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Njuma OJ, Davis I, Ndontsa EN, Krewall JR, Liu A, Goodwin DC. Mutual synergy between catalase and peroxidase activities of the bifunctional enzyme KatG is facilitated by electron hole-hopping within the enzyme. J Biol Chem 2017; 292:18408-18421. [PMID: 28972181 DOI: 10.1074/jbc.m117.791202] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2017] [Revised: 09/22/2017] [Indexed: 11/06/2022] Open
Abstract
KatG is a bifunctional, heme-dependent enzyme in the front-line defense of numerous bacterial and fungal pathogens against H2O2-induced oxidative damage from host immune responses. Contrary to the expectation that catalase and peroxidase activities should be mutually antagonistic, peroxidatic electron donors (PxEDs) enhance KatG catalase activity. Here, we establish the mechanism of synergistic cooperation between these activities. We show that at low pH values KatG can fully convert H2O2 to O2 and H2O only if a PxED is present in the reaction mixture. Stopped-flow spectroscopy results indicated rapid initial rates of H2O2 disproportionation slowing concomitantly with the accumulation of ferryl-like heme states. These states very slowly returned to resting (i.e. ferric) enzyme, indicating that they represented catalase-inactive intermediates. We also show that an active-site tryptophan, Trp-321, participates in off-pathway electron transfer. A W321F variant in which the proximal tryptophan was replaced with a non-oxidizable phenylalanine exhibited higher catalase activity and less accumulation of off-pathway heme intermediates. Finally, rapid freeze-quench EPR experiments indicated that both WT and W321F KatG produce the same methionine-tyrosine-tryptophan (MYW) cofactor radical intermediate at the earliest reaction time points and that Trp-321 is the preferred site of off-catalase protein oxidation in the native enzyme. Of note, PxEDs did not affect the formation of the MYW cofactor radical but could reduce non-productive protein-based radical species that accumulate during reaction with H2O2 Our results suggest that catalase-inactive intermediates accumulate because of off-mechanism oxidation, primarily of Trp-321, and PxEDs stimulate KatG catalase activity by preventing the accumulation of inactive intermediates.
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Affiliation(s)
- Olive J Njuma
- From the Department of Chemistry and Biochemistry, Auburn University, Auburn, Alabama 36849-5312
| | - Ian Davis
- the Department of Chemistry, University of Texas at San Antonio, San Antonio, Texas 78249-0698, and.,the Department of Chemistry, Georgia State University, Atlanta, Georgia 30303
| | - Elizabeth N Ndontsa
- From the Department of Chemistry and Biochemistry, Auburn University, Auburn, Alabama 36849-5312
| | - Jessica R Krewall
- From the Department of Chemistry and Biochemistry, Auburn University, Auburn, Alabama 36849-5312
| | - Aimin Liu
- the Department of Chemistry, University of Texas at San Antonio, San Antonio, Texas 78249-0698, and
| | - Douglas C Goodwin
- From the Department of Chemistry and Biochemistry, Auburn University, Auburn, Alabama 36849-5312,
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Gasselhuber B, Graf MMH, Jakopitsch C, Zamocky M, Nicolussi A, Furtmüller PG, Oostenbrink C, Carpena X, Obinger C. Interaction with the Redox Cofactor MYW and Functional Role of a Mobile Arginine in Eukaryotic Catalase-Peroxidase. Biochemistry 2016; 55:3528-41. [PMID: 27293030 PMCID: PMC4928148 DOI: 10.1021/acs.biochem.6b00436] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
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Catalase-peroxidases
(KatGs) are unique bifunctional heme peroxidases
with an additional posttranslationally formed redox-active Met-Tyr-Trp
cofactor that is essential for catalase activity. On the basis of
studies of bacterial KatGs, controversial mechanisms of hydrogen peroxide
oxidation were proposed. The recent discovery of eukaryotic KatGs
with differing pH optima of catalase activity now allows us to scrutinize
those postulated reaction mechanisms. In our study, secreted KatG
from the fungus Magnaporthe grisea (MagKatG2) was used to analyze the role of a remote KatG-typical mobile
arginine that was shown to interact with the Met-Tyr-Trp adduct in
a pH-dependent manner in bacterial KatGs. Here we present crystal
structures of MagKatG2 at pH 3.0, 5.5, and 7.0 and
investigate the mobility of Arg461 by molecular dynamics simulation.
