The native grape Kirmizi Kismisi cultivar was gathered from the Necefali village of Igdir province
in Turkey, and then caried into the laboratory and stored in deep-frozen at -20°C. Polyphenol oxidase (PPO) was
partial purified 5.45 times using the cold acetone precipitation from Kirmizi Kismisi Grape and was characterized.
50 gr of Kirmizi Kismisi Grape were placed in a porcelain mortar and pestled in order to decompose cell membranes.
The frozen Kirmizi Kismisi Grapes were homogenised by using a porcelain mortar in 100 mL of 50 mM sodium
acetate buffer (pH 5.0) containing 1% (w/v) polyethylene glycol (PEG). Then homogenate was percolated through
4-fold muslin and the resulting filtrate was santrifuged for 30 minutes at 10,000 rpm at 4°C. The supernatant
obtained after centrifugation was mixed with cold acetone as much as the volume of the supernatant in the ice
bath and the mixture was incubated overnight at 4°C for precipitation of proteins. After centrifugation at 10,000
rpm for 30 min at 4°C, the precipitate was redissolved in 20 mL 50 mM sodium acetate buffer (pH 5.0). Protein
concentration was determined according to the Lowry method. Protein concentrations of crude extract and acetone
precipitation were determined as 7.04 and 3.83 mg/mL, respectively. Optimum pH and temperature values were
found to be 6.0 and 20°C, respectively, using catechol as a substrate. In addition, some biochemical properties
such as Km and Vmax values were investigated. PPO activity was inhibited from ascorbic acid, citric acid, sodium
metabisulfite and benzoic acid and the IC50 for each inhibitor was calculated.The data obtained from this study
showed that this enzyme could be useful for food industrial purposes.
Primary Language | Turkish |
---|---|
Subjects | Chemical Engineering |
Journal Section | Kimya / Chemistry |
Authors | |
Publication Date | December 30, 2018 |
Submission Date | May 16, 2018 |
Acceptance Date | June 14, 2018 |
Published in Issue | Year 2018 Volume: 8 Issue: 4 |