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1.
1. The neutral collagenase released into the culture medium by explants of human skin tissue was purified by ultrafiltration and column chromatography. The final enzyme preparation had a specific activity against thermally reconstituted collagen fibrils of 32mug of collagen degraded/min per mg of enzyme protein, representing a 266-fold increase over that of the culture medium. Electrophoresis in polyacrylamide disc gels showed it to migrate as a single protein band from which enzyme activity could be eluted. Chromatographic and polyacrylamide-gel-elution experiments provided no evidence for the existence of more than one active collagenase. 2. The molecular weight of the enzyme estimated from gel filtration and sodium dodecyl sulphate/polyacrylamide-gel electrophoresis was approx. 60000. The purified collagenase, having a pH optimum of 7.5-8.5, did not hydrolyse the synthetic collagen peptide 4-phenylazobenzyloxycarbonyl-Pro-Leu-Gly-Pro-d-Arg-OH and had no non-specific proteinase activity when examined against non-collagenous proteins. 3. It attacked undenatured collagen in solution at 25 degrees C, producing the two characteristic products TC(A)((3/4)) and TC(B)((1/4)). Collagen types I, II and III were all cleaved in a similar manner by the enzyme at 25 degrees C, but under similar conditions basement-membrane collagen appeared not to be susceptible to collagenase attack. At 37 degrees C the enzyme attacked gelatin, producing initially three-quarter and one-quarter fragments of the alpha-chains, which were degraded further at a lower rate. As judged by the release of soluble hydroxyproline peptides and electron microscopy, the purified enzyme degraded insoluble collagen derived from human skin at 37 degrees C, but at a rate much lower than that for reconstituted collagen fibrils. 4. Inhibition of the skin collagenase was obtained with EDTA, 1,10-phenanthroline, cysteine, dithiothreitol and sodium aurothiomaleate. Cartilage proteoglycans did not inhibit the enzyme. The serum proteins alpha(2)-macroglobulin and beta(1)-anti-collagenase both inhibited the enzyme, but alpha(1)-anti-trypsin did not. 5. The physicochemical and enzymic properties of the skin enzyme are discussed in relation to those of other human collagenases.  相似文献   

2.
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.  相似文献   

3.
Collagenase of human basal cell epithelioma was purified by sequential ammonium sulfate precipitation, Sephadex gel filtration and affinity chromatography on collagen-polyacrylamide gel. The collagenase, when partially purified, was found to have an approximate molecular weight of 50,000. The purified enzyme contained no caseinolytic activity. On polyacrylamide gel electrophoresis, the purified enzyme gave a single protein band. The purified collagenase cleaved native acid-soluble guinea pig skin collagen at 37 degrees C with a pH optimum of 8. The enzyme was inhibited by EDTA, cysteine, and human serum but not by soybean trypsin inhibitor. Heparin did not stimulate the enzyme activity. Purified collagenase reduced the specific viscosity of native acid-soluble guinea pig skin collagen to 50 per cent of its original value at 27 degrees C. Polyacrylamide gel disc electrophoresis of the reaction products showed bands corresponding to alphaA, betaA, and alphaB fragments. Electron microscopic examination of SLS aggregates of the reaction products showed that the cleavage site by the enzyme was at a point 75 per cent from the "A" end (TCA75) and 25 per cent from the "B" end (TCB25) of the collagen molecule.  相似文献   

