Bone Sialoprotein (BSP)

Bone sialoprotein (BSP) is a component of mineralized tissues such as bone, dentin, cementum and calcified cartilage. BSP is a significant component of the bone extracellular matrix and has been suggested to constitute approximately 8% of all non-collagenous proteins found in bone and cementum. BSP was originally isolated from bovine cortical bone as a 23-kDa glycopeptide with high sialic acid content, as described in separate reports by Williams and Peacocke and Andrews and Herring Native BSP has an apparent molecular weight of 60-80 kDa based on SDS-PAGE, which is a considerable deviation from the predicted weight of approximately 33 kDa. The mammalian BSP cDNAs encode for proteins averaging 327 amino acids,, which includes the 16-residue preprotein secretory signal peptide.