Browsing by Author "Mwabulili, Fred"

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    PROSS-assisted engineering enhances the thermal and storage stability of an AFB1-degrading superoxide dismutase
    (Elsevier, 2026-09-26) Zhang, Yan; Zhang, Yiqian; Mwabulili, Fred
    Aflatoxin B1, Superoxide dismutase, PROSS, Thermostability, Storage stability Aflatoxin B1 (AFB1) contamination threatens feed safety, highlighting the need for enzymatic detoxification strategies. In this study, an AFB1-degrading strain, HNGD-122, was isolated and identified as a Priestia mega-terium-related strain. Genome-guided mining identified a superoxide dismutase (SOD) with AFB1-degrading activity. To improve enzyme stability, PROSS-assisted design was applied, yielding the M163K mutant. M163K retained AFB1-degrading activity and exhibited enhanced thermostability, with half-lives at 70 and 80 ◦C extended to 32.2 and 20.7 h, respectively. It exhibited higher AFB1 degradation rates than wild-type (WT)-SOD during storage at 4 ◦C and following freeze-drying. Molecular dynamics simulations suggested that M163K maintained SOD–AFB1 interactions while improving thermostability through enhanced local stabilizing in-teractions. In zebrafish assays, it reduced developmental toxicity and oxidative stress after M163K treatment. In naturally contaminated corn flour and corn bran, M163K degraded approximately 66.5% and 61.9% of AFB1, respectively, supporting its potential for AFB1 control in corn-based feed ingredients.