4.
A specific collagenase from rabbit fibroblasts in monolayer culture   总被引:33,自引:15,他引:18  
1. Explants of rabbit skin and synovium in tissue culture secreted a specific collagenase into their culture media. Primary cultures of fibroblast-like cells, which were obtained from these tissues and maintained in culture for up to 14 subculture passages, also secreted high activities of a specific collagenase into serum-free culture medium. Secretion of enzyme activity from the cell monolayer was at constant rate for over 100h and continued for up to 8 days in serum-free culture medium. The enzymic activity released was proportional to the number of cells in the monolayer. 2. The fibroblast collagenase was maximally active between pH7 and 8. At 24 degrees C the collagenase decreased the viscosity of collagen in solution by 60%. The collagen molecule was cleaved into three-quarters and one-quarter length fragments as demonstrated by electron microscopy of segment-long-spacing crystallites (measured as native collagen molecules aligned with N-termini together along the long axis), and by polyacrylamide-gel electrophoresis of the denatured products. The collagenase hydrolysed insoluble collagen, reconstituted collagen fibrils and gelatin, but had no effect on haemoglobin or Pz-Pro-Leu-Gly-Pro-d-Arg (where Pz=4-phenylazobenzyloxycarbonyl). 3. The fibroblast collagenase was partially purified by gel filtration and the molecular weight was estimated as 38000. The activity of the partially purified enzyme was stimulated by 4-chloromercuribenzoate, inhibited by EDTA, cysteine, 1,10-phenanthroline and serum, but was unaffected by di-isopropyl phosphorofluoridate, Tos-LysCH(2)Cl and pepstatin. 4. Long-term cell cultures originating from rabbit skin or synovium from rabbits with experimentally induced arthritis also secreted specific collagenase. Human fibroblasts released only very small amounts of collagenase.  相似文献   

5.
A collagenase was purified from homogenates of V2 ascites-cell carcinoma growing in rabbit muscle. (NH4)2SO4 precipitation, ion-exchange and gel-filtration chromatography, and affinity chromatography (by using the CB7 CNBr) cleavage fragment of alpha 1(I) collagen linked to agarose) gave a 268000-fold purification and a sevenfold increase in total enzyme units recovered. The specific activity, defined as mumol of collagen in solution cleaved/h per mg of enzyme at 35 degrees C, WAS 1.74.2. The collagenase had a broad pH optimum from pH7.0 to 9.5, and a mol.wt. of between 33000 and 35000. It was inhibited by dithiothreitol, L-cysteine, D-penicillamine, EDTA and 1,10-phenanthroline, and by both rabbit and human serum. 3. Removal of cations by a chelating resin (Chelex 100) produced as inactive enzyme that could be reactiviated by the addition of Ca2+ ions at concentrations as low as 1muM. Other bivalent cations were not effective. 4. The purified collagenase cleaved peptides alpha2 and alpha1-CB7 (denatured polypeptides of collagen) at 37 degrees C at one site only. [alpha1 (I)]2alpha2 and [alpha1(III)]3 collagens in solution were cleaved at the same site approximately five times more rapidly than [alpha1 (II)]3. 5. An inhibitor of the enzyme in the tumour extracts, which was dissociable from the enzyme at the (NH4) 2SO4 precipitation step of purification, had a mol. wt. of between 40000 and 50000 but was distinct from the alpha1 trypsin inhibitor. 6. Studies with zonal density-gradient centrifugation suggested that the enzyme was bound to fibrillar substrate (collagen) extracellularly, but that it was not associated with enzymes originating in cell mitochondria, microsomal preparations or lysosomes.  相似文献   

6.
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.  相似文献   

7.
Purification of rabbit bone inhibitor of collagenase.   总被引:20,自引:7,他引:20       下载免费PDF全文
1. Rabbit bones in tissue culture synthesize an inhibitor of collagenase during the first 4 days of culture. 2. The inhibitor was purified by a combination of gel filtration, concanavalin A--Sepharose chromatography, ion-exchange chromatography and zinc-chelate affinity chromatography. 3. The purified inhibitor migrated as a single band on sodium dodecyl sulphate/polyacrylamide-gel electrophoresis and had a mol.wt. of 28000. 4. The inhibitor blocked the activity of the metalloproteinases collagenase, gelatinase, neutral proteinase III (proteoglycanase), human leucocyte collagenase and gelatinase, but not thermolysin or bacterial collagenase. The serine proteinases plasmin and trypsin were not inhibited. 5. The inhibitor interacted with purified rabbit bone collagenase with 1:1 stoichiometry. 6. The inhibitory activity was lost after incubation for 1 h at 90 degrees C, after treatment with trypsin (250 micrograms/ml) at 37 degrees C for 30 min and after reduction and alkylation.  相似文献   

