31P-NMR and ESR studies of the oxidation states of manganese in Staphylococcus aureus

Ezra, F. S.; Lucas, Donald S.; Russell, Anne F.

doi:10.1016/0167-4889(84)90059-4

Cited by 14 publications

(5 citation statements)

References 19 publications

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“…5 indicate that Mn 2+ is indeed oxidized to Mn a+ under the assay conditions used in our studies. Ezra and co-workers [14] reported that Mn a+ is reduced to Mn 2+ by 2-mercaptoethanol. We observed the same; full activation of threonine dehydrogenase by Mn a + in the presence of 2-mercaptoethanol as well as disappearance of the ultraviolet band for the Mna+-pyrophosphate complex following the addition of 2-mercaptoethanol to a solution containing Mn a + demonstrated the reduction of Mn 3 + Mn 2+ in our system.…”

Section: Discussionmentioning

confidence: 99%

Cd2+ activation of l-threonine dehydrogenase from Escherichia coli K-12

Craig

Dekker

1988

Biochimica et Biophysica Acta (BBA) - Protein Structure and Mol

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Homogeneous preparations of L-threonine dehydrogenase (L-threonine:NAD+ oxidoreductase, EC 1.1.1.103) from Escherichia coli K-12, after having been dialyzed against buffers containing Chelex-100 resin, have a basal level of activity of 10-20 units/mg. Added Cd2+ stimulates dehydrogenase activity approx. 10-fold; this activation is concentration-dependent and is saturable with an activation Kd = 0.9 microM. Full activation by Cd2+ is obtained in the absence of added thiols. The pH-activity profile of the Cd2+-activated enzyme conforms to a theoretical curve for one-proton ionization with a pKa = 7.85. Mn2+, the only other activating metal ion, competes with Cd2+ for the same binding site. Km values for L-threonine and NAD+ as well as the Vmax for 'demetallized', Cd2+-activated, and Mn2+-activated threonine dehydrogenase were determined and compared.

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Section: Discussionmentioning

confidence: 99%

Cd2+ activation of l-threonine dehydrogenase from Escherichia coli K-12

Craig

Dekker

1988

Biochimica et Biophysica Acta (BBA) - Protein Structure and Mol

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“…Mn(II) participates in the aerobic metabolism of S. aureus (Ezra et al , 1983; 1984). Using high‐resolution 31 P‐NMR and ESR spectroscopies, it was shown that Mn(II) hexaquo ions are sensitive to the oxygenation state of the cells, such that Mn(II) was oxidized to Mn(III) in aerated cells, and Mn(III) was reduced to Mn(II) under anaerobic conditions.…”

Section: Discussionmentioning

confidence: 99%

“…The reduced transport of Mn(II) in N. gonorrhoeae increased its sensitivity to intracellular and extracellular sources of superoxide without altering the overall level of enzymatic SOD activity. In contrast to L. plantarum , in which Mn(II) associates with polyphosphate (Archibald and Fridovich, 1982), the Mn(II) in S. aureus associates with orthophosphate and was suggested to impart superoxide scavenging activity (Ezra et al , 1984). High‐resolution 31 P nuclear magnetic resonance (NMR) and ESR spectroscopies have demonstrated that, in S. aureus and S. epidermidis , the oxidation state of intracellular Mn is dependent on the oxygenation state of the cells (Ezra et al , 1983; 1984).…”

Section: Introductionmentioning

confidence: 99%

“…In contrast to L. plantarum , in which Mn(II) associates with polyphosphate (Archibald and Fridovich, 1982), the Mn(II) in S. aureus associates with orthophosphate and was suggested to impart superoxide scavenging activity (Ezra et al , 1984). High‐resolution 31 P nuclear magnetic resonance (NMR) and ESR spectroscopies have demonstrated that, in S. aureus and S. epidermidis , the oxidation state of intracellular Mn is dependent on the oxygenation state of the cells (Ezra et al , 1983; 1984). In addition to SOD activity, Mn(II) will dismutate H 2 O 2 in bicarbonate buffer (Stadtman et al , 1990); however, the physiological importance of this reaction in bacteria has not been determined.…”

