Catalase in peroxidase clothing: Interdependent cooperation of two cofactors in the catalytic versatility of KatG

Njuma, Olive J.; Ndontsa, Elizabeth N.; Goodwin, Douglas C.

doi:10.1016/j.abb.2013.11.007

Cited by 37 publications

(32 citation statements)

References 121 publications

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“…They both involve the reduction of H 2 O 2 and generation of water, however, KatG’s catalase and peroxidase catalytic functions are different as they require different hydrogen donors. Catalase reduces the H 2 O 2 in a two-electron oxidation reaction using small organic substrates like ethanol with the generation of oxygen [37]. Peroxidase, instead, requires long-chain or aromatic compounds as hydrogen donors to complete its single-electron oxidation reaction [37].…”

Section: Resultsmentioning

confidence: 99%

“…Catalase reduces the H 2 O 2 in a two-electron oxidation reaction using small organic substrates like ethanol with the generation of oxygen [37]. Peroxidase, instead, requires long-chain or aromatic compounds as hydrogen donors to complete its single-electron oxidation reaction [37]. In this study, we specifically measured the peroxidase activity since the aromatic compound 3,3′,5,5′-Tetramethylbenzidine (TMB) was used as the hydrogen donor.…”

Section: Resultsmentioning

confidence: 99%

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Virulence of Mycobacterium tuberculosis after Acquisition of Isoniazid Resistance: Individual Nature of katG Mutants and the Possible Role of AhpC

Mehaffy

Creissen

et al. 2016

PLoS ONE

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In the last decade, there were 10 million new tuberculosis cases per year globally. Around 9.5% of these cases were caused by isoniazid resistant (INHr) Mycobacterium tuberculosis (Mtb) strains. Although isoniazid resistance in Mtb is multigenic, mutations in the catalase-peroxidase (katG) gene predominate among the INHr strains. The effect of these drug-resistance-conferring mutations on Mtb fitness and virulence is variable. Here, we assessed differences in bacterial growth, immune response and pathology induced by Mtb strains harboring mutations at the N-terminus of the katG gene. We studied one laboratory and one clinically isolated Mtb clonal pair from different genetic lineages. The INHr strain in each pair had one and two katG mutations with significantly reduced levels of the enzyme and peroxidase activity. Both strains share the V1A mutation, while the double mutant clinical INHr had also the novel E3V katG mutation. Four groups of C57BL/6 mice were infected with one of the Mtb strains previously described. We observed a strong reduction in virulence (reduced bacterial growth), lower induction of proinflammatory cytokines and significantly reduced pathology scores in mice infected with the clinical INHr strain compared to the infection caused by its INHs progenitor strain. On the other hand, there was a subtle reduction of bacteria growth without differences in the pathology scores in mice infected with the laboratory INHr strain. Our results also showed distinct alkyl-hydroperoxidase C (AhpC) levels in the katG mutant strains, which could explain the difference in the virulence profile observed. The difference in the AhpC levels between clonal strains was not related to a genetic defect in the gene or its promoter. Cumulatively, our results indicate that the virulence, pathology and fitness of INHr strains could be negatively affected by multiple mutations in katG, lack of the peroxidase activity and reduced AhpC levels.

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Section: Resultsmentioning

confidence: 99%

Section: Resultsmentioning

confidence: 99%

Virulence of Mycobacterium tuberculosis after Acquisition of Isoniazid Resistance: Individual Nature of katG Mutants and the Possible Role of AhpC

Mehaffy

Creissen

et al. 2016

PLoS ONE

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“…Currently, isoniazid is a frontline drug used against tuberculosis. This pyridinic acylhydrazide compound is a prodrug, whose mechanism of action has been elucidated during the last two decades [5][6][7]. Isoniazid requires an oxidative electron-transfer process mediated by a catalase-peroxidase enzyme KatG [8,9] (Scheme 1).…”

Section: Introductionmentioning

confidence: 99%

[Fe(CN)5(isoniazid)]3−: An iron isoniazid complex with redox behavior implicated in tuberculosis therapy

Sousa

Vieira

Butler

et al. 2014

Journal of Inorganic Biochemistry

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“…The underlying mechanism involves polarization of the Fe-O bond (between heme iron and oxygen), after which Hb is oxidized spontaneously and produces peroxide (16). CAT is a type of conjugase that uses iron porphyrin as its prosthetic group and has a strong radical scavenging function, which can protect the tissues from oxidative damage (17 (18). The present study identified that with the increase of the sevoflurane concentration, the hemolysis rate of erythrocytes increased initially and then showed a downward trend.…”

Section: Discussionmentioning

confidence: 52%

Sevoflurane inhibits the antioxidant capacity of erythrocytes

Yuan³

et al. 2015

Experimental and Therapeutic Medicine

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Abstract. The aim of the present study was to observe the effects of sevoflurane on the antioxidant capacity, endothelial nitric oxide synthase (eNOS) content and lifespan of erythrocytes. A 2% erythrocyte suspension was prepared from whole blood collected from healthy volunteers and then treated with sevoflurane at different concentrations (group A, 0%; group S1, 1%; group S3, 3%; and group S5, 5%), in the presence or absence of 200 µmol/l hydrogen peroxide (H 2 O 2 , or H in group names). In order to evaluate the effects of sevoflurane on the antioxidant capacity and NO metabolism of erythrocytes, the hemolysis rate, catalase (CAT) content and eNOS content were determined, while the labeled phosphatidylserine rate and forward scatter of erythrocytes were detected using flow cyto metry. Group S3 showed the highest hemolysis rate in the absence H 2 O 2 , while treatment with H 2 O 2 increased the hemolysis rate of groups S1 and S3 (P= 0.027). The CAT content in groups treated with sevoflurane was significantly lower compared with that in the control (group A, air group). The CAT content in groups S1+H, S3+H and S5+H remained significantly lower compared with group A+H (P<0.05). The eNOS content of group A was similar to that of group S3, while the content in group S1 was similar to that in group S5. In addition, the eNOS content of groups A and S3 increased, while that of groups S1 and S5 was reduced upon H 2 O 2 treatment (P<0.05). The results indicated that sevoflurane reduced the antioxidative activity of erythrocytes, decreasing the resistant ability to H 2 O 2 damage and increasing the hemolysis rate. The underlying mechanism may be associated with the inhibitory effect on the CAT activity of erythrocytes. Sevoflurane also inhibited the generation of nitric oxide in erythrocytes and reduced the tolerance of erythrocytes against oxidative stress damage due to H 2 O 2 .

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Catalase in peroxidase clothing: Interdependent cooperation of two cofactors in the catalytic versatility of KatG

Cited by 37 publications

References 121 publications

Virulence of Mycobacterium tuberculosis after Acquisition of Isoniazid Resistance: Individual Nature of katG Mutants and the Possible Role of AhpC

Virulence of Mycobacterium tuberculosis after Acquisition of Isoniazid Resistance: Individual Nature of katG Mutants and the Possible Role of AhpC

[Fe(CN)5(isoniazid)]3−: An iron isoniazid complex with redox behavior implicated in tuberculosis therapy

Sevoflurane inhibits the antioxidant capacity of erythrocytes

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