Study of the role played by NfsA, NfsB nitroreductase and NemA flavin reductase from Escherichia coli in the conversion of ethyl 2-(2′-nitrophenoxy)acetate to 4-hydroxy-(2H)-1,4-benzoxazin-3(4H)-one (D-DIBOA), a benzohydroxamic acid with interesting biological properties

Valle, Antonio; Borgne, Sylvie Le; Bolı́var, Jorge; Cabrera, Gema; Cantero, Domingo

doi:10.1007/s00253-011-3787-0

Cited by 19 publications

(27 citation statements)

References 30 publications

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“…Taking into account the previous results described by Valle et al . () , this NfsA‐NfsB oxygen‐insensitive pathway could be substrate dependent. Under anaerobic conditions, the deletion of nfsA and nfsB had no impact on the reduction in 7NCCA, suggesting that the metabolic pathways could involve oxygen‐sensitive nitroreductases (not described to date) in that case.…”

Section: Discussionmentioning

confidence: 89%

“…thanks to single mutants nfsA and nfsB (Valle et al . ). Moreover, the double mutant nfsA/nfsB showed no nitroreductase activity on their substrate (2‐(2′‐nitrophenoxyacetate)) under aerobic conditions, indicating that NfsA and NfsB were the only enzymes involved in the degradation of this substrate (Valle et al .…”

Section: Discussionmentioning

confidence: 97%

“…Moreover, the double mutant nfsA/nfsB showed no nitroreductase activity on their substrate (2‐(2′‐nitrophenoxyacetate)) under aerobic conditions, indicating that NfsA and NfsB were the only enzymes involved in the degradation of this substrate (Valle et al . ). According to our data, in case of 7NCCA reduction, NfsA did not seem more efficient than NfsB, but each enzyme was more efficient than AzoR.…”

Section: Discussionmentioning

confidence: 97%

“…In E. coli species, NfsA and NfsB were described by Bryant et al (1981) as major and minor nitroreductases, respectively. Moreover, the major role of NfsA compared with NfsB was supported by the study of Valle et al thanks to single mutants nfsA and nfsB (Valle et al 2012). Moreover, the double mutant nfsA/nfsB showed no nitroreductase activity on their substrate (2-(2′-nitrophenoxyacetate)) under aerobic conditions, indicating that NfsA and NfsB were the only enzymes involved in the degradation of this substrate (Valle et al 2012).…”

Section: Nitro Reduction By Escherichia Coli Under Aerobic and Anaeromentioning

confidence: 90%

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Characteristics of majorEscherichia colireductases involved in aerobic nitro and azo reduction

et al. 2013

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Aims: Escherichia coli is able to reduce azo compounds such as methyl red (MR) and nitro compounds such as 7-nitrocoumarin-3-carboxylic acid (7NCCA). The aim of this study was to clarify the specificity of the major E. coli reductases. Methods and Results: Enzymatic assays with pure enzymes obtained after cloning, overproduction and purification under native or denaturing conditions were performed on three enzymes: AzoR, NfsA and NfsB. Their dependence on putative cofactors such as flavin mononucleotide (FMN), NADH and NADPH was studied as well as the reductase capacity of E. coli mutants depleted for one, two or three of the corresponding genes. Conclusions: AzoR was able to reduce both MR and 7NCCA, whereas NfsA and NfsB could only reduce the nitro compound. AzoR and NfsB were strictly FMN dependent in contrast to NfsA. At a low oxygen concentration, the three proteins were not mandatory for azo reduction and nitro reduction, but in optimal aerobic conditions, azoR was essential for MR reduction, and an nfsA/nfsB combination was important for 7NCCA reduction. Overexpression of azoR gene was able to compensate for the loss of nfsA and nfsB under aerobic conditions. Significance and Impact of Study: These data provide new insights into the substrate specificity of major E. coli nitroreductases and demonstrate that oxygen is an important parameter to take into account in studies of nitroreductase activity.