8.
Type X collagen was extracted with 1 M NaCl and 10 mM dithiothreitol at neutral pH from fetal human growth plate cartilage and purified to homogeneity by gel filtration and anion-exchange chromatography. The purified protein migrates in SDS/polyacrylamide gels with an apparent Mr of 66,000 under reducing conditions, and as a high-Mr oligomer under non-reducing conditions. Purified collagenase digests most of the molecule; pepsin digestion at 4 degrees C decreases the Mr of the monomer to 53,000. A rabbit antiserum was raised against purified human type X collagen; the IgG fraction was specific for this collagen by criteria of ELISA and immunoblotting after absorption with collagen types I, II, VI, IX and XI. Immunohistological studies localized type X collagen exclusively in the zone of hypertrophic and calcifying cartilage.  相似文献   

9.
Purified polymorphonuclear leukocyte elastase degraded native human liver type III collagen at 27 degrees C by making a cleavage through the triple helix. The enzyme had no effect on human type I collagen. The reaction was inhibited by phenylmethanesulfonyl fluoride (PhCH2SO2F) but not by EDTA. The collagen reaction products were identical with those generated by human rheumatoid synovial collagenase when analyzed by polyacrylamide gel electrophoresis and gel filtration. NH2-trminal sequence analysis indicated that the enzyme cleaved at an isoleucyl-threonyl bond located 4 residues on the carboxyl side of the established cleavage site for animal collagenases. Therefore, it is likely that in pathologic states, type III collagen can be selectively depleted from the matrix by this enzyme.  相似文献   

10.
The action of purified rheumatoid synovial collagenase and human neutrophil elastase on the cartilage collagen types II, IX, X and XI was examined. At 25 degrees C, collagenase attacked type II and type X (45-kDa pepsin-solubilized) collagens to produce specific products reflecting one and at least two cleavages respectively. At 35 degrees C, collagenase completely degraded the type II collagen molecule to small peptides whereas a large fragment of the type X molecule was resistant to further degradation. In contrast, collagen type IX (native, intact and pepsin-solubilized type M) and collagen type XI were resistant to collagenase attack at both 25 degrees C and 35 degrees C even in the presence of excess enzyme. Mixtures of type II collagen with equimolar amounts of either type IX or XI did not affect the rate at which the former was degraded by collagenase at 25 degrees C. Purified neutrophil elastase, shown to be functionally active against soluble type III collagen, had no effect on collagen type II at 25 degrees C or 35 degrees C. At 25 degrees C collagen types IX (pepsin-solubilized type M) and XI were also resistant to elastase, but at 35 degrees C both were susceptible to degradation with type IX being reduced to very small peptides. Collagen type X (45-kDa pepsin-solubilized) was susceptible to elastase attack at 25 degrees C and 35 degrees C as judged by the production of specific products that corresponded closely with those produced by collagenase. Although synovial collagenase failed to degrade collagen types IX and XI, all the cartilage collagen species examined were degraded at 35 degrees C by conditioned culture medium from IL1-activated human articular chondrocytes. Thus chondrocytes have the potential to catabolise each cartilage collagen species, but the specificity and number of the chondrocyte-derived collagenase(s) has yet to be resolved.  相似文献   

