Investigation monophenolase and difenolase activities of polyphenoloxidase from yomra apple (Malus sylvestris)

In this study, polyhphenol oxidase (ppo) activity in the extracts prepared from Yomra Apple (Malus Slyvestris) was investigated in detail from the point of biochemical data. 4-methyl catecol, catecol, dopa (dihidroksifenilalanin), MHPPA3-(3,4,hidroksifenil propiyonik asit), and activity was linear up to 0,05 mg protein/ml. The enzyme showed different activities at specific pH and temperature values for each substrate. Kinetic studies have shown that the medlar PPO enzyme obeys the simple Michaelis- Menten kinetic with the greatest degree of affinity for catecol and the order of affinity was displayed to be catecol> 4- methyl catecol> MHPPA > L-Tirozin> L-Dopa. Moreover, the four of the prevelant inibitors, of PPO enzymes, ascorbic acid, sodium azide, benzoic acid and sodium metabisulfite, all inhibited the activity very effectively. All the support the presence of a activity in Malus Slyvestris having similar properties to other polyphenol oxidases.