Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:3.4.24.3 (collagenase)
 18,340 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The susceptibility of the organic matrix from permanent bovine incisor roots to proteolytic breakdown after in vitro lesion formation was investigated. Root surfaces were exposed to 0.1 M acetic acid, pH 4.0, to produce erosive lesions or to 0.1 M lactic acid, 0.2 mM methane hydroxy diphosphonate, pH 5.0, to produce subsurface lesions. After demineralization, the roots were treated with a bacterial collagenase. The quantity of enzyme-degradable collagen in the root tissue was found to be proportional to the calcium released during demineralization, until a plateau value was reached at calcium concentrations in solution of 3.3 mM at pH 4.0 and 2.7 mM at pH 5.0. The degradability of collagen was found to be substantially less in subsurface lesions than in erosive lesions. The presence of cementum-free areas did not affect the results. These findings suggest that the mineral component of the roots is composed of several fractions which differ in their solubility properties in weak acids.
Caries Res 1991
PMID:Susceptibility of the collagenous matrix from bovine incisor roots to proteolysis after in vitro lesion formation. 164 3

The effect of 2-O-stearoyl glycerol-1,3-bisphosphate (Glydip) on caries lesion formation in root surfaces of sound human third molars was investigated in vitro. For this purpose parts of the root surfaces were treated with Glydip. Adjacent parts of the surfaces were not treated and served as control. Lesions were obtained by demineralization with an acetate buffer of pH 5.0. It was found that Glydip had no inhibiting effect on the rate of lesion formation. Additionally, pretreatments were performed with lauryl sulphate, a chloroform-methanol mixture, an aqueous solution of sodium hypochlorite, and collagenase prior to the treatment with Glydip to enhance the accessibility of the tissue for Glydip. None of these pretreatments or combinations of them revealed an inhibiting effect of Glydip on the rate of caries lesion formation. This result is in contrast to the effect of Glydip on the demineralization of enamel.
Caries Res 1991
PMID:Effect of 2-O-stearoyl glycerol-1,3-bisphosphate on in vitro demineralization of dental root surfaces. 165 70

This study deals with the role of collagen in the remineralization of bovine incisor root lesions. The degradability of the collagenous matrix after in vitro remineralization was also investigated. The root surfaces were exposed to 0.1 M acetic acid, pH 4.0, to produce erosive lesions or to 0.1 M lactic acid, 0.2 mM methane hydroxy diphosphonate, pH 5.0, to produce subsurface lesions. After demineralization, the roots were subjected to remineralization, with or without prior treatment with a bacterial collagenase to remove accessible collagen. Remineralization was carried out in solutions with a Ca/Pi molar ratio of 1.67, and [Ca]. [Pi] concentration products of 0.6, 1.35 or 2.4 mM2, with all solutions having an ionic strength of 0.15 M, and a pH of 7.0. After remineralization, the roots that were not treated with collagenase were incubated with the enzyme. The results indicate that remineralization of erosive lesions is surface-controlled and that of subsurface lesions diffusion-controlled. For both lesion types it was shown that the removal of collagen before remineralization did not affect the rate of mineral deposition in the root lesions. Nevertheless, remineralization in those lesions where accessible collagen had not been removed resulted in a significant reduction in the amount of degradable collagen. The observations of this study suggest that remineralization did not occur by nucleation of mineral on the organic matrix but rather by growth of residual crystals in the partially demineralized root tissue.
Caries Res 1991
PMID:Remineralization of bovine incisor root lesions in vitro: the role of the collagenous matrix. 207 Mar 81

When observed by SEM, after being treated with the HCl-collagenase method, the odontoblast processes extended throughout the whole thickness of dentin in intact teeth and the whole thickness of normal and the inner carious dentin in carious teeth. Small holes and depressions were found on the processes in the transparent layer.
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PMID:The extent of the odontoblast process in normal and carious human dentin. 630 79

