Self‐Assembly of Minimalist Amyloid Peptides to Produce Metal‐Free Nanofibrils Possessing Robust and Photoswitchable Metallooxidase‐Mimetic Catalytic Functions

Abstract Achieving metal‐free biomimetic catalysis, traditionally mediated by metalloenzymes, has been intriguing research for the development of metal‐free carbon catalysts and for understanding the natural evolution of enzymes. In this study, the self‐assembly of Fmoc‐F‐based dipeptides as minimalistic building blocks is reported, which, in the absence of metal or organic cofactors, exhibit catalytic functions similar to those of heme‐dependent peroxidases. These dipeptides form β‐sheet‐based nanofibrils that organize functional groups in an ordered arrangement, facilitating the catalysis of H₂O₂ reduction through the formation of ternary complex intermediates. The influence of metal impurities on the catalysis is also ruled out through ICP‐MS analysis and the addition of transition metal ions. Remarkably, the activity of this biomimetic catalyst can be fully restored after ten or more cycles of thermal or acid treatment. Additionally, the catalyst can be dynamically photo‐switched between ON and OFF states by the noncovalent introduction of a photoisomerizable azobenzene derivative into the assemblies, indicating its robustness and adaptability. These findings provide new insights into the design of advanced catalytic materials and offer a valuable understanding of the functional principles of primitive cofactor‐free enzymes.