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Polyclonal antibodies against a 44-KD phosphoprotein (44K BPP) from rat bone were raised in rabbits, affinity-purified, and used as probes to study the protein's distribution in various types of developing bones from newborn rats. Three immunostaining procedures were applied utilizing indirect immunofluorescence, avidin-biotin-peroxidase complex, and(More)
Bone gamma-carboxyglutamic acid (Gla)-containing protein (BGP or osteocalcin) and 44 kDa bone phosphoprotein (44K BPP, also called Sialoprotein I or osteopontin) have been localized at the ultrastructural level in osteoblasts from woven bones of newborn rats. Frozen, undecalcified sections of periodate-lysine-paraformaldehyde fixed specimens were incubated(More)
Newly synthesized proteoglycans of rat incisors were labelled in vivo for 6h with [35S]-sulphate in order to facilitate their detection during purification and characterization. Proteoglycans were extracted from non-mineralized portions (predentine) of rat incisors with 4M-guanidinium chloride and subsequently from dentine by demineralization with a(More)
Several acidic glycoproteins with apparent molecular weights of 85,000 (bone sialoprotein, BSP), 80,000, 67,000, 60,000, 40,000 (osteonectin) and 30,000 were isolated from adult bovine compact bone. About 20-25% of the 67 K preparation was serum albumin. This contaminant was removed by passing the protein through Blue Sepharose CL-6B; the material that(More)
Vascular lesions resulting from injury are characterized by a thickening of the intima brought about in part through the production of increased amounts of extracellular matrix proteins by the vascular smooth muscle cells (VSMCs). In this study, we tested the hypothesis that cGMP-dependent protein kinase (PKG), an important mediator of NO and cGMP signaling(More)
Osteopontin (OPN), an extracellular matrix cell adhesion protein, was found to serve as a substrate for the incorporation of radiolabelled putrescine mediated by a commercial preparation of guinea pig liver transglutaminase. Preliminary evidence also suggests that OPN serves as a substrate for the plasma transglutaminase, Factor XIIIa. While the protein(More)
We investigated the effects of 1,25-dihydroxyvitamin D3 on the synthesis of osteopontin, a phosphorylated cell attachment glycoprotein, in ROS 17/2.8 cells, a clonal osteoblast-like rat osteosarcoma cell line. We observed a dose dependent increase in uptake of [32PO4] into osteopontin secreted into the medium. An increased incorporation of [35S]-methionine(More)
Malignant gliomas are the most common primary intracranial neoplasms in adults and are largely refractory to post-surgical therapy despite intensive therapeutic efforts. Using a number of different brain tumor-derived cell lines we have demonstrated that the mRNA for osteopontin (OPN), which is substantially over-expressed by some tumors in comparison with(More)
Osteopontin (OPN) is a ubiquitous multiphosphorylated secretory glycoprotein. Twenty-seven phosphorylated serines have been identified in bovine milk OPN (E. S. Sorensen et al. (1995) Protein Sci. 4, 2040-2049). Nineteen of these phosphoacceptor sites are fully conserved in rat OPN, all displaying the consensus for the Golgi apparatus casein kinase, G-CK(More)
A phosphorylated glycoprotein was purified from the mixture of proteins extracted by demineralization of rat bone with 0.5 M EDTA in 4 M guanidinium chloride. A high level of purity for the preparation was indicated by a single band on sodium dodecyl sulfate (SDS)-gradient gel electrophoresis, sedimentation equilibrium ultracentrifugal data, and by(More)