Application of Aqueous Two-Phase System to the Purification of Persimmon Polyphenol Oxidase

Polyphenol oxidases (PPOs), which have recently become very popular among many researchers, catalyze the oxidation of phenolic compounds. Polyphenol oxidases are generally found in plants. Among them, persimmon (Diospyros kaki L.) is known as a good source for polyphenol oxidases. In this study, the polyphenol oxidase enzyme was purified from persimmon fruit using aqueous two-phase (ATPS). The optimized system was composed of 18% (w/w) PEG4000, 7% (w/w) NaH2 P04 and 1% (w/w) NaCl (pH 8.5, 25°C and 5 g). The PPO enzyme was obtained from the system by 4.8-fold purification with 191% activity recovery. The molecular weight of the enzyme, 28 kDa, was determined by sodium dodecyl sulfate polyacrylamide gel electrophoresis. In summary, it has been shown that the PPO enzyme can be obtained from persimmon in a short time and at low cost using a non-chromatographic method-ATPS.