The extracellular matrix of developing enamel contains two major classes of proteins, the hydrophobic proline-rich amelogenins and the acidic serine-, glycine-, and aspartic-rich enamelins. These proteins have been postulated as playing a major role in the mineralization and structural organization of developing enamel. To identify and further characterize these different proteins and their possible role in this complex process of biological mineralization, we have in recent years been concerned with the production of specific probes for these proteins. Previously, we have reported on the successful production of specific polyclonal antibodies against enamelin proteins, which did not cross-react with amelogenins, and against amelogenin proteins, which did not cross-react with enamelins (Deutsch et al., 1986, 1987). We now report the production of monoclonal antibodies against a major bovine amelogenin protein (28 kDa) and against a major bovine enamelin protein (66 kDa). One monoclonal antibody against amelogenin and one against enamelin are described. The results showed that the monoclonal antibody against the amelogenin protein reacted strongly with the 28-kDa amelogenin protein band but did not cross-react with enamelins, and the one against the enamelin protein reacted with the 66-kDa enamelin protein but did not cross-react with amelogenins. These monoclonal antibodies provide a specific and powerful tool to distinguish between and further characterize these different classes of proteins, and to improve our understanding of the process of enamel formation.
