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 sensitivity and utility of proteinase assays employing fluorescamine, a compound which reacts with primary amines to form a fluorescent adduct, was assessed. As little as 1 ng of purified trypsin or clostridiopeptidase A could be detected within 3 h of incubation at 37 degrees C, using casein or gelatin as substrates. Increasing the incubation period to 18 h permitted the detection of 250 pg of each enzyme. When gelled collagen was utilized as substrate, the sensitivity to clostridiopeptidase A was reduced to 2.5 ng at 3 h and 500 pg at 18 h. The techniques could be used to measure the gelatinase, caseinase, and collagenase activities of culture media conditioned by synovial tissue. The main disadvantage of this assay is its susceptibility to interference by compounds which fluoresce or quench. This, in turn, necessitates additional blanks, which may render the assay tedious.
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PMID:An evaluation of fluorometric proteinase assays which employ fluorescamine. 609 62

Cerebral endothelium is being studied rather extensively in tissue culture, but no reports are available describing the tissue culture of cerebral microvascular smooth muscle. The present paper describes for the first time the isolation and culture of non-neoplastic mouse cerebral vascular smooth muscle. Microvessels from a dounce homogenate of mouse brain are plated onto plastic culture dishes in Dulbecco's modified Eagle media plus 20% fetal bovine serum and treated briefly with collagenase. Cells migrate from vessels and proliferate sufficiently to be transferred out of primary culture in 2 to 3 wk. Light microscopy reveals generally broad, polygonal cells that grow collectively in a "hill and valley" pattern. By transmission electron microscopy the cells possess many characteristics of smooth muscle: basal laminas, clusters of pinocytotic vesicles, and bundles of thin filaments. Several ill-defined cell-to-cell junctions are also present. Isoelectric focusing and sodium dodecyl sulfate-electrophoresis of cellular proteins on polyacrylamide gels after pulse labeling cultures with [S-35]methionine demonstrate that these cells actively synthesize a smooth-muscle-specific isoactin, alpha-actin. The identity of alpha-actin is confirmed by analysis of NH2-terminal peptides after actin digestion with trypsin and subsequent peptide cleavage with thermolysin. Both their morphology and active synthesis of alpha-actin strongly suggest that these cells are of smooth-muscle origin. Future studies of their metabolism and interactions with endothelium and astrocytes should provide a better understanding of the cerebral microcirculation.
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PMID:Cerebral microvascular smooth muscle in tissue culture. 623 74

A study of the influence of chemical modifications on the activity of Achromobacter iophagus collagenase (EC 3.4.24.8) has led to the following conclusions: a modification of 4 out of 80 COOH groups with carbodiimide led to 90% loss of enzymic activity. A 70% inactivation was found after modification of two tyrosines out of 30 with tetranitromethane. The modification of four to six tryptophans out of 16 with 2-hydroxy-5-nitrobenzyl bromide decreased enzyme activity to 36%. This inactivation is accelerated in the presence of collagen. An increase of reagent/enzyme molar ratio led to a modification of 16 tryptophan residues and denaturation of Acahromobacter collagenase. A modification of two arginines out of 18 with 1,2-cyclohexanedione and eight NH2 groups out of 24 with 2,3-dimethyl maleic anhydride does not change the collagenolytic activity. All NH2 groups become available for 2,3-dimethyl maleic anhydride after dissociation of the dimer. A possible analogy of hydrolytic site of collagenase with that of two other known bacterial metalloproteinases (thermolysin and Bacillus subtilis neutral proteinase (EC 3.4.24.4)) is discussed.
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PMID:Chemical modifications of Achromobacter collagenase and their influence on the enzymic activity. 625 92

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.
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PMID:Specific cleavage of human type III collagen by human polymorphonuclear leukocyte elastase. 625 89

During the growth of Empedobacter collagenolyticum on a medium with gelatin, only one proteinase, a collagenase, was excreted in the culture medium. No other proteolytic activity was detected in the extracellular medium or in acellular extracts. The other proteases of this bacteria are principally intracellular peptidases. By electrophoresis of an acellular extract five peptidases were separated; they were aminopeptidases and dipeptidases. Some of them exhibited a specificity towards peptides with aminoacid frequently found in collagen; Gly-Leu, Gly-Pro, Pro-Gly-Gly. Two other peptidases seem to have special specificity, one of them hydrolyses peptides with lysine residues at the NH2 terminal end, the other one hydrolyses dipeptides of the structure Lys-X. These enzymes were also found in the culture medium; they certainly play an important role in bacterial nutrition.
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PMID:[Inventory of proteolytic activity of a new collagenolytic bacteria Empedobacter collagenolyticum]. 627 74

