Stoichiometry of the reaction of sulfites with hydrogen sulfide ion

Heunisch, George W.

doi:10.1021/ic50172a033

Cited by 31 publications

(23 citation statements)

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“…In the absence of taurine, negligible amounts of sulfide were formed. We thus presume that there is DSR activity in the extract but that sulfide reacts with other components in the aqueous mixture (13) and that formation of sulfide is underestimated. The enzyme rapidly lost activity, so its purification depended on assaying its physical properties.…”

Section: Resultsmentioning

confidence: 98%

Dissimilatory Sulfite Reductase (Desulfoviridin) of the Taurine-Degrading, Non-Sulfate-Reducing Bacterium Bilophila wadsworthia RZATAU Contains a Fused DsrB-DsrD Subunit

et al. 2001

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A dissimilatory sulfite reductase (DSR) was purified from the anaerobic, taurine-degrading bacterium Bilophila wadsworthia RZATAU to apparent homogeneity. The enzyme is involved in energy conservation by reducing sulfite, which is formed during the degradation of taurine as an electron acceptor, to sulfide. According to its UV-visible absorption spectrum with maxima at 392, 410, 583, and 630 nm, the enzyme belongs to the desulfoviridin type of DSRs. The sulfite reductase was isolated as an ␣ 2 ␤ 2 ␥ n (n > 2) multimer with a native size of 285 kDa as determined by gel filtration. We have sequenced the genes encoding the ␣ and ␤ subunits (dsrA and dsrB, respectively), which probably constitute one operon. dsrA and dsrB encode polypeptides of 49 (␣) and 54 kDa (␤) which show significant similarities to the homologous subunits of other DSRs. The dsrB gene product of B. wadsworthia is apparently a fusion protein of dsrB and dsrD. This indicates a possible functional role of DsrD in DSR function because of its presence as a fusion protein as an integral part of the DSR holoenzyme in B. wadsworthia. A phylogenetic analysis using the available Dsr sequences revealed that B. wadsworthia grouped with its closest 16S rDNA relative Desulfovibrio desulfuricans Essex 6.Bilophila wadsworthia is a strictly anaerobic, gram-negative bacterium (2) which belongs to the family Desulfovibrionaceae in the delta subdivision of the Proteobacteria, but does not reduce sulfate (2, 25). B. wadsworthia has been found quite frequently in patients with appendicitis and its complications and is the third most common anaerobic isolate in such infections (11), but can also be isolated from a wide variety of other infections, e.g., biliary tract infection (41), liver abscess (41), and ear infections (39). B. wadsworthia has also been found in the normal fecal flora (2). The organism lacks classical virulence factors like capsules, fimbriae, and extracellular enzymes (2). However, preliminary studies have indicated that B. wadsworthia exerts cytotoxic effects on two cell lines, and endotoxic activity of B. wadsworthia has been described (2, 34).We recently isolated from a communal sewage plant a strain of B. wadsworthia which utilizes organic sulfonates (e.g., taurine [2-aminoethanesulfonate]) as a carbon source and electron sink. B. wadsworthia respires taurine anaerobically with electrons derived mainly from formate oxidation and oxidation of the taurine carbon (25). Taurine is transaminated to sulfoacetaldehyde (22), which is cleaved to sulfite and an unidentified organic product (K. Denger and A. M. Cook, unpublished). Finally, sulfite is reduced to sulfide by a dissimilatory sulfite reductase (DSR) (6, 25). In addition, sulfite or thiosulfate serves as an electron acceptor for anaerobic respiration with formate as the electron donor in B. wadsworthia (25).DSR, a key enzyme in dissimilatory sulfate reduction, occurs in all organisms capable of reducing sulfite during anaerobic respiration investigated so far (9, 33). Otherwise, DSRs are rare....

