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At least 19 recordsLinked to original sources
PubMed1975

Purification and properties of thiosulfate reductase from Desulfovibrio gigas.

Thiosulfate reductase of the dissimilatory sulfate-reducing bacterium Desulfovibrio gigas has been purified 415-fold and its properties investigated. The enzyme was unstable during the different steps of purification as well as during storage at - 15 degrees C. The molecular weight of thiosulfate reductase estimated from the chromatographic behaviour of the enzyme on Sephadex G-200 was close to 220000. The absorption spectrum of the purified enzyme exhibited a protein peak at 278 nm without characteristic features in the visible region. Thiosulfate reductase catalyzed the stoichiometric production of hydrogen sulfide and sulfite from thiosulfate, and exhibited tetrathionate reductase activity. It did not show sulfite reductase activity. The optimum pH of thiosulfate reduction occurred between pH 7.4 and 8.0 and its Km value for thiosulfate was calculated to be 5 - 10(-4)M. The sensitivity of thiosulfate reductase to sulfhydryl reagent and the reversal of the inhibition by cysteine indicated that one or more sulfhydryl groups were involved in the catalytic activity. The study of electron transport between hydrogenase and thiosulfate reductase showed that the most efficient coupling was obtained with a system containing cytochromes c3 (Mr = 13000) and c3 (Mr = 26000).

Cold Temperature↗
PubMed1978

Effect of sodium nitroprusside alone and in combination with sodium thiosulfate on the acid-base balance, and on thiocyanate and iron plasma levels in the rabbit.

An infusion of 7.5 mg/kg.h sodium nitroprusside (SNP) produced a fatal cyanide intoxication in conscious rabbits (n=6) after 60.8 +/- 6.7 min (chi +/- S.E.). When, however, the cyanide antidote sodium thiosulfate was infused simultaneously at a rate of 31.25 or 62.5 mg/kg.h, i.e. a molar SNP/thiosulfate ratio of 1:5 or 1:10 respectively, this high dose of SNP was well tolerated. In both concentrations, thiosulfate abolished the development of the severe metabolic acidosis that results from the infusion of toxic doses of SNP alone. In the presence of thiosulfate, the plasma level of thiocyanate rose linearly with the infusion time indicating a rapid detoxification of cyanide released in vivo from SNP, whereas at the end of the infusion of SNP alone no increase in plasma thiocyanate could be measured. No clear advantage of the higher thiosulfate dosage over the lower one could be established. The iron plasma level only rose during the first hour of SNP plus thiosulfate infusions reaching the iron binding capacity of plasma, and then remained stable throughout the experiment. This indicates that the iron plasma level is an unsuitable parameter for the control of SNP therapy. We suggest the simultaneous administration of SNP and thiosulfate at a molar ratio of 1:5 to make SNP a safer drug.

Acid-Base Equilibrium↗
PubMed1977

Characterization of a novel thiosulfate-forming enzyme isolated from Desulfovibrio vulgaris.

An enzyme that formed thiosulfate from bisulfite and trithionate was purified from extracts of Desulfovibrio vulgaris. This enzyme, designated as "thiosulfate-forming" enzyme, required the presence of both bisulfite and trithionate. Various 35S-labeling studies showed that thiosulfate was formed from bisulfite and the inner sulfur atom of trithionate. This involved a nucleophilic attack by the bisulfite ion, resulting in the displacement of the two outer sulfonate groups of trithionate that recycled to participate as free bisulfite in subsequent reactions. This reaction required a reduction, presumably by a concerted mechanism with thiosulfate formation. The natural electron carrier cytochrome c3 participated in this reductive formation of thiosulfate. This reaction was coupled to the bisulfite reductase-catalyzed reaction, which resulted in the reconstruction of a thiosulfate-forming pathway from bisulfite.

Cytochrome c Group↗
PubMed1979

Cyanide intoxication in sheep: enhancement of efficacy of sodium nitrite, sodium thiosulfate, and cobaltous chloride.

For treatment of cyanide intoxication of ruminants, the present recommended doses of sodium nitrite (5 mg/kg of body weight) and sodium thiosulfate (25 to 50 mg/kg) are smaller than those recommended for other animals; the decrease is partially attributed to the greater susceptibility of ruminants to the toxic effects of sodium nitrite. Based on the high tissue concentration and activity rate of rhodanese in ruminants, sulfur donors such as sodium thiosulfate could be utilized more efficaciously. Doses of sodium nitrite and sodium thiosulfate (up to 22 and 660 mg/kg, respectively) were evaluated in the present studies. Adjustment of the antidotal combination provided almost three times the protection afforded by the previously recommended doses. Moreover, under the conditions tested, the newly adjusted dose levels of sodium thiosulfate alone were more effective than the previously used antidotal combination of sodium nitrite and sodium thiosulfate and this protective effect was enhanced by cobaltous chloride (10.6 mg/kg) or sodium nitrite. The present recommended therapeutic approach to cyanide intoxication in sheep should be based primarily on administration of a much higher dose of sodium thiosulfate in combination with sodium nitrite or cobaltous chloride (or both).

