清华大学学报(英文版)
清華大學學報(英文版)
청화대학학보(영문판)
TSINGHUA SCIENCE AND TECHNOLOGY
2004年
1期
94-97
,共4页
刘卫群%饶学明%潘继承%周海梦
劉衛群%饒學明%潘繼承%週海夢
류위군%요학명%반계승%주해몽
tobacco%polyphenol oxidase%kinetics%irreversible inhibition
In this study, the kinetics of inhibition of polyphenol oxidase by L-cysteine has been investigated.The inhibition of tobacco polyphenol oxidase was studied using the progress-of-substrate-reaction method proposed by Tsou, following the substrate reaction during irreversible inhibition of the enzyme activity. Analysis of the inhibition kinetics shows that inhibition occurs by an irreversible and non-complexation reaction. The microscopic rate constants were determined for reaction of the inhibitor both with the free enzyme and with the enzyme-substrate complex. The results show that the presence of the substrate has a significant protective effect of the enzyme against inactivation by L-cysteine.
