PROSS-assisted engineering enhances the thermal and storage stability of an AFB1-degrading superoxide dismutase
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Date
2026-09-26
Authors
Zhang, Yan
Zhang, Yiqian
Mwabulili, Fred
Journal Title
Journal ISSN
Volume Title
Publisher
Elsevier
Abstract
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.
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This article was published by Elsevier
Keywords
Aflatoxin B1, Superoxide dismutase, PROSS, Thermostability, Storage stability