摘要
从蘑菇子实体制成的丙酮粉中,通过硫酸铵分级沉淀,脱盐,DEAE-纤维素柱层析,得到三个酚氧化酶同功酶,其中酶B的含量极高,该酶经葡聚糖凝胶G-200柱层析得到纯化,在pH5.8时与多巴胺及邻苯二酚作用之K_m值分别为1.11m mol/l及0.31m mol/l,其最适pH为5.4～6.0,在pH5.0～7.0间稳定,其表观最适温度为20—40℃,70℃以上酶活力才下降,通过对酶B的底物特异性实验表明,该酶作用于部分邻位有修饰的单酚、二酚或三酚,而不作用于对、间位的二酚类,二硫苏糖醇、硫脲、苯基硫脲、亚硫酸钠、偏重亚硫酸钠等对此酶都有不同程度的抑制。
Three polyphenol oxidases were obtained from acetone-extracted powder of mushroom (Agaricus bisporus) through precipitation with ammonium sulfate and chromtography on dithylaminoethyl DEAE-CELLULOSE column. EnzymeB, whose content was the higest, was purified through Sephadex gel chromatography.The Michaelis content of enzyme B acting on the two substrates DL-dihydroxyphenylanine and catechol was 1.11mM and 0.31mM, respectively. Enzyme B was rather stable when Buffer's pH ranged between 5.0—7.0. Its optimum reacting pH ranged between 5.4—6.0, its optimum reacting temperature ranged from 20—40℃, and it was inactive at temperatures above 70℃. This enzyme could react on some monophenol, diphenol and triphenol with ortho modifying group.Thiourea, phenylthiourea, sodium metabisulfite, sodium sulfite, dithothreitol and ascorbic acid all had inhibiting effect on polyphenol oxidase in mushroom.
出处
《上海农业学报》
CSCD
1990年第2期75-80,共6页
Acta Agriculturae Shanghai
基金
上海市农业科学院青年基金
关键词
蘑菇
多酚氧化酶
分离纯化
Mushroom (Agaricus bisporus), Polyphenol oxidase
