Abstract.
Sialoproteins such as bone sialoprotein (BSP) and dentin sialoprotein (DSP) accumulate at the mineralization fronts in bone and dentin, respectively, suggesting they have some function in the mineralization process. BSP, a highly phosphorylated protein rich in polyglutamate repeats, is an effective nucleator of hydroxyapatite (HA) formation in vitro. The present study examines the effect of DSP, a low phosphorylated but related sialoprotein, on the formation and growth of HA. In vitro, in a gelatin gel diffusion system, DSP at low concentrations (<25 μg/ml) slightly increased the yield of HA formed at 3.5 and 5 days, while at higher concentrations (50–100 μg/ml) it slightly inhibited accumulation. Fewer mineral crystals were formed in the presence of high concentrations of DSP but they tended to aggregate (making them appear larger by electron microscopic analysis) than those formed in DSP-free gels. X-ray diffraction line broadening analysis failed to show significant changes in c-axis crystal dimensions with increasing DSP concentration. When HA-seed crystals were coated with DSP before inclusion in the gelatin gel there was a reduction in mineral accumulation relative to HA-seeds which had not been coated with DSP, but the extent of inhibition was significantly less than that seen in this system with other mineralized tissue matrix sialoproteins, such as osteopontin or BSP. The low affinity of DSP for well-characterized seed crystals and the limited effect of this protein on HA formation and growth suggest that the role of DSP in dentin is not primarily that of a mineralization regulator.
Similar content being viewed by others
Author information
Authors and Affiliations
Additional information
Received: 25 April 2000 / Accepted: 21 July 2000 / Online publication: 2 November 2000
Rights and permissions
About this article
Cite this article
Boskey, A., Spevak, L., Tan, M. et al. Dentin Sialoprotein (DSP) Has Limited Effects on In Vitro Apatite Formation and Growth. Calcif Tissue Int 67, 472–478 (2000). https://doi.org/10.1007/s002230001169
Published:
Issue Date:
DOI: https://doi.org/10.1007/s002230001169