Amyloid‐Guided Assembly of Magnetically Recyclable Enzymatic Nanofibers Toward Sustainable Biocatalysis

ABSTRACT

The rational construction of recyclable protein‐based catalytic materials requires connecting molecular enzyme design with higher‐order supramolecular organization and functional recovery interfaces. This study establishes a hierarchical design strategy that integrates fusion‐enzyme engineering, amyloid‐guided self‐assembly, and magnetic immobilization. The primary amine oxidase DPAO4 and the flavin‐containing amine oxidase DMAO7 were joined through flexible or rigid linkers, and the rigid (EAAAK) ₃ variant provided broad substrate coverage, greater tolerance to process‐relevant stresses, and lower interdomain fluctuations in molecular dynamics simulations. N‐terminal Sup35 ^1‐61 or Ure2 ^1‐80 domains promoted the formation of ThT‐responsive fibrillar assembly, and the resulting enzymatic nanofibers were coupled to amino‐functionalized Fe ₃ O ₄ @SiO ₂ ‐NH ₂ nanoparticles. The composites enabled magnetic separation within 30 s, catalyzed the degradation of eight biogenic amines under acidic, thermal, saline, and ethanol‐containing conditions, and retained an average of 53.2% of their initial activity after four recovery cycles. As proof‐of‐concept evaluation in complex matrices, selected systems removed up to 70.6% of total biogenic amines from fermented beverages and 69.7% from soy sauce. The distinct responses of the Sup35‐ and Ure2‐based composites suggest an association between assembly‐domain identity and catalytic performance in complex matrices. This work demonstrates a hierarchical design approach for recyclable protein‐based catalytic materials and sustainable biocatalysis.