双酶作用体系下呕吐毒素的高效降解  

Efficient degradation of deoxynivalenol by double enzyme

作　　者：施妍 张玉磊 徐炜 张文立 沐万孟[1,2] SHI Yan;ZHANG Yu-Lei;XU Wei;ZHANG Wen-Li;MU Wan-Meng(State Key Laboratory of Food Science and Technology,Jiangnan University,Wuxi 214122,China;Joint Laboratory of International Cooperation on Food Safety,Jiangnan University,Wuxi 214122,China)

机构地区：[1]江南大学食品科学与技术国家重点实验室,无锡214122 [2]江南大学食品安全国际合作联合实验室,无锡214122

出　　处：《食品安全质量检测学报》2023年第6期108-117,共10页Journal of Food Safety and Quality

基　　金：国家重点研发计划项目(2019YFC1604602);中央高校基本科研业务费专项(JUSRP622008)。

摘　　要：目的挖掘呕吐毒素(deoxynivalenol,DON)降解酶,应用双酶体系实现呕吐毒素的高效降解。方法利用生物信息学技术从国家生物技术信息中心(National Center for Biotechnology Information,NCBI)数据库筛选潜在DON降解酶AKR18A2,在大肠杆菌EscherichiacoliBL21(DE3)中进行重组和异丙基-β-D-硫代半乳糖苷(isopropylβ-D-thiogalactoside,IPTG)诱导表达,经镍亲和层析纯化并鉴定AKR18A2的酶学性质,构建德沃斯氏菌(Devosiasp.)来源的DON降解酶QDDH和AKR18A2双酶作用体系,实现DON的高效降解。结果来自鞘氨醇单胞菌属(Sphingomonas sp.)的呕吐毒素降解酶(AKR18A2)由343个氨基酸组成。该酶属于醛酮还原酶超家族,45℃和pH7.0为最适反应条件。AKR18A2可在24h内降解15.42%DON,而双酶(QDDH和AKR18A2)协同作用4h后对DON的降解率可提高至98.02%。结论本研究鉴定了一种新型DON降解酶AKR18A2,并首次创新建立双酶联用体系进一步实现DON的高效降解。Objective To dig out the degrading enzyme of deoxynivalenol(DON),and apply the double enzyme system to realize the efficient degradation of DON.Methods The potential DON-degrading enzyme(AKR18A2)was screened from National Center for Biotechnology Information(NCBI)database by bioinformatics analysis,and recombined in Escherichia coli BL21(DE3)and induced by isopropylβ-D-thiogalactoside(IPTG).AKR18A2 was purified by nickel affinity purification.The enzymatic properties were characterized,and a dual enzymatic system of DON degrading enzyme QDDH of Devosia sp.origin and AKR18A2 was constructed to achieve efficient DON degradation.Results A novel DON-degrading enzyme from Sphingomonas sp.(AKR18A2)containing 343 amino acids was successfully screened and identified.The recombinant enzyme belonged to the aldo-ketone reductase superfamily,having an optimum temperature at 45℃and pH at 7.0.Although the degradation rate of AKR18A2 against DON was merely 15.42%after 24 h,the double enzyme systmes of QDDH and AKR18A2 could efficiently degrade 98.02%of DON after 4 h.Conclusion In this study,a novel DON-degrading enzyme AKR18A2 is identified,and a dual-enzyme combination system is innovatively established for the first time to further achieve high-efficient degradation of DON.

关 键 词：呕吐毒素 酶法降解 醛酮还原酶 双酶作用 

分 类 号：TS201.6[轻工技术与工程—食品科学]