D-来苏糖异构酶的酶学性质研究  

Characterization of Recombinant D-Lyxose Isomerase

作　　者：黄嘉苇 施悦 张文立 张涛[1,2] 江波[1,2] 沐万孟[1,2] HUANG Jiawei;SHI Yue;ZHANG Wenli;ZHANG Tao;JIANG Bo;MU Wanmeng(State Key Laboratory of Food Science and Technology,Jiangnan University,Wuxi 214122,China;Collaborative Innovation Center,Jiangnan University,Wuxi 214122,China)

机构地区：[1]食品科学与技术国家重点实验室江南大学,江苏无锡214122 [2]江南大学协同创新中心,江苏无锡214122

出　　处：《食品与生物技术学报》2019年第1期83-92,共10页Journal of Food Science and Biotechnology

基　　金：江南大学食品科学与技术国家重点实验室自主研究课题(SKLF-ZZA-201802;SKLF-ZZB-201814);国家食品科学与工程一流学科建设项目(JUFSTR20180203);2018年江苏省研究生科研创新计划项目(KYCX18_1784)

摘　　要：为探索D-甘露糖的高效酶法合成途径,作者克隆了来源于Peptococcaceae bacterium 1109的D-来苏糖异构酶基因,将其导入到E. coli BL21(DE3)中进行表达。该酶的最适底物为D-来苏糖,并可以高效催化D-果糖与D-甘露糖之间的差向异构反应。以D-果糖为底物时,重组表达的D-来苏糖异构酶的比酶活可达2.5 U/mg,该酶的最适pH为7.5,最适温度为70℃,Co^(2+)可以显著提高该酶的活力。在最适条件下以500 g/L的果糖为底物,反应8 h达到平衡,平衡转化率达19.17%,生产D-甘露糖95.85 g/L。In this study,the D-lyxose isomerase gene derived from Peptococcaceae bacterium 1109 was cloned and introduced into E. coli BL21(DE3) for expression. The optimal substrate for the recombinant D-LI is D-lyxose,and it can efficiently catalyze the epimerization reaction between D-fructose and D-mannose. The specific activity of recombinantly expressed D-lysose isomerase can reach 2.544 U/mg when used D-fructose as substrate. It displayed maximal activity in presence of 1 mM Co2+ at pH 7.0 and 70 ℃. Under optimum conditions,95.85 g/L D-mannose was produced from 500 g/L D-fructose after reaction for 5 h,giving a conversion yield of 19.17%.

关 键 词：D-甘露糖 D-来苏糖异构酶 生物制备 

分 类 号：Q814[生物学—生物工程]