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)

Specific collagenases responsible for the initial enzymic step leading to degradation of the collagen fibrils of connective tissues have been found in both latent and active forms. The most important factor controlling the local activity of collagenase extracellularly may be an inhibitor that is synthesised by connective tissues, and it is proposed that latent enzymes are all enzyme-inhibitor complexes.
 ...
PMID:A new factor that may control collagen resorption. 6 39

By means of a tissue culture assay the activity of the collagenolytic system of ten human umbilical cords was estimated. I found collagenolytic activity in the dimensions of about 10(-3) units of collagenase by comparing the tissue explants with known collagenase concentration on filter paper. EDTA, which is known to inhibit collagenases from human granulocytes, did not prevent the lysis. Normal human serum in a concentration of 1 mg/ml was found to inhibit the enzyme effect up to 36.34% (mean percentage of inhibition 29.67%). It is supposed that the rest of the activity is due to a tissue collagenolytic system. The whole activity was only by o-phenanthroline to be prevented. As a result can be said that the regression of the human umbilical cord is not primarily mumification but due to the activity of the collagenolytic enzyme system.
 ...
PMID:Collagenase activity in the human umbilical cord. 7 Jul 72

Immunolocalization studies of rheumatoid tissues employing specific synovial collagenase antibody have demonstrated immunoreactive enzyme at the cartilage/pannus junction. Collagenase was not detected in chondrocytes or the cartilage matrix remote from the resorbing front, and relatively little enzyme was observed in the hypertrophied synovial membrane itself. These observations directly support the idea that synovial collagenase participates in cartilage erosion in rheumatoid arthritis.
 ...
PMID:Collagenase at sites of cartilage erosion in the rheumatoid joint. 7 Nov 52

Clostridial collagenase, elastase, medium material of human skin culture, dithioerythritol and citrate buffer, pH 3.5, were applied to fresh human skin specimens. Phenomena of degradation of dermal fibrils were observed by electron microscopy.
 ...
PMID:Degradation of dermal fibrillar structures: effects of collagenase, elastase, dithioerythritol and citrate. 7 2

1. Explants of dog gingiva, maintained in culture for 9 days in the absence of serum, released a collagenase (EC 3.4.24.3) into the medium. The yield of active enzyme reached a maximum after 5-8 days with concomitant release of collagen degradation products from the explants. 2. The enzyme attacked undenatured collagen in solution at 25 degrees C resulting in a 58% loss of specific viscosity and producing the two characteristic products TCA(3/4) and TCB(1/4). Electron microscopy of segment-long-spacing crystallites of these reaction products showed the cleavage locus of the collagen molecule at interband 40. 3. Optimal enzyme activity was observed over the pH range 7.5-8.5 and a molecular weight of approximately 35,000 was derived from gel filtration studies. EDTA, 1,10-phenanthroline, cysteine and dithiothreitol all inhibited collagenase activity. Proteoglycan derived from porcine and human cartilage did not inhibit the enzyme. 4. The enzyme was inhibited by the dog serum proteins alpha2-macroglobulin and a smaller component of molecular weight approximately 40,000. This small component was purified by column chromatography utilising Sephadex G-200, DEAE A-50, and G-100 (superfine grade). Agarose electrophoresis of the purified component showed it to represent a beta-serum protein. alpha1-Antitrypsin did not inhibit the enzyme. 5. The physiological importance of the natural serum inhibitors and gingival collagenase are discussed in relation to latent enzyme and periodontal disease.
 ...
PMID:Characterization and serum inhibition of neutral collagenase from cultured dog gingival tissue. 7 61

Collagenase released from rheumatoid synovial cells in culture is in a latent form. Subsequently, it may be activated by limited proteolysis. This study was designed to determine whether latent enzyme could bind to collagen fibrils and await activation. The data showed that latent collagenase bound to fibrils equally well at 24 degrees C and 37 degrees C, but that this represented little more than half the binding achieved by active enzyme at temperatures lower than that at which fibrils can be degraded. Binding was not inhibited by the presence of alpha2 macroglobulin, the principal proteinase inhibitor of plasma which cannot complex with inactive or latent collagenase but readily complexes with active species of enzyme. The data support the hypotheses that inactive forms of collagenase accumulate in tissues by binding to substrate, and that activation by proteases such as plasmin initiates collagen breakdown.
 ...
PMID:Binding of latent rheumatoid synovial collagenase to collagen fibrils. 7 45