Collagenolytic activity in human carious and non-carious dentine matrix was compared. Results confirmed the presence of latent collagenase in demineralized dentine and indicated a slow rate of degradation of collagen substrate. Collagenolytic activity was enhanced with the addition of trypsin-TPCK to the demineralized dentine. More activity was observed in the carious dentine, suggesting the presence of collagenase activators or partial enzymic destruction of the inhibitor in the collagen-collagenase-inhibitor complex. It seems that during dentine development collagenase-inhibitor complex is secreted and bound to collagen-dentine matrix, and the enzyme can be activated during the process of dental caries.
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PMID:A preliminary study of activation of collagenase in carious human dentine matrix. 630 37

The mechanisms of organic matrix breakdown in the root caries process are not well understood. Therefore, the combined and separate effects of lactic acid and proteolytic enzymes on the degradation of human dentin collagen, glycoproteins, proteoglycans and phosphoproteins were investigated in the present study. Dentin powder was pretreated with lactic acid (pH 4.0), distilled and deionized (dd) water (pH 7.0) and EDTA/guanidine HCl (pH 7.4) for 24 h. Pellets of acid- or dd water-pretreated dentin powder were washed, dried, and then treated with trypsin, bacterial or mammalian tissue collagenase, or control buffer for 3 h. The released dentin proteins were analyzed by reducing sodium dodecyl sulfate-polyacrylamide gel electrophoresis and immunoblotting to identify degraded type I collagen, proteoglycans, glycoproteins and phosphoproteins. All water and acid pretreatment and enzyme treatment groups demonstrated two collagen fragment bands with molecular weights at approximately 79 kD. Further studies showed that the 79 kD proteins from acid-pretreated dentin collagen were degraded by tissue collagenase, suggesting that endogenous collagenase may be involved in the degradation of root dentin collagen. Dentin proteoglycans were detectable in all the treatment groups by protein slot blotting. Relatively few distinct glycoproteins and proteoglycans, and no phosphoproteins were detected by immunoblotting. Results from this study suggest that both acids and proteolytic enzymes from either host or microbial origin are important in the degradation of human dentin matrix and the mechanisms involved in the release of various noncollagenous proteins may be different.
Caries Res 1995
PMID:Effect of lactic acid and proteolytic enzymes on the release of organic matrix components from human root dentin. 855 53

Phosphoprotein appears to play an important role in the mineralization of dentin during tooth development and remineralization after demineralization by dental caries. To better understand this role, we describe the extraction and characterization of phosphoprotein from immature, human root apex dentin during and after EDTA demineralization. The extraction procedure included dissociation of the demineralized dentin matrix by guanidine hydrochloride (Gdn.HCl) followed by subsequent digestion with cyanogen bromide (CNBr) and collagenase. Characterization of these extracts included 'Stains-All' staining of SDS polyacrylamide gels (SDS-PAGE) and amino acid, protein and phosphorus analyses. The ability of these matrices to remineralize was determined by TEM and measuring calcium levels in the remineralized tissue by atomic absorption spectroscopy. The staining of SDS-PAGE gels and amino acid analysis showed that an intact phosphophoryn was extracted from the dentin of the immature apices during EDTA demineralization and that it had an apparent Mr approximately 140,000. In the subsequent extracts and digests, the phosphoprotein has a range of molecular weights, some of which may have been degraded products of the intact phosphoprotein. A greater quantity of phosphoprotein was found in the EDTA-demineralized dentin matrices than in dentin after Gdn.HCl, CNBr and collagenase digests. These EDTA-demineralized matrices also remineralized to a greater extent than those dissociated with Gdn.HCl. The differences in both the quantity and the quality, as defined by the amino acid residue profile, of the phosphoprotein in the sequential extracts of the root apex dentin may be important in affecting the ability of this tissue to remineralize.
Caries Res 1998
PMID:Phosphoprotein analysis of sequential extracts of human dentin and the determination of the subsequent remineralization potential of these dentin matrices. 970 61

