A peptide that inhibits hydroxyapatite growth is in an extended conformation on the crystal surface

摘要: Proteins play an important role in the biological mechanisms controlling hard tissue development, but details of molecular recognition at inorganic crystal interfaces remain poorly characterized. We have applied a recently developed homonuclear dipolar recoupling solid-state NMR technique, with windowless sequence (DRAWS), to directly probe conformation acidic peptide adsorbed hydroxyapatite (HAP) crystals. The phosphorylated hexapeptide, DpSpSEEK (N6, where pS denotes serine), was derived from N terminus salivary protein statherin. Constant-composition kinetic characterization demonstrated that, like native statherin, this inhibits growth HAP seed crystals when preadsorbed surface. DRAWS technique used measure internuclear distance between two 13C labels carbonyl positions adjacent phosphoserine residues. Dipolar dephasing measured short mixing times yielded mean separation 3.2 ± 0.1 Å. Data obtained by using longer suggest broad distribution conformations about average distance. Using more complex model discrete α-helical and extended did not yield better fit data consistent chemical shift analysis. These results that is predominantly rather than state on Solid-state approaches can thus be determine biologically relevant peptides surfaces. A understanding biomineral surfaces may provide design principles useful for modification orthopedic dental implants coatings factors are designed enhance biocompatibility surrounding tissue.