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 polyphenolic compound tannic acid and the cationic stains ruthenium red, Alcian blue and lanthanum chloride have been used to reinvestigate the ultrastructural organization of the tectorial membrane matrix. Tannic acid treatment reveals that the matrix both in between and within the Type A protofibril bundle system has a high degree of structural organization. The basic unit of this matrix is best described as a 'striated sheet'. These striated sheets are formed by alternating 'dark' and 'light' fibrils which run parallel to one another and lie within the plane of each sheet. In sodium based buffers both light and dark fibrils have diameters of approximately 7 nm and the distance between each dark fibril in a sheet varies from 30 to 46 nm. Dark and light fibrils are coupled by periodic, staggered cross-bridges which occur at approximately 12 nm intervals along the fibrils. Fibril diameters in tectorial membranes prepared and fixed in potassium based buffers are from 10-20% greater than they are in tectorial membranes prepared and fixed in sodium based buffers. Fine fibrils can also be resolved in the matrix with the cationic stains lanthanum chloride and ruthenium red, but the organization of these fibrils into a regular matrix structure is most clearly resolved with tannic acid treatment. The striated sheets are largely destroyed by treating the tectorial membranes with neutral trypsin and are insensitive to treatment with bacterial collagenase. In contrast, the Type A protofibril system is trypsin resistant and collagenase sensitive. Treatment of tectorial membranes with salt solutions containing either 5 nM EDTA or 5 mM EGTA and 2 mM MgCl2 results in a complete loss of organized striated sheets and the appearance of randomly dispersed fibrillar material and small particles. Re-addition of Ca2+ ions causes the striated sheets to reform, indicating that the structure can undergo at least one cycle of depolymerization and polymerization in vitro. Reduction of disulphide bonds with beta-mercaptoethanol causes a loss of structural organization similar to that observed after EDTA or EGTA treatment. The results demonstrate that the non-collagenous components of the tectorial form a matrix with a degree of organization that has been previously unrecognised.
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PMID:The ultrastructural organization and properties of the mouse tectorial membrane matrix. 246 Apr 26

Tannic acid was found to fix and stain glycocalyx heavily. After removal of the major component of surface glycopeptides by trypsin, the surface coat was stained vaguely, and after the treatment with collagenase, the surface coat was moderately stained. It is concluded that tannic acid stained non-specific surface glycopeptides.
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PMID:On tannic acid fixation and staining. 615 94

The purpose of this study was to investigate cross-linking of (damaged) collagen by tannic acid, with a view to reconsider its use as a possible therapeutical agent in the treatment of burn wounds. Because of contradictory reports in the literature, and increased purity of tannic acid, this method has again become valuable for re-evaluation. A laboratory study using dermal sheep collagen was conducted to analyse the influence of several metal ions on collagen cross-linking with tannic acid. The tannic acid concentration vs degree of cross-linking, tannic acid uptake and release, influence of the addition of metal ions, and the rate of degradation of treated collagen were established. We have shown that tannic acid mediated collagen cross-linking in a concentration-dependent manner. Cross-linking was influenced by the presence of metal ions: Fe3+ and Ag+ were shown to exert a stimulatory effect on the degree of cross-linking by a 2% tannic acid solution, whereas Zn2+ had an inhibitory effect Ce3+ Ca2+ and Na+ did not influence the degree of cross-linking. The degree of cross-linking was proportional to the uptake of tannic acid, which variod between 6 and 35 wt%. Reversibility of cross-linking was established. Tannic acid-treated dermal sheep collagen showed a slow degradation rate relative to differently cross-linked collagen materials when subjected to collagenase or pancreatic proteolytic enzymes. The results of this study suggest that tannic acid could have a function in vivo in burn treatment by binding burn toxins and inhibiting degradation of the (remaining) dermal matrix, and allows combination with metal ions as antimicrobials. Optimal cross-linking was obtained using a 2 wt% tannic acid solution; combination with Ce3+ as a potential antimicrobial agent is possible without diminishing cross-linking.
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PMID:Cross-linking of dermal sheep collagen with tannic acid. 915 58

Collagen based cosmetic fillers require repeat treatments due to collagenase derived degradation of the filler in the intradermal injection site. The objective of this study was to investigate the inhibition of this degradation by the galloyl-containing compounds tannic acid, epigallocatechin gallate (EGCG), epicatechin gallate (ECG) and gallic acid (GA). A gel permeation chromatography assay was developed to quantitate the collagenase induced reductions in collagen molecular weight. The binding of the compounds to collagen was measured using HPLC. The stabilization of collagen was measured using Differential Scanning Calorimetry (DSC). Tannic acid, EGCG and ECG (but not GA) were found to strongly inhibit collagen degradation at concentrations in the low micromolar range. The compounds bound strongly to collagen and stabilized collagen. It is concluded that tannic acid, EGCG and ECG bind to collagen via extensive hydrogen bonding augmented by some hydrophobic interactions and prevent the free access of collagenase to active sites on the collagen chains.
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PMID:The inhibition of collagenase induced degradation of collagen by the galloyl-containing polyphenols tannic acid, epigallocatechin gallate and epicatechin gallate. 2016 29

Tannic acid nanoparticles were synthesized from an aqueous solution without the use of stabilizers via a sonochemical process. In order to avoid the dissolution of the formed nanoparticles, the sonochemical reaction was performed in the presence of a cotton fabric: following their formation, the tannic acid nanoparticles were embedded into the cotton substrate in a one-step process. The bioactive properties of the tannic acid coated surface were examined towards the inhibition of myeloperoxidase and collagenase, two major enzymes related with inflammatory processes. In addition, the antibacterial activity of the tannic acid nanoparticles coated textiles was evaluated against Staphylococcus aureus and Pseudomonas aeruginosa.
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PMID:Tannic acid NPs - synthesis and immobilization onto a solid surface in a one-step process and their antibacterial and anti-inflammatory properties. 2436 23