Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts: Gene/Protein Disease Symptom Drug Enzyme Compound   Target Concepts: Gene/Protein Disease Symptom Drug Enzyme Compound

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Query: EC:3.4.24.3 (collagenase)
18,340 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The distribution of ossified collagen (bone) and uncalcified collagen (fibrous tissue and cartilage) was compared histologically for rat and dog calvaria at birth. The relative amount of bone and uncalcified collagen was quantitated morphologically for rat calvaria during the first four weeks of rapid growth. Whereas dog calvaria are essentially ossified at birth, rat calvaria at birth consist mostly of fibrous tissue but rapidly become ossified with growth. Bacterial collagenase was used to separate uncalcified collagen from calcified collagen of whole membranous bones (frontal and parietal) and long bones (femur and humerus) at birth from man, monkey, dog, guinea pig, rabbit and rat. By this means quantitative changes in the relative fractions of the two forms of collagen were determined during the first eight weeks of postnatal growth for each type of rat bone. Quantitative biochemical data on whole rat bones (calvarium, femur, humerus) confirmed measurements based on histology which showed that at birth rat calvaria are mostly uncalcified as compared to other species whose bones are mostly ossified at birth. With growth rat membranous bones ossify more rapidly than long bones.
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PMID:Comparison of whole calvarial bones and long bones during early growth in rats. Histology and collagen composition. 16 16

An organ culture method suitable for the maintenance of viable human breast cancer for at least 14 days has been described. This method was applied to a total of 94 breast cancer specimens. It allowed good survival of "soft" tumors of various histological types, with loose connective stroma even in hormone-free medium. In contrast, "scirrhous" cancers showed poor survival in hormone-free medium; viable cells were maintained only at the very periphery of the explants. Supplementation of the medium with insulin (10 mug/ml), ovine prolactin (5 mug/ml), and hydrocortisone (1 mug/ml) in various combinations seemed to induce enlargement of viable cancer cells and moderate loosening of the stroma in some cases. However, it did not improve the survival of central tumor cords in scirrhous explants. Further supplementation of the medium with 17 beta-estradiol (minimum effective dose, 0.1 to 10 ng/ml), although it did not affect soft tumors, markedly improved survival of the cancer cells of scirrhous tumors throughout the whole explants, with evidence of collagen digestion around the neoplastic cells. This was observed in 18 of 20 scirrhous cancers subjected to this treatment. Estradiol need not be present during the whole culture period; the results at 14 days were identical in explants treated with estradiol for the first 7 days only or for the entire period. Addition of purified collagenase during the first 24 or 48 hr of culture resulted in complete dissolution of the collage. After such treatment, culture under the usual conditions resulted in excellent survival of the explants without improvement from hormone supplementation; thus, while estradiol was necessary when collagen was present, it was not longer required after collagen digestion. It can be concluded that breast cancer cells in organ culture are only slightly, or not at all, hormone dependent for survival, provided that they are not restrained by a dense collagen barrier. The estrogen-induced changes allowing survival inside the scirrhous explants strongly suggest the presence of an estrogen-dependent collagenolytic enzyme system in the collagen-rich breast cancers. This system could represent an important component of the hormone dependency of human breast cancer growth.
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PMID:Estradiol-dependent collagenolytic enzyme activity in long-term organ culture of human breast cancer. 16 44

Collagen-synthesizing polysomes were isolated by low-speed centrifugation of the post-mitochondrial supernatant of chick homogenates. Electron microscopy of the fraction thus isolated shows it to be exclusively composed of ribosomes. Amino acid incorporation in vitro showed that these particles were efficient in the incorporation of proline, but not tryptophan, as opposed to ribosomes obtained from the supernatant of the low-speed centrifugation. The incorporation process was highly dependent on GTP, and exibited an optimal Mg2+concentration of 5.6mM. The reaction was inhibited by RNase, elongation inhibitors as anysomycin, sparsomycin, fusidic acid and GDPCP. It was also moderately inhibited by initiation inhibitors such as aurintricarboxilic acid and pyrocatechol violet. The product of the incorporation was characterized as collagen by its sensitivity towards purified collagenase, lack of tryptophan, chromatography in CM-cellulose and molecular sieve chromatography in Sephadex G-200.
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PMID:Isolation and characterization of collagen-synthesizing polysomes from chick embryos. 16 69

