Rational Screening of Four Peroxidases with High Aflatoxin B1 Degradation Efficiency via Integrated Computational Simulations

Aflatoxin B1 (AFB1) degradation remains a critical challenge due to limitations of conventional methods. This study proposed a computational screening strategy to screen the AFB1-degrading enzymes, and four peroxidases derived from Agrocybe pediades (ApeLip), Klebsiella pneumoniae (KpDyp), Trametopsis cervina (TrcLip), and Pleurotus eryngii (VPL2) were selected. The enzymes heterologously expressed and purified in Escherichia coli Shuffle T7-B possessed the ability to efficiently degrade AFB1 and a certain degree of alkaline tolerance. The enzymes ApeLip, KpDyp, TrcLip, and VPL2 degraded AFB1 by 90.06, 91.55, 91.93, and 92.91%, respectively, under optimal conditions. Molecular dynamics simulations indicated that van der Waals interactions are the main binding mechanism, especially acting through hydrophobic residues. UPLC-QTOF-MS analysis confirmed the hydroxylation of the C8═C9 bond of AFB1 to produce AFB1–8,9-dihydrodiol with lower toxicity. The combined computer simulation and practical framework establishes an effective platform for rational enzyme discovery and effectively promotes the development of mycotoxin mitigation strategies.