Enamel proteins are a complex mixture of proteins, which probably play a central role in amelogenesis, and the determination of their number, structure and sequence of appearance and disappearance during enamel formation is essential to our understanding of that process. It is not known whether each of the protein components is the product of an individual gene, or whether the components are interrelated. Possibly the multiple components are derived from the breakdown of a limited number of proteins. The major overall objective of this proposal is to characterize the enamel proteins and to attempt to define their role in amelogenesis. Monoclonal antibodies have been prepared to amelogenins and shown to fall into 3 classes which interact with different epitopes. These antibodies are now being used in in situ immunohistologic and ultrastructural studies. Experiments attempting to clone amelogenin cDNA have been started.