Systematic purification of free and matrix-bound phosphophoryns of bovine dentin: Presence of matrix-bound phosphophoryn as a distinct molecular entity

Fujisawa, Ryuichi; Takagi, Tohru; Kuboki, Yoshinori; Sasaki, Satoshi

doi:10.1007/bf02405323

Cited by 37 publications

(14 citation statements)

References 11 publications

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“…Some researchers dispute whether the phosphate in dentin collagen is covalently bound (7) . However, attempts to separate the phosphoprotein from dentin collagen have included using high ionic strengths, a variety of chaotropic agents, and the degradation of collagen with periodate, cyanogen bromide, and proteolytic enzymes were unsuccessful (3–5,8–11) …”

Section: Introductionmentioning

confidence: 99%

Apatite Induction by Insoluble Dentin Collagen

Saito¹,

Yamauchi²,

Crenshaw³

1998

Journal of Bone and Mineral Research

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Phosphoproteins are thought to play a role in mineral formation in dentin. A portion of this phosphoprotein is bound to collagen. We have investigated the requirement for bound phosphate in mineral induction by isolated dentin collagen. Insoluble bovine dentin collagen obtained by ethylene-diamino-tetra-acetic acid (EDTA) demineralization had 19.5 mol of P/mol of collagen that could not be extracted with 0.5 M EDTA in 4 M guanidine HCl. When this collagen was incubated in supersaturated solutions that did not spontaneously precipitate, apatite was induced. With progressive enzymatic dephosphorylation, induction times for mineral formation became progressively longer. The dentin did not induce mineral formation when 90% of the ester phosphate was removed. Insoluble bone collagen, which had even less phosphate, also did not induce mineral formation. Mineral induction times by dentin collagen increased with decreasing solution saturations. Using these data, the interfacial tension for mineral induction was determined to be 90 ergs/cm 2 . This value approximated that of phosphatidic acid liposomes and of phosvitin cross-linked to agarose beads, and it might reflect the energetics of heterogeneous nucleation on a highly phosphorylated surface. Sequestering of calcium-phosphate clusters on the phosphoprotein probably accounts for the observed calcium binding by dentin collagen in excess of that required to neutralize the phosphate esters of the collagen. Because the phosphoprotein is immobilized at a low density on the collagen, it cannot self-associate in calcium-phosphate solutions as it does when it is free in solution. This immobilized phosphoprotein allows the mineral clusters formed on its surface to grow into a crystalline order. (J Bone Miner Res 1998;13:265-270)

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Section: Introductionmentioning

confidence: 99%

Apatite Induction by Insoluble Dentin Collagen

Saito¹,

Yamauchi²,

Crenshaw³

1998

Journal of Bone and Mineral Research

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“…The amounts ofBGP or osteonectin found in dentin are less than those in bone (Price et al, 1976;Fujisawa and Kuboki, 1989). Several serum proteins, such as serum difference between dentin and bone is the presence of a unique phosphoprotein, phosphophoryn, in dentin (Lee et al, 1977;Fujisawa et al, 1984). Phosphophoryn is the most abundant non-collagenous protein in dentin, and its level increases with maturation of dentin (Takagi et al, 1986;Fujisawa and Kuboki, 1988).…”

Section: Introductionmentioning

confidence: 99%

Differences in Composition of Cell-attachment Sialoproteins between Dentin and Bone

et al. 1993

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Matrices of dentin and bone were compared with respect to the content of cell-attachment sialoproteins. The levels of two sialoproteins, osteopontin (OPN) and bone sialoprotein (BSP), were determined in dentin and bone by immunochemical procedures. Polyclonal antibodies against bovine BSP and an antibody against the amino-terminal decapeptide of rat OPN were used. The relative levels of OPN and BSP in dentin were less than one-tenth of the levels in bone. The differences between dentin and bone levels of OPN and BSP were thus larger than those for osteonectin or bone Gla protein in the two tissues. The scarcity of the cell-attachment proteins in dentin may reflect the metabolic inactivity of dentin.

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“…Dentin phosphophoryns were precipitated with calcium and purified chromatographically as described previously (Kuboki et al, 1979;Fujisawa et al, 1984). The purity of the proteins was ascertained by gel electrophoresis.…”

Section: Methodsmentioning

confidence: 99%

“…Moreover, they have affinity to both collagen (Fujisawa and Kuboki, 1992;Fujisawa et al, 1994) and hydroxyapatite (Fujisawa et al, 1986;Fujisawa and Kuboki, 1991) and modify the crystal shape by their specific adsorption to crystal faces (Addadi and Weiner, 1985;Addadi et al, 1987;Furedi-Milhofer et al, 1994). These non-collagenous proteins include bone Gla protein (BGP)/osteocalcin (Price et al, 1976), osteonectin (SPARC) (Termine et al, 1981), bone proteoglycans (Franzen and Heinegard, 1984), bone sialoprotein (BSP) (Fisher et al, 1983), osteopontin (Zhang et al, 1990), and dentin phosphophoryns (Fujisawa et al, 1984).…”

Section: Introductionmentioning

confidence: 99%

Electrophoretic Gels of Dentin Matrix Proteins as Diffusion Media for in vitro Mineralization

et al. 1996

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Non-collagenous proteins of dentin and bone have important effects on mineralization which have been studied by various in vitro systems. We developed an in vitro mineralization system using electrophoretic gels as diffusion media of calcium and phosphate ions. Calcium and phosphate ions were diffused naturally or propelled by electric potential. Calcium phosphate was precipitated in the gel, and the precipitation was affected by proteins in the gel which had been separated by electrophoresis. We applied this system to analysis of non-collagenous proteins of dentin. Among the proteins, phosphophoryns promoted calcium phosphate precipitation in the natural-diffusion system. A non-collagenous protein having a molecular mass of 60 kDa inhibited precipitation. The results were different, however, in the electric-diffusion system, in which phosphophoryns had a negative effect. The present system enabled us to compare the effects of plural proteins rapidly, even using unpurified material.

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Systematic purification of free and matrix-bound phosphophoryns of bovine dentin: Presence of matrix-bound phosphophoryn as a distinct molecular entity

Cited by 37 publications

References 11 publications

Apatite Induction by Insoluble Dentin Collagen

Apatite Induction by Insoluble Dentin Collagen

Differences in Composition of Cell-attachment Sialoproteins between Dentin and Bone

Electrophoretic Gels of Dentin Matrix Proteins as Diffusion Media for in vitro Mineralization

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