Enamel proteins: biosynthesis and chemistry.

Bovine ameloblast cell layer was incubated in 3H-proline containing medium and the incorporation of radioactivity into protein fractions of the cell and the medium was investigated by SDS- polyacrylamide gel electrophoresis. The results suggest that the ameloblasts synthesize and secrete a protein having a molecular weight of 25,000 daltons which is supposed to be the prototype of enamel proteins. This protein was degraded into dialyzable sizes by the cell extract. After a longer period of incubation another low molecular weight protein fraction appeared in the medium. Purification procedure with SDS gel filtration of the enamel protein is reported.