11.
A metalloproteinase inhibitor present in human rheumatoid synovial fluid was purified by a combination of heparin-Sepharose chromatography, concanavalin A-Sepharose chromatography, ion-exchange chromatography and gel filtration. The Mr of the purified inhibitor was 28000 by SDS/polyacrylamide-gel electrophoresis and 30000 by gel filtration. The inhibitor blocked the activity of the metalloproteinases collagenase, gelatinase and proteoglycanase, but not thermolysin or bacterial collagenase. The serine proteinase trypsin was not inhibited. The inhibitory activity was lost after treatment with trypsin (0.5 micrograms/ml) at 37 degrees C for 30 min, 4-aminophenylmercuric acetate (1 mM) at 37 degrees C for 3 h, after incubation for 30 min at 90 degrees C and by reduction and alkylation. These properties suggest that the inhibitor closely resembles the tissue inhibitor of metalloproteinases ('TIMP') recently purified from connective-tissue culture medium.  相似文献   

12.
1. Active type collagenase was purified as much as 140-fold from the explant medium of bovine dental sacs and showed a single band on disc gel electrophoresis. Purified collagenase cleaved native collagen at only one locus under physiological conditions, but hydrolyzed neither gelatin nor alpha-casein. The optimal pH was about 7.8. 2. The molecular weight of active type enzyme was 35,000 by gel filtration and 34,000 by gel electrophoresis. The activation of latent type of collagenase resulted in the reduction of molecular weight from 45,000 to 38,000 by gel filtration. 3. A small but detectable amount of collagenase was directly extracted from frozen and thawed bovine dental sacs. In explant media of frozen and thawed tissue and fresh tissue with actinomycin D, some activity was detected for the first 2 days, but essentially no collagenase activity was detected in the explant medium after day 3. 4. The latent type collagenase was activated by trypsin, 4-aminophenylmercuric acetate (4-APMA), thiocyanate and deoxycholate (DOC). DOC showed irreversible dissociation of latent type enzyme in similar fashion to that exerted by 4-APMA. 5. The purified collagenase was inhibited by bovine serum, EDTA, o-phenanthroline, cysteine and dithiothreitol.  相似文献   

13.
A 1, 3-beta-glucanase of Bacillus No. 221 has been extensively purified by a DEAE-cellulose column followed by a Sephadex G-75 gel filtration, and crystallized in ammonium sulfate solution. The crystalline enzyme is homogenous on the basis of polyacrylamide gel electrophoresis, sedimentation in ultracentrifuge (3.2 S), Ampholine electrofocusing (pI=4.1) and dodecylsulfate-polyacrylamide gel electrophoresis (Mr=36 000). The enzyme has an optimum pH for enzyme action at 8.5 which is higher than those of other 1, 3-beta-glucanases so far reported. The enzyme is very thermostable; about 90% of activity remains after being heated at 70 degrees C for 10 min, and no effect of Ca-2's obversed. The enzyme does not hydrolyse laminaritriose, but hydrolyses laminaritetraose, and yields glucose and laminaritriose. The enzyme splits laminaran at random and yields glucose, laminaribiose, laminaritriose and higher oligosaccharides. From these results, this enzyme is a type of endo-1, 3-beta-glucanase.  相似文献   

14.
In order to examine the potential role of bacterial collagenases in periodontal tissue destruction, we recently isolated a gene, prtC, from Porphyromonas gingivalis ATCC 53977, which expressed collagenase activity (N. Takahashi, T. Kato, and H. K. Kuramitsu, FEMS Microbiol. Lett. 84:135-138, 1991). The nucleotide sequence of the gene has been determined, and the deduced amino acid sequence corresponds to a basic protein of 37.8 kDa. In addition, Southern blot analysis indicated that the prtC gene is conserved among the three major serotypes of P. gingivalis. The enzyme has been purified to near homogeneity from Escherichia coli clone NTS1 following Mono Q anion exchange and sequential gel filtration chromatography. The molecular mass of the purified enzyme was estimated by sodium dodecyl sulfate-polyacrylamide gel electrophoresis to be ca. 35 kDa, and the active enzyme behaved as a dimer following gel filtration chromatography. The collagenase degraded soluble and reconstituted fibrillar type I collagen, heat-denatured type I collagen, and azocoll but not gelatin or the synthetic collagenase substrate 4-phenylazobenzyloxycarbonyl-Pro-Leu-Gly-Pro-D-Arg. Enzyme activity was enhanced by Ca2+ and inhibited by EDTA, sulfhydryl-blocking agents, and the salivary peptide histatin. Preliminary evidence for the existence of a second collagenase expressed by strain 53977 was also obtained.  相似文献   

