The Ascorbate Transporter of
            <i>Escherichia coli</i>

Zhang, Zhongge; Aboulwafa, Mohammad M.; Smith, Meghan H.; Saier, Milton H.

doi:10.1128/jb.185.7.2243-2250.2003

Cited by 72 publications

(90 citation statements)

References 29 publications

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“…Presently, no data explaining what was observed in this study or differences between the bacteriostatic activity of AA compared with AAE are available. At the moment, the metabolism of AA in microbial biochemical pathways was described sufficiently for Escherichia coli 30,31) but not for other clinically important microorganisms. Therefore, the importance of AA ethylation remains an open question.…”

Section: Discussionmentioning

confidence: 99%

Selected Physicochemical and Biological Properties of Ethyl Ascorbic Acid Compared to Ascorbic Acid

Golonka

Oleksy

Junka

et al. 2017

Biological & Pharmaceutical Bulletin

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The aim of the work was the evaluation of selected biological and physicochemical, applicative properties of ethylated ascorbic acid (AAE) compared to ascorbic acid (AA). Thermogravimetry (TG), differential thermogravimetry (DTG), and differential thermal analysis (DTA) were conducted, followed by the evaluation of AAE decomposition by the UV-Vis spectroscopic method including the influence of temperature and pH. Scavenging, antimicrobial activity and cytotoxicity against L929 fibroblasts were also performed. The difference in mass loss between AA and AAE was 30% via TG. DTA revealed characteristic exothermic and endothermic effects. The AAE solution was more thermally stable than AA. The calculated zero-order rate constants of free-radical scavenging kinetics for AAE were in the range of 4.9 10 3 -1.35 10 2 s 1 . The activation energy for the process was 11,2281 kJ/mol. AAE was active against Staphylococcus (S.) aureus and Enterococcus (E.) faecalis and acted stronger against Candida (C.) albicans than AA. The concentrations of AA ≥2.5% were cytotoxic, whereas in the case of AAE, a 10% concentration was considered cytotoxic. DTG enables the detailed differentiation between AA and AAE. AAE in aqueous solution is more stable compared to AA. The antioxidant activity of AAE is significant. However, the reaction with 2,2-diphenyl-1-picrylhydrazyl (DPPH) indicates prolonged activity compared to AA. Variability in the antimicrobial activity of AAE may find practical application in the pharmaceutical and cosmetic industries. The potential for applicative aims may be supported by the relatively low in vitro toxicity of AAE.

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Section: Discussionmentioning

confidence: 99%

Selected Physicochemical and Biological Properties of Ethyl Ascorbic Acid Compared to Ascorbic Acid

Golonka

Oleksy

Junka

et al. 2017

Biological & Pharmaceutical Bulletin

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“…In the following years, the proteins forming the glucose-and mannose-specific PTSs in E. coli (202,203) and the lactose-specific PTS in S. aureus (204) were identified, and their role in transport and phosphorylation of the two hexoses and the disaccharide was established. Since then, a huge number of PTSs transporting a large variety of substrates, including hexoses, 6-deoxy-hexoses (14), amino sugars, N-acetyl-amino sugars, gluconic acids (205), pentitols (206,207), ascorbate (208), and disaccharides, have been identified. We recently obtained evidence that the E. faecalis maltose-specific EIICBA Mal (MalT) (15) also transports and phosphorylates the trisaccharide maltotriose and the tetrasaccharide maltotetraose (J. Deutscher, A. Hartke, J. Thompson, C. Magni, C. Henry, V. Blancato, G. Repizo, N. Sauvageot, A. Pikis, T. Kentache, and A. Mokhtari, unpublished results).…”

Section: Discussionmentioning

confidence: 99%

The Bacterial Phosphoenolpyruvate:Carbohydrate Phosphotransferase System: Regulation by Protein Phosphorylation and Phosphorylation-Dependent Protein-Protein Interactions

