Adsorption of an Ionic Complementary Peptide on the Hydrophobic Graphite Surface

Protein adsorption plays a crucial role in bioactive implant devices and drug delivery materials design. Ionic complementary peptides are novel nanobiomaterials with many biomedical applications. In this work, molecular dynamics simulations of the ionic complementary peptide EAK16-II on the hydrophobic HOPG surface were performed. The adsorption and initial assembly process of EAK16-II on the surface were revealed. Hydrophobic alanine residues are found to be energetically favorable when in contact with the HOPG surface. It is the hydrophobic interaction that drives the adsorption of the first peptide molecule. Both hydrophobic and electrostatic interactions contribute to the adsorption of the second peptide molecule. The effect of hydrogen bonding is found to be less significant in the adsorption. The adsorption of the peptide on the HOPG surface is stable. These results provide a basis for understanding the fundamentals of peptide adsorption on the surface, which is critical for peptide applications in biotechnology and nanotechnology.