Immunoblotting Study of Developing Enamel Matrix Proteins

Abstract

It is generally thought that the calcification mechanism of epidermally derived enamel is strikingly different from that of dentin and bone, both of which are of mesenchymal origin. One of the reasons for this is that developing enamel contains specific matrix proteins, namely, “Amelogenins and Enamelins” [1,2]. With regard to enamel matrix proteins, we have demonstrated the presence of some common functional proteins such as carbonic anhydrase (CA), troponin subunit, and calmodulin in the extracellular matrix of developing enamel of the rat incisor by means of an immunological technique[3–5). These findings gave us the idea that other matrix proteins of developing enamel, which have not yet been identified, may not be specific to enamel. Therefore, using polyclonal antibody against 25K enamel matrix protein, we conducted experiments to demonstrate the presence of immunoreactive protein in other calcifying and non-calcifying tissues. If the immunoreactive proteins are really present in other calcifying and non-calcifying tissues, we can assume that the calcification mechanism among vertebrate hard tissues is controlled by a similar basic mechanism. The present work is the initial step for an understanding of the exact functions of these substances.