High impact information on IBSP

• Nucleation of hydroxyapatite by bone sialoprotein [1].
• These findings suggest that the nucleation of hydroxyapatite by BSP involves one or both of the glutamic acid-rich sequences [2].
• Bone sialoprotein (BSP) is a bone-specific glycoprotein containing phosphoserine and sulphotyrosine residues and regions of contiguous glutamic acid residues [2].
• Secreted phosphoprotein 1 (SPP1, commonly referred to as osteopontin and formerly known as bone sialoprotein 1, early T-lymphocyte activation 1) is an extracellular matrix/adhesion molecule that is upregulated in the pregnant uterus of all mammals examined to date [3].
• In this way, phosphoproteins such as osteopontin, bone sialoprotein, dentin phosphophoryn, and other acidic glycoproteins are visualized at higher sensitivity (greater than fivefold) and staining stability than normally achieved with just Stains-all [4].

Biological context of IBSP

• While it is evident from these and other studies that both BSP and OPN are associated with bone formation, the differences observed in cellular expression indicate distinct roles for these proteins in bone formation [5].

Anatomical context of IBSP

• More moderate expression of BSP was observed in 'older' osteoblasts and in some of the newly-entrapped osteocytes [5].
• Results of in situ hybridization on the same tissues demonstrated that BSP mRNA expression was restricted to differentiated osteoblasts with particularly strong signals evident at sites of de novo bone formation [5].
• Bone sialoprotein (BSP) is a prominent component of bone tissues that is expressed by differentiated osteoblastic cells [6].
• The variations in the distribution and cellular expression of BSP, SPARC and SPP-1 in bone and mineralizing cartilage indicate these proteins perform different functions in the formation and remodelling of mineralized connective tissues [6].
• Affinity-purified antibodies to BSP were prepared and used in combination with biotin-conjugated peroxidase-labeled second antibodies to demonstrate the distribution of this protein in sections of demineralized foetal porcine tibia and calvarial bone [6].

Associations of IBSP with chemical compounds

• Bone sialoprotein (BSP) and osteopontin (OPN) are two major non-collagenous proteins in bone that have similar biochemical properties and can mediate cell attachment through an RGD (Arg-Gly-Asp) motif that recognizes the vitronectin receptor [5].
• Biosynthesis of bone proteins by fetal porcine calvariae in vitro. Rapid association of sulfated sialoproteins (secreted phosphoprotein-1 and bone sialoprotein) and chondroitin sulfate proteoglycan (CS-PGIII) with bone mineral [7].

Other interactions of IBSP

• Immunohistochemical localization of bone sialoprotein in foetal porcine bone tissues: comparisons with secreted phosphoprotein 1 (SPP-1, osteopontin) and SPARC (osteonectin) [6].
• SPP-1 (secreted phosphoprotein 1, osteopontin) was the major non-collagenous protein deposited into the bone matrix, with lesser amounts of BSP (bone sialoprotein), osteocalcin and chondroitin sulfate proteoglycans (CS-PG II and CS-PG III) [7].

Analytical, diagnostic and therapeutic context of IBSP

• In addition, 35S-labelled antisense riboprobes were prepared to demonstrate the cellular expression of BSP and OPN in the same tissues using in situ hybridization [5].
• Purified porcine BSP was treated with trypsin and digests fractionated by gel filtration [8].

References