Proteomic identification of proteinase inhibitors in the porcine enamel matrix derivative, EMD®

Background and Objective: The porcine enamel matrix derivative, EMD (R), which is the active component of Emdogain (R), is used widely in periodontics because of its ability to promote the regeneration of soft and hard tissues and to reduce inflammation. Previous studies have used indirect methods to explain its angiogenic and proliferative effects on cells associated with wound healing. In this study we used proteomic techniques to identify proteins in EMD other than amelogenins. Material and Methods: Proteins in EMD were separated by two-dimensional gel electrophoresis and were identified using mass spectrometry. Proteomic results were validated by western blot analysis of Emdogain. Results: Fourteen proteins of porcine origin were identified and included the serine and cysteine proteinase inhibitors alpha1-antichymotrypsin and fetuin A, respectively. Alpha1-antichymotrypsin is an acute-phase factor that has been reported to indirectly down-regulate the expression of the gelatinase MMP-9. Fetuin A, a major glycoprotein component of bone and teeth, is a potent inhibitor of ectopic calcification of vascular and soft tissues and has been implicated in both osteogenesis and bone resorption. It also facilitates plasma membrane repair in damaged fibroblasts. Conclusion: EMD contains a number of high-molecular-weight compounds which include the proteinase inhibitors, fetuin A and alpha1-antichymotrypsin.