Bovine high molecular weight amelogenin proteins.

The existence of high molecular weight amelogenins in the matrix of developing fetal bovine dental enamel was investigated. After ion-exchange and gel filtration chromatography, a 40,000 dalton amelogenin protein has been isolated. This species was homogeneous on both guanidine hydrochloride gel filtration and sodium dodecyl sulfate (SDS) gel electrophoresis, but heterogeneous on conventional gel electrophoresis. This high molecular weight amelogenin may be a precursor to the complex of smaller sized amelogenins characteristic of the secretory phase of enamel formation.