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)

Benign and malignant prostatic tissue was removed in surgery and partitioned for (a) ultrastructural study, (b) tissue culture, and (c) (c) immunochemical study. Fourteen malignant and 18 benign prostatic cancer specimens were examined by transmission electron microscopy (TEM) for the presence of viruses or virus-like particles. Viruses could not be identified with assurity in thin sections. Acinar cells of normal, benign prostatic hypertrophy (BPH), and neoplastic prostate tissue were examined in the scanning electron microscope and TEM and found to be extremely heterogenous in their surface morphologies. Three major types of surface morphologies were present: microvillous, ruffled, and bare. All three types of cells were present in normal, BPH, and neoplastic acini. A collagenase procedure was utilized to remove the stromal cells from glandular structures prior to in vitro cultivation. Partially purified extracts from 71 human urothelial tumors and 75 human urothelial nontumor tissues were used as competing antigens in competition radioimmunoassay in an effort to detect the presence of one of the structural components of type-C ribonucleic acid viruses, the p30 core protein. The urothelial tumors tested included 42 BPH specimens and 18 prostatic carcinoma specimens. Thirty-eight percent of the prostatic carcinoma tissues and 48% of the BPH tissues demonstrated the presence of a protein antigenically similar to the p30 core protein of an oncogenic RNA virus.
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PMID:Morphologic and immunologic studies of human prostatic carcinoma. 6 19

Decorin, a small collagen-binding dermatan sulfate proteoglycan, is widely distributed as a component of extracellular matrices. Using a solid phase binding assay, we showed that decorin bound C1q at physiologic pH and ionic strength. The interaction did not require divalent cations and was time and temperature dependent reaching equilibrium in 4 h at 37 degrees C. Binding was specific and saturable with an apparent dissociation constant of 7.6 x 10(-9) M. Decorin was shown to bind pepsin-derived fragments containing the collagenous domain of C1q and collagenase-derived fragments containing the globular domain of C1q. Because these fragments share a short sequence of amino acids, this finding suggests that decorin binds to a region of C1q located near the junction of the two domains. Competition studies using purified preparations of the decorin core protein and the glycosaminoglycan chains showed that only the former inhibited binding of decorin to C1q indicating that the interaction is mediated by the decorin core protein. Decorin was shown to inhibit the hemolytic activity of purified C1 as well as C1 in normal human serum. Approximately 50% inhibition was observed at a decorin concentration of 2 micrograms/ml. Inhibition was not observed if C1 was bound to Ag-complexed antibody. Furthermore, neither the core protein nor the glycosaminoglycan chain of decorin inhibited C1, indicating that the intact proteoglycan is necessary for functional activity.
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PMID:The proteoglycan decorin binds C1q and inhibits the activity of the C1 complex. 143 Nov 41

The action of purified rabbit bone stromelysin was investigated on proteoglycan aggregates from pig laryngeal cartilage. The enzyme caused a rapid fall in viscosity of proteoglycan aggregate solution (6 mg/ml), and the products of a partial digest (60% loss of relative viscosity) and a complete digest (95% loss of relative viscosity) were characterized. Analysis by gel chromatography on Sepharose 2B under associative conditions showed that 95% of the glycosaminoglycans in the complete digest were in small-sized fragments, whereas most of the hyaluronan-binding G1 domain and link protein remained intact and bound to hyaluronan. In contrast, there was extensive digestion of the G2 domain which resulted in 76% loss in its detection by immunoassay. Analysis of the partial digest also showed considerable loss (40%) of detection of the G2 domain, but the glycosaminoglycan-rich fragments were much larger than in the complete digest. There was also much less cleavage to create small fragments containing the G1 domain. This was evident on SDS/PAGE analysis where a 58 kDa G1 domain fragment was abundant in the complete digest, but was only present in small amounts in the partial digest. There was also only very limited conversion of link protein from a 44 kDa form to a 40 kDa form. The digestion of proteoglycan aggregate (6 mg/ml) by stromelysin was unaffected by the addition of a high concentration of extra chondroitin sulphate chains (14 mg/ml), and the digestion of proteoglycan monomer showed that the G1 domain was resistant to stromelysin digestion even when not bound to hyaluronan and link protein. The results show that stromelysin degrades the proteoglycan protein core with major cleavages close to, but not within, the G1 domain, and extensive cleavage in other regions. Experiments with purified collagenase, a metalloproteinase structurally related to stromelysin, showed that it too cleaved proteoglycan at several sites within the glycosaminoglycan-rich region of the core protein. Metalloproteinase attack on proteoglycan thus not only occurs with stromelysin but also with collagenase.
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PMID:Metalloproteinase digestion of cartilage proteoglycan. Pattern of cleavage by stromelysin and susceptibility to collagenase. 165 87

