title: Purification of polyphenol oxidase free of the storage protein patatin from potato tuber.
abstract: Routine protein purification to homogeneity from potato tuber, as from other storage tissues and seeds, is often hindered due to the large amounts of storage protein present. In potato, patatin, the major storage protein of the tuber, often contaminates preparations. The present work describes the purification of polyphenol oxidase (PPO) from the potato tuber (Solanum tuberosum cv Cara) to homogeneity including the critical step of hydrophobic chromatography on Octyl-Sepharose which was sufficient to completely remove patatin. The purified PPO was found to be a doublet of M(r) 60,000 and 69,000 when analysed by SDS-PAGE with a Km 4.3 +/- 0.3 mM for L-dihydroxyphenylalanine. Both bands were found to have similar N-terminal corresponding to PPO isoforms when sequenced.
authors.affiliation: Division of Biochemistry, School of Biological Sciences, Royal Holloway College, University of London, Egham, Surrey, U.K.
authors.forename: J C
authors.initials: JC
authors.lastname: Partington
authors.forename: G P
authors.initials: GP
authors.lastname: Bolwell
mesh_terms: D000595:Amino Acid Sequence; D002265:Carboxylic Ester Hydrolases; D004156:Catechol Oxidase / Q000737:chemistry / Q000302:isolation & purification* / Q000378:metabolism; D002850:Chromatography, Gel; D002852:Chromatography, Ion Exchange; D004591:Electrophoresis, Polyacrylamide Gel; D007700:Kinetics; D008969:Molecular Sequence Data; D008970:Molecular Weight; D010446:Peptide Fragments / Q000737:chemistry / Q000302:isolation & purification; D010940:Plant Proteins / Q000302:isolation & purification*; D018517:Plant Roots; D017386:Sequence Homology, Amino Acid; D011198:Solanum tuberosum / Q000201:enzymology*
chemical_list: D010446:Peptide Fragments; D010940:Plant Proteins; C043222:patatin protein, Solanum tuberosum; D004156:Catechol Oxidase; D002265:Carboxylic Ester Hydrolases