摘要
本文研究了pH、温度、金属离子、EDTA、还原剂对菠萝蛋白酶单宁复合物酶促反应速度的影响 ,结果表明 ,该酶的最适pH为 7.1,最稳定的pH范围为 3.9～ 4 .2 ,最适反应温度为 5 5℃ ,一般的金属盐NaCl、kCl对酶反应影响不大 ,MgCl2 、CaCl2 在高浓度下对酶有一定程度的抑制作用 ,在低浓度下影响不显著 ,半胱氨酸在一定浓度的范围内 ,对酶反应速度有促进作用。EDTA本身对菠萝蛋白酶没有激活作用 ,它能鳌合酶反应所需的金属离子 ,使酶活降低。
This paper studies the effect of several factors on bromelain.The results show that the optimal pH value for reaction is 7.1,and the optimal temperature is 55℃.The enzyme is stable relatively in the pH range from 3.9 to 4.2,NaCl and kCl don't obviously affect enzyme activity, MgCl 2.CaCl 2 of higher concentration inhibit the enzyme activity,with lower concentration hasn't distinctness inhibition.Within the certain range of concentration,Cysteine can promote the reaction.EDTA doesn't stimulate the bromelain,it can reduce the enzyme activity by chelating the metal ion needed for the reaction of enzyme.