NG2 is a chondroitin sulfate proteoglycan previously found to be expressed by glial progenitor cells of the O2A lineage. We have examined the expression of NG2 in the developing rat limb by immunohistochemistry and northern blot analysis. Staining of embryonic day 14 (E14) rat limb bud sections with polyclonal and monoclonal anti-NG2 antibodies reveals reactivity in the precartilaginous mesenchymal condensation. The staining intensity increases with the differentiation of chondrocytes until E16. NG2 staining is not detected in the mature hypertrophic chondrocytes of E17 and postnatal day 3 (P3) limbs even after treatment of the sections with hyaluronidase or collagenase. Immuno-precipitations with anti-NG2 antibody using 125I-labeled limb cells in culture showed a 400 to 800 x 10(3) Mr proteoglycan species with a core protein size of 300 x 10(3) Mr, comparable to NG2 from O2A cells and neural cell lines. Northern blot analysis reveals the expression of an 8.9 kb mRNA in E16 limbs and at a lower level in P1 cartilage. The northern blot analyses also show that NG2 is distinct from the large aggregating proteoglycan of the cartilage. Our results indicate that in the developing limb cartilage, as in the differentiating oligodendrocytes, NG2 is present on immature cells in the process of differentiating, but its expression is downregulated as terminal differentiation of chondrocytes takes place.
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PMID:The expression of NG2 proteoglycan in the developing rat limb. 187 62

Human skin fibroblasts express, in addition to versican, a second large chondroitin sulfate/dermatan sulfate proteoglycan, which has been investigated with the aid of a specific antiserum in cultures of fetal fibroblasts. Its core protein, obtained after chondroitin ABC lyase treatment, exhibits an apparent molecular mass of about 740 kDa in the absence of a reducing agent whereas reduction produces two core proteins of 460 and 300 kDa, respectively. Both subunits carry one or very few dermatan sulfate chains of about 20 kDa which are of similar chemical composition irrespective of the type of subunits to which they are attached. Tryptic peptide maps of [35S]methionine-labeled core proteins indicated that both subunits are related neither to each other nor to versican, suggesting that the proteoglycan exists predominantly as a heterodimeric molecule. It is insensitive to collagenase and does not interact with hyaluronan. Pulse-chase experiments suggested that the core proteins are different gene products. Dimerization begins soon after core protein synthesis but requires more than 2 h for completion. Glycosaminoglycan synthesis occurs immediately prior to secretion. A small proportion of both subunits may be secreted in form of a monomeric proteoglycan. The heterodimeric proteoglycan is a major proteoglycan species of fetal fibroblasts. The secreted product represents 10-20% of [35S]methionine and about 5-10% of [35S]sulfate incorporated into secreted proteoglycans.
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PMID:A novel large dermatan sulfate proteoglycan from human fibroblasts. 207

