Abstract
This study determined if dentin proteases are denatured by phosphoric acid (PA) used in etch-and-rinse dentin adhesives. Dentin beams were completely demineralized with EDTA for 30 days. We "acid-etched" experimental groups by exposing the demineralized dentin beams to 1, 10, or 37 mass% PA for 15 sec or 15 min. Control beams were not exposed to PA but were incubated in simulated body fluid for 3 days to assay their total endogenous telopeptidase activity, by their ability to solubilize C-terminal crosslinked telopeptides ICTP and CTX from insoluble dentin collagen. Control beams released 6.1 ± 0.8 ng ICTP and 0.6 ± 0.1 ng CTX/mg dry-wt/3 days. Positive control beams pre-incubated in p-aminophenylmercuric acetate, a compound known to activate proMMPs, released about the same amount of ICTP peptides, but released significantly less CTX. Beams immersed in 1, 10, or 37 mass% PA for 15 sec or 15 min released amounts of ICTP and CTX similar to that released by the controls (p > 0.05). Beams incubated in galardin, an MMP inhibitor, or E-64, a cathepsin inhibitor, blocked most of the release of ICTP and CTX, respectively. It is concluded that PA does not denature endogenous MMP and cathepsin activities of dentin matrices.
Publication types
-
Research Support, N.I.H., Extramural
-
Research Support, Non-U.S. Gov't
MeSH terms
-
Cathepsins / antagonists & inhibitors
-
Collagen Type I / analysis
-
Collagenases / drug effects
-
Cysteine Proteinase Inhibitors / pharmacology
-
Dentin / drug effects*
-
Dentin / enzymology
-
Dipeptides / pharmacology
-
Enzyme Activators / pharmacology
-
Enzyme Precursors / drug effects
-
Humans
-
Leucine / analogs & derivatives
-
Leucine / pharmacology
-
Materials Testing
-
Matrix Metalloproteinase Inhibitors / pharmacology
-
Matrix Metalloproteinases / drug effects
-
Peptide Hydrolases / drug effects
-
Peptides / analysis
-
Phenylmercuric Acetate / analogs & derivatives
-
Phenylmercuric Acetate / pharmacology
-
Phosphoric Acids / pharmacology*
-
Protein Denaturation
-
Sulfhydryl Reagents / pharmacology
-
Time Factors
Substances
-
Collagen Type I
-
Cysteine Proteinase Inhibitors
-
Dipeptides
-
Enzyme Activators
-
Enzyme Precursors
-
Matrix Metalloproteinase Inhibitors
-
N-(2(R)-2-(hydroxamidocarbonylmethyl)-4-methylpentanoyl)-L-tryptophan methylamide
-
Peptides
-
Phosphoric Acids
-
Sulfhydryl Reagents
-
collagen type I trimeric cross-linked peptide
-
4-aminophenylmercuriacetate
-
phosphoric acid
-
Cathepsins
-
Peptide Hydrolases
-
Collagenases
-
Matrix Metalloproteinases
-
Leucine
-
Phenylmercuric Acetate
-
E 64