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Sublethal Paraquat Confers Multidrug Tolerance in Pseudomonas aeruginosa by Inducing Superoxide Dismutase Activity and Lowering Envelope Permeability.

Author(s): Martins D, McKay GA, English AM, Nguyen D

Stressors and environmental cues shape the physiological state of bacteria, and thus how they subsequently respond to antibiotic toxicity. To understand how superoxide stress can modulate survival to bactericidal antibiotics, we examined the effect of intra...

Article GUID: 33101252
Ctt1 catalase activity potentiates antifungal azoles in the emerging opportunistic pathogen Saccharomyces cerevisiae.

Author(s): Martins D, Nguyen D, English AM

Sci Rep. 2019 Jun 24;9(1):9185 Authors: Martins D, Nguyen D, English AM

Article GUID: 31235707
Derivatization of yeast cytochrome c peroxidase with pentaammineruthenium(III).

Author(s): Fox T, English AM, Gibbs BF

Derivatization of yeast cytochrome c peroxidase with pentaammineruthenium(III).
Bioconjug Chem. 1994 Jan-Feb;5(1):14-20
Authors: Fox T, English AM, Gibbs BF
Abstract
Cytochrome c peroxidase (CCP) was derivatized using aquopentaamminerutheniu...

Article GUID: 8199229
Mass spectral analysis of protein-based radicals using DBNBS. Nonradical adduct formation versus spin trapping.

Author(s): Filosa A, English AM

J Biol Chem. 2001 Jun 15;276(24):21022-7 Authors: Filosa A, English AM

Article GUID: 11262405
Heme nitrosylation of deoxyhemoglobin by s-nitrosoglutathione requires copper.

Author(s): Romeo AA, Capobianco JA, English AM

J Biol Chem. 2002 Jul 05;277(27):24135-41 Authors: Romeo AA, Capobianco JA, English AM

Article GUID: 11970954
S-nitrosation of Ca(2+)-loaded and Ca(2+)-free recombinant calbindin D(28K) from human brain.

Author(s): Tao L, Murphy ME, English AM

Biochemistry. 2002 May 14;41(19):6185-92 Authors: Tao L, Murphy ME, English AM

Article GUID: 11994015
Different pathways of radical translocation in yeast cytochrome c peroxidase and its W191F mutant on reaction with H(2)O(2) suggest an antioxidant role.

Author(s): Tsaprailis G, English AM

J Biol Inorg Chem. 2003 Feb;8(3):248-55 Authors: Tsaprailis G, English AM

Article GUID: 12589560
Mechanism of S-nitrosation of recombinant human brain calbindin D28K.

Author(s): Tao L, English AM

Biochemistry. 2003 Mar 25;42(11):3326-34 Authors: Tao L, English AM

Article GUID: 12641465
Quantitative analysis of the yeast proteome by incorporation of isotopically labeled leucine.

Author(s): Jiang H, English AM

J Proteome Res. 2002 Jul-Aug;1(4):345-50 Authors: Jiang H, English AM

Article GUID: 12645890
Scavenging with TEMPO* to identify peptide- and protein-based radicals by mass spectrometry: advantages of spin scavenging over spin trapping.

Author(s): Wright PJ, English AM

J Am Chem Soc. 2003 Jul 16;125(28):8655-65 Authors: Wright PJ, English AM

Article GUID: 12848573
ESI-MS and FTIR studies of the interaction between the second PDZ domain of hPTP1E and target peptides.

Author(s): Papp R, Ekiel I, English AM

Biochem Cell Biol. 2003 Apr;81(2):71-80 Authors: Papp R, Ekiel I, English AM

Article GUID: 12870871
Superoxide dismutase targets NO from GSNO to Cysbeta93 of oxyhemoglobin in concentrated but not dilute solutions of the protein.

Author(s): Romeo AA, Capobianco JA, English AM

J Am Chem Soc. 2003 Nov 26;125(47):14370-8 Authors: Romeo AA, Capobianco JA, English AM

Article GUID: 14624585
Protein S-glutathiolation triggered by decomposed S-nitrosoglutathione.

Author(s): Tao L, English AM

Biochemistry. 2004 Apr 06;43(13):4028-38 Authors: Tao L, English AM

Article GUID: 15049710
Mass spectrometric analysis of nitroxyl-mediated protein modification: comparison of products formed with free and protein-based cysteines.

Author(s): Shen B, English AM

Biochemistry. 2005 Oct 25;44(42):14030-44 Authors: Shen B, English AM

Article GUID: 16229492
Hemoglobin S-nitrosation on oxygenation of nitrite/deoxyhemoglobin incubations is attenuated by methemoglobin.

