Molecular Dynamics Simulation Of Collagen Peptides Interacting With Gold Surfaces

The interaction between proteins and metal surfaces is widely present in biomedical applications such as wound treatment and drug delivery.As a major component of the extracellular matrix,collagen has potentially advantageous biomedical applications due to its excellent biocompatibility and elasticity properties.Therefore,a mechanistic comprehension of collagen and gold interaction pattern and influence factors is important for the clinical application of collagen-gold complexes.However,the dynamic behavior of collagen on gold sheets at the molecular level are extremely difficult to capture for the current experimental conditions.Here,using molecular dynamics simulations,we investigated the adsorption process and conformation behavior of the tripeptide of GLY-PRO-HYP as the repetitive unit of the collagen superhelix on the gold surface as a function of number of repeating units from1 to 10.The different number of repeating units all prefer to approach the gold surface and adsorb via charged residues at the C-terminal or N-terminal ends,tending to form arch structures on the gold surface.Compared with the various tripeptide units in solution still attaining the native polyproline II(PPII)conformation,the presence of the gold surface affects the formation of hydrogen bonds between the protein and water molecules,thus disrupting the PPII conformation of collagen.Specifically,the interaction between the gold surface and HYP limited the rotation of the dihedral angle of collagen,resulting in a tendency for the PPII conformation of the gold surface to transfer to the a random coil structure.Overall,this research investigated the interaction between collagen peptides and gold surfaces at the molecular level,which provides indications on how to improve the interaction of the terminal groups with the gold surface for the design of a biocompatible protein-gold material for medicine.