Effects of phosphoprotein on collagen fibril formation in vitro

Transmission electron microscopy showed that when either dentinal phosphoprotein or calcium-treated phosphoprotein or phosvitin were introduced during type I collagen fibrillogenesis the fibrils formed were significantly wider and the cross-banding was more distinct than in the absence of phosphoprotein. The collagen fibril width also increased with increasing concentrations of these molecules. When either bovine serum albumin (BSA) or dephosphorylated dentine phosphoprotein were used, no differences in the fibril characteristics were seen when compared to the controls that contained no phosphoprotein or BSA. When these dialysed matrices were placed into mineralizing solutions, no mineral was observed in any of the samples.