To obtain viable cells from normal human skin, clostridial collagenase was used. Crude collagenase digestion of collagen fibres and basal lamina results in free dermal cells and sheets of epidermis. The collagenase was tested at various concentrations, solvents and incubation periods. The specimens digested were either split or full thickness skin of varying size. The optimal result was obtained by using small (3mm across) split skin pieces incubated in 2 mg/ml collagenase. The choice of solvent MEM, MEM supplemented with serum, and Tris buffer, was less important. 3 hours' incubation the epidermis was peeled off in sheets and finally dissociated by trypsin-EDTA. The corium was completely digested after 6 hours. After 6 hours' incubation no viable cells could be seen. The epidermal cells appeared mainly as polygonal cells of various sizes and a few little dendritic cells. The dermal cells had a heterogeneous morphology during the first weeks of cultivation. After 2 weeks the cells appeared as fibroblast-like cells.
 ...
PMID:Enzymatic liberation of viable cells of human skin. 7 32

Free collagenase activity was demonstrated in all 13 normal, 5 osteoarthrotic and 54 rheumatoid synovial fluids studied. Osteoarthrotic, normal, and rheumatoid fluids showed a free collagenase content increasing in that order. However, the total activities after trypsin activation did not differ significantly. The concentrations of alpha1-at and alpha2-M in synovial fluids reflected those in sera. The complex interactions between serum inhibitors, and free or latent collagenase released from both synovial cells and leukocytes are discussed.
 ...
PMID:Collagenase in synovial fluid. 7 18

Nine cultures of fibroblast cell types and 13 epithelial-like cell types were maintained for 1 week in media supplemented with L-asborbic acid (50 microgram per ml). All fibroblast-like cultures produced extracellular fibers that stained positively by a silver-impregnation reticulin stain. Nine of the 13 epithelial-like cultures produced fibers that stained positively for reticulin. Nearly all cultures not supplemented with ascorbic acid showed no fiber staining. Those few lines that stained positively for reticulin in the absence of ascorbic-acid supplementation demonstrated only slight reticulin formation. Reticulin from one fibroblast culture and one epithelial culture was examined by electron microscopy, and the silver-impregnated fibrils were morphologically identical to collagen. The reticulin was digestible with collagenase, providing further evidence that the silver-impregnation reticulin stain identifies collagen in culture. The demonstartion of collagen can be performed easily in histology laboratories using Formalin-fixed cells, and provides a means of assaying a functional property of cells in culture which is characteristic of connective tissue fibroblasts in general as well as certain specialized epithelia.
 ...
PMID:Histochemical demonstration of collagen fibers in ascorbic-acid-fed cell cultures. 8 Mar 77

Cardiac myocytes from adult rat were isolated by heart perfusion in the presence of collagenase and incubated in the absence and presence of oxygen. As a result of anoxia, there was a gradual increase in plasma membrane permeability, noted as an increase in succinate-stimulated oxygen uptake, a decrease in trypan blue exclusion frequency, a leakage of cytosolic lactate dehydrogenase activity and an increased proportion of swollen, irregularly contracting myocytes. The contractions of the damaged myocytes resembled the known non-physiologic contractions of the heart, i.e. extrasystoles, arrhythmia, fibrillation or block. After different periods of time of anoxia myocyte pellets were fixed in formalin, sectioned and examined by light microscopy. The appearances of the myocytes in suspension were compared with those in paraffin-embedded sections. Special attention was given to the hematoxylin basic fuchsin picric acid stain and it was noted that the basic fuchsin was taken up by contracted or damaged myocytes, which according to their morphology in suspension revealed irregular contractions, but not by undamaged or necrotic myocytes.
 ...
PMID:Comparison of anoxic changes in isolated rat cardiac myocytes in suspension and in histological sections. 8 68


<< Previous 1 2 3 4 5 6 7 8 9 10 Next >>