Animals↗
PubMed1975

The use of thiosulfate to increase polymerization of IgM subunits.

Sodium thiosulfate was used to enhance in vivo the polymerization of myeloma IgM, deficient in disulfide cross-links. The therapy sharply decreased the amount of low molecular weight IgM fractions, while increasing the serum content of molecules of higher molecular weight. The degree of disulfide cross-linking in IgM increased under the influence of thiosulfate. The rate of secretion into the serum and urine of some membrane-related glycopeptides and species rich in sialic acid was reduced. Also, the discharge of L chains to the urine was lowered during the thiosulfate trial. All these changes were attributed to enhancement of disulfide-interchanging enzyme activity by thiosulfate.

Binding Sites↗
PubMed1975

Biochemical studies on sulfate-reducing bacteria. XIV. Enzyme levels of adenylylsulfate reductase, inorganic pyrophosphatase, sulfite reductase, hydrogenase, and adenosine triphosphatase in cells grown on sulfate, sulfite, and thiosulfate.

Sulfate-reducing bacteria, Desulfovibrio vulgaris, strain Miyazaki, were grown on either sulfate, sulfite, or thiosulfate as the terminal electron acceptor. Better growth was observed on sulfite and less growth on thiosulfate than on sulfate. Enzyme levels of adenylylsulfate (APS) reductase [EC 1.8.99.2], reductant-activated inorganic pyrophosphatase [EC 3.6.1.1], sulfite reductase [EC 1.8.99.1] (desulfoviridin), hydrogenase [EC 1.12.2.1], and Mg2+-activated ATPase [EC 3.6.1.3] were compared in crude extracts of these cells at various stages of growth. 1) The specific activity of APS reductase in sulfite-grown cells was only one-fourth that in sulfate-grown cells throughout growth. Thiosulfate-grown cells had an activity intermediate between those of sulfate- and sulfite-grown cells. 2) Cells grown on sulfite had lower specific activity of reductant-activated inorganic pyrophosphatase than cells grown on sulfate or thiosulfate. 3) The specific activity of sulfite reductase (desulfoviridin) was highest in sulfite-grown cells. The sulfite medium gave the enzyme in high yield as well as with high specific activity. 4) The specific activities of hydrogenase and Mg2+-ATPase were not significantly altered by electron acceptors in the growth medium.

Adenosine Monophosphate↗
PubMed1978

Oxidation kinetics and chemostat growth kinetics of Thiobacillus ferrooxidans on tetrathionate and thiosulfate.

Growth of Thiobacillus ferrooxidans in batch culture on 10 mM potassium tetrathionate was optimal at pH 2.5 (specific growth rate, 0.092 h-1). Oxygen electrode studies on resting cell suspensions showed that the apparent Km for tetrathionate oxidation (0.13 to 8.33 mM) was pH dependent, suggesting higher substrate affinity at higher pH. Conversely, oxidation rates were greatest at low pH. High substrate concentrations (7.7 to 77 mM) did not affect maximum oxidation rates at pH 3.0, but produced substrate inhibition at other pH values. Tetrathionate-grown cell suspensions also oxidized thiosulfate at pH 2.0 to 4.0. Apparent Km values (1.2 to 25 mM) were of the same order as for tetrathionate, but kinetics were complex. Continuous culture on growth-limiting tetrathionate at pH 2.5, followed by continuous culture on growth-limiting thiosulfate at pH 2.5, indicated true growth yield values (grams [dry weight] per gram-molecule of substrate) of 12.2 and 7.5, and maintenance coefficient values (millimoles of substrate per gram [dry weight) of organisms per hour) of 1.01 and 0.97 for tetrathionate and thiosulfate, respectively. Yield was increased on both media at low dilution rates by increase in CO2 supply. The apparent maintenance coefficient was lowered without affecting YG, suggesting better energy coupling in CO2-rich environments. Prolonged continuous cultivation on tetrathionate or thiosulfate did not affect the ability of the organism to grow subsequently in ferrous iron medium.

