一种甘露糖醛酸C-5差向异构酶的Loop区域结构对酶活性的影响  

Effect of Loop on one kind of mannuronan C-5 epimerase.s activity

作　　者：孙明 李唐 赵小明[2] 阎圣刚 尹恒[2] SUN Ming;LI Tang;ZHAO Xiaoming;YAN Shenggang;YIN Heng(College of Transportation Engineering,Dalian Maritime University,Dalian 116026,China;Natural Products&Glycoconjugate Research Group,Liaoning Provincial Key Laboratory of Carbohydrates,Dalian Institute of Chemical Physics,Chinese Academy of Sciences,Dalian 116023,China)

机构地区：[1]大连海事大学交通运输工程学院,大连116026 [2]中国科学院大连化学物理研究所,辽宁省碳水化合物重点实验室天然产物与糖工程研究组,大连116023

出　　处：《生物学杂志》2021年第2期32-35,共4页Journal of Biology

基　　金：国家重点研发计划(2017YFD0201302);国家自然基金(31770847);农业部海藻类肥料重点实验室开放基金资助项目(MAKLSF1802)。

摘　　要：利用大肠杆菌(Escherichia coli)表达系统,成功异源表达并纯化了来自Pseudomonas syringae的一种周质甘糖醛酸C-5差向异构酶AlgG_PSEAM及其loop^(439-455)截短体。通过对产物进行分析发现,截去loop^(439-455)后,该甘露糖醛酸C-5差向异构酶的活性提高了14.7%。进一步分析,发现AlgG_PSEAM同时具有褐藻多糖裂解酶活性且通过测定其裂解酶活性发现,截去loop^(439-455)后,裂解酶活性提高了23.3%。截去loop^(439-455),可同时提高AlgG_PSEAM的甘露糖醛酸C-5差向异构酶和褐藻多糖裂解酶活性。The periplasmic protein AlgG_PSEAM and its loop^(439-455)-truncation from Pseudomonas syringae were successfully heterologously expressed.It was found that the epimerase activity was increased by 14.7%after removing the loop^(439-455).Through further investigation,it was found that AlgG_PSEAM also had alginate lyase activity and the alginate lyase activity also increased by 23.3%after removing the loop^(439-455).Therefore,two functional activities of the enzyme can be improved by removing the loop.

关 键 词：LOOP 异源表达 甘露糖醛酸C-5差向异构酶 褐藻多糖裂解酶 

分 类 号：Q55[生物学—生物化学]