双酶作用体系下呕吐毒素的高效降解

Efficient degradation of deoxynivalenol by double enzyme

中文关键词:  呕吐毒素  酶法降解  醛酮还原酶  双酶作用

英文关键词:deoxynivalenol  enzymatic degradation  aldo-ketone reductase  double enzyme

中文摘要:

      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Escherichia coli BL21 (DE3)中进行重组和异丙基-β-D-硫代半乳糖苷(isopropyl β-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(Devosia sp.)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pH 7.0为最适反应条件。AKR18A2可在24 h内降解15.42% DON, 而双酶(QDDH和AKR18A2)协同作用4 h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。

英文摘要:

      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 isopropyl β-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.