Matrix metalloproteinases (MMPs) are a family of enzymes which, in concert, are capable of degrading collagen. We investigated whether human MMPs could participate in the degradation of dentin organic matrix after demineralization. We performed Western blot analyses using MMP-specific antibodies to identify MMPs in human dental caries lesions. Enzymography and functional activity assays, with 125I-labeled gelatin as substrate or quantitating the degradation of type I collagen, were used to determine the activity of purified and salivary gelatinolytic (MMP-2 and MMP-9) and collagenolytic (MMP-8) enzymes with and without acid-activation in pHs relevant to caries. Respective analyses were done with caries-related bacteria. We performed electron microscope analyses to assess the degradative activity of sterilized salivary host MMPs on demineralized human dentin. Human MMP-2, MMP-8, and MMP-9 were identified in demineralized dentinal lesions. The latent purified forms of these enzymes were activated at low pH (4.5), followed by neutralization, mimicking the conditions during caries progression. Incubation of human saliva at low pH followed by neutralization resulted in a four-fold increase in the gelatinolytic activity. No gelatinolytic or collagenolytic activity was observed in bacterial samples. The activated enzymes in saliva degraded demineralized dentin organic matrix in vitro. These results demonstrate the pH-dependent activation mechanism of MMPs, which may have a distinct role in different physiological and pathological conditions. They further demonstrate that host MMPs, activated by bacterial acids, have a crucial role in the destruction of dentin by caries.
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PMID:The activation and function of host matrix metalloproteinases in dentin matrix breakdown in caries lesions. 971 36

The aim of this study was to investigate the individual capabilities of the proteolytic enzyme preparation Pronase, the enzyme collagenase and sodium hypochlorite to disintegrate and solubilize carious dentin. Samples of carious dentin, and samples of sound dentin for comparison, were extracted 4 times in succession for 24 h with buffered solutions of Pronase. Separate carious dentin samples were extracted in the same manner with buffered solutions of collagenase or with aqueous sodium hypochlorite. The extracts, the solid residues left over after the extractions and untreated samples of carious and sound dentin were digested with sulfuric acid-H(2)O(2) and then analyzed for nitrogen content by a special adaptation of the Berthelot color reaction. Although Pronase did not attack sound dentin, it solubilized more than 90% of the nitrogen present in carious dentin. Collagenase solubilized approximately 66% of the nitrogen, whereas sodium hypochlorite released only 12-20% of the nitrogen of carious dentin. In clinical dentistry, chemical disintegration of carious dentin may reduce the need for mechanical removal of sound tooth structure.
Caries Res
PMID:Pronase digestion of carious dentin. 1052 33

Dentine root caries is a process of demineralization and degradation of the organic matrix by proteinases. In this in situ study, the presence and activity of the matrix metalloproteinases 1, 2 and 9 (MMP-1, MMP-2, MMP-9) in saliva and in completely demineralized dentine specimens were investigated. Furthermore, the activity of cathepsin B was determined in saliva. A correlation between these enzymes and the level of degraded collagen was investigated. Demineralized dentine specimens were mounted in the partial prosthesis of 17 volunteers. Saliva samples were taken at 0, 2 and 4 weeks. After 4 weeks, the enzymes were extracted from the dentine specimens and the collagen loss was assessed. The collagen loss varied between 0 and 40.3%. Zymography of the saliva and the dentine extract samples showed that (pro-)MMP-2 and (pro-)MMP-9 were present. The levels of active MMPs were assessed, using fluorogenic MMP-specific substrates. All but 3 of the 51 saliva samples showed MMP-1 activity ranging from 1.5 to 101.1 relative fluorescence units (RFU)/s. Forty-eight saliva samples showed gelatinolytic MMP-2/MMP-9 activity (1.7-141.1 RFU/s). MMP-1 activity was shown in all dentine extracts varying between 3.5 and 295.0 RFU/s. From the dentine extracts, 15 showed MMP-2/MMP-9 activity (0.2-13.7 RFU/s). The MMP activity from both saliva and dentine extracts did not correlate with the collagen loss. The activity of salivary cathepsin B varied from 4.8 to 42.2 arbitrary units/min. A positive correlation was found between salivary MMP activity and cathepsin B activity. This study revealed that gelatinolytic enzyme activity was present both in saliva and dentine collagen. No correlation could be observed, however, between the level of enzyme activity and the collagen loss of the dentine specimens.
Caries Res
PMID:Host-derived proteinases and degradation of dentine collagen in situ. 1256 41


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