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)

Isolated chick embryo tendon cells were used in [14C]proline and [14C]lysine labelling experiments to investigate the effect of divalent cations on collagen biosynthesis with a special reference to prolyl hydroxylation and lysyl modifications. The following metals were studied by adding them to the incubation medium of the cells: Ca2+, Cd2+, Co2+, Hg2+, Mg2+, Mn2+, Ni2+, Pb2+ and Zn2+. Zn2+ caused a potent reductin in collagen prolyl hydroxylation with a concomitant increased cellular retention of collagenase-digestible material. These effects were detectable even at physiological concentrations. At the same concentrations of Zn2+, lysyl hydroxylation was considerably less inhibited than prolyl hydroxylation, and the extent of hydroxylysyl glycosylation was even increased. Co2+ was also an efficient inhibitor of collagen prolyl hydroxylation, but at concentrations ten times higher than those of Zn2+. In the presence of other metal ions, no or only up to 10% inhibition of prolyl hydroxylation was noted even at those concentrations at which [14C]proline incorporation into the protein was decreased. However, an increased cellular retention of collagen was detected in the presence of some metal ions. No reduction in lysyl hydroxylation was found in the presence of Ca2+ or Mg2+.
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PMID:Effects of divalent cations on collagen biosynthesis in isolated chick embryo tendon cells. 677 78

Parenchymal and non-parenchymal cells were isolated from the livers of control, starved, Zn2+-injected and Cd2+-injected rats. Parenchymal cells were prepared by differential centrifugation after perfusion of the liver with collagenase. Non-parenchymal cells were separated from parenchymal cells by unit-gravity sedimentation and differential centrifugation. Yields of 2 x 10(8) non-parenchymal cells with greater than 95% viability and less than 0.2% contamination with parenchymal cells were obtained without exposing cells to Pronase. Metallothioneins-I and -II were identified in parenchymal cells and non-parenchymal cells from Zn2+-treated rats. The metallothionein contents of parenchymal cells, non-parenchymal cells and intact liver were quantified by a competitive 203Hg-binding assay. Administration of heavy-metal salts significantly increased the metallothionein content of both cell populations, although the concentration of the protein was approx. 2.5-fold greater in parenchymal cells than in non-parenchymal cells. Overnight starvation increased the metallothionein content of parenchymal cells without altering that of non-parenchymal cells. The potential significance of this differential response by different liver cell types with regard to the influence of Zn2+ on stress-mediated alterations in hepatic metabolism is discussed.
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PMID:Identification of metallothionein in parenchymal and non-parenchymal liver cells of the adult rat. 711 46

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

The zinc contents of samples of human fibroblast collagenase (HFC) purified by different procedures and of samples purified by the same procedure but prepared for analysis by different dialysis protocols have been determined by atomic absorption spectroscopy. Both the purification method and dialysis conditions affect the zinc stoichiometry. Samples purified with and without the use of a zinc-chelate chromatography step and prepared by dialysis against 1 mM CaCl2 had zinc to enzyme ratios of 1.46 and 1.22, respectively. When the first sample was prepared by dialysis against 0 and 10 mM CaCl2, the values changed to 0.15 and 1.94, respectively. Thus, the zinc content of HFC is critically dependent upon the dialysis conditions used to free the enzyme from adventitious metals. This could account for the disparate reports in the literature that give zinc stoichiometries for members of the matrix metalloproteinase (MMP) family of between 1 and 2. The mechanism of inhibition of the one zinc form of HFC by 1,10-phenanthroline (OP) and 4-(2-pyridylazo)resorcinol has been studied in detail. Inhibition by both chelating agents is time dependent and biphasic. There is an initial, instantaneous inhibition characterized by the involvement of a single inhibitor molecule that corresponds to the formation of a ternary complex between the zinc atom, enzyme, and chelator. This is followed by a second, slower phase involving removal of the zinc atom from the enzyme and its chelation by two molecules of inhibitor. Inhibition of four other human MMPs by OP shows similar characteristics and is thought to occur by the same mechanism.
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PMID:Zinc content and function in human fibroblast collagenase. 749 2

Matrix metalloproteinases are a family of zinc endopeptidases involved in tissue remodeling. They have been implicated in various disease processes including metastasis, joint destruction, and neurodegeneration. Human neutrophil collagenase (HNC, MMP-8) represents one of the three "interstitial" collagenases that cleave triple-helical collagens types I, II, and III. Its 163-residue catalytic domain (Met80 to Gly242) has been expressed in Escherichia coli and crystallized as a noncovalent complex with the hydroxamate inhibitor batimastat. The crystal structure, refined to 2.1 A, demonstrates that batimastat binds to the S1-S2' sites and coordinates to the catalytic zinc in a bidentate manner via the hydroxyl and carbonyl oxygens of the hydroxamate group. The batimastat-collagenase complex is described in detail, and the activities of batimastat analogues are discussed in the light of the protein-inhibitor interactions revealed by the crystallography studies.
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PMID:Structure determination and analysis of human neutrophil collagenase complexed with a hydroxamate inhibitor. 757 99

The structural gene prtVp encoding the extracellular protease of Vibrio parahaemolyticus strain 93 was cloned in Escherichia coli and sequenced. The cloned DNA fragment contained a 1761 bp ORF encoding a 587 amino acid protein. The deduced polypeptide is composed of a 25 amino acid signal peptide and a 562 amino acid extracellular polypeptide with a calculated molecular mass of 63,156 Da. Protease analysis using a gelatin-containing SDS-polyacrylamide gel detected the presence of a 62 kDa protease that was present in the culture supernatant fractions of the wild-type V. parahaemolyticus strain and of E. coli bearing a pUC119 recombinant with the prtVp DNA insert. The protease activity was inhibited by zinc- and metal-specific inhibitors such as EDTA and 1,10-phenanthroline, which suggested that it is a metalloprotease. The deduced amino acid sequence of PrtVp has 32% identity with that of the collagenase of Vibrio alginolyticus, but has no identity with those of the bacterial proteases. A conserved zinc-binding domain was also found in PrtVp from homology comparison with other metalloproteases. This PrtVp can cause weak haemolysis on blood agar.
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PMID:Molecular analysis of an extracellular protease gene from Vibrio parahaemolyticus. 758 17

Release of 92-kd type IV collagenase/gelatinase, also known as gelatinase B, by inflammatory and tumor cells is increasingly recognized and is believed to facilitate cellular migration across basement membranes. It has been implicated in the pathogenesis of many diseases, but little is known of its cellular origin(s) and function in liver. In this study we have demonstrated synthesis and release of gelatinase B by human and rat Kupffer cells in primary culture. Northern analysis of RNA extracted from Kupffer cells stimulated with phorbol ester demonstrated a 2.8 kb transcript for gelatinase B. Immunoblotting and zymography of serum-free Kupffer cell-conditioned media demonstrated extracellular release of immunoreactive enzyme and gelatinase activity, Mr 92,000 (95,000 from rat cells). The organomercurial 4-aminophenyl mercuric acetate (APMA) activated the enzyme in vitro, indicating secretion primarily as a proenzyme. Stimulation of Kupffer cells by phorbol ester markedly induced gelatinase B release, which was inhibited by cycloheximide. In contrast, cycloheximide had no effect on constitutive secretion in culture, suggesting that there is some intracellular storage. Kupffer cell-derived gelatinase B was also partially purified and characterized. After separation by gelatin sepharose and gel filtration chromatogrpahy, gelatin-degrading activities of 95, 88, 75, and 65 kd were detected, the three lower-molecular-weight species probably representing activated forms. Enzyme activity was inhibited by ethyl-enediaminetetra-acetