摘要
应用化学修饰剂焦碳酸二乙酯(DEPC)、碳二亚胺(EDC)对纤维酶-壳聚糖酶双功能酶(CCBE)进行修饰。结果表明:DEPC对CCBE中组氨酸残基的修饰研究显示,每摩尔酶分子的水解壳聚糖及纤维素的活性中心仅需约1mol组氨酸残基参与;盐酸羟胺的脱羧基作用结果表明,盐酸羟胺能使CCBE的两种酶活力恢复到相似的水平,证明了组氨酸是CCBE两种酶活力的活性中心氨基酸残基,且同一个组氨酸残基是CCBE两种酶活性中心氨基酸;EDC对天门冬氨酶/谷氨酸残基的化学修饰研究表明,每摩尔CCBE的两种活性中心均需1mol天门冬氨酶/谷氨酸残基参与。
The cellulase-chitosanase bifunctional enzyme （CCBE） was modified with diethylpyrocarbonate （DEPC） and 1- ethyl-3-carbodiimide （EDC） respectively. The kinetic analysis of the CCBE modification by DEPC revealed that about one mole histidine （His） residue is essential for both cellulase activity and chitosanase activity of one mole CCBE. Treatment of inactivated enzyme with hydroxylamine results in nearly complete restoration of original activity, which confirms the abovementioned conclusion. The result of the modification of CCBE by EDC showed that the number of reactive carboxylate for both its cellulase activity and chitosanase activity center is one.
出处
《食品科学》
EI
CAS
CSCD
北大核心
2008年第8期460-463,共4页
Food Science
基金
国家自然科学基金项目(20576104)
