Purification and biochemical characterization of polyphenol oxidases from embryogenic and nonembryogenic cotton (Gossypium hirsutum L.) cells.
Polyphenol oxidases (PPOs) were isolated from cell suspensions of two cultivars of cotton (Gossypium hirsutum L.), and their biochemical characteristics were studied. PPO from Coker 312, an embryogenic cultivar, showed a highest affinity to catechol 20 mM, and PPO from R405-2000, a nonembryogenic cultivar, showed a highest affinity to 4-methylcatechol 20 mM. The optimal pH for PPO activity was 7.0 and 6.0 for Coker 312 and R405-2000, respectively. The enzyme had an optimal temperature of 25 degrees C and was relatively stable at 20-30 degrees C. Reducing sodium metabisulfite, ascorbic acid, dithiothreitol, SnCl(2), and FeCl(3) markedly inhibited PPO activity, whereas its activity was highly enhanced by Mg(2+), Ca(2+), and Mn(2+) and was moderately inhibited by Ba(2+), Cu(2+), and Zn(2+). The analysis revealed a single band on the sodium dodecyl sulfate polyacrylamide gel electrophoresis which corresponded to a molecular weight of 55 kDa for Coker 312 and 42 kDa for R405-2000.
Kouakou
Tanoh Hilaire
TH
Groupe d'Etude des Substances Végétales à Activités Biologiques, Institut des sciences de vigne et du Vin, UFR des Sciences Pharmaceutiques, Université de Bordeaux 2, 146 rue Léo-Saignat, 33076 Bordeaux cedex, France.
Kouadio
Yatty Justin
YJ
Kouamé
Patrice
P
Waffo-Téguo
Pierre
P
Décendit
Alain
A
Mérillon
Jean-Michel
JM
D001205:Ascorbic Acid / Q000378:metabolism; D001464:Barium / Q000494:pharmacology; D002118:Calcium / Q000494:pharmacology; D004156:Catechol Oxidase / Q000378:metabolism*; D002396:Catechols / Q000378:metabolism; D002712:Chlorides; D003300:Copper / Q000494:pharmacology; D004229:Dithiothreitol / Q000378:metabolism; D004591:Electrophoresis, Polyacrylamide Gel; D004789:Enzyme Activation / Q000187:drug effects; D004791:Enzyme Inhibitors / Q000494:pharmacology; D005290:Ferric Compounds / Q000494:pharmacology; D003368:Gossypium / Q000201:enzymology*; D006863:Hydrogen-Ion Concentration; D008274:Magnesium / Q000494:pharmacology; D008345:Manganese / Q000494:pharmacology; D013447:Sulfites / Q000378:metabolism; D013696:Temperature; D017971:Tin Compounds / Q000494:pharmacology; D015032:Zinc / Q000494:pharmacology
D002396:Catechols; D002712:Chlorides; D004791:Enzyme Inhibitors; D005290:Ferric Compounds; D013447:Sulfites; D017971:Tin Compounds; C018599:4-methylcatechol; C023599:stannous chloride; D001464:Barium; D008345:Manganese; C005200:sodium metabisulfite; D003300:Copper; D004156:Catechol Oxidase; D008274:Magnesium; D015032:Zinc; D001205:Ascorbic Acid; D002118:Calcium; D004229:Dithiothreitol; C024555:ferric chloride