1. The contents of the fibrous proteins collagen and elastin in the pleural and parenchymal regions of bovine lungs were determined. The collagen content was approx. 70% (g/100g of salt-extracted defatted powder) in each tissue, and the elastin content was 28% in pleura and 13.5% in parenchyma. 2. Purification of the insoluble collagen from the pleura and parenchyma of bovine lungs by various methods was attempted. The collagen fractions isolated after incubation of the pulmonary tissues with the proteolytic enzymes collagenase ("collagenase-soluble" fraction) or pancreatic elastase ("elastase-insoluble" fraction) each contained approx. 87% of the total collagen initially present. 3. Both collagen fractions were chemically analysed for their amino acid and carbohydrate contents and were found to be similar to those of the intact interstitial collagens isolated from skin, bone and tendon. 4. The contents of the two aldimine cross-linking compounds, dehydrohydroxylysinonorleucine and dehydrodihydroxylysinonorleucine, were determined in the bovine pulmonary collagen fractions, and were found to decrease with increasing age of the animals, and were similar to the values found in intact collagens from bone and tendon.
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PMID:Isolation and chemical characterization of collagen in bovine pulmonary tissues. 16 65

As the proliferative lesion of rheumatoid arthritis becomes polarized and invasion of articular cartilage and subchondral bone begins, it is likely that many mesenchymal cells, including periosteal and perichondral cells, and perhaps even the chondrocytes and osteoblasts themselves can be activated to produce destructive enzymes. Early in the course of RA cartilage proteoglycans are depleted, leaving the remaining collagen more susceptible to mechanical breakdown as well as to enzymatic breakdown. Specific collagenases are released by synovial cells and, in addition, by polymorphonuclear leukocytes. The latter enzyme may account for free collagenase found in synovial fluid, a finding possibly related to saturation of inhibitory proteins by proteases with greater affinity for them, leaving collagenase active. At this time in the course of rheumatoid arthritis, a joint would be under double jeopardy from enzymes released by the invading pannus as well as by collagenase free and active in the synovial fluid. Rapid destruction could occur. Although cartilage collagen has an intrinsic resistance to collagenase conferred by its primary structure and by higher order structure (e.g. intermolecular cross-links), it seems wise to cool down hot joints because increased temperature may increase the rate of collagen degradation and, therefore, cartilage destruction. In addition, superimposed sepsis or acute flares of rheumatoid disease result in enough influx of polymorphonuclear leukocytes into the joints to result in free collagenolytic activity being present. This provides a rationale for frequent aspiration of any joint fluid, septic or otherwise, containing high polymorphonuclear leukocyte counts.
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PMID:Collagenolytic systems in rheumatoid arthritis. 16 97

Gross, light microscopic, and electron microscopic examination of the rabbit corneal destruction produced by experimental Pseudomonas aeruginosa infections revealed a combination of acute inflammation and liquefaction necrosis of the cornea. Degeneration of the epithelial cells and the start of polymorphonuclear leukocyte infiltration of the cornea occurred initially. These changes were followed by loss of the epithelium, degeneration and loss of the keratocytes and endothelium, loss of the characteristic weblike pattern of the proteoglycan ground substance, dispersal of ultrastructurally normal collagen fibrils, extensive accumulation followed by degeneration of polymorphonuclear leukocytes, and accumulation of plasma proteins and fibrin in the necrotic cornea. Histochemical examination of the cornea suggested a loss of the proteoglycan ground substance but not of collagen. Rabbit corneas injected with Clostridium histolyticum collagenase showed gross and cellular changes similar to those observed during the pseudomonal infections; however, histochemical examination suggested a loss of collagen, and electron microscopy revealed ultrastructurally abnormal collagen fibrils. The results support the idea (i) that a bacterial or host-derived collagenase is not required for extensive corneal damage during a P. aeruginosa corneal infection, and (ii) that a P. aeruginosa corneal infection may severly damage the cornea by producing extensive corneal edema and by causing the loss of the corneal proteoglycan ground substance, thus resulting in dispersal of undamaged collagen fibrils, weakening of the cornea, and subsequent descemetocele formation and corneal perforation by the anterior chamber pressure.
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PMID:Rabbit corneal damage produced by Pseudomonas aeruginosa infection. 16 2

By electron microscopic studies collagenase, hyaluronidase, HCl, ascorbic acid, and iron ions have been found to attack the collagen fibers of bovine vitreous. Because of the possible role of ascorbic acid in collagen synthesis and the ability of ascorbic acid to degrade hyaluronic acid and collagen we suggest that the ascorbic acid of the vitreous essentially participates in construction and metabolism of the vitreous body.
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PMID:[Electron microscopic investigations of vitreous collagen after treating the vitreous with liquefying substances (author's transl)]. 16 9

