Molecular-level understanding of the adsorption mechanism of a graphite-binding peptide at the water/graphite interfaceElectronic supplementary information (ESI) available: (1) Full exemplar trajectory; (2) peptide-surface interaction energy over first 25 ns of exemplar trajectory (3) MSD of GrBP5 in bulk solvent and adsorbed at water/graphite interface; (4) movie of exemplar trajectory. See DOI: 10.1039/c5sm00123d

• Main Authors: Penna, M. J, Mijajlovic, M, Tamerler, C, Biggs, M. J
• Format: Journal Article
• Language: English
• Published: 24.06.2015
• ISSN: 1744-683X; 1744-6848
• DOI: 10.1039/c5sm00123d

The association of proteins and peptides with inorganic material has vast technological potential. An understanding of the adsorption of peptides at liquid/solid interfaces on a molecular-level is fundamental to fully realising this potential. Combining our prior work along with the statistical analysis of 100+ molecular dynamics simulations of adsorption of an experimentally identified graphite binding peptide, GrBP5, at the water/graphite interface has been used here to propose a model for the adsorption of a peptide at a liquid/solid interface. This bottom-up model splits the adsorption process into three reversible phases: biased diffusion, anchoring and lockdown. Statistical analysis highlighted the distinct roles played by regions of the peptide studied here throughout the adsorption process: the hydrophobic domain plays a significant role in the biased diffusion and anchoring phases suggesting that the initial impetus for association between the peptide and the interface may be hydrophobic in origin; aromatic residues dominate the interaction between the peptide and the surface in the adsorbed state and the polar region in the middle of the peptide affords a high conformational flexibility allowing strongly interacting residues to maximise favourable interactions with the surface. Reversible adsorption was observed here, unlike in our prior work focused on a more strongly interacting surface. However, this reversibility is unlikely to be seen once the peptide-surface interaction exceeds 10 kcal mol −1 . The association of proteins and peptides with inorganic material has vast technological potential.