Purification and Characterization of Polyphenol Oxidase Enzyme from Igd?r Apple and Inhibition Effects of Some Chemicals

Polyphenol oxidase enzyme (PPO, E. C.1.14.18.1) is a member of the class of oxidoreductase which causes blackening in plants. In this study, the enzyme Igdir apple was extracted and purified using Sepharose 4B-L-tyrosine-p-amino benzoic acid affinity gel. The sample obtained by affinity chromatography was used to investigate the characterization of the enzyme PPO and the effect of some inhibitors. For this purpose, optimum pH, temperatureand optimum ionic strenght values were determined by using different substrates. The best substrate of PPO was 4-methyl catechol. The optimum pH, temperature and ionic intensity values for this substrate were determined as 6.0 and 30 oC and 0.16 M, respectively. In this study ten inhibitors were studied and the IC50 values were calculated separately for the molecules which were inhibited by these methods. While tyrosine, 2-mercapto ethanol, copper sulfate, citric acid, sodium bisphosphate, chemicals have no effective inhibition, Inhibition from sodium azide, benzoic acid, ascorbic acid, sulfosalicylic acid, p-amino benzoic acid compounds was observed and the best inhibition molecule was found to be ascorbic acid.