In phototrophic sulfur bacteria, sulfite is a well-established intermediate during reduced sulfur compound oxidation. Sulfite is generated in the cytoplasm by the reverse-acting dissimilatory sulfite reductase DsrAB. Many purple sulfur bacteria can even use externally available sulfite as a photosynthetic electron donor. Nevertheless, the exact mode of sulfite oxidation in these organisms is a ...

The biochemical basis for sulfite accumulation by sulfate-using revertants of Salmonella pullorum was determined. All of the sulfate-using mutants isolated from wild-type S. pullorum accumulated sulfite when grown at 37 but not at 25 C. The specific activity of reduced nicotinamide adenine dinucleotide (NADPH)-dependent sulfite reductase (H2S-NADP oxidoreductase, EC 1.8.1.2) and of reduced meth...

Urocanase is inactivated in vivo and is reactivated by ultraviolet radiation. The chemistry of this photoregulation of urocanase was studied. Purified enzyme was inactivated by 25 pM sulfite (tl,z, 15 min). Dialyzed sulfite-treated inactive enzyme was photoactivatable. The activity can be cycled repeatedly by alternate ultraviolet light and sulfite treatments. Active enzyme binds 5 times more [...

UNLABELLED BACKGROUND Corn cob residue (CCR) is a kind of waste lignocellulosic material with enormous potential for bioethanol production. The moderated sulphite processes were used to enhance the hydrophily of the material by sulfonation and hydrolysis. The composition, FT-IR spectra, and conductometric titrations of the pretreated materials were measured to characterize variations of the ...

The superoxide dismutase (dismutase) which has already been found to be useful in detecting the role of O2 ain certain enzymic reactions has here been shown to be applicable to the study of nonenzymic reactions, as well. The aerobic oxidation of sulfite, which proceeds by a free radical chain mechanism, has been investigated with the aid of superoxide dismutase. The “spontaneous” oxidation of s...

Sulfites are used as food preservatives and excessive sulfite might disturb the body systems including the brain. Curcumin shows protective effects on the nervous system toxicity. The present study aimed to evaluate the protective role of curcumin in sulfite-induced anxiety in rats. Male rats were divided into five groups. The rats in groups I to V received distilled water (vehicle of sulfite, ...

BACKGROUND During long-term intravenous infusions, sulfite in sulfite-containing propofol emulsions can cause the peroxidation of lipid and dimerization of propofol. This study evaluated the role of lipid in sulfite-dependent propofol dimerization by determining the effects of individual fatty acids in soybean oil emulsion and peroxidized lipids in a model system. METHODS Individual fatty aci...

BACKGROUND Sodium metabisulfite is added to a commercial propofol emulsion as an antimicrobial agent. The sulfite ion (SO3(-2)) is capable of undergoing a number of reactions, including autooxidation and the promotion of lipid peroxidation. This study evaluated sulfite reactivity in propofol emulsions by determining thiobarbituric acid reacting substances (TBARS), sulfite depletion, and emulsio...

DDTC, SOD, Sulfite Oxidation 50 U SOD in 1 ml or 10 m M DDTC do not much change sulfite oxidation due to the free radicals procuding system xanthin-xanthin oxidase. Sulfite oxidation due to the activity of this free radicals producing system proceeds probably as the univalent oxidation o f sulfite. The role o f SOD in SO, resistance mechanism in plants and the role o f DDTC as S 0 2 oxidation e...

The chemical reaction networks (CRNs), which led to the transition on early Earth from geochemistry biochemistry remain unknown. We show that simplest substances—bicarbonate, sulfite/sulfate, and ammonium—were converted peptides in one geological setting Sammox (sulfite/sulfate reduction coupled anaerobic ammonium oxidation)-driven CRNs under mild hydrothermal conditions. Peptides comprise 15 p...