Role of matrix proteases in processing enamel proteins.

This article reviews the current status of research on proteases of the enamel layer that are capable of processing and degrading proteins of the enamel matrix. Following a brief survey of the historical development of this discipline, a summary is presented of the current status. Two proteases have recently been cloned: EMSP-1 (enamel matrix serine protease-1), a serine protease, and enamelysin, a metalloprotease. These two are placed into their appropriate families: the chymotrypsin family S1 of clan SA of the serine protease class and the matrixin family or matrix metalloproteinase family, M10 of clan MB (the metzincins) of the metalloprotease class. The major features of these two families are outlined. The article concludes with some suggested areas for future research--identifying further proteases and characterizing those now known.