Molecular co-assembly of multicomponent peptides for the generation of nanomaterials with improved peroxidase...

Molecular self-assembly of peptides provides an effective approach for the fabrication of biomimetic enzymes in recent years. However, due to sophisticated architectures of native peroxidases, precise mimicking of the structure of hemin pockets within peroxidases with a single component of peptide is a great challenge. Herein, we decided to explore the potential of multicomponent peptide assembly to prepare artificial peroxidases with biomimetic hemin pockets. Hydrophobic peptides (e.g., KH, QH, NH, NHNH and NHNHNH) provide a supramolecular scaffold to form an appropriate hydrophobic binding pocket, and a proximal histidine ligand to bind hemin through the coordination between imidazole and hemin iron. A peptide with hydrophilic residues (e.g., NapFFHEKRH) was incorporated to supply distal histidine residues and hydrophilic amino acids in the distal pocket to promote H₂O₂ binding and stabilize a high oxidation state. Due to the synergistic molecular interactions, the components of NH, NapFFHEKRH and hemin could self-assemble into nanostructures with biomimetic microenvironments for increased substrate binding and catalytic rates of TMB oxidation, compared to the catalytic system of NH_hemin without NapFFHEKRH. This work illustrates an approach for fabricating artificial peroxidases with biomimetic structural features and improved catalytic activities from co-assembly of multicomponent peptides.