Because rheumatoid inflammation is associated with the presence of large numbers of leukocytes in joint effusions, the question of whether enzymatic splitting of collagen and fibrin can lead to generation of chemotactic factors was investigated. Fibrinogen was purified from the plasma of four different species, and the homogeneity of the preparations was established by physicochemical and immunologic techniques. Fibrin was prepared and then lysed with plasmin to obtain fibrin degradation products (FDP). Similarly, purified collagenase was used to lyse collagen in vitro, and the chemotactic activity of the reaction mixtures was analyzed. The experiments presented indicate that fibrinogen, fibrin, and plasmin do not possess any intrinsic chemotactic activity. However, when fibrin was split by plasmin, FDP of human, bovine, sheep, and equine origin all proved to be strong leukotactic agents for polymorphonuclear leukocytes (PMN). Purified collagenase per se was found to be a cell type-specific chemotactic agent for PMN. Not only were collagen degradation products not chemotactic, but they also inhibited the leukotactic activity of the purified collagenase. Furthermore, this inhibition of the chemotactic activity of collagenase was independent of its enzymatic activity. The results presented suggest that there is a direct correlation between the process of fibrinolysis and the chemotactic attraction of leukocytes and between the presence of collagenase and leukotaxis. This system may serve as a model to explain the mechanisms by which cells accumulate in inflamed joints.
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PMID:The chemotaxis of selected cell types to connective tissue degradation products. 16 19

1. Enzymes that may contribute to liquefaction of the cornea in retinol-deficient animals and in man have been studied using rat cornea. The established technique of culturing tissue fragments and determining the activity of collagenase (EC 3-4-24-3) and other enzymes in the medium after different periods of culture was used. 2. A collagenolytic system was detected in the media from cultures of rat corneas. This system probably consists of at least two enzymes, a collagenase and a neutral proteinase. 3. Both proteolytic and specific collagenolytic activity were greater in media from retinol-deficient rat corneas. The hydroxyproline level increased in parallel with the increase in enzyme activity. 4. In the final stages of retinol deficiency the cornea is invaded by granulocytes and other cells of the blood and we suggest that destruction of cornea collagen may be due largely to the activity of the enzymes from these cells.
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PMID:Collagenase and other proteinases in the cornea of the retinol-deficient rat. 16 77

1. The neutral collagenase released into the culture medium by explants of ehrumatoid synovial tissue has been purified by ultrafiltration and column chromatography, utilising Sephadex G-200, Sephadex QAE A-50 and Sephadex G-100 superfine. 2. The final collagenase preparation had a specific activity against thermally reconstituted collagen fibrils of 312 mug collagen degraded min-1 mg enzyme protein-1, representing more than a 1000-fold increase over that of the active culture medium. 3. Electrophoresis in polyacrylamide disc-gels with and without sodium dodecyl sulphate showed the enzyme to migrate as a single protein band. Elution experiments from polyacrylamide gels and chromatography columns have provided no evidence for the existence of more than one collagenase. 4. The molecular weight of the enzyme, as determined by dodecylsulphate-polyacrylamide gel electrophoresis, was 33000. 5. Data obtained from sutdies with the ion-exchange resin and from gel electrophoresis in acid and alkaline buffer systems suggested a basically charged enzyme. 6. It did not hydrolyse the synthetic collagen peptide Pz-Pro-Leu-Gly-Pro-D-Arg and non-specific protease activity was absent. 7. The collagenase attacked undenatured collagen in solution at 25 degrees C resulting in a 58% loss of viscosity and producing the two characteristic products TCA(3/4) and TCB(1/4). 8. At 37 degrees C and pH 8.0 both reconstituted collagen fibrils and gelatin were degraded to peptides of less than 10000 molecular weight. 9. As judged by the release of soluble hydroxyproline peptides and electron microscopic appearances the enzyme degraded human insoluble collagens derived from tendon and soft juxta-articular tissues although rates of attack were less than with reconstituted fibrils. 10. The data suggests that pure rheumatoid synovial collagenase at 37 degrees C and neutral pH can degrade gelatin, reconstituted fibrils and insoluble collagens without the intervention of non-specific proteases. 11. The different susceptibilities of various collagenous substrates to collagenase attack are discussed.
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PMID:Purification of rheumatoid synovial collagenase and its action on soluble and insoluble collagen. 17 94


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