title: Purification and partial biochemical characterization of polyphenol oxidase from mango (Mangifera indica cv. Manila).
abstract: Polyphenol oxidase (PPO) is an enzyme widely distributed in the plant kingdom that has been detected in most fruits and vegetables. PPO was extracted and purified from Manila mango (Mangifera indica), and its biochemical properties were studied. PPO was purified 216-fold by hydrophobic interaction and ion exchange chromatography. PPO was purified to homogeneity, and the estimated PPO molecular weight (MW) by SDS-PAGE was ≈31.5 kDa. However, a MW of 65 kDa was determined by gel filtration, indicating a dimeric structure for the native PPO. The isolated PPO showed the highest affinity to pyrogallol (Km = 2.77 mM) followed by 4-methylcatechol (Km = 3.14 mM) and catechol (Km = 15.14 mM). The optimum pH for activity was 6.0. PPO was stable in the temperature range of 20-70 °C. PPO activity was completely inhibited by tropolone, ascorbic acid, sodium metabisulfite, and kojic acid at 0.1 mM.
authors.affiliation: Unidad Profesional Interdisciplinaria de Biotecnologı́a, Departamento de Bioingenierı́a, Instituto Politécnico Nacional , Acueducto s/n, Col. La Laguna Ticoman, Delegación Gustavo A. Madero, C.P. 07340, México, D.F., Mexico.
authors.forename: Gisela
authors.initials: G
authors.lastname: Palma-Orozco
authors.forename: Norma A
authors.initials: NA
authors.lastname: Marrufo-Hernández
authors.forename: José G
authors.initials: JG
authors.lastname: Sampedro
authors.forename: Hugo
authors.initials: H
authors.lastname: Nájera
mesh_terms: D004156:Catechol Oxidase / Q000037:antagonists & inhibitors / Q000302:isolation & purification* / Q000378:metabolism*; D002396:Catechols / Q000378:metabolism; D002850:Chromatography, Gel; D002852:Chromatography, Ion Exchange; D004791:Enzyme Inhibitors / Q000494:pharmacology; D004795:Enzyme Stability; D006863:Hydrogen-Ion Concentration; D031022:Mangifera / Q000201:enzymology*; D008970:Molecular Weight; D010940:Plant Proteins / Q000302:isolation & purification / Q000378:metabolism; D011748:Pyrogallol / Q000378:metabolism; D013379:Substrate Specificity; D013696:Temperature
chemical_list: D002396:Catechols; D004791:Enzyme Inhibitors; D010940:Plant Proteins; D011748:Pyrogallol; C018599:4-methylcatechol; D004156:Catechol Oxidase; C034221:catechol
keywords: Manila mango (Mangifera indica); enzymatic browning; inhibitors; polyphenol oxidase; purification