed mutagenesis.
www.biochem.ubc.ca /fac_research/faculty/mauk.html   (2193 words)

  
 Replacement of the Axial Histidine Ligand with Imidazole in Cytochrome c Peroxidase. 1. Effects on Structure,
In this paper, we describe the effects of pH and buffer ion on the crystal structure of the H175G mutant of cytochrome c peroxidase, in which the histidine tether between the heme and the protein backbone is replaced by bound imidazole.
The structures show that imidazole can occupy the proximal H175G cavity under a number of experimental conditions, but that the details of the interaction with the protein and the coordination to the heme are markedly dependent on conditions.
This is similar to the structure of WT CCP except that the iron lies closer in the heme plane, and the hydrogen bond between imidazole and Asp-235 (d
www.pubs.acs.org /cgi-bin/abstract.cgi/bichaw/2001/40/i05/abs/bi002089r.html   (496 words)

  
 LABPV Newsletter issue 13
The peroxidases utilize a peroxide to create free radicals which may have several fates, one of which is to be scavenged by molecular oxygen.
Similarly, crayfish peroxidase (CrPO) over peroxonectin (7) It would appear to be too late to rename prostaglandin H synthase as a peroxidase, or to stop use of the erroneous COX-1 and COX-2 abbreviations, which imply a direct role of the enzyme in oxygen scavenging of carbon radicals.
The heme peroxidases are sometimes identified by their source, as for horseradish peroxidase, and sometimes by one of their substrates, as for manganese peroxidase.
www.unige.ch /LABPV/newsletters/newsl13/n13p65.html   (2181 words)

  
 [No title]
After cytochrome c (cyt c) is synthesized in the cytoplasm as apocytochrome c, it is transported through the outer mitochondrial membrane to the intermembrane space, where haem is covalently attached to two cysteine residues.
Cyt c is required during oxidative phosphorylation as an electron shuttle between Complex III (cyt c reductase) and IV (cyt c oxidase).
In mammals, cyt c triggers the assembly of the apoptosome, consisting of cyt c, Apaf-1 and dATP, which activates caspase-9, leading to cell death [1].
www.ebi.ac.uk /interpro/IEntry?ac=IPR012282   (559 words)

  
 ccp
Cytochrome c peroxidase (CcP) is a heme-containing enzyme that catalyzes the reduction of H
Two molecules of cytochrome c then reduce compound I back to the resting state via the one-electron intermediate compound II.
We have shown that yeast CcP adsorbs in an electroactive state to a pyrolytic graphite edge (PGE) electrode and can be investigated using protein film voltammetry.
www.chem.ox.ac.uk /icl/faagroup/ccp.html   (514 words)

  
 Thermodynamic Volume Cycles for Electron Transfer in the Cytochrome c Oxidase and for the Binding of Cytochrome c to ...
The closed circles represent the concentration of cyt c, and the open circles are the concentration of cyt c oxidase monomer.
At the peak of the oxidase profile in the main figure, r is ~0.12 mole of cyt c bound per mole of oxidase (1.66 µM excess cyt c)/(14.2 µM cyt c oxidase monomer).
Cytochrome c reactivity in its complexes with mammalian cytochrome c oxidase and yeast peroxidase.
www.biophysj.org /cgi/content/full/75/1/435   (6377 words)

  
 3D Supergroup Publications
Goodin, D. and McRee, D. (1993) "The Asp-His-Fe Triad of Cytochrome c Peroxidase Controls the Reduction Potential, Electronic Structure, and Coupling of the Tryptophan Free Radical to the Heme" Biochemistry 32, 3313-3324.
Houseman, A. P., Doan, P. E., Goodin, D. and Hoffman, B. "Comprehensive Explanation of the Anomalous EPR Spectra of Wild-Type and Mutant Cytochrome c Peroxidase Compound ES" Biochemistry 32, 4430-4443.
Goodin, D. B., Mauk, A. and Smith, M. (1986) "Studies of the radical species in compound ES of cytochrome c peroxidase altered by site-directed mutagenesis" Proc.
www.scripps.edu /research/3d/publications.html   (1129 words)

  
 PGHS-1 Peroxidase
Structural comparisons between fungal peroxidases and mammalian peroxidases suggest that they arose from a common percursor.
Accessible surface area views of the fungal peroxidases and mammalian peroxidases show how buried the heme (red) is in many peroxidases except PGHS, which uses larger hydrophobic hydroperoxides (e.g., PGG2, 15-HPETE, etc.) as substrates rather than hydrogen peroxide.
The structures shown are lignin peroxidase (LiP), cytochrome c peroxidase (CCP), myeloperoxidase (MPO), and PGHS peroxidase.
www.bch.msu.edu /faculty/garavito/pghs_pox.htm   (273 words)