Data suggest that at pH ≥4.5 Arg461 mostly interacts with the
deprotonated adduct Tyr. Elimination of Arg461 by mutation to Ala
slightly increases the thermal stability but does not alter the active
site architecture or the kinetics of cyanide binding. However, the
variant Arg461Ala lost the wild-type-typical optimum of catalase activity
at pH 5.25 (kcat = 6450 s–1) but exhibits a broad plateau between pH 4.5 and 7.5 (kcat = 270 s–1 at pH 5.5). Moreover,
significant differences in the kinetics of interconversion of redox
intermediates of wild-type and mutant protein mixed with either peroxyacetic
acid or hydrogen peroxide are observed. These findings together with
published data from bacterial KatGs allow us to propose a role of
Arg461 in the H2O2 oxidation reaction of KatG.
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Affiliation(s)
- Bernhard Gasselhuber
- Department of Chemistry, Division of Biochemistry, BOKU-University of Natural Resources and Life Sciences , Muthgasse 18, A-1190 Vienna, Austria
| | - 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
| | - Christa Jakopitsch
- Department of Chemistry, Division of Biochemistry, BOKU-University of Natural Resources and Life Sciences , Muthgasse 18, A-1190 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
| | - Andrea Nicolussi
- Department of Chemistry, Division of Biochemistry, BOKU-University of Natural Resources and Life Sciences , Muthgasse 18, A-1190 Vienna, Austria
| | - Paul G Furtmüller
- 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
| | - Xavi Carpena
- 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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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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Ivancich A, Donald LJ, Villanueva J, Wiseman B, Fita I, Loewen PC. Spectroscopic and kinetic investigation of the reactions of peroxyacetic acid with Burkholderia pseudomallei catalase-peroxidase, KatG. Biochemistry 2013; 52:7271-82. [PMID: 24044787 DOI: 10.1021/bi400963j] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Catalase-peroxidases or KatGs can utilize organic peroxyacids and peroxides instead of hydrogen peroxide to generate the high-valent ferryl-oxo intermediates involved in the catalase and peroxidase reactions. In the absence of peroxidatic one-electron donors, the ferryl intermediates generated with a low excess (10-fold) of peroxyacetic acid (PAA) slowly decay to the ferric resting state after several minutes, a reaction that is demonstrated in this work by both stopped-flow UV-vis absorption measurements and EPR spectroscopic characterization of Burkholderia pseudomallei KatG (BpKatG). EPR spectroscopy showed that the [Fe(IV)═O Trp330(•+)], [Fe(IV)═O Trp139(•)], and [Fe(IV)═O Trp153(•)] intermediates of the peroxidase-like cycle of BpKatG ( Colin, J. Wiseman, B. Switala, J. Loewen, P. C. Ivancich, A. ( 2009 ) J. Am. Chem. Soc. 131 , 8557 - 8563 ), formed with a low excess of PAA at low temperature, are also generated with a high excess (1000-fold) of PAA at room temperature. However, under high excess conditions, there is a rapid conversion to a persistent [Fe(IV)═O] intermediate. Analysis of tryptic peptides of BpKatG by mass spectrometry before and after treatment with PAA showed that specific tryptophan (including W330, W139, and W153), methionine (including Met264 of the M-Y-W adduct), and cysteine residues are either modified with one, two, or three oxygen atoms or could not be identified in the spectrum because of other undetermined modifications. It was concluded that these oxidized residues were the source of electrons used to reduce the excess of PAA to acetic acid and return the enzyme to the ferric state. Treatment of BpKatG with PAA also caused a loss of catalase activity towards certain substrates, consistent with oxidative disruption of the M-Y-W adduct, and a loss of peroxidase activity, consistent with accumulation of the [Fe(IV)═O] intermediate and the oxidative modification of the W330, W139, and W153. PAA, but not H2O2 or tert-butyl hydroperoxide, also caused subunit cross-linking.
