Partial purification of polyphenol oxidase from plums (Prunus domestica L., cv. Stanley)

• Published in: Journal of food biochemistry Vol. 20; no. 5; pp. 111 - 123
• Main Authors: Siddiq, M, Sinha, N.K, Cash, J.N, Hanum, T
• Format: Journal Article
• Language: English
• Published: Oxford, UK Blackwell Publishing Ltd 01.10.1996; Blackwell
• Subjects: ACTIVIDAD ENZIMATICA; ACTIVITE ENZYMATIQUE; Biological and medical sciences; CALOR; CATECHOL OXIDASE; CATECHOL OXYDASE; CATECOL OXIDASA; CHALEUR; CIRUELA; ENZYMIC ACTIVITY; EXTRACCION; EXTRACTION; Food industries; Fruit and vegetable industries; Fundamental and applied biological sciences. Psychology; HEAT; HEAT STABILITY; INACTIVATION; KINETICS; PLUMS; PRUNE; PURIFICACION; PURIFICATION; RESISTANCE A LA TEMPERATURE; RESISTENCIA A LA TEMPERATURA; STORAGE STABILITY; SUBSTRATES; TEMPERATURA; TEMPERATURE; TEMPERATURE RESISTANCE; Plum; Fruit; Enzymatic activity; Enzyme; Catechol oxidase; Oxidoreductases; Physicochemical properties
• ISSN: 0145-8884; 1745-4514
• DOI: 10.1111/j.1745-4514.1996.tb00576.x

Polyphenol oxidase (PPO) was extracted and purified from Stanley plums (Prunus domestica L.). Crude PPO showed pH optima of 5.8 to 6.4 with different substrates. Heating for 5 min at 75 C completely inactivated this enzyme. Plum PPO was stable at -20 C for 16 weeks. Km of this enzyme ranged from 17.5 mM with 4-methylcatechol to 31.2 mM with chlorogenic acid. The enzyme was purified 36-fold through (NH4)2SO4 fractionation and chromatography on DEAE-cellulose and Sephadex G-100. PAGE of crude and purified plum PPO showed 7 and 3 bands, respectively, when stained for activity with catechol. The molecular weight of 3 subunits of purified PPO was estimated in the range of 45-66kD