Investigating the Interaction Between Hydroxyapatite and Binding Peptide

Human hard tissues, such as bones and teeth, are an organic-inorganic composite material. This material consists mainly of an organic phase of collagen-I fibrils and the mineral hydroxyapatite. The process that leads to the formation of biological composite materials is termed biomineralization. This process is not yet completely understood, however, it is thought to be related to the surface interactions between the organic and inorganic phases. The exact mechanisms of adhesion of peptides and proteins to inorganic surfaces are not clear. It is still not yet understood why peptides adhere to specific surfaces and not others, nor why completely different peptide sequences bind to a specific surface. Therefore, our ability to predict how peptides and surfaces interact is limited.

The purpose of this study is to investigate the interactions between a peptide and hydroxyapatite as a model for the organic-inorganic hybrid material in human bone tissue.

The interactions between hydroxyapatite substrates and the SVSVGMKPSPRP peptide sequence, which is known to adhere to hydroxyapatite, were investigated using single molecule force spectroscopy (SMFS) by atomic force microscope (AFM), and quartz crystal microbalance with dissipation (QCM-D).

Our findings show that the amino acids serine and valine in the SVSV segment of the peptide have an important role in the interactions with the mineral surface.