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Affiliation(s)
- Anabella Ivancich
- CNRS, Unité de Recherche Mixte CNRS/CEA/Université Paris Sud (UMR 8221), Laboratoire de Bioénergétique, Métalloprotéines et Stress, Centre d'Etudes de Saclay/iBiTec-S , 91191 Gif-sur-Yvette, France
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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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Disruption of the H-bond network in the main access channel of catalase–peroxidase modulates enthalpy and entropy of Fe(III) reduction. J Inorg Biochem 2010; 104:648-56. [DOI: 10.1016/j.jinorgbio.2010.02.006] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2010] [Revised: 02/15/2010] [Accepted: 02/23/2010] [Indexed: 01/06/2023]
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The dynamic role of distal side residues in heme hydroperoxidase catalysis. Interplay between X-ray crystallography and ab initio MD simulations. Arch Biochem Biophys 2010; 500:37-44. [PMID: 20447375 DOI: 10.1016/j.abb.2010.04.021] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2010] [Revised: 04/27/2010] [Accepted: 04/27/2010] [Indexed: 11/20/2022]
Abstract
The enzymatic cycle of hydroperoxidases involves the resting Fe(III) state of the enzyme and the high-valent iron intermediates Compound I and Compound II. These states might be characterized by X-ray crystallography and the transition pathways between each state can be investigated using atomistic simulations. Here we review our recent work in the modeling of two key steps of the enzymatic reaction of hydroperoxidases: the formation of Cpd I in peroxidase and the reduction of Cpd I in catalase. It will be shown that small conformational motions of distal side residues (His in peroxidases and His/Asn in catalases), not,or only partially, revealed by the available X-ray structures, play an important role in the catalytic processes examined.
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Probing hydrogen peroxide oxidation kinetics of wild-type Synechocystis catalase-peroxidase (KatG) and selected variants. BIOCHIMICA ET BIOPHYSICA ACTA-PROTEINS AND PROTEOMICS 2010; 1804:799-805. [DOI: 10.1016/j.bbapap.2009.12.007] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/30/2009] [Revised: 12/02/2009] [Accepted: 12/08/2009] [Indexed: 11/21/2022]
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Spectroscopic studies of the oxidation of ferric CYP153A6 by peracids: Insights into P450 higher oxidation states. Arch Biochem Biophys 2009; 493:184-91. [PMID: 19879854 DOI: 10.1016/j.abb.2009.10.014] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2009] [Revised: 10/25/2009] [Accepted: 10/27/2009] [Indexed: 11/21/2022]
Abstract
Our previous rapid-scanning stopped-flow studies of the reaction of substrate-free cytochrome P450cam with peracids [T. Spolitak, J.H. Dawson, D.P. Ballou, J. Biol. Chem. 280 (2005) 20300-20309; J. Inorg. Biochem. 100 (2006) 2034-2044; J. Biol. Inorg. Chem. 13 (2008) 599-611] spectrally characterized compound I (ferryl iron plus a porphyrin pi-cation radical (Fe(IV)O/Por(.+))), Cpd ES, and Cpd II (Fe(IV)O/Tyr() or Fe(IV)O). We now report that reactions of CYP153A6 with peracids yield all these intermediates, with kinetic profiles allowing better resolution of all forms at pH 8.0 compared to similar reactions with WT P450cam. Properties of the reactions of these higher oxidation state intermediates were determined in double-mixing experiments in which intermediates are pre-formed and ascorbate is then added. Reactions of heptane-bound CYP153A6 (pH 7.4) with mCPBA resulted in conversion of P450 to the low-spin ferric form, presumably as heptanol was formed, suggesting that CYP 153A6 is a potential biocatalyst that can use peracids with no added NAD(P)H or reducing systems for bioremediation and other industrial applications.
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