Clarified and standardized apple juice was ultraviolet-irradiated to inactivate polyphenol oxidase enzyme and microbiota, and its effect on bioactive compounds and stability during storage was also evaluated. Apple juice was irradiated with 345.6 J/cm² and treatment effect was evaluated in terms of color, antioxidant capacity, polyphenol content, pH, titratable acidity and total soluble solids....

The corneas of albino rabbits were irradiated (5 min exposure once a day) with UVB rays (312 nm) for 4 days (shorter procedure) or 8 days (longer procedure). The eyes were examined microbiologically and only the corneas of sterile eyes or eyes with non-pathogenic microbes were employed. Histochemically, the activities of reactive oxygen species (ROS)-generating oxidases (xanthine oxidase, D-ami...

The presence of the xanthine oxidase enzyme system has been demonstrated in the rheumatoid synovium. This supplies a reactive oxygen species generating system to synovium that is subjected to hypoxic-reperfusion cycles (cf inflamed rheumatoid synovium). An antibody to bovine milk xanthine oxidase has been used to localise the enzyme by immunohistochemistry to synovial endothelium. This implicat...

Yeast cytochrome c oxidase has been isolated by ion exchange chromatography using lauryl maltoside (n-dodecyl beta-D-maltoside) as the solubilizing detergent. The enzyme prepared in this way has a heme aa3 concentration of 8-9 nmol/mg of protein and a turnover number in the range of 180-210 s-1 at pH 6.2 in 0.01% lauryl maltoside at 20 degrees C. Yeast cytochrome c oxidase prepared by any of se...

The biphasic effect of anions on the activity of isolated bovine heart cytochrome c oxidase is paralleled by changes in the visible oxidized spectra, indicating the different conformational changes in the enzyme induced by bromide, chloride, sulphate, phosphate, ADP and ATP. Photoaffinity-labelling of most subunits of the isolated enzyme by low concentrations of 8-azido-[gamma-32P]ATP is strong...

High Quality Antibodies, FISH probes and Kits.Join Memeber Online Order TutorialA Simple Method for Assaying Total Protein, Polyphenol Oxidase and. Several assay procedures have been described for PPO and POD from lychee. PPO.Polyphenoloxidase Activity. The enzyme polyphenoloxidase or tyrosiuase, studying its. Zyme preparation and the general assay procedure.Polyphenol Oxidase Assay. The latter...

The ability of cyanide to inhibit the oxygen consumption of biological systems has long been known (cf. (4, 13)). Warburg (12, 13) appears to be the first to suggest that this action of cyanide was due t,o its combination with the ferric form of the enzyme, called by hi the Atmungaferment and later called cytochrome oxidase by Keilin and Hartree (5). In this paper we make use of this reaction o...

A simple method that allows easy identification of rifamycin B-producing strains is described. This method involves the use of an enzyme, rifamycin oxidase, which converts inactive rifamycin B to active rifamycin S. In this method, colonies to be tested are grown in pairs. The two colonies are then transferred to two plates seeded with a sensitive strain of Staphylococcus aureus, one plate of w...

D-Amino acid oxidase is a key enzyme in the production of semisynthetic cephalosporins. The Trigonopsis variabilis D-amino acid oxidase with 12amino-acid peptide at N-terminus was expressed in Escherichia coli BL21(DE3), in a series of short fed-batch cultivations. The strategy of gradual induction and gradual feeding with D-methionine during expression resulted in active enzyme production twic...