Sulfite dehydrogenases (SDHs) are enzymes that catalyze the oxidation of the toxic and mutagenic compound sulfite to sulfate, thereby protecting cells from adverse effects associated with sulfite exposure. While some bacterial SDHs that have been characterized to date are able to use cytochrome c as an electron acceptor, the majority of these enzymes prefer ferricyanide as an electron acceptor ...

BACKGROUND The effectiveness of the enzymatic hydrolysis of cellulose in plant cell wall is strongly influenced by the access of enzymes to cellulose, which is at least in part limited by the presence of lignin. Although physicochemical treatments preceding the enzymatic catalysis significantly overcome this recalcitrance, the residual lignin can still play a role in the process. Lignin is sugg...

A proposed heat precipitation and thrombin interaction technic for fibrinogen isolation has been compared with a sulfite fractionation technic. All three methods exhibit a high degree of correlation. Fibrinogen, which has been separated from plasma by these technics, may be quantitated by the colorimetric modified biuret and phenol-biuret reaction. For direct measurement of fibrinogen, heat pre...

A gas diffusion sequential injection system with amperometric detection using aboron-doped diamond electrode was developed for the determination of sulfite. A gasdiffusion unit (GDU) was used to prevent interference from sample matrices for theelectrochemical measurement. The sample was mixed with an acid solution to generategaseous sulfur dioxide prior to its passage through the donor channel ...

DeazaFMN-containing glycolate oxidase has been prepared and shown to catalyze the stereospecific transfer of the alpha-hydrogen from substrate to enzyme-bound deazaFMN. The reaction of sulfite, cyanide, and hydroxylamine with several deazaflavin-containing enzymes (glycolate oxidase, D-amino acid oxidase, glucose oxidase, N-methylglutamate synthetase) and free deazaFMN has been examined. All th...

Background: A facile and sensitive electrochemical sensor platform has been explored based on gold nanoparticles (Au NPs) dispersed in amine-functionalized three-dimensional (3D) silicate sol–gel network for ((aminopropyl)triethoxysilane (APS)-Au NPs) for multi-analytes such as hydrazine, sulfite, and nitrite. Methods: Au NPs dispersed silicate network was prepared via a single-step chemical re...

A chromosomal locus of Salmonella typhimurium which complements S. typhimurium asr (anaerobic sulfite reduction) mutants and confers on Escherichia coli the ability to produce hydrogen sulfide from sulfite was recently cloned (C. J. Huang and E. L. Barrett, J. Bacteriol. 172:4100-4102, 1990). The DNA sequence and the transcription start site have been determined. Analysis of the sequence and ge...

In this demonstration, we show a qualitative analysis of sulfite ions in white wine with strontium ions. In base solution, a white precipitation occurs from strontium sulfite that disappears after a strong acid is added. This demonstration nicely illustrates chemical equilibrium in a school chemistry experiment.

Enzymes capable of catalyzing the hydroxylamine-dependent. oxidation of pyridine nucleotides have been studied in Salmonella typhimurium (1, 2), Escherichia coli (3-5), Bacillus subtilis (6, 7), Azotobacter agile (8, 9), Neurospora crassa (lo), and soybean leaves (11). Siegel, Click, and Monty (1) and Siegel and Monty (2) demonstrated that reduced triphosphopyridine nucleotide-specific hydroxyl...

approved: Alan T. Bakalinsky Sulfite mutants representing five complementation groups, previously derived from an ethyl methanesulfonate-treated haploid strain of Saccharomyces cerevisiae were studied. Although the wildtype 5. cerevisiae strain used (isogenic to X2180-1 A) had a basal tolerance for sulfite (7 |iM free H2SO3), the sensitive and resistant mutants were found to tolerate less than ...