来源于Wenyingzhuangia属海洋细菌的一种β-琼胶酶的克隆表达及性质研究  

Cloning,expression,and characterization of a β-agarase from marine bacterium Wenyingzhuangia fucanilytica

作　　者：田雪健 申晶晶[1] 常耀光[1] TIAN Xuejian;SHEN Jingjing;CHANG Yaoguang(College of Food Science and Engineering,Ocean University of China,Qingdao 266003,China)

机构地区：[1]中国海洋大学食品科学与工程学院,山东青岛266003

出　　处：《食品与发酵工业》2019年第8期22-28,共7页Food and Fermentation Industries

基　　金：国家自然科学基金(31671883);国家自然科学基金(U1606403)

摘　　要：琼胶是一种重要的海洋多糖,其寡糖被证实具有丰富的生理调节功能。该研究拟从微生物基因组出发,利用生物信息学及分子生物学技术发掘新型琼胶酶。以海洋细菌Wenyingzhuangia fucanilytica CZ1127~T为实验材料,从该菌的基因组中发掘出1条潜在的GH16家族β-琼胶酶编码基因序列aga16A,通过分子克隆、异源表达及分离纯化,证实其编码的蛋白Aga16A_Wf具有琼胶酶活力。酶学性质及作用方式分析表明,Aga16A_Wf的最适反应温度(50℃)高于琼胶的凝胶温度,且该酶展现出适冷性;Aga16A_Wf的动力学常数K_m为3.6 g/L,K_(cat)为287.88 s^(-1);该酶为内切型水解酶,最小作用底物为四糖,最小产物为二糖。Aga16A_Wf可作为高效制备琼胶寡糖的工具酶,该酶的获取为琼胶及琼胶寡糖的进一步研究与应用提供了良好支撑。Agarose is an important marine polysaccharide and its oligosaccharides were considered to have a series of bioactive functions.A gene,aga16A,encoding a putative GH16 amily β-agarase was recovered from the genome of Wenyingzhuangia funcanilytica CZ1127^T,and heterologously expressed and purified.The recombinant Aga16A_Wf was confirmed to be an agarase with the optimum reaction temperature of 50 ℃,higher than the gelling temperature of agar.Besides,the enzyme was active under cold environment.Its kinetic constants K m and K cat were 3.6 g/L and 287.88 s^-1,respectively.Aga16A_Wf was an endo-acting enzyme,its smallest substrate and product were tetrasaccharide and disaccharide,respectively.Aga16A_Wf could be served as a favorable tool to produce agar oligosaccharides efficiently.It is also useful for further studies on agar and its oligosaccharides.

关 键 词：Β-琼胶酶 克隆表达 琼胶寡糖 

分 类 号：Q78[生物学—分子生物学] Q936