Designed Self-Assembly of Peptides with G-Quadruplex/Hemin DNAzyme into Nanofibrils Possessing Enzyme-Mimicking Active Sites and Catalytic Functions

Enzymes fold into three-dimensional structures to arrange their active groups exquisitely for the remarkable catalytic properties. We are inspired to design and assemble Gln-containing peptides with G-quadruplex DNA/hemin complexes to form the catalytic nanofibrils that possess the horseradish peroxidase-mimicking active sites and catalytic functions. Theoretical simulation results revealed that the intermolecular association of Gln peptide may result in local enrichment and proper orientation of carboxamide groups, which provide potential multivalent hydrogen bonds for enhancing H2O2 affinity to hemin and may behave similarly to distal Arg in a natural heme pocket. The self-folded DNA can provide a guanine base as the axial ligand, and a supramolecular scaffold for supporting and orienting hemin. The β-sheet forming capability of the Q peptides is found to significantly affect the catalytic synergy between the G-DNA and the peptide. The role of hydrogen bonds network provided by self-assembled Gln peptid...