Author(s): Laterreur J, English AM

J Inorg Biochem. 2007 Nov;101(11-12):1827-35 Authors: Laterreur J, English AM

Article GUID: 17889368
ESI-MS quantitation of iron as its 4-(2-pyridylazo)resorcinol (PAR) complex: application to pharmaceutical tablets containing iron oxide pigment.

Author(s): Susanto D, English AM, Sharma R, Kwong E

J Mass Spectrom. 2011 May;46(5):508-16 Authors: Susanto D, English AM, Sharma R, Kwong E

Article GUID: 21520348
SOD1 oxidation and formation of soluble aggregates in yeast: relevance to sporadic ALS development.

Author(s): Martins D, English AM

Redox Biol. 2014;2:632-9 Authors: Martins D, English AM

Article GUID: 24936435
Targeted proteomics identify metabolism-dependent interactors of yeast cytochrome c peroxidase: implications in stress response and heme trafficking.

Author(s): Kathiresan M, English AM

Metallomics. 2016 Apr;8(4):434-43 Authors: Kathiresan M, English AM

Article GUID: 26980054
LC-MS/MS suggests that hole hopping in cytochrome c peroxidase protects its heme from oxidative modification by excess H2O2.

Author(s): Kathiresan M, English AM

Chem Sci. 2017 Feb 01;8(2):1152-1162 Authors: Kathiresan M, English AM

Article GUID: 28451256
Superoxide dismutase activity confers (p)ppGpp-mediated antibiotic tolerance to stationary-phase Pseudomonas aeruginosa.

Author(s): Martins D, McKay G, Sampathkumar G, Khakimova M, English AM, Nguyen D

Proc Natl Acad Sci U S A. 2018 09 25;115(39):9797-9802 Authors: Martins D, McKay G, Sampathkumar G, Khakimova M, English AM, Nguyen D

Article GUID: 30201715
Title:LC-MS/MS suggests that hole hopping in cytochrome c peroxidase protects its heme from oxidative modification by excess H2O2.
Authors:Kathiresan M,  English AM
Link:https://www.ncbi.nlm.nih.gov/pubmed/28451256?dopt=Abstract
Category:Chem Sci
PMID:28451256
Dept Affiliation: CHEMBIOCHEM
1 Concordia University Faculty of Arts and Science, and PROTEOhttp://www.proteo.ca/index.html , Chemistry and Biochemistry , Montreal , Canada . Email: ann.english@concordia.ca.

Description:

LC-MS/MS suggests that hole hopping in cytochrome c peroxidase protects its heme from oxidative modification by excess H2O2.

Chem Sci. 2017 Feb 01;8(2):1152-1162

Authors: Kathiresan M, English AM

Abstract

We recently reported that cytochrome c peroxidase (Ccp1) functions as a H2O2 sensor protein when H2O2 levels rise in respiring yeast. The availability of its reducing substrate, ferrocytochrome c (CycII), determines whether Ccp1 acts as a H2O2 sensor or peroxidase. For H2O2 to serve as a signal it must modify its receptor so we employed high-performance LC-MS/MS to investigate in detail the oxidation of Ccp1 by 1, 5 and 10 M eq. of H2O2 in the absence of CycII to prevent peroxidase activity. We observe strictly heme-mediated oxidation, implicating sequential cycles of binding and reduction of H2O2 at Ccp1's heme. This results in the incorporation of ~20 oxygen atoms predominantly at methionine and tryptophan residues. Extensive intramolecular dityrosine crosslinking involving neighboring residues was uncovered by LC-MS/MS sequencing of the crosslinked peptides. The proximal heme ligand, H175, is converted to oxo-histidine, which labilizes the heme but irreversible heme oxidation is avoided by hole hopping to the polypeptide until oxidation of the catalytic distal H52 in Ccp1 treated with 10 M eq. of H2O2 shuts down heterolytic cleavage of H2O2 at the heme. Mapping of the 24 oxidized residues in Ccp1 reveals that hole hopping from the heme is directed to three polypeptide zones rich in redox-active residues. This unprecedented analysis unveils the remarkable capacity of a polypeptide to direct hole hopping away from its active site, consistent with heme labilization being a key outcome of Ccp1-mediated H2O2 signaling. LC-MS/MS identification of the oxidized residues also exposes the bias of electron paramagnetic resonance (EPR) detection toward transient radicals with low O2 reactivity.

PMID: 28451256 [PubMed]