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Section: Resultsmentioning

confidence: 98%

Dissimilatory Sulfite Reductase (Desulfoviridin) of the Taurine-Degrading, Non-Sulfate-Reducing Bacterium Bilophila wadsworthia RZATAU Contains a Fused DsrB-DsrD Subunit

et al. 2001

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“…At pH values of between 6 and 9 (the pH for most natural waters), about two thirds are HS – and about one third H 2 S (the S 2 – form is present in negligible concentration) [44, 62, 63]. …”

Section: Discussionmentioning

confidence: 99%

Antioxidant Effect of Sulphurous Thermal Water on Human Neutrophil Bursts: Chemiluminescence Evaluation

et al. 2007

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Background: The activities of the HS (sulfhydryl or thiolic) group in the cysteine of glutathione or various low-weight soluble molecules (thiolic drugs), such as N-acethylcysteine, mesna, thiopronine and dithiotreitol or stepronine and erdosteine (prodrugs), include its antioxidant activity in the airways during the release of reactive oxygen or nitrogen species (ROS, RNS) by polymorphonuclear neutrophils (PMNs) activated in response to exogenous or endogenous stimuli. Objective: In addition to being administered by means of thiolic molecules, the HS group can also be given by means of the inhalation of sulphurous thermal water. The aim of this study was to investigate the effect of sulphurous thermal water on the release of ROS and RNS during the bursts of human PMNs. Methods: The luminol-amplified chemiluminescence methodology was used to investigate the ROS and RNS released by PMNs stimulated with N-formyl-methionyl-leucyl-phenylalanine and phorbol-12-myristate-13-acetate, before and after incubation with sulphurous water. Effects on cell-free systems were also investigated. Results: The water significantly reduced the luminol-amplified chemiluminescence of N-formyl-methionyl-leucyl-phenylalanine- andphorbol-12-myristate-13-acetate-activated PMNs on average from 0.94 to 15.5 µg/ml of HS, even after the addition of L-arginine, a nitric oxide (NO) donor. Similar findings have also been obtained in a cell-free system, thus confirming the importance of the presence of the HS group (reductive activity). Conclusions: The positive effects of the activity of sulphurous thermal waters has been partially based on the patients’ subjective sense of wellbeing and partially on not always easy to quantify symptomatic (or general) clinical improvements. Our findings indicate that, in addition to their known mucolytic activity and trophic effects on respiratory mucosa, the HS groups present in the sulphurous thermal water of this spring also have antioxidant activity that contributes to the therapeutic effects of the water in upper and lower airway inflammatory diseases.

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“…Under oxic conditions sulfite is rapidly oxidized to sulfate (Zhang and Millero, 1991), whereas it reacts to thiosulfate in the presence of RH 2 S or S 0 (Chen and Morris, 1972;Heunisch, 1977). Incubation experiments with RH 2 S, S 2 O 3 2À or SO 3 2À additions to shelf sediments of the Black Sea revealed that SO 3 2À disappeared at the highest rate of the three compounds and was transformed partly to S 2 O 3 2À (Zopfi et al, 2004).…”

Section: Sulfur Intermediatesmentioning

confidence: 98%

Biogeochemistry of sulfur and iron in Thioploca-colonized surface sediments in the upwelling area off central chile

Zopfi

Böttcher

Jørgensen

2008

Geochimica et Cosmochimica Acta

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Stoichiometry of the reaction of sulfites with hydrogen sulfide ion

Cited by 31 publications

References 0 publications

Dissimilatory Sulfite Reductase (Desulfoviridin) of the Taurine-Degrading, Non-Sulfate-Reducing Bacterium Bilophila wadsworthia RZATAU Contains a Fused DsrB-DsrD Subunit

Dissimilatory Sulfite Reductase (Desulfoviridin) of the Taurine-Degrading, Non-Sulfate-Reducing Bacterium Bilophila wadsworthia RZATAU Contains a Fused DsrB-DsrD Subunit

Antioxidant Effect of Sulphurous Thermal Water on Human Neutrophil Bursts: Chemiluminescence Evaluation

Biogeochemistry of sulfur and iron in Thioploca-colonized surface sediments in the upwelling area off central chile

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