<?xml version='1.0' encoding='UTF-8'?><xml><records><record><source-app name="HighWire" version="7.x">Drupal-HighWire</source-app><ref-type name="Journal Article">17</ref-type><contributors><authors><author><style face="normal" font="default" size="100%">Nakamura, Kazuo</style></author><author><style face="normal" font="default" size="100%">Amano, Yoshifumi</style></author><author><style face="normal" font="default" size="100%">Kagami, Motoo</style></author></authors><secondary-authors></secondary-authors></contributors><titles><title><style face="normal" font="default" size="100%">Purification and Some Properties of a Polyphenol Oxidase from Koshu Grapes</style></title><secondary-title><style face="normal" font="default" size="100%">American Journal of Enology and Viticulture</style></secondary-title></titles><dates><year><style  face="normal" font="default" size="100%">1983</style></year><pub-dates><date><style  face="normal" font="default" size="100%">1983-01-01 00:00:00</style></date></pub-dates></dates><pages><style  face="normal" font="default" size="100%">122-127</style></pages><doi><style  face="normal" font="default" size="100%">10.5344/ajev.1983.34.2.122</style></doi><volume><style face="normal" font="default" size="100%">34</style></volume><issue><style face="normal" font="default" size="100%">2</style></issue><abstract><style  face="normal" font="default" size="100%">Polyphenol oxidase (EC 1.10.3.1) was extracted from an acetone powder prepared from Koshu grapes. The enzyme was purified 172-fold by ammonium sulfate fractionation followed by three successive column chromatographies on O-(carboxymethyl) cellulose, O-(diethylaminoethyl) cellulose and hydroxylapatite. The purified enzyme was homogeneous on polyacrylamide gel electrophoresis. The molecular weight of this enzyme was estimated to be 39 000 - 41 000 by gel filtration and sodium dodecyl sulfate polyacrylamide gel electrophoresis, and the enzyme molecule had no subunit. The temperature and pH optima were 25°C and 6.0, respectively. The enzyme was stable in the alkaline pH range (between pH 7.0 and pH 11.0) and at temperatures up to 30°C. The enzyme exhibited high activity toward o-diphenolic compounds and showed no activity toward monophenols.</style></abstract></record></records></xml>