Ferrous Compounds↗
PubMed1979

Thiosulfate formation and associated isotope effects during sulfite reduction by Clostridium pasteurianum.

During growth of Clostridium pasteurianum on sulfite, approximately half the sulfite was reduced to sulfide and half to thiosulfate. Sulfide was enriched in 32S or 34S at different stages of growth and thiosulfate was enriched in 32S, particularly in the sulfane atom. It is suggested that thiosulfate in these bacterial cultures arose from a secondary chemical reaction. The chemical formation of thiosulfate from sulfide and sulfite was also accompanied by sulfur isotope fractionation. The implications of these results with respect to 'inverse' isotopic effects are discussed.

Clostridium↗
PubMed1978

Formation of thiosulfate [35S] by neutron irradiation of potassium chloride and preparation of elementary sulfur [35S].

Potassium chloride was subjected to various kinds of pretreatments and irradiated in a nuclear reactor. Irradiated potassium chloride was dissolved in deaerated aqueous solution of several sulfur-salts. A portion of the solution was chromatographed on a thin layer chromatographic plate and the distribution of 35S-chemical species was determined. Irradiation of potassium chloride degassed at 3x10(-4)Torr resulted in the formation of about 60% of 35S in the form of thiosulfate and remainder was distributed among sulfide, sulfate and elementary sulfur. Thiosulfate[35S] was converted to elementary sulfur[35S] first by reducing to hydrogen sulfide [35S] with nascent hydrogen and then by oxidizing the latter to elementary sulfur[35S] with hexacyanoferrate(III). Elementary sulfur[35S] was finally extracted into benzene. Radiochemically pure elementary sulfur[35S] could be produced by simple procedures with a yield of about 60%. Thiosulfate[35S] was decomposed with acid to elementary sulfur[35S] and sulfur[35S] dioxide. The former was separated by centrifuging and dispersed in boiling water to form colloidal suspension of elementary sulfur[35S]. Approximately 40% of 35S was recovered as colloid.

Chemical Phenomena↗
PubMedDate not supplied

[Kinetics of sodium thiosulfate-35S fixation and effect of some sulfur compounds on iodine-131 fixation in ray thyroid gland].

In order to invalidate or confirm the affirmation that non antithyroid sulphide molecules alter the measure of the thyroid fixation rate of iodine 131 we undertook on the rat: on one hand a kinetic study of thyroid fixation of sodium thiosulfate labelled with sulphur 35, which showed a very low captation not exceeding 0,01% of injected radioactivity; on the other hand the study of the effects of some sulphide molecules on thyroid fixation of iodine 131 in the rat: sodium thiosulfate, association of sodium thiosulfate + metalloidal sulphur + methionine, carbutamide and dimethylsulfoxyde in various kinds of dose administration and periods. None of the products used in our work conditions produced a significant decrease of the fixation rate of iodine 131. In three different experimental protocols (sulfur association and dimethylsulfoxide), we showed a significant light increase of the fixation rate.

Animals↗
PubMed1975

On the molecular weight of thiosulfate sulfurtransferase.

Bovine liver thiosulfate sulfurtransferase (rhodanese) (EC 2.8.1.1) HAS BEEN REPORTED TO EXIST IN SOLUTION IN A RAPID, PH-dependent equilibrium between monomeric and dimeric forms of molecular weights 18 500 and 37 000 (Volini, M., DeToma, F. and Westley, J. (1967), J. Biol. Chem. 242, 5220). We have reinvestigated the proposed dissociation using sodium dodecylsulfate-polyacrylamide gel electrophoresis. The smallest rhodanese species observed has a molecular weight around 35 000, which is not reduced by severe denaturing conditions, including alkylation in 8 M guanidine-HCl or dialysis against 2% sodium dodecylsulfate and 5% mercaptoethanol. After limited CNBr cleavage, intermediate products of greater than 18 500 molecular weight are formed. The apparent molecular weight of these intermediate fragments is not changed by addition of mercaptoethanol. The total apparent molecular weights of the CNBr fragments after exhaustive cleavage is approx. 45 000 plus or minus 15 000. These results are not consistent with a monomer molecular weight of approx. 18 500 for thiosulfate sulfurtransferase.

Animals↗
PubMed1978

Chromatium sulfite reductase. I. Characterization of thiosulfate-forming activity at the cell extract level.

