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چکیده
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Peroxidase (PODS; EC 1.11.1.X) in different types of living organisms (animals, plants and microorganisms) is expanding [1]. This enzyme belongs to oxidoreductase enzymes family which catalyzes the oxidation reaction of some substrates, including phenolic compounds such as guaiacol, pyrogallol, chlorogenic acid and catechol in the presence of hydrogen peroxide H2O2 or organic hydroperoxides as electron acceptor [2]. Peroxidases have wide applications in various fields of medical biochemistry, biotechnology, food industry and increases their attractiveness on the study to detoxification and removal of organic contaminants from wastewaters [3]. In this investigation, peroxidase were extracted and partially purified from cabbage leaves and the enzyme activity were determined. A crude extract from fresh white cabbage leaves was homogenized, centrifuged and precipitate by ammonium sulfate (40-75%) at 4ºC. The enzyme activity in the crude extract and dialysate was monitored in 470 nm with H2O2 as substrate and guaiacolas electron donor in phosphate-citrate buffer with pH 5 (optimum pH) and at 55o C (optimum temperature). Total activity and the specific activity of peroxidase were 3012.63 U and 1.87 U/mg in crude extract and 2922.63 U and 30.98 U/mg in dialysate after ammonium sulfate precipitation. While for red cabbage in phosphate-citrate buffer with pH 5.5 (optimum pH) and at 60o C (optimum temperature). Total activity and the specific activity of peroxidase were 3425.97U and 0.69U/mg in crude extract and 2766.65U and 20.01 U/mg in dialysate after ammonium sulfate precipitation.According to our study the antioxidant activity of white cabbage have been more than red cabbage. Our study suggested that the cabbage leaves can be used as a source of peroxidase enzyme for study on activity and kinetic characterizations in food industry and pharmaceutical.
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