15.
Purification and characterization of a streptomycete collagenase   总被引:1,自引:0,他引:1  
A soil streptomycete designated as Streptomyces sp. A8 produced an extracellular collagen hydrolysing enzyme that appeared to be 'true collagenase' as it degraded native collagen under physiological conditions and cleaved the synthetic hexapeptide 4-phenylazobenzyloxycarbonyl-L-prolyl-L-leucyl-glycyl-L-prolyl-D-a rginine into two tripeptides. The enzyme was purified by diethyl aminoethyl cellulose chromatography and Sephadex G-150 gel filtration. The purified enzyme had an apparent molecular weight of about 75,000 by SDS-polyacrylamide gel electrophoresis. Treatment with lithium chloride did not dissociate it into subunits. A strong inhibition was observed with chelating agents such as alpha-alpha-dipyridyl and 8-hydroxyquinoline. Ethylene diamine tetraacetate completely inhibited the enzyme activity. Among the cations tested only Ca2+ and Mg2+ enhanced the collagenase activity. Heavy metal ions like Pb2+, Ag+, Cu2+ and Zn2+ strongly inhibited the enzyme. The EDTA inhibition could be reversed with Ca2+. Cysteine and reduced glutathione caused significant reduction in enzyme activity. Parachloromercuribenzoate and iodoacetamide had no effect on the collagenase. Amino acid analysis revealed the absence of cysteine and tyrosine. Many of the properties were the same as collagenases of Clostridium histolyticum and Vibrio alginolyticus.  相似文献   

16.
Acid trehalase was purified from the yeast suc2 deletion mutant. After hydrophobic interaction chromatography, the enzyme could be purified to a single band or peak by a further step of either polyacrylamide gel electrophoresis, gel filtration, or isoelectric focusing. An apparent molecular mass of 218,000 Da was calculated from gel filtration. Polyacrylamide gel electrophoresis of the purified enzyme in the presence of sodium dodecyl sulfate suggested a molecular mass of 216,000 Da. Endoglycosidase H digestion of the purified enzyme resulted after sodium dodecyl sulfate gel electrophoresis in one distinct band at 41,000 Da, representing the mannose-free protein moiety of acid trehalase. The carbohydrate content of the enzyme was 86%. Amino acid analysis indicated 354 residues/molecule of enzyme including 9 cysteine moieties and only 1 methionine. The isoelectric point of the enzyme was estimated by gel electrofocusing to be approximately 4.7. The catalytic activity showed a maximum at pH 4.5. The activity of the enzyme was not inhibited by 10 mM each of HgCl2, EDTA, iodoacetic acid, phenanthrolinium chloride or phenylmethylsulfonyl fluoride. There was no activation by divalent metal ions. The acid trehalase exhibited an apparent Km for trehalose of 4.7 +/- 0.1 mM and a Vmax of 99 mumol of trehalose min-1 X mg-1 at 37 degrees C and pH 4.5. The acid trehalase is located in the vacuoles. The rabbit antiserum raised against acid trehalase exhibited strong cross-reaction with purified invertase. These cross-reactions were removed by affinity chromatography using invertase coupled to CNBr-activated Sepharose 4B. Precipitation of acid trehalase activity was observed with the purified antiserum.  相似文献   

17.
A soil streptomycete designated as Streptomyces sp. A8 produced an extracellular collagen hydrolysing enzyme that appeared to be 'true collagenase'as it degraded native collagen under physiological conditions and cleaved the synthetic hexapeptide 4-phenylazobenzyloxycarbonyl-L-prolyl-L-leucyl-glycyl-L-prolyl-D-arginine into two tripeptides. The enzyme was purified by diethyl aminoethyl cellulose chromatography and Sephadex G-150 gel filtration. The purified enzyme had an apparent molecular weight of about 75000 by SDS-polyacrylamide gel electrophoresis. Treatment with lithium chloride did not dissociate it into subunits. A strong inhibition was observed with chelating agents such as α-α-dipyridyl and 8-hydroxyquinoline. Ethylene diamine tetracetate completely inhibited the enzyme activity. Among the cations tested only Ca2 + and Mg2 + enhanced the collagenase activity. Heavy metal ions like Pb2 +, Ag+, Cu2 + and Zn2 + strongly inhibited the enzyme. The EDTA inhibition could be reversed with Ca2 +. Cysteine and reduced glutathione caused significant reduction in enzyme activity. Parachloromercuribenzoate and iodoacetamide had no effect on the collagenase. Amino acid analysis revealed the absence of cysteine and tyrosine. Many of the properties were the same as collagenases of Clostridium histolyticum and Vibrio alginolyticus.  相似文献   

18.
Latent and active collagenase were extracted from human polymorphonuclear leukocytes. Separation of the two forms of the enzyme was performed by gel filtration on Sepharose 6 B. The latent form of the enzyme was detected from chromatographic fractions after a brief treatment with trypsin or exposure of the fractions to the sulfhydryl reagent phenylmercuric chloride. Latent enzyme eluted before active enzyme from the column, indicating a higher apparent molecular weight. Partially purified latent enzyme exhibited an apparent molecular size of 70-75 kDa as estimated by gel filtration. A value of 50-55 kDa was obtained for active enzyme. Without activation the latent enzyme did not degrade soluble collagen substrate. This was demonstrated by a quantitative viscometric assay and also by sodium dodecyl sulfate polyacrylamide gel electrophoresis, when no typical cleavage products of collagen could be seen. Latent enzyme could not be obtained unless serine protease inhibitors were present during the extraction and purification procedures. The effects of the activators trypsin, phenylmercuric chloride, phenylmethyl sulfonyltrypsin, and N-ethylmaleimide on the latent human polymorphonuclear leukocyte collagenase were studied. Contrary to the suggestion that inactive proteases activate latent human polymorphonuclear leukocyte collagenase, the inactive phenylmethyl sulfonyl-trypsin could not activate latent collagenase.  相似文献   

19.
A method is described for the purification of clostridial collagenase from a crude enzyme preparation employing cation exchange chromatography on SP Sephadex, anion exchange chromatography on DEAE cellulose and gel filtration on Sephacryl S-200. Emphasis was placed on purity using continuous shallow gradients for the ion exchange separations to increase resolution and monitoring eluates both with respect to ultraviolet light absorption at 230 nm and analytical disc gel acrylamide electrophoresis. In addition, protein fractions were assayed for collagenolytic and non-specific proteolytic activity. The purity of the final preparation was assessed by acrylamide electrophoresis, gel filtration and amino acid analysis. The isolated enzyme hydrolyzed between 30 and 40% of rat tail tendon collagen in 1 h at 37 degrees C and lacked measurable trypsin or elastase-like activity.  相似文献   

20.
A specific collagenase (EC 3.4.24.3) has been found and purified from serum-free culture medium of 11095 epidermoid carcinoma of rat prostate. The molecular weight of this collagenase was estimated at 71 000 and the pH optimum was approx. 7. At 26 degrees C, the collagenase cleaved collagen at a site 3/4 the length from the N-terminus. At 37 degrees C, this collagenase degraded collagen to smaller peptides. The enzyme activity was inhibited by serum, cysteine and EDTA, but not by protease inhibitors. The presence of collagenase in rat tumor tissue suggests that this enzyme might play a significant role in tissue invasion by cancer cells.  相似文献   

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