‘赤霞珠’果实中2种己糖激酶同工酶部分酶学性质的研究  

Studies on Partial Enzymatic Properties of Hexokinase Isozymes from 'Cabernet Sauvignon' Fruit

作　　者：于菲[1] 王秀芹[1] 黄卫东[1] 战吉宬[1] 

机构地区：[1]中国农业大学食品科学与营养工程学院,北京100083

出　　处：《中国农学通报》2011年第22期234-238,共5页Chinese Agricultural Science Bulletin

基　　金：国家自然科学基金"己糖激酶介导糖调控酿酒葡萄果实蔗糖代谢关键酶基因表达机制的研究"(30871698);"葡萄果实糖积累过程中己糖激酶基因功能表达及对植物激素信号的响应"(31071764)

摘　　要：研究‘赤霞珠’果实中己糖激酶同工酶HXK1及HXK2的生化性质,以期为己糖激酶的研究提供基础数据。将前期RT-PCR及体外原核表达所得粗酶液用不同底物处理,紫外分光光度法测其动力学常数及最佳pH,双缩脲法测等电点。本实验表明,两种同工酶的米氏常数由大到小依次为果糖、甘露糖与葡萄糖,以葡萄糖为最佳反应底物。最大反应速度均在以果糖为底物的反应中出现。两种同工酶的等电点分别为5.8和5.6,最佳pH均为8.0左右。‘赤霞珠’同工酶HXK1及HXK2的生化性质符合己糖激酶的酶学特征。This paper aimed to study the biochemical characteristics of two hexokinase（HXK） isozymes-HXK1 and HXK2 which derived from ＇Cabernet Sauvignon＇ fruits.Crude enzyme,which obtained from former experiment,was treated with different substrates,and the activity of hexokinase was characterized by changes of absorbance 340 nm.The pI of the enzyme was determined by biuret method.The results showed that the ascending Km values of different hexoses were fructose,mannose and glucose,which proved that glucose was the optimal substrate.The maximum reaction rate of both isozymes appeared in fructose reaction.The pI of HXK1 and HXK2 was 5.8 and 5.6,and the optimum pH of two isozymes was about 8.0.It was concluded that the biochemical properties of HXK1 and HXK2 corresponded with the characterization of HXK.

关 键 词：'赤霞珠’ 己糖激酶 同工酶 酶学性质 

分 类 号：S663.1[农业科学—果树学]