The proteolytic processing of amelogenin by enamel matrix metalloproteinase (MMP-20) is controlled by mineral ions |
| |
Authors: | Feroz Khan Haichuan Liu Aileen Reyes H Ewa Witkowska Olga Martinez-Avila Li Zhu Wu Li Stefan Habelitz |
| |
Institution: | 1. Division of Biomaterials and Bioengineering, Department of Preventive and Restorative Dental Sciences, University of California, 707 Parnassus Avenue, San Francisco, CA 94143, USA;2. Department of Obstetrics, Gynecology & Reproductive Sciences and UCSF Sandler-Moore Mass Spectrometry Core Facility, University of California, 521 Parnassus Avenue, San Francisco, CA 94143, USA;3. Department of Orofacial Sciences, University of California, 513 Parnassus Avenue, San Francisco, CA 94143, USA |
| |
Abstract: | BackgroundEnamel synthesis is a highly dynamic process characterized by simultaneity of matrix secretion, assembly and processing during apatite mineralization. MMP-20 is the first protease to hydrolyze amelogenin, resulting in specific cleavage products that self-assemble into nanostructures at specific mineral compositions and pH. In this investigation, enzyme kinetics of MMP-20 proteolysis of recombinant full-length human amelogenin (rH174) under different mineral compositions is elucidated.MethodsRecombinant amelogenin was cleaved by MMP-20 under various physicochemical conditions and the products were analyzed by SDS-PAGE and MALDI-TOF MS.ResultsIt was observed that mineral ions largely affect cleavage pattern, and enzyme kinetics of rH174 hydrolysis. Out of the five selected mineral ion compositions, MMP-20 was most efficient at high calcium concentration, whereas it was slowest at high phosphate, and at high calcium and phosphate concentrations. In most of the compositions, N- and C-termini were cleaved rapidly at several places but the central region of amelogenin was protected up to some extent in solutions with high calcium and phosphate contents.ConclusionThese in vitro studies showed that the chemistry of the protein solutions can significantly alter the processing of amelogenin by MMP-20, which may have significant effects in vivo matrix assembly and subsequent calcium phosphate mineralization.General significanceThis study elaborates the possibilities of the processing of the organic matrix into mineralized tissue during enamel development. |
| |
Keywords: | Enamelysin Amelogenin Enamel Tooth Proteolysis Enzyme kinetics |
本文献已被 ScienceDirect 等数据库收录! |
|