Uncovering Sequence Effects in Titanium Binding Peptides Adsorption on TiO₂: A Molecular Dynamics Study

Titanium binding peptides are useful tools for material functionalization in both biomedical and nanotechnology applications because of their ability to attach selectively to titanium surfaces. In this work, we investigate the adsorption behav- ior of a series of 360 six amino acids long peptides obtained by permutations of titanium binding peptide residues, RKLPDA, on hydroxylated anatase TiO2 (101) surfaces using extensive atomistic molecular dynamics (MD) simulations, with the purpose identifying sequences with stronger adsorption affinity to tita- nium. Our results show that small changes in amino acid order can significantly affect both binding strength and structural conformations. Peptides with argi- nine at the N-terminus and lysine or aspartic acid near the C-terminus tended to exhibit more stable adsorption. The clustering and radial distribution function (RDF) analyzes revealed different binding modes and key atomic interactions, with nitrogen-containing groups and, in some cases, Na+ ions playing a signif- icant role in the anchoring of peptides to the surface. These findings suggest a detailed sequence-level understanding of peptide-TiO2 interactions and can guide the design of improved peptides for titanium functionalization.