草菇多酚氧化酶及过氧化物酶特性的研究

STUDY ON THE CHARACTERISTICS OF POLYPHENOL OXIDASE AND PEROXIDASE IN VOLVARIELLA VOLVACEA (BULL EX FR) SING

草菇多酚氧化酶（ｐｏｌｙｐｈｅｎｏｌｏｘｉｄａｓｅ）与过氧化物酶（ｐｅｒｏｘｉｄａｓｅ）的最适ｐＨ分别为６０～６８、６７～７４，最适温度分别为３０～３２℃、２５～２８℃在最适条件下，前者的活性远高于后者，当ｐＨ８６及温度４３℃或４８℃处理１ｍｉｎ，二者活力显著降低；但是，先在３５～３８℃保温１ｈ再测定，发现二者的最适温度分别达４０～４１℃、５２～５３℃，升温至８０℃１０ｓ，过氧化物酶仍表现活性Ｏ２对多酚氧化酶活性影响极大，而对过氧化物酶活性影响较小金属离子Ｍｎ２＋、Ｚｎ２＋、Ｍｇ２＋对二者均有强烈激活作用，Ｃａ２＋对二者的作用都很弱，Ｆｅ２＋、Ｃｕ２＋对前者作用明显强于后者二者的反应进程及酶浓度与反应速度的关系。

In this paper, the characteristics of polyphenol oxidase and peroxidase in Volvariella volvacea are studied. The result shows: the optimum pH are 6.0～6 8 and 6 7～7 4 seperately, and the optimum temperature are 30～32℃ and 25～28℃; Under the optimum conditions, the activity of Polyphenol oxidase is much higher than that of peroxidase; When they are treated for 1 minute, at pH 8.6 and temperature 43℃, the activity of both enzymes will decrease greatly. If they are kept at 35～38℃ for 1 h, the optimum temperature will change into 40～41℃, 52～53℃; seperately, even at 80℃ for 10 s, Peroxidase remains active. O 2 has great effect on the activity of Polyphenol oxidase but has only a little effect on that of peroxidase. Mn 2+ 、Zn 2+ and Mg 2+ can activate both of enzymes obviously, but Ca 2+ can hardly activate them, Fe 2+ 、Cu 2+ has much greater effect on polyphebol oxidase than on peroxidase. Two enzymes show great difference in their reaction speed and process under different content of enzyme.