A Streptococcus mutans superoxide dismutase that is active with either manganese or iron as a cofactor.

Martı́n, Mercedes; Byers, B. R.; Olson, Matthew S.; Salin, Marvin L.; Arceneaux, J. E. L.; Tolbert, C.

doi:10.1016/s0021-9258(18)67663-x

Cited by 155 publications

(47 citation statements)

References 20 publications

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“…As stated in early reports, the endogenous SmSOD was isolated as a Mn-or Fe-containing enzyme, depending on metal source availability. 13,17 In order to inspect which metal was bound in the active site of rSmSOD during its heterologous production in E. coli, the iron and manganese content of four purified samples of the recombinant enzyme has been determined and reported in Table 1. Also the possible presence of nickel was evaluated because of the usage of the Ni-NTA Agarose chromatography; however, an insignificant amount of nickel (0.010-0.018 mol mol À1 rSmSOD) was thoroughly detected in any protein sample.…”

Section: Molecular Properties and Metal Content Of Rsmsodmentioning

confidence: 99%

“…[14][15][16] The SOD obtained when the microorganism was grown aerobically in chemically defined media has been characterised: essentially, a Mn-or a Fe-SOD was found, when the culture medium was supplemented with Mn or Fe ions, respectively. 13,17 The two SOD forms had identical amino acid compositions and N-terminal sequences, thus suggesting that SOD from S. mutans (SmSOD) was a cambialistic enzyme; in particular, SmSOD was synthesised as an apoenzyme and formed the Fe-or Mn-SOD form, depending on metal availability. 17 The nucleotide sequence of the corresponding gene, and the lack of enzyme activity in mutants where this gene was inactivated, suggested that this microorganism contained a unique SOD gene, 18 as later confirmed with the completion of genome sequencing of S. mutans.…”

Section: Introductionmentioning

confidence: 99%

“…13,17 The two SOD forms had identical amino acid compositions and N-terminal sequences, thus suggesting that SOD from S. mutans (SmSOD) was a cambialistic enzyme; in particular, SmSOD was synthesised as an apoenzyme and formed the Fe-or Mn-SOD form, depending on metal availability. 17 The nucleotide sequence of the corresponding gene, and the lack of enzyme activity in mutants where this gene was inactivated, suggested that this microorganism contained a unique SOD gene, 18 as later confirmed with the completion of genome sequencing of S. mutans. 19 In this work, a recombinant SmSOD (rSmSOD) was produced and characterised regarding to metal content, specific activity, heat stability and sensitivity to inhibitors and inactivators.…”

Section: Introductionmentioning

confidence: 99%

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Regulation of the properties of superoxide dismutase from the dental pathogenic microorganism Streptococcus mutans by iron- and manganese-bound co-factor

et al. 2010

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Streptococcus mutans, the main pathogen involved in the development of dental caries, is an aerotolerant microorganism. The bacterium lacks cytochromes and catalase, but possesses other antioxidant enzymes, such as superoxide dismutase (SmSOD). Previous researches suggested that SmSOD belongs to the 'cambialistic' group, functioning with Fe or Mn in the active site. A recombinant SmSOD (rSmSOD) with a His-tail has been produced and characterised. Studies on metal uptake and exchange proved that rSmSOD binds either Fe or Mn as a metal co-factor, even though with a consistent preference for Fe accommodation. The analysis of several enzyme samples with different values of the Mn/Fe ratio in the active site proved that the type of metal is crucial for the regulation of the activity of rSmSOD. Indeed, differently from the significant preference for Fe displayed by the enzyme in the binding reaction, its Mn-form was 71-fold more active compared to the Fe-form. The rSmSOD was endowed with a significant thermostability, its half-inactivation occurring after 10 min exposure at 71 or 73 degrees C, depending on the bound metal. Moreover, the enthalpic and entropic contribution to the heat inactivation process of rSmSOD were strongly regulated by the Mn content of the enzyme. The effect of typical inhibitors/inactivators has been investigated. rSmSOD was inhibited by sodium azide, and its sensitivity increased in the presence of higher Mn levels. Concerning two physiological inactivators, the enzyme displayed a different behaviour, being quite resistant to hydrogen peroxide and significantly sensitive to sodium peroxynitrite. Furthermore, the Mn co-factor had an amplifying role in the regulation of this different sensitivity. These results confirm the cambialistic nature of SmSOD and prove that its properties are regulated by the different metal content. The adaptative response of S. mutans during its aerobic exposure in the oral cavity could involve a different metal uptake by SmSOD.

