The matrix metalloproteinase gelatinase A in human dentine.
A dentine protein extraction protocol was modified in order to identify matrix metalloproteinase gelatinolytic activities in the non-mineralized and mineralized phases of human dentine. Dentine proteins from 24 individual permanent molars from patients aged 15-73 years were sequentially extracted, first with guanidinium chloride (G1 extract), then EDTA (E extract), and after this demineralization step, again by guanidinium chloride (G2 extract) to dissociate collagen-associated proteins. Extracts were analysed by sodium dodecyl sulphate-polyacrylamide gel electrophoresis and the gels were processed by Western blotting and zymography to detect gelatinolytic activities. Active and latent forms of gelatinase A were identified in the non-mineralized dentine fraction (G1 extract) of 58% of the teeth. Other gelatinolytic species were also detected by zymography with apparent M(r) of 92, 54 and 30 kDa. Although gelatinase A was detected in the G1 extracts of teeth from all ages, indicating more recent synthesis and remodelling of the predentine, gelatinase A was never detected in any E extract or in the G2 extracts of patients older than 41 years. The presence of the active form of gelatinase A in mineralized human dentine implicates this enzyme in dentine mineralization.
Martin-De Las Heras
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S
Department of Forensic Medicine and Forensic Odontology, Faculty of Medicine, University of Granada, 18071 Granada, Spain.
Valenzuela
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A
Overall
C M
CM
D000293:Adolescent; D000328:Adult; D000367:Age Factors; D000368:Aged; D000375:Aging / Q000502:physiology; D015153:Blotting, Western; D003648:Decalcification Technique; D003804:Dentin / Q000201:enzymology*; D004591:Electrophoresis, Polyacrylamide Gel; D016326:Extracellular Matrix Proteins / Q000032:analysis; D005260:Female; D006801:Humans; D008297:Male; D020778:Matrix Metalloproteinase 2 / Q000032:analysis*; D008875:Middle Aged; D008963:Molar / Q000201:enzymology; D014074:Tooth Calcification; D017001:Tooth Demineralization / Q000378:metabolism
D016326:Extracellular Matrix Proteins; D020778:Matrix Metalloproteinase 2