Deutscher

Aké

Derkaoui

et al. 2014

Microbiol Mol Biol Rev

340

374

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SUMMARY The bacterial phosphoenolpyruvate (PEP):carbohydrate phosphotransferase system (PTS) carries out both catalytic and regulatory functions. It catalyzes the transport and phosphorylation of a variety of sugars and sugar derivatives but also carries out numerous regulatory functions related to carbon, nitrogen, and phosphate metabolism, to chemotaxis, to potassium transport, and to the virulence of certain pathogens. For these different regulatory processes, the signal is provided by the phosphorylation state of the PTS components, which varies according to the availability of PTS substrates and the metabolic state of the cell. PEP acts as phosphoryl donor for enzyme I (EI), which, together with HPr and one of several EIIA and EIIB pairs, forms a phosphorylation cascade which allows phosphorylation of the cognate carbohydrate bound to the membrane-spanning EIIC. HPr of firmicutes and numerous proteobacteria is also phosphorylated in an ATP-dependent reaction catalyzed by the bifunctional HPr kinase/phosphorylase. PTS-mediated regulatory mechanisms are based either on direct phosphorylation of the target protein or on phosphorylation-dependent interactions. For regulation by PTS-mediated phosphorylation, the target proteins either acquired a PTS domain by fusing it to their N or C termini or integrated a specific, conserved PTS regulation domain (PRD) or, alternatively, developed their own specific sites for PTS-mediated phosphorylation. Protein-protein interactions can occur with either phosphorylated or unphosphorylated PTS components and can either stimulate or inhibit the function of the target proteins. This large variety of signal transduction mechanisms allows the PTS to regulate numerous proteins and to form a vast regulatory network responding to the phosphorylation state of various PTS components.

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“…The strains used in this study were BW25113 and an isogenic crp mutant derivative, LJ3017, constructed as described by Zhang et al (43). Strains were grown at 37°C with agitation at 250 rpm in Luria-Bertani (LB) broth containing 50 mM potassium phosphate, pH 7.4, and 0.2 mM L-cysteine with or without 0.4% glucose.…”

Section: Methodsmentioning

confidence: 99%

Transcriptome Analysis of Crp-Dependent Catabolite Control of Gene Expression in Escherichia coli

et al. 2004

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We report here the transcriptome analyses of highly expressed genes that are subject to catabolite repression or activation mediated by the cyclic AMP receptor protein (Crp). The results reveal that many operons encoding enzymes of central carbon metabolic pathways (e.g., Krebs cycle enzymes), as well as transporters and enzymes that initiate carbon metabolism, are subject to direct Crp-mediated catabolite repression. By contrast, few enzyme-encoding genes (direct regulation) but many ribosomal protein-and tRNA-encoding genes (indirect regulation) are subject to Crp-dependent glucose activation. Additionally, Crp mediates strong indirect catabolite repression of many cytoplasmic stress response proteins, including the major chaperone proteins, five ATP-dependent protease complexes, and several cold and heat shock proteins. These results were confirmed by (i) phenotypic analyses, (ii) real-time PCR studies, (iii) reporter gene fusion assays, and (iv) previously published reports about representative genes. The results serve to define and extend our appreciation of the Crp regulon.A dominant mechanism by which Escherichia coli and other related bacteria sense carbon sufficiency involves cyclic AMP and its receptor protein, Crp (15,35). The mechanisms by which Crp regulates gene expression in response to variable cytoplasmic levels of cyclic AMP have been extensively investigated with primary emphasis on E. coli and Salmonella strains (5,34,35,41). Dozens of operons have been shown to be subject to Crp-mediated control by using classical approaches (17). Transcriptome and proteome approaches have been used to study the control of various regulons, as well as to facilitate glucose flux analyses (10, 39). Indeed, the transcriptome approach has allowed investigators to challenge established paradigms, and the technology has enjoyed rapid adoption among researchers (7). However, no report has focused on genomewide analyses of Crp-mediated catabolite regulation in E. coli. In this study, we corrected this deficiency by conducting combined transcriptome, phenotypic, and bioinformatic analyses of the Crp-mediated responses of E. coli to exogenous glucose availability. We also tabulated comparative data derived from the classical literature and confirmed representative regulatory responses by using alternative approaches. We show here that a variety of stress-related genes, encoding chaperones (1, 4, 38), ATP-dependent proteases (9,11,20), and certain temperature shock proteins (12,31,40), are regulated in response to the presence of Crp, apparently by an indirect mechanism. MATERIALS AND METHODSBacterial strains and growth conditions. The strains used in this study were BW25113 and an isogenic crp mutant derivative, LJ3017, constructed as described by Zhang et al. (43). Strains were grown at 37°C with agitation at 250 rpm in Luria-Bertani (LB) broth containing 50 mM potassium phosphate, pH 7.4, and 0.2 mM L-cysteine with or without 0.4% glucose. Cells were grown in 25 ml of medium in 250-ml shake flasks starting at an opt...

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The Ascorbate Transporter of Escherichia coli

Cited by 72 publications

References 29 publications

Selected Physicochemical and Biological Properties of Ethyl Ascorbic Acid Compared to Ascorbic Acid

Selected Physicochemical and Biological Properties of Ethyl Ascorbic Acid Compared to Ascorbic Acid

The Bacterial Phosphoenolpyruvate:Carbohydrate Phosphotransferase System: Regulation by Protein Phosphorylation and Phosphorylation-Dependent Protein-Protein Interactions

Transcriptome Analysis of Crp-Dependent Catabolite Control of Gene Expression in Escherichia coli

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