Section: Introductionmentioning

confidence: 99%

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MntR modulates expression of the PerR regulon and superoxide resistance in Staphylococcus aureus through control of manganese uptake

Horsburgh

Wharton

Cox

et al. 2002

Molecular Microbiology

219

290

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MntR modulates expression of the PerR regulon and superoxide resistance in Staphylococcus aureus through control of manganese uptake co-ordinated regulation of metal ion homeostasis and oxidative stress resistance via the regulators MntR, PerR and Fur of S. aureus is discussed. IntroductionThe acquisition of metal ions is essential for the life of all organisms. During bacterial infection, the host restricts the availability of some metal ions, such as iron. With the exception of Borrelia burgdorferi (Posey and Gherardini, 2000), successful colonization requires that pathogenic bacteria overcome this iron limitation (Wooldridge and Williams, 1993). Although B. burgdorferi does not need iron, it has an obligate requirement for manganese (Mn) (Posey and Gherardini, 2000). Manganese uptake has recently been shown to be important for a number of other pathogens. Bacterial Nramp homologues, called MntH, are selective Mn transporters that play a role in the response to reactive oxygen species and may have a role in pathogenesis (Kehres et al., 2000;Makui et al., 2000). In addition, the ATP-binding cassette (ABC) family of Mn transporters (Claverys, 2001) was clearly shown to be important during infections caused by Enterococcus faecalis (Singh et al., 1998), Streptococcus pneumoniae and Streptococcus parasanguinis (Burnette-Curley et al., 1995;Berry and Paton, 1996) and Yersinia pestis (Bearden and Perry, 1999). Thus, Mn can be added to the in vivo growth requirements of many pathogens (Posey and Gherardini, 2000).In bacteria, specific cellular roles have been determined for Mn as a cofactor in enzymes for metabolism, catabolism, signal transduction and photosynthesis (reviewed by Yocum and Pecoraro, 1999;Jakubovics and Jenkinson, 2001). In addition, an enzymatic and a non-enzymatic role for Mn in the protection of the cell from oxidative stress has been described. Many bacteria, including Staphylococcus aureus (Clements et al., 1999;Valderas and Hart, 2001), contain a Mn-superoxide dismutase (SOD) that catalyses the reduction of superoxide radicals to produce H 2 O 2 . Furthermore, inactivation of sodA, which encodes Mn-SOD, reduces virulence of Strep. pneumoniae in a murine intranasal infection (Yesilkaya et al., 2000).Simple Mn(II) salts are known to catalyse the dismutation of superoxide radical (Archibald and Fridovich, 1981a,b;. A number of bacteria have been shown SummaryThe Staphylococcus aureus DtxR-like protein, MntR, controls expression of the mntABC and mntH genes, which encode putative manganese transporters. Mutation of mntABC produced a growth defect in metal-depleted medium and increased sensitivity to intracellularly generated superoxide radicals. These phenotypes resulted from diminished uptake of manganese and were rescued by the addition of excess Mn(II). Resistance to superoxide was incompletely rescued by Mn(II) for STE035 (mntA mntH), and the strain had reduced virulence in a murine abscess model of infection. Expression of mntABC was repressed by Mn(II) in an MntR-dependent manner, which cont...

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“…The ability of this bacterium to tolerate oxygen exposure despite the lack of superoxide dismutase was ascribed to the spontaneous formation of Mn(II) complexes with small cellular ligands, like phosphate and lactate, which act in vitro as superoxide or hydrogen peroxide scavengers [2,3]. This contention was supported by the observation that in Staphylococcus aureus Mn(II) forms a complex with lactate and orthophosphate and that the metal oxidation state in such complexes is influenced by oxygenation of the cell [4,5].…”

Section: Introductionmentioning

confidence: 98%