摘要
以假交替单胞菌(Pseudoalteromonas sp.zb7-4)发酵制备褐藻胶裂解酶粗酶液,采用弱阴离子DEAE交换层析分离褐藻胶裂解酶,分析纯化褐藻胶裂解酶Alg L的酶学特性.结果表明:Alg L的表观分子质量约为32 ku,比活力为(208.26±5.87)U·mg-1;其最适反应pH为7.0,在pH为6.0~10.0范围内稳定性较好,保温1 h仍能保持80%以上的相对酶活力;最适反应温度50℃,在40℃保温30 min,其残余酶活力高于80%;Cu2+、Cr3+、Co2+、Ba2+、Sr2+、Hg2+对该酶具有不同程度的抑制作用,Hg2+抑制作用最为明显;该酶具有较好的盐耐受性,在3 mol·L-1Na Cl反应体系中保温2 h,仍残余66%酶活力.动力学参数Km、Vmax、Kcat测定表明,该酶对聚古罗糖醛酸钠(PG)亲和力较高,为偏好聚甘露糖醛酸钠(PM)裂解作用的双功能酶.
Alginate lyase AlgL was successfully purified from fermented broth of Pseudoalteromonas sp. zb7-4 by DEAE weak anion exchange chromatography and the enzymatic properties of alginate lyase were characterized. The results showed that the purified alginate lyase was a monomer with apparent molecular weight of approximately 32 ku and specific activity of （208.26±5.87） U· mg-1. The opti- mum pH for enzyme was 7.0, it was stable in the pH range of 6.0 to 10.0, and its relative enzyme activity could still maintain more than 80% after 1 h＇ s incubation. The optimum temperature for enzyme was 50 ℃, and its residual enzyme activity was still 80% after 30 min＇ s incubation at 40℃. Cu2＋, Cr3＋, Co2＋ , Ba2＋, Sr2＋, Hg2＋ showed inhibitory effects on the enzyme activity while Hg2＋ was the most obvious. The enzyme had a good ability of salt tolerance, and its relative enzyme activity retained more than 66% after 2 h＇ s incubation in 3 mol·L-1 NaCl. The values of Km , Vmax, Kcat showed that the enzyme was a bifunctional enzyme which prefered sodium polymannuronate （Poly M）.
作者
韩伟
许鑫琦
叶秀云
林娟
HAN Wei;XU Xinqi;YE Xiuyun;LIN Juan(Fujian Key Laboratory of Marine Enzyme Engineering, College of Bioiogical Seienee and Technology, Fuzhou University, Fuzhou, Fujian 350116, China)
出处
《福州大学学报（自然科学版）》
CAS
北大核心
2018年第1期136-142,共7页
Journal of Fuzhou University(Natural Science Edition)
基金
福州市科技计划资助项目(2016-G-42)
海洋经济创新发展区域示范项目(2014FJPT02)
福建省企业技术创新资助项目(闽经信投资[2015]205号)
关键词
褐藻胶裂解酶
假交替单胞菌
纯化
酶学性质
alginate lyase
Pseudoalteromonas sp.
purification
enzymatic property
