来自Yeosuana marina sp.JLT21内切型海藻酸裂解酶的异源表达及酶学表征  

Heterologous Expression and Characterization of Endo-type Alginate Lyase from Yeosuana marina sp.JLT21

作　　者：常晴 束月蓉 王文韬 蒋昊 延泉德 钱政 高雪纯 吴金鸿[2] 张勇 CHANG Qing;SHU Yue-rong;WANG Wen-tao;JIANG Hao;YAN Quan-de;QIAN Zheng;GAO Xue-chun;WU Jin-hong;ZHANG Yong(State Key Laboratory of Microbial Metabolism,School of Life Sciences and Biotechnology,Shanghai Jiao Tong University,Shanghai 200240;Department of Food Science&Technology,School of Agriculture and Biology,Shanghai Jiao Tong University,Shanghai 200240)

机构地区：[1]上海交通大学生命科学技术学院微生物代谢国家重点实验室,上海200240 [2]上海交通大学农业生物技术学院农业与生物学院食品科学与工程系,上海200240

出　　处：《生物技术通报》2022年第2期123-131,共9页Biotechnology Bulletin

基　　金：国家重点研发计划(2019YFD0901901);国家自然科学基金项目(31770846)。

摘　　要：褐藻寡糖有着丰富的生物学功能,酶法制备功能性褐藻寡糖具有重要实践应用价值。为发掘高活性及稳定性的褐藻寡糖制备酶,对浅海热液嗜热菌Yeosuana marina sp.JLT21中的海藻酸裂解酶YMA-1的基因在大肠杆菌中进行表达、纯化及酶活鉴定。结果发现YMA-1由306个氨基酸残基构成,是多糖裂解酶家族7(PL7)新成员;重组YMA-1酶的最适催化条件是55℃,pH 9.0,比活力1.3×10^(4) U/mg,Cu^(2+)可有效促进酶活;在37℃,pH 9.0条件下,该酶对海藻酸钠、聚甘露糖醛酸和聚古罗糖醛酸的比活力分别达到(5201.21±86.46)U/mg、(6399.73±253.12)U/mg和(3751.68±116.25)U/mg,酶解海藻酸钠终产物多为不饱和三糖和四糖,表现出内切双功能型海藻酸裂解酶活性。YMA-1酶作为PL7家族中较宽底物谱、高活性及稳定性的内切海藻酸裂解酶,在高效绿色生产功能性褐藻寡糖上有着潜在应用价值。Alginate oligosaccharides(AO)have rich biological activity,preparing AO using enzymatic approach is of important,practical and applicable value.To mine highly active and stable enzymes for preparing AO,a gene from an alginate lyase YAM-1 of Yeosuana marina sp.JLT21 was expressed in Escherichia coli,and the enzyme was purified and characterized.As one of polysaccharide lyase family 7(PL7)members,YMA-1 consisted of 306 amino acids.The recombinant YMA-1 showed the optimal activity of 1.3×10;U/mg at pH 9.0 and 55℃,and Cu^(2+)efficiently stimulated its activity.YMA-1 also demonstrated a highly catalytic activity towards sodium alginate,poly G and poly M,and their specific activities were(5 201.21±86.46),(6 399.73±253.12)and(3 751.68±116.25)U/mg,respectively under 37℃ and pH 9.0.The end-products from the enzymolysis of sodium alginate were mainly unsaturated trisaccharides and tetrasaccharides.Duo to its broad substrate spectrum,high activity and thermostability,YMA-1 as endo-type alginate lyase in PL7 family has potential applications in green and efficient production of alginate oligosaccharides.

关 键 词：内切型海藻酸裂解酶 重组表达 酶学性质 Yeosuana marina sp.JLT21 

分 类 号：Q946[生物学—植物学]