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Section: Molecular Properties and Metal Content Of Rsmsodmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

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Regulation of the properties of superoxide dismutase from the dental pathogenic microorganism Streptococcus mutans by iron- and manganese-bound co-factor

et al. 2010

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“…Additionally, few families of SODs also use a Ni ion as cofactor at their catalytic core to initiate its functions [27]. A study has shown that superoxide dismutase from Streptococcus is capable of making a cofactor substitution with Fe in place of Mn [28]. On the other hand, Leishmania tropica, Trypanosoma brueci, and Crithidia fasciculate have superoxide dismutase, which is insensitivity to cyanide but sensitive to azide and peroxide [29].…”

Section: Superoxide Dismutasementioning

confidence: 99%

Superoxide Dismutase: A Key Enzyme for the Survival of Intracellular Pathogens in Host

Maurya¹,

Namdeo²

2022

Biochemistry

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Superoxide dismutase (SOD) is a crucial enzyme required to maintain the redox potential of the cells. It plays a vital role in protecting normal cells from reactive oxygen species (ROS) produced during many intracellular pathogens infections. SOD removes excess superoxide radicals (O2−) by converting them to hydrogen peroxide (H2O2) and molecular oxygen (O2). Several superoxide dismutase enzymes have been identified based on the metal ion as a cofactor. Human SOD differs from the intracellular pathogens in having Cu/Zn and Mn as metal cofactors. However, SOD of intracellular pathogens such as Trypanosoma, Leishmania, Plasmodium, and Mycobacterium have iron (Fe) as metal cofactors. Iron Superoxide Dismutase (FeSOD) is an essential enzyme in these pathogens that neutralizes the free radical of oxygen (O−) and prevents the formation of Peroxynitrite anion (ONOO−), helping the pathogens escape from redox-based cytotoxic killing. Moreover, most intracellular bacteria hold MnSOD or FeSOD in their cytoplasm such as Salmonella and Staphylococcus, whereas periplasm of some pathogenic bacteria and fungi are also cofactors with Cu/Zn and identified as CuZnSOD. This chapter will review the various types SOD present in intracellular pathogens and their role in the survival of these pathogens inside their host niche.

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“…Nonetheless, the findings suggest that the availability of Mn may play a role in either stimulating or limiting the growth of this sulfolane-assimilating bacterium. Mn is known to be used by bacteria as a cofactor in superoxide dismutase enzymes which are important in defending against oxygen toxicity by catalyzing the transformation of oxygen radicals into water (Martin et al, 1986;Miller, 2012). These manganese-containing enzymes have been shown to be upregulated by bacteria in the presence of oxygen (Amo et al, 2003).…”

Section: Plume-wide Abundance and Environmental Drivers Of Rhodoferax Sp Distributionmentioning

confidence: 99%

Distribution of a Sulfolane-Metabolizing Rhodoferax sp. Throughout a Contaminated Subarctic Aquifer and Two Groundwater Treatment Systems

2021

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An extensive plume of the emerging contaminant sulfolane has been found emanating from a refinery in Interior Alaska, raising questions about the microbial potential for natural attenuation and bioremediation in this subarctic aquifer. Previously, an aerobic sulfolane-assimilating Rhodoferax sp. was identified from the aquifer using stable isotope probing. Here, we assessed the distribution of known sulfolane-assimilating bacteria throughout the contaminated subarctic aquifer using 16S-rRNA-amplicon analyses of ~100 samples collected from groundwater monitoring wells and two groundwater treatment systems. One treatment system was an in situ air sparging system where air was injected directly into the aquifer. The other was an ex situ granular activated carbon (GAC) filtration system for the treatment of private well water. We found that the sulfolane-assimilating Rhodoferax sp. was present throughout the aquifer but was significantly more abundant in groundwater associated with the air sparge system. The reduction of sulfolane concentrations combined with the apparent enrichment of sulfolane degraders in the air sparging zone suggests that the addition of oxygen facilitated sulfolane biodegradation. To investigate other environmental controls on Rhodoferax populations, we also examined correlations between groundwater geochemical parameters and the relative abundance of the Rhodoferax sp. and found only manganese to be significantly positively correlated. The sulfolane-assimilating Rhodoferax sp. was not a major component of the GAC filtration system, suggesting that biodegradation is not an important contributor to sulfolane removal in these systems. We conclude that air sparging is a promising approach for enhancing the abundance and activity of aerobic sulfolane-degraders like Rhodoferax to locally stimulate sulfolane biodegradation in situ.

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A Streptococcus mutans superoxide dismutase that is active with either manganese or iron as a cofactor.

Cited by 155 publications

References 20 publications

Regulation of the properties of superoxide dismutase from the dental pathogenic microorganism Streptococcus mutans by iron- and manganese-bound co-factor

Regulation of the properties of superoxide dismutase from the dental pathogenic microorganism Streptococcus mutans by iron- and manganese-bound co-factor

Superoxide Dismutase: A Key Enzyme for the Survival of Intracellular Pathogens in Host

Distribution of a Sulfolane-Metabolizing Rhodoferax sp. Throughout a Contaminated Subarctic Aquifer and Two Groundwater Treatment Systems

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