  
 Farmer Research Group - UC Irvine
A similar protein-shortcircuit oxidation to a catalytically active Trp is crucial to the activity of cytochrome c peroxide, CcP; in ongoing work we have generated and determined the lifetime of the often-invoked porphyrin radical of CcP, never before observed.
We have crystallographically characterized CcP hybrids using two different regioisomers of mesopone-- in both cases only one enantiomer of the oxochlorin is observed, i.e.
The crosslink was shown to result from Fe activation of peroxide, and similar metal-dependent crosslinks have been found in cytochrome c oxidase and tyrosinase metalloproteins.
chem.ps.uci.edu /~pfarmer/grp2/pchem.htm   (695 words)

  
 Implications for Evolution: The Anatomy & Taxonomy of Protein Structure
106 shows the two domains of rhodanese as an example); in two cases (cytochrome c peroxidase and aspartate transcarbamylase regulatory chain) the level of similarity is ambiguous; while in the other 16 cases the structures are totally different and presumably could not be the result of internal gene duplication (e.g., Fig.
Probably the most dramatic case is the proteolytic enzymes: although the trypsin-like serine proteases form a structurally related group, the proteases as a whole are represented by six widely different structures, including two textbook examples of convergent evolution: subtilisin versus the trypsin family and thermolysin versus carboxypeptidase.
Two logically distinct problems are involved: the first problem is evaluating the significance of a given similarity relative to the probability of its "chance" or "random" occurrence, the second problem is estimating the likelihood that a given significant resemblance was produced by divergent rather than convergent evolution.
kinemage.biochem.duke.edu /~jsr/html/anatax.4b.html   (2225 words)

  
 Research - Peroxidases   (Site not responding. Last check: )
The peroxidase family of proteins includes mammalian (e.g., myelo-, lacto- and thyroid peroxidases), fungal (e.g., lignin and cytochrome c peroxidases), and plant (horseradish peroxidase) enzymes.
horseradish peroxidase) or protein (cytochrome c peroxidase) radical cation, or in some instances appears to exist in both forms (lactoperoxidase).
The links common to myeloperoxidase, lactoperoxidase, eosinophil peroxidase, and probably thyroid peroxidase are two ester bonds between aspartic or glutamic acid residues and hydroxyl groups on the 1- and 5-methyl groups of the heme (Figure 1).
www.sacs.ucsf.edu /home/Ortiz/res-po.htm   (380 words)

  
 tag appears at the top of the browser window and is saved as the name of the page if anyone saves the location as a ...
Interestingly, peroxidases like CCP have little, if any, catalase activity.
We are exploring the role of individual amino acids and the heme prosthetic group in the active site of catalase/peroxidase to determine the structural basis for the ability of this protein to perform two distinct catalytic functions.
Goodwin, D.C.; Laband, K.A.; Hertwig, K.M. Oxidation of capsaicinoids by peroxidases: kinetic, structural, and physiological considerations.
www.auburn.edu /~goodwdc   (704 words)

  
 Dr Emma Raven Research Interests
Heme peroxidases are an important class of iron-containing enzymes that catalyse the H2O2 -dependent oxidation of a variety of substrates.
Using a model heme peroxidase – ascorbate peroxidase (which catalyses the H2O2 -dependent oxidation of vitamin C) – we have recently made major progress in understanding substrate specificity in the heme peroxidases (collaborative work with Dr Peter Moody, Biochemistry http://www.le.ac.uk/biochem/staff/pcem1/pcem1.html).
We have recently shown that autocatalytic formation of covalently-linked heme is possible in ascorbate peroxidase by placement of a methionine residue close to the heme.
www.le.ac.uk /chemistry/staff/el10_resint.html   (1042 words)

  
 .:IBiS Graduate Program :: Faculty :: Brian M. Hoffman:.
We are applying this approach to physiological electron transfer reactions, such as between yeast cytochrome c peroxidase (CCP) and cytochrome c (cyt c).
The use of different cyt c species and of site-directed mutagenesis to vary individual residues of cyt c gives a precise means of investigating both the role of the protein matrix in electron transfer and the influence of conformational dynamics at the protein-protein interface.
The systems we are studying include peroxidases, copper proteins containing the blue-copper center, and proteins that contain multimetal centers such as aconitase, cytochrome oxidase, and hydrogenase.
www.biochem.northwestern.edu /ibis/faculty/hoffman.htm   (675 words)

  
 Dalton Transactions Articles   (Site not responding. Last check: )
Cytochrome c peroxidase (CcP) and ascorbate peroxidase (APX) both involve reactive haem oxoferryl intermediates known as
Compound I intermediates have three unpaired electrons, two of which are always situated on the Fe—O core, whilst the third is located in a porphyrin orbital in APX and many other compound I species.
In CcP, however, this third unpaired electron is positioned on a tryptophan residue lying close to the haem ring.
chemistry.rsc.org /Publishing/Journals/DT/article.asp?doi=b505407a   (247 words)

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