Document Detail

The proteolytic processing of amelogenin by enamel matrix metalloproteinase (MMP-20) is controlled by mineral ions.
MedLine Citation:
PMID:  23201201     Owner:  NLM     Status:  MEDLINE    
BACKGROUND: Enamel 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.
METHODS: Recombinant amelogenin was cleaved by MMP-20 under various physicochemical conditions and the products were analyzed by SDS-PAGE and MALDI-TOF MS.
RESULTS: It 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.
CONCLUSION: These 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 SIGNIFICANCE: This study elaborates the possibilities of the processing of the organic matrix into mineralized tissue during enamel development.
Feroz Khan; Haichuan Liu; Aileen Reyes; H Ewa Witkowska; Olga Martinez-Avila; Li Zhu; Wu Li; Stefan Habelitz
Publication Detail:
Type:  Journal Article; Research Support, N.I.H., Extramural; Research Support, Non-U.S. Gov't; Research Support, U.S. Gov't, Non-P.H.S.    
Journal Detail:
Title:  Biochimica et biophysica acta     Volume:  1830     ISSN:  0006-3002     ISO Abbreviation:  Biochim. Biophys. Acta     Publication Date:  2013 Mar 
Date Detail:
Created Date:  2013-05-14     Completed Date:  2013-06-20     Revised Date:  2014-05-29    
Medline Journal Info:
Nlm Unique ID:  0217513     Medline TA:  Biochim Biophys Acta     Country:  Netherlands    
Other Details:
Languages:  eng     Pagination:  2600-7     Citation Subset:  IM    
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MeSH Terms
Amelogenesis / physiology
Amelogenin / chemistry*,  metabolism
Amino Acid Sequence
Apatites / chemistry*
Calcium / chemistry*
Dental Enamel / metabolism
Electrophoresis, Polyacrylamide Gel
Escherichia coli / genetics
Matrix Metalloproteinase 20 / chemistry*
Molecular Sequence Data
Peptide Fragments / analysis,  chemistry*
Recombinant Proteins / chemistry,  metabolism
Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization
Grant Support
2R01DE015821/DE/NIDCR NIH HHS; P30 CA082103/CA/NCI NIH HHS; R01 DE015821/DE/NIDCR NIH HHS; R01-017529S2//PHS HHS
Reg. No./Substance:
0/Amelogenin; 0/Apatites; 0/Peptide Fragments; 0/Recombinant Proteins; 0/Solutions; EC 3.4.24.-/Matrix Metalloproteinase 20; SY7Q814VUP/Calcium

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine

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