Some typical enzyme-like activities of PepNzymes. (A) The assembly mechanism of Pep-1/hemin nanotubes and peroxidase-like activities displaying a ping-pong pathway for ABTS oxidation with H2O2. Reproduced with permission from Ref. [69], copyright 2022, Springer Nature. (B) Self-assembly of flavin adenine dinucleotide (FAD), Fmoc-amino acids (e.g., Fmoc-lysine), and Cu2+ to form supramolecular aggregates containing oxidase-like copper cluster active sites. Reproduced with permission from Ref. [70], copyright 2023, American Chemical Society. (C) The role of cysteine fragments in the nickel binding loop in Ni (II)-containing SOD-like activity. Reproduced with permission from Ref. [72], copyright 2020, American Chemical Society. (D) A di-copper peptidyl complex mimicking catalase activity. Reproduced with permission from Ref. [74], copyright 2021, American Chemical Society.