Thiosulfate and sulfide were detected in the sulfite reductase reaction catalyzed by a cell-free extract of photoautotrophically grown Chromatium vinosum. Hydrogen was consumed upon addition of sulfite to the extract in the presence of hydrogenase and methylviologen. Hydrogen uptake proceeded biphasically. During the first phase, thiosulfate and sulfide were formed concomitant with the decrease in sulfite. After the disappearance of sulfite, hydrogen was consumed with reduced velocity and sulfide accumulated as the final product with the total consumption of three mol of hydrogen per mol of sulfite. The molecular weight of a major sulfite reductase was estimated to be about 180,000 by the polyacrylamide disc electrophoresis method using enzyme staining. Arsenite. EDTA, alpha,alpha'-dipyridyl, cyanide, or azide did not inhibit the activity at the concentration of 1 mM. The activity was present in the soluble fraction and was stable at --20 degrees C.

2,2'-Dipyridyl↗
PubMed1978

[Effect of sodium thiosulfate on the pancreas in experimental pancreatitis].

Histological and histochemical study of the pancreas of albino rats and experimental pancreatitis showed the use of sodium thiosulfate to considerably inhibit the progress of necrotic changes and circulatory disturbance. The preparation prevented recidivation of pancreatitis and inhibited sclerotic changes in the gland. Sodium thiosulfate stimulated the regenerative process including regenerative hypertrophy and expressed epimorphosis.

Acute Disease↗
PubMed2026

Melioribacter sulfuriphilus sp. nov., facultatively anaerobic thermophilic sulfur- and thiosulfate-respiring bacterium from Karmadon hot springs of North Ossetia (Russian Federation).

Novel facultatively anaerobic moderately thermophilic bacteria, strains OK-6-MeT and OK-1-Me, were isolated from the hot springs of Karmadon (North Ossetia, Russian Federation). Gram-stain-negative, motile rods were present singly, in rosettes, and formed biofilms. Both strains grew optimally at 55 °C, pH 7.0 and did not require sodium chloride. They were chemoorganoheterotrophs, growing on mono-, di- and polysaccharides (cellulose, xylan, lichenan, xyloglucan, mannan, locust bean gum, pectin) as well as proteinaceous substrates (gelatin, casein). Growth under anaerobic conditions was observed both in the presence and absence of external electron acceptors (sulfur, thiosulfate, nitrite, arsenate, Fe-citrate, ferrihydrite). Major cellular fatty acids of both strains were iso-C15:0, anteiso-C15:0, and anteiso-C17:0. The size of the genomes were 3.3 and 3.2 Mb for strain OK-6-MeT and OK-1-Me, respectively. Genomic DNA G + C content was 37% for both strains. According to the 16S rRNA gene sequence and conserved protein sequences phylogenies, the strains represented a new species of the genus Melioribacter of family Melioribacteraceae within the class Ignavibacteria, for which the name Melioribacter sulfuriphilus sp. nov. is proposed, with type strain OK-6-MeT (= B-3972T = CGMCC 1.18264 T = BIM B-2154T = UQM 41932T). Analysis of OK-1 and OK-6 metagenomes revealed presence of various genes involved in carbon (CO2 fixation, carbohydrate hydrolysis, hydrocarbons degradation, fermentation), nitrogen (nitrate, nitrite, NO and N2O reduction) and sulfur cycles (sulfate reduction, sulfur or thiosulfate reduction, oxidation of sulfur compounds). MAGs OK-1-035 and OK-6-024 almost identical to genomes of strain OK-1-Me and OK-6-MeT presumably are integral part of these complex trophic chains.

Facultative anaerobe↗
PubMed1979

Metal-binding abilities of radioprotective aminoalkyl disulfides and thiosulfates.

Mental-binding stability constants for several heterocyclic aminoalkyl disulfides and thiosulfates with Ni(II) and Al(III) were determined. The data obtained indicated that both classes of compounds were acting as bidentate chelating agents and that the heterocyclic rings apparently prevented tridentate behavior of the disulfides because of steric hindrance. The magnitude of the constants indicated that metal complexes of these compounds could exist in a cellular environment, but no correlation with radiation-protective activity was apparent.

Aluminum↗
PubMed1979

Steps of thiosulfate oxidation by Thiobacillus thioparus and Th. coproliticus.

Chromatographic analysis was used for studying steps of thiosulfate oxidation by Thiobacillus thioparus and Th. coproliticus strains, isolated from Egyptian soil. Th. thioparus strains oxidized S2O3 to SO4 with the formation of polythionates, tetrathionate in particular, during the course of oxidation. However, strains differed in other polythionates formed. Th. coproliticus, in turn, oxidized S2O3 to SO4 without polythionate formation. However, H2S was the only intermediate compound detected during oxidation.

Chromatography, Paper↗