Fluoride does not inhibit enamel protease activity.
J Dent Res
; 90(4): 489-94, 2011 Apr.
Article
in En
| MEDLINE
| ID: mdl-21118795
ABSTRACT
Fluorosed enamel can be porous, mottled, discolored, hypomineralized, and protein-rich if the enamel matrix is not completely removed. Proteolytic processing by matrix metalloproteinase-20 (MMP20) and kallikrein-4 (KLK4) is critical for enamel formation, and homozygous mutation of either protease results in hypomineralized, protein-rich enamel. Herein, we demonstrate that the lysosomal proteinase cathepsin K is expressed in the enamel organ in a developmentally defined manner that suggests a role for cathepsin K in degrading re-absorbed enamel matrix proteins. We therefore asked if fluoride directly inhibits the activity of MMP20, KLK4, dipeptidyl peptidase I (DPPI) (an in vitro activator of KLK4), or cathepsin K. Enzyme kinetics were studied with quenched fluorescent peptides with purified enzyme in the presence of 0-10 mM NaF, and data were fit to Michaelis-Menten curves. Increasing concentrations of known inhibitors showed decreases in enzyme activity. However, concentrations of up to 10 mM NaF had no effect on KLK4, MMP20, DPPI, or cathepsin K activity. Our results show that fluoride does not directly inhibit enamel proteolytic activity.
Full text:
1
Collection:
01-internacional
Database:
MEDLINE
Main subject:
Peptide Hydrolases
/
Dental Enamel
/
Dental Enamel Proteins
/
Fluorides
Limits:
Animals
Language:
En
Journal:
J Dent Res
Year:
2011
Document type:
Article