We have recently described the characterization and expression of a murine gene highly homologous to the human tissue inhibitor of metalloproteinases/erythroid potentiating activity (TIMP/EPA) gene. We have also reported that expression of this gene is regulated in response to virus infection. In the present report we describe the use of a cDNA clone derived from mRNA isolated from Newcastle disease virus-induced murine cells to direct in vitro synthesis of proteins encoded by this murine TIMP/EPA gene. This approach was used to analyze structural and functional parameters of the TIMP/EPA protein. Translation experiments using microsomes revealed a murine protein similar in size to that of human TIMP: Mr of approximately 22,000 for the core protein and 28,000 for the processed protein. Processing in microsomes involved N-glycosylation and cleavage of the signal peptide. Both the processed and unprocessed proteins were able to inhibit degradation of collagen by collagenase but unable to inhibit virus replication. Synthesis of truncated TIMP proteins showed that the collagenase-inhibiting activity was not encoded within a delimited portion of the molecule. This result suggests that conformation is probably essential for TIMP activity.
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PMID:In vitro synthesis of the active tissue inhibitor of metalloproteinases encoded by a complementary DNA from virus-infected murine fibroblasts. 244 90

Early steps in the biosynthesis of chondroitin sulfate proteoglycan (CSPG) and collagenous cartilage matrix molecules were examined by the comparison of products translated in mRNA-directed cell-free reactions and those synthesized by intact cartilage cells. RNA isolated from embryonic chicken sterna was used to direct cell-free translation reactions. Chicken sternal chondrocytes in culture were pulse-labeled with [35S]-methionine. The CSPG core protein was identified by immunoprecipitation. The Mr of the cartilage cell-synthetized core protein was determined to be 370K, approximately 10-15K greater than that of the comparable cell-free translation product. Experimental results strongly support the view that the observed difference in Mr reflects the cotranslational addition of mannose-rich, N-asparagine-linked oligosaccharides to the cell-synthesized core protein: 1) the cell-synthesized product was labeled with [3H]-mannose and precipitated by concanavalin A-sepharose beads; 2) the incorporated [3H]-mannose could be subsequently removed by digestion with endoglycosidase H (Endo H); 3) the Mr of the cell-synthesized core protein was reduced by Endo H digestion to that of the comparable cell-free translation product; 4) the core protein synthesized by tunicamycin-treated chondrocytes (inhibited in their ability to add N-asparagine-linked mannose-rich oligosaccharides to proteins) was comparable in electrophoretic mobility to that of the core protein cell-free translation product; and 5) the core protein translated in microsome-coupled cell-free reactions had an Mr 8-10K greater than that of the core protein translated in the absence of microsomes. For the purpose of examining biosynthetic intermediates, chondrocytes were labeled continuously or pulse-chase labeled for varying times. No biosynthetic CSPG intermediates migrating between the core protein and the CSPG monomer were detected. However, a band of 355Kdal appeared to share certain characteristics with the 307Kdal core protein (including its immunoprecipitability with CSPG antibodies), and a 340Kdal band was noted. Type II procollagen and other collagenase-sensitive products of 205Kdal and 110Kdal were observed among translation and chondrocyte-synthesized products. In chondrocytes, all three products exhibited labeling or chase time-dependent increases in Mr which were accelerated by ascorbate supplements and inhibited by the addition of alpha, alpha'-dipyridyl. These results suggest that the observed time-dependent increases in Mr are a consequence of collagen hydroxylation. The 110Kdal and 205Kdal collagenous proteins may be related to the minor collagens recently described in cartilage.
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PMID:Biosynthetic precursors of cartilage chondroitin sulfate proteoglycan. 330 Nov 84

Pig articular cartilage, overlaid with a minced preparation of synovium from the same joint, underwent extensive matrix degradation during a two-week culture period. This degradation was associated with de novo synthesis by the synovium of specific neutral proteoglycan- and collagen-degrading enzymes. Both enzymes exhibited neutral pH optima, and were inhibited by serum and the metal ion chelators EGTA and 1,10-phenanthroline. The neutral proteoglycanase cleaved the core protein of isolated proteoglycan. The effects of some anti-inflammatory drugs on synovial enzyme production and cartilage metabolism were investigated. The steroids, dexamethasone and prednisolone, inhibited production of both enzymes whereas the non-steroidal anti-inflammatory drugs (NSAID's), flurbiprofen and indomethacin, slightly increased medium enzyme levels. Flurbiprofen and indomethacin had no effect on the extent of synovium-mediated cartilage degradation as assessed histologically. Inhibition by the steroids of synovial collagenase production correlated with inhibition of cartilage collagen breakdown, whereas inhibition of synovial proteoglycanase production did not prevent extensive proteoglycan breakdown. Experiments using radiotracer techniques indicated that dexamethasone, whilst partially inhibiting synovium-mediated proteoglycan degradation, severely inhibited cartilage proteoglycan synthesis thus resulting in net proteoglycan loss.
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PMID:Studies on the release of proteolytic enzymes during synovium-induced cartilage breakdown in vitro and the actions of anti-inflammatory drugs. 632 20

