金属离子对马铃薯多酚氧化酶活力的影响

Abstract

以马铃薯多酚氧化酶为对象,研究金属离子对该酶活性的影响.实验结果表明,lI+、k+、bA2+和Mg2+对酶活力几乎没有影响,CA2+和nA+对酶活力有微弱的抑制作用,Cu2+则表现出较强烈的抑制作用,其IC50为0.248 MMOl/l.Al3+、fE3+、Cd2+、CO2+、Mn2+和zn2+则对马铃薯多酚氧化酶有不同程度的激活作用.本研究为探讨多酚氧化酶的催化活性和催化机理提供理论基础.

In this paper,we studied the effects of some metal ions on the activity of polyphenol oxidase purified from potato.The results showed that Li+,K+,Ba2+ and Mg2+ had no effects on the enzyme activity.Ca2+ and Na+ showed a slight inhibition.Cu2+ could strongly inhibit the enzyme and the IC50 value was estimated to be 0.248 mmol/L.Al3+,Fe3+,Cd2+,Co2+,Mn2+ and Zn2+ activated the activity of polyphenol oxidase.This paper laid the foundation for the studies of the enzyme activity,catalytic mechanism of polyphenol oxidase.