Mineralization by Dendritic Oligomers of Apatite-Binding Peptide under Body Fluid Conditions

A peptide derivative having the sequence based on the hydroxyapatite-binding peptide (HABP) and its dendritic oligomers were designed and synthesized. Their ability to lead to mineralization under body fluid (SBF) conditions was evaluated. The peptide HABP-C having a MLPHHGA sequence that is missing two cysteine groups necessary for intermolecular disulfide bond formation, induced calcium phosphate (CaP) deposition, which resulted from the formation of peptide-CaP hybrids having tape-like morphologies. The dendritic dimer and tetramer of HABP-C also induced formation of peptide-CaP hybrids having basically similar morphologies. Oligomerization of the HABP-C sequence did not affect the resulting morphology of the hybrids. On the other hand, the dendritic tetramer clearly accelerated the initial steps, i.e. the interaction between the peptides and CaP nanoparticles spontaneously formed in SBF, of the hybrids formation, which demonstrated that clusters of peptides affect their mineralization abilities.