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Section: Discussionmentioning

confidence: 89%

Section: Discussionmentioning

confidence: 97%

Section: Discussionmentioning

confidence: 97%

Section: Nitro Reduction By Escherichia Coli Under Aerobic and Anaeromentioning

confidence: 90%

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Characteristics of majorEscherichia colireductases involved in aerobic nitro and azo reduction

et al. 2013

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“…Moreover, our results suggest that in E. coli BL21(DE3), the strain used in these experiments, endogenous nitroreductases are expressed even under aerobic growth conditions, which is fully consistent with previously published results. 20,21,33 While these endogenous nitroreductases reduce metronidazole to toxic intermediates, GlNR2 detoxifies them, thus eliminating metronidazole toxicity against E. coli. The fact that E. coli BL21(DE3) is susceptible to metronidazole has been reported earlier.…”

Section: Discussionmentioning

confidence: 99%

Metabolism of nitro drugs metronidazole and nitazoxanide in Giardia lamblia: characterization of a novel nitroreductase (GlNR2)

Müller

Schildknecht

Müller

2013

Journal of Antimicrobial Chemotherapy

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Objectives: The protozoan parasite Giardia lamblia causes giardiasis, a persistent diarrhoea. Nitro drugs such as the nitroimidazole metronidazole and the nitrothiazolide nitazoxanide are used for the treatment of giardiasis. Nitroreductases may play a role in activating these drugs. G. lamblia contains two nitroreductases, GlNR1 and GlNR2. The aim of this work was to elucidate the role of GlNR2.Methods: Expression of GlNR2 was analysed by reverse transcription PCR. Recombinant GlNR2 was overexpressed in G. lamblia and drug susceptibility was analysed. Recombinant GlNR2 was subjected to functional assays. Escherichia coli expressing full-length or truncated GlNR1 and GlNR2 were grown in the presence of nitro compounds. Using E. coli reporter strains for nitric oxide and DNA damage responses, we analysed whether GlNR1 and GlNR2 elicited the respective responses in the presence, or absence, of the drugs.Results: G. lamblia trophozoites overexpressing GlNR2 were less susceptible to both nitro drugs as compared with control trophozoites. GlNR2 was a functional nitroreductase when expressed in E. coli. E. coli expressing GlNR1 was more susceptible to metronidazole under aerobic and semi-aerobic and to nitazoxanide under semi-aerobic growth conditions. E. coli expressing GlNR2 was not susceptible to either drug. In reporter strains, GlNR1, but not GlNR2, elicited nitric oxide and DNA repair responses, even in the absence of nitro drugs.Conclusions: These findings suggest that GlNR2 is an active nitroreductase with a mode of action different from that of GlNR1. Thus, susceptibility to nitro drugs may depend not only on activation, but also on inactivation of the drugs by specific nitroreductases.

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Expanding the Genetic Code for a Dinitrophenyl Hapten

Ren

Wang

et al. 2015

ChemBioChem

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Haptens, such as dinitrophenyl (DNP) are small molecules that induce strong immune responses when attached to proteins or peptides and, as such, have been exploited for diverse applications. We engineered a Methanosarcina barkeri pyrrolysyl-tRNA synthetase (mbPylRS) to genetically encode a DNP-containing unnatural amino acid, N(6) -(2-(2,4-dinitrophenyl)acetyl)lysine (DnpK). Although this moiety was unstable in Escherichia coli, we found that its stability was enhanced in mammalian HEK 293T cells and was able to induce selective interactions with anti-DNP antibodies. The capability of genetically introducing DNP into proteins is expected to find broad applications in biosensing, immunology, and therapeutics.

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Study of the role played by NfsA, NfsB nitroreductase and NemA flavin reductase from Escherichia coli in the conversion of ethyl 2-(2′-nitrophenoxy)acetate to 4-hydroxy-(2H)-1,4-benzoxazin-3(4H)-one (D-DIBOA), a benzohydroxamic acid with interesting biological properties

Cited by 19 publications

References 30 publications

Characteristics of majorEscherichia colireductases involved in aerobic nitro and azo reduction

Characteristics of majorEscherichia colireductases involved in aerobic nitro and azo reduction

Metabolism of nitro drugs metronidazole and nitazoxanide in Giardia lamblia: characterization of a novel nitroreductase (GlNR2)

Expanding the Genetic Code for a Dinitrophenyl Hapten

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