polyphenol oxidase (ppo), also known as tyrosinase (ec 1.14.18.1), is a copper-containing enzyme widely distributed in microorganisms, animals, and plants. this enzyme is responsible not only for browning in plants but also for melanization in animals. thus, tyrosinase inhibitors have a huge impact on industry and the economy. in the current study, we first purified the enzyme, then evaluated i...

xanthine oxidase plays crucial roles in the production of reactive oxygen species (ros), and uric acid in blood which may lead to gout, one of the oldest known forms of arthritis amongst humans. summer savory (satureja hortensis l.) a medicinal/spice exhibits antioxidant activity, but unknown effects on xanthine oxidase activity. here, for the first time, we examined the effects of s. hortensis...

Tomato plants, Lycopersicon esculentum L. cv. Tmknvf(2), and watermelon plants, Citrullus lanatus [Thomb.] Mansf. cv. Dulce maravilla, were grown for 30 days at different temperatures (15, 25 and 35 degrees C). We analysed soluble phenolics, enzymatic activities (phenylalanine ammonia-lyase, polyphenol oxidase and peroxidase), and dry weight. The impact of the three temperatures was different i...

Polyphenol oxidase from apricot (Prunus armeniaca) (PaPPO) was purified in its latent form (L-PaPPO), and the molecular weight was determined to be 63 kDa by SDS-PAGE. L-PaPPO was activated in the presence of substrate at low pH. The activity was enhanced by CuSO4 and low concentrations (≤ 2 mM) of SDS. PaPPO has its pH and temperature optimum at pH 4.5 and 45 °C for catechol as substrate. It s...

background and objectives : the attempts were made to describe the development of a whole cell immobilization of p. pastoris by entrapping the cells in polyacrylamide gel beads. the alcohol oxidase activity of the whole cell pichia pastoris was evaluated in comparison with yeast biomass production. materials and methods : methylotrophic yeast p. pastoris was obtained from collection of standard...

There are presented the results of a comparative study in an experimental culture central agro-climatic zone Belarus, influence method vegetative propagation plants (cuttings and microclonal) on antioxidant enzymatic (catalase, peroxidase polyphenol oxidase)activity fruits early ripening (Weymouth) late (Elizabeth Atlantik) varieties V. corymbosum L. It was shown that against background signifi...