부산대학교 도서관

Zearalenone (ZEA), a nonsteroidal estrogenic mycotoxin produced by multiple Fusariumspecies, contaminates cereals and threatens the health of both humans and animals by inducing hepatotoxicity, immunotoxicity, and genotoxicity. A new alkali tolerant enzyme named Ase, capable of degrading ZEA without H2O2, was derived from Acinetobactersp. SM04 in this study. The Asegene shares 97% sequence identity with hypothetical proteins from Acinetobacter pittiistrain WCHAP 100004 and YMC 2010/8/T346 and Acinetobacter calcoaceticusPHEA-2, respectively. Based on the Acinetobactergenus database, the gene encoding Ase was cloned and extracellularly expressed in Escherichia coliBL21. After degrading 88.4% of ZEA (20 µg/mL), it was confirmed through MCF-7 cell proliferation assays that Ase can transform ZEA into a nonestrogenic toxic metabolite. Recombinant Ase (molecular weight: 28 kDa), produced by E. coliBL21/pET32a(+)-His-Ase, was identified as an oxygen-utilizing and cytochrome-related enzyme with optimal activity at 60 °C and pH 9.0.Graphical AbstractAse can process 88.40% of total ZEA (20 µg/mL) in 8 h at 50 °C and pH 9.0. The estrogenic activity of Ase degradation products was lower than ZEA.