1887

Abstract

Ferrimycobactin reductase activity from grown under iron-deficient conditions had a for ferrimycobactin of less than 4 μ and a for NADH of 1·75 m. Salicylate (0·12 m), which is synthesized by this bacterium, could substitute for EDTA as an acceptor of Fe in the assay system. Reagents which react with thiol groups (HgCl, -ethylmaleimide) at 0·1 m inhibited activity by about 40%; other inhibitors (KCN, NaN, carbonyl cyanide -chlorophenylhydrazone and 2,4-dinitrophenol) were less effective (though these inhibited active iron transport, which uses exochelin and not mycobactin; Stephenson & Ratledge, 1979 ). The rate of ferrimycobactin reduction in extracts was about ten times faster than the rate observed following a shift-up of low-iron cells to high-iron status. Reduction of iron in ferri-ferrioxamine B, ferriexochelin MS and ferric ammonium citrate occurred at comparable rates to ferrimycobactin reduction.

Ferrimycobactin reductase activity was undiminished in grown under iron-sufficient conditions. A similar activity was found in extracts of and where it still required NADH. Yeast alcohol dehydrogenase reduced ferrimycobactin independently of NADH; this activity was attributed to the free thiol groups of this protein. Reductase activity therefore may be associated with a protein whose principal function need not be that of a siderophore reductase.

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1979-07-01
2021-10-16
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References

  1. Brändén C.I., Jörnvall H., Eklund H., Furugren B. 1970; Alcohol dehydrogenases. In The Enzymes, 3rd edn. 11 part A pp. 103–190 Boyer P.D. Edited by New York, San Francisco & London: Academic Press.;
    [Google Scholar]
  2. Braun V. 1978; Structure-function relationships of the Gram-negative bacterial cell envelope. Symposia of the Society for General Microbiology 28:111–138
    [Google Scholar]
  3. Brown K.A., Ratledge C. 1974; Iron transport in Mycobacterium smegmatis: ferrimycobactinreductase [NAD(P)H: ferrimycobactin oxidoreductase], the enzyme releasing iron from its carrier. FEBS Letters 53:262–266
    [Google Scholar]
  4. Dailey H.A., Lascelles J. 1977; Reduction of iron and synthesis of protoheme by Spirillumitersonii and other organisms. Journal of Bacteriology 129:815–820
    [Google Scholar]
  5. Emery T. 1976; Fungal ornithine esterases: relationship to iron transport. Biochemistry 15:2723–2728
    [Google Scholar]
  6. Ernst J.F., Winkelmann G. 1977; Enzymatic release of iron from sideramines in fungi: NADH: sideramineoxidoreductase in Neurospora crassa. Biochimica et biophysica acta 500:27–41
    [Google Scholar]
  7. Ernst J.F., Bennett R.L., Rothfield L.I. 1978; Constitutive expression of the iron-enterochelin and ferrichrome uptake systems in a mutant strain of Salmonella typhimurium. Journal of Bacteriology 135:928–934
    [Google Scholar]
  8. Greenwood K.B.T., Luke R.K.J. 1978; Enzymatic hydrolysis of enterochelin and its iron complex in Escherichia coli. Biochimica et biophysica acta 525:209–218
    [Google Scholar]
  9. Lascelles J., Burke K.A. 1978; Reduction of ferric iron by l-lactate and dl-glycerol-3-phosphate in membrane preparations from Staphylococcus aureus and interactions with the nitrate reductase. Journal of Bacteriology 134:585–589
    [Google Scholar]
  10. Loach P.A. 1970; Oxidation-reduction potentials, absorbance bands and molar absorbance of compounds used in biochemical studies. In Handbook of Biochemistry, Selected Data for Molecular Biology, 2nd edn. pp. J33–J40 Sober H.A. Edited by Cleveland, Ohio, U.S.A.: The Chemical Rubber Co.;
    [Google Scholar]
  11. Macham L.P., Stephenson M.C., Ratledge C. 1977; Iron transport in Mycobacterium smegmatis: the isolation, purification and function of exochelin MS. Journal of General Microbiology 101:41–49
    [Google Scholar]
  12. Mccready K.A., Ratledge C. 1978; Amounts of iron, haem and related compounds in Mycobacterium smegmatis grown in various concentrations of iron. Biochemical Society Transactions 6:421–423
    [Google Scholar]
  13. Ratledge C., Hall M.J. 1971; Influence of metal ions on the formation of mycobactin and salicylic acid in Mycobacterium smegmatis grown in static culture. Journal of Bacteriology 108:312–319
    [Google Scholar]
  14. Ratledge C., Marshall B.J. 1972; Iron transport in Mycobacterium smegmatis: the role of mycobactin. Biochimica et biophysica acta 279:58–74
    [Google Scholar]
  15. Ratledge C., Snow G.A. 1974; Isolation and structure of nocobactin NA, a lipid-soluble ironbinding compound from Nocardia asteroides. Biochemical Journal 139:407–413
    [Google Scholar]
  16. Ratledge C., Macham L.P., Brown K.A., Marshall B.J. 1974; Iron transport in Mycobacterium smegmatis: a restricted role for salicylic acid in the extracellular environment. Biochimica et biophysica acta 372:39–51
    [Google Scholar]
  17. Stephenson M.C., Ratledge C. 1979; Iron transport in Mycobacterium smegmatis: uptake of iron from ferriexochelin. Journal of General Microbiology 110:193–202
    [Google Scholar]
  18. White A.J., Snow G.A. 1968; Methods for the separation and identification of mycobactins from various species of mycobacteria. Biochemical Journal 108:593–597
    [Google Scholar]
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