Speech Title: Identification of Hydroxyapatite-Interacting Proteins in Bone
Abstract: Biomineralization involves proteins directly in controlling the mineral crystal nucleation/induction, growth, and maturation. We have identified these ~30 proteins in bone (Ann N Y Acad Sci. 2007 Nov;1116:323-326). In the present study ~20 additional proteins were identified by chromatography on a DE-52 column to separate basic/neutral and acidic proteins followed on a hydroxyapatite column in combination with mass spectrometry. Prominent among the newly identified hydroxyapatite-interacting proteins are extracellular matrix proteins such as collagen types V and X, bone sialoprotein, osteopontin and versican, cell growth and differentiation factors pleiotrophin and γ interferon, etc., indicating that the mineral crystals are regulated by the specific proteins secreted by bone cells and in turn can affect the cells via their proteins.