The tectorial membrane is a gel-like, acellular connective tissue overlying the microscopic organ of Corti--the auditory sensory structure. It is instrumental in the sound-synchronous deflection of the stereocilia of the hair cells, a central event in auditory transduction. It is well established that collagen, primarily type II, constitutes the major protein of the tectorial membrane, with smaller amounts of types IX and XI also present. However, conclusive information on the proteoglycans in this structure is lacking. Tectorial membranes were extracted with a 4 M guanidine--HCl solvent, and proteoglycans isolated after ethanol precipitation and collagenase treatment. A colorimetric assay based on the binding of the cationic dye safranin O to glycosaminoglycans, in combination with enzymatic techniques, detected significant amounts of chondroitin sulfate and keratan sulfate (0.29 and 0.17% on a wet weight basis, respectively). Agarose-polyacrylamide electrophoresis of chondroitinase-digested samples revealed a core protein with a similar molecular mass to that of the large cartilage proteoglycan aggrecan. This proteoglycan reacted with the antibody 3-B-3 (recognizing modified chondroitin 6-sulfate linkage region oligosaccharides). Sodium dodecyl sulfate-polyacrylamide gel electrophoresis revealed several low molecular mass proteins which reacted with 5-D-4, specific for keratan sulfate, one of which showed characteristics of fibromodulin. Comparison of the quantitative aspects of various connective tissue components of tectorial membrane with other type II collagen-containing structures revealed that this tissue resembles highly hydrated cartilage.
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PMID:Uronic acid-containing glycosaminoglycans and keratan sulfate are present in the tectorial membrane of the inner ear: functional implications. 827 27

Using an in vitro model of rat epiphyseal chondrocyte differentiation in which cells are maintained in a three-dimensional cell pellet, we show that exogenous TGF-beta 1 reversibly prevents terminal differentiation of epiphyseal chondrocytes into hypertrophic cells. Through maintenance of gene expression for the cartilage matrix proteins type II collagen and aggrecan core protein, and with coordinate inhibition of expression of genes encoding the metalloproteases collagenase and stromelysin, TGF-beta 1 stabilizes the phenotype of the prehypertrophic epiphyseal chondrocyte. This ability of TGF-beta 1 to stabilize the cartilage phenotype is critically dependent on culture conditions. Epiphyseal chondrocytes cultured as a subconfluent monolayer of cells dedifferentiate (reduce type II collagen and aggrecan core protein expression, increase metalloprotease expression, and acquire a spindled morphology) in response to short-term TGF-beta 1 treatment. Increasing the initial seeding density and allowing the cells to become multilayered prior to the addition of growth factor reverse the effects of TGF-beta 1 on type II collagen and transin/stromelysin gene expression and maintain a rounded cellular morphology. This finding emphasizes the importance of considering cell density and environmental context in the analysis of the regulatory action of peptide growth factors in general and of the TGF-beta s in particular. We propose that one function of TGF-beta 1 during endochondral ossification is regulation of chondrocyte growth and differentiation through modulation of the relative expression of cartilage matrix proteins and metalloproteases. This function of TGF-beta 1 helps illustrate how the regulation of diverse cellular processes such as matrix synthesis, matrix degradation, and cell growth and differentiation may be coordinated at the molecular level by a single peptide growth factor.
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PMID:TGF-beta 1 prevents hypertrophy of epiphyseal chondrocytes: regulation of gene expression for cartilage matrix proteins and metalloproteases. 834 60


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