Expression, purification and characterization of a novel zearalenone hydrolase from Rhinocladiella mackenziei

Abstract:

[Background] Zearalenone (ZEN) is one of the most widely contaminated mycotoxins, which causes huge economic losses to feed industry and animal husbandry. The lactonase ZHD101 is the most widely studied ZEN-detoxifying enzyme. However, its application in industry was limited by the low thermostability. [Objective] In order to realize the application of zearalenone-degrading enzyme in industry, this study explored a ZEN-detoxifying enzyme with more prominent enzymatic properties. [Methods] We found an Rmzhd gene from Rhinocladiella mackenziei CBS 650.93 in the GenBank database, and constructed the pET-46-Rmzhd plasmid. E. coli system was used to express the target protein. The protein was purified by using affinity chromatography and ion exchange purification system. Enzymatic properties were analyzed by high performance liquid chromatography (HPLC). [Results] In this study, we characterized a novel ZEN hydrolase, denoted as RmZHD. RmZHD exhibits the highest activity at pH 8.6 and 45 °C, and has a higher thermostability. Analyzing the structure of RmZHD, we found that the higher contents of salt bridges and solvent-exposed prolines might contribute to higher protein thermostability. [Conclusion] This study provides foundation for improving the industrial applications of zearalenone hydrolases.