The gelatinolytic activity of human skin fibroblast collagenase was examined on denatured collagen types I-V. All denatured substrates were cleaved, including types IV and V, which are resistant to collagenase in native form. Interestingly, the earliest major cleavage in denatured collagen types I-III occurred at a 3/4-1/4 locus, resulting in products electrophoretically identical with TCA and TCB fragments of mammalian collagenase action on these native collagens. However, in the denatured substrates, multiple additional proteolytic cleavages followed. The propensity for cleavage at a 3/4-1/4 site in denatured collagen, where sequence is the major specifier of enzymatic action, would seem to indicate that the most favorable amino acid sequence of gamma chains for catalysis is located in this region. The peptide bond specificity of human fibroblast collagenase on gelatin was examined by amino acid sequencing of extensively cleaved denatured type I collagen. Analysis of the NH2-terminal amino acid residues from the resultant gelatin peptides showed sequences of "-H2N-Ile-Y-Gly" and "H2N-Leu-Y-Gly" only (where Y indicates that any amino acid can be found in that position), indicating that Gly-Ile and Gly-Leu bonds are the only sites of collagenase cleavage in this substrate. Whereas the gamma1 chains of denatured collagen types I-III were cleaved at similar rates, fibroblast collagenase was a much better gamma2-gelatinase than gamm1-gelatinase on denatured type 1 collagen. This preference for the cleavage of gamma2(I) was the result of both a higher kcat (750 versus 230 h-1) and lower Km (3.7 versus 7.0 microM) than for a gamma1(1), resulting in an overall selectivity (kcat/Km) of greater than 6-fold. Compared to such kinetic parameters on native collagen, these values indicate that gelatinolysis is somewhat slower than collagenolysis.
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PMID:The gelatinolytic activity of human skin fibroblast collagenase. 628 90

Human skin fibroblasts maintained in cell culture secrete a collagenase inhibitor which has been purified to homogeneity from serum-containing culture medium using a combination of salt precipitation, and ion-exchange, phenylboronate-agarose, gel filtration, and high pressure liquid chromatography. The pure inhibitor retained full activity and exhibited a 1:1 molar inhibition of collagenase. A single band of Mr = 28,500 was seen on sodium dodecyl sulfate-polyacrylamide gel electrophoresis. The amino acid composition was remarkable for the presence of 24 half-cystine residues. No free sulfhydryls were present and the resultant 12 disulfide bridges may account for the remarkable stability of this protein to extremes of pH, temperature, pressure, as well as to denaturing agents. A total of 13 hexose residues/molecule were found. NH2-terminal sequence analysis revealed the presence of a single polypeptide chain and the first 23 residues were identified. A monospecific antibody was produced which abolished the functional activity of the inhibitor. Fibroblast inhibitor was found to migrate with the beta-globulins by immunoelectrophoresis. A chromatographically and immunologically identical collagenase inhibitor was partially purified from human serum, suggesting the possibility that the fibroblast-derived inhibitor and the previously reported serum beta 1-anticollagenase (Woolley, D. E., Roberts, D. R., and Evanson, J. M., (1975) Biochem. Biophys. Res. Commun. 66, 747-754) are similar, if not identical, proteins. The fibroblast collagenase inhibitor was found to be clearly distinct from other collagenase inhibitors of leukocyte and serum origin.
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PMID:Human skin fibroblast collagenase inhibitor. Purification and biochemical characterization. 631 47

A proteinase inhibitor which has strong anti-collagenase activity was found in chicken egg white. The inhibitor (pI = 4.9) was purified by poly(ethylene glycol) (5.5-10%) precipitation and chromatography on Ultrogel AcA 34, DEAE-cellulose, and Sephacryl S-300. The final product was homogeneous on 5% polyacrylamide gel electrophoresis. Stoichiometric inhibition was observed with the inhibitor and rabbit synovial collagenase and thermolysin (1:1 molar ratio with thermolysin). The inhibitor ran on sodium dodecyl sulfate-gel electrophoresis with reduction as a single protein band of Mr = 165,000. The molecular weight of the native inhibitor was estimated to be 780,000 by sedimentation equilibrium centrifugation. Centrifugation analysis in 6 M guanidine hydrochloride and of the reduced sample gave M omega = 380,000 and M omega = 195,000, respectively, where M omega is the weight-average molecular weight determined by equilibrium ultra-centrifugation. The results indicated that the inhibitor molecule is a tetramer of identical subunits linked in pairs by disulfide bonds. Since the molecular weight and the quaternary structure of the inhibitor were similar to those of alpha 2-macroglobulin (alpha 2M) in plasma, chicken alpha 2M was isolated and compared with the inhibitor. The inhibitor was not sensitive to methylamine, whereas chicken alpha 2M was. No immunocross-reactivity was observed between the inhibitor and chicken alpha 2M. The NH2-terminal sequence of the egg white inhibitor is Lys-Glu-Pro-Glu-Pro-Gln-Tyr-Val-Leu-Met-Val-Pro-Ala. The sequence of chicken alpha 2M is Ser-Thr-Val-Thr-Glu-Pro-Gln-Tyr-Met-Val-Leu-Leu-Pro-Phe. Considerable homology was found between the two sequences and to the NH2-terminal sequence of human alpha 2M. Monospecific antibody raised against the egg white inhibitor was employed to examine the tissue distribution of the inhibitor. The inhibitor was found only in oviduct and egg white, but not in other tissues or serum of chickens.
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PMID:Ovostatin: a novel proteinase inhibitor from chicken egg white. I. Purification, physicochemical properties, and tissue distribution of ovostatin. 640 74

A highly unusual endothelial cell collagen (Sage, H., Pritzl, P., and Bornstein, P., (1980) Biochemistry 19, 5747-5755) has been characterized in greater detail. Pulse-chase experiments with bovine aortic endothelial cells revealed two nondisulfide-bonded collagens, of apparent chain Mr = 177,000 and 125,000, with an estimated synthesis and secretion time of 75 min. Stepwise, quantitative processing to stable lower molecular weight forms as described for type I procollagen was not observed. Endothelial collagen was secreted over a temperature range of 24-37 degrees C and, prior to heat denaturation, did not display affinity for a gelatin-binding fragment of fibronectin coupled to Sepharose. The presence of a pepsin-resistant domain (Mr = 50,000) in both the soluble and cell layer-associated forms of this protein was shown by ion exchange chromatography and sodium dodecyl sulfate-polyacrylamide gel electrophoresis. Endothelial collagen was cleaved by vertebrate collagenase into several discrete fragments that differed in molecular weight from the characteristic alpha A and alpha B fragments generated from the interstitial collagens. Nontriple helical domains corresponding to the NH2- and COOH-terminal propeptides of other procollagen types were not found after incubation of endothelial collagen with bacterial collagenase. Additional evidence for the lack of extended noncollagenous sequences was provided by studies with mast cell proteases, which convert native procollagen to collagen but are unreactive toward native interstitial collagens. Endothelial collagen was not cleaved by these enzymes at 37 degrees C, but, as observed for interstitial collagen alpha chains, required prior heating at elevated temperatures for cleavage to occur. In view of this unique set of structural characteristics, and a distribution that is not restricted to the endothelium, we have designated this protein as type VIII collagen.
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PMID:Biosynthetic and structural properties of endothelial cell type VIII collagen. 663 Feb 35

To correlate structural data on substrates of human fibroblast collagenase with their interaction with the enzyme, we have studied: Ac-PLG-s-LLG-O-ethyl ester (I), Dnp-PLGLWA(d-Arg)-NH2 (II), AcGPEGLRVG-O-ethyl ester (III) and Succ-GPLGP-O-amidomethylcoumaryl ester (IV). Peptides I and II represent collagenase cleavage sequences in collagen, peptide III is a mimic for the cleavage site in alpha 2-macroglobulin and peptide IV represents a non-substrate model. Kinetic data showed that peptides I, II and III were substrates of the enzyme. In contrast, peptide IV was not acted upon by the enzyme. Circular dichroism data on the peptides showed that the peptides assume ordered structures in water and trifluoroethanol. In the latter solvent, peptides I and III bound Ca2+ and Zn2+ while peptide II bound Ca2+ but not Zn2+. Peptide IV did not bind either cation in this solvent. Together with the kinetic data, the results suggest that the collagenase cleavage segments in collagen and non-collagen substrates of collagenase could interact with Ca2+ and the enzyme to form a ternary complex. This, in turn, would imply a cofactor role for Ca2+ in collagenase action in addition to the solely structural role ascribed so far to this cation.
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PMID:Interaction of peptide substrates of fibroblast collagenase with divalent cations: Ca2+ binding by substrate as a suggested recognition signal for collagenase action. 748 80


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