مقالههای Leila Parsiavash
توجه: محتویات این صفحه به صورت خودکار پردازش شده و مقالههای نویسندگانی با تشابه اسمی، همگی در بخش یکسان نمایش داده میشوند.
۱Investigating on the Stability of Peroxidase Extracted from Soybean (Glycine max var. Williams) and Effects of Na+ and K+ Ions on its Activity
اطلاعات انتشار: Journal of Cell and Molecular Research، هفتم،شماره۲، ۲۰۱۵، سال ۰
تعداد صفحات: ۸
In the present study, some techniques were used for Soybean peroxidase (SBP) purification including: ammonium sulfate fractionation, DEAE Sephadex anion exchange chromatography and Concanavalin A Sepharose 4B affinity chromatography. Molecular weight of purified SBP was estimated about 44 kDa by SDS–PAGE as a single polypeptide band. The optimal pH and temperature for enzyme activity were found to be 4.5 and 70◦C, respectively. The enzyme was more stable in alkaline pH than acidic ones and could tolerate 10 minutes heating in 40–50◦C without any loss of its activity. Both NaCl and KCl were found to have significant effects on the enzyme stability, but presence of NaCl was more effective than KCl. Our results showed that after 24 hours incubation of the enzyme in the presence of 20 mM NaCl, more than 60٪ of the enzyme activity was remained while it would fall to 3٪ if incubation was not accompanied by NaCl. Purified peroxidase from seed hull of soybean relative to the other identified peroxidases was more stable, for this reason a lot of benefit will be considered by use of this enzyme in different industry.
۲Purification and Kinetic Properties of Guaiacol Peroxidase in Turnip (Brassica napus var. okapi) Root During Different Growth Stages
اطلاعات انتشار: Progress in Biological Sciences، دوم،شماره۱، ۲۰۱۲، سال ۰
تعداد صفحات: ۱۱
In this study, we present changes of peroxidase (E. C. 1.11.1. 7) activities in the root of Brassica napus var. Okapi during rosette stage until ripening of the fruits. Peroxidase activity was determined seasonally over an eight month period. Results showed that total peroxidase activity in the root was highest in mid June and the lowest activities were observed from time of winter dormancy until the beginning of April at which time morphogenic competence of tissues started to increase. Pattern of isoperoxidase bands on poly acrylamide gels (PAGE) showed that there was six inducible isoforms, named as TPA1, TPB1, TPB2, TPC1, TPC2 and TPC3. The isoform TPC3 was purified and partially characterized. Purification of peroxidase from turnip root was achieved by two ammonium sulphate precipitation steps followed by DEAE–sephadex chromatography. The effects of pH and temperature on enzyme activity were determined with guaiacol as electron donor. Highest activity was obtained at pH 6.0–6.5 and at a temperature of 50 °C. The enzyme was active at pH values below 7.0 even after 24 h and remained active after heat treatment at 70 °C for 30 min. It was inhibited by sodium cyanide rather than sodium azide. Loss of TPC3 peroxidase activity in the extracts of non–senescent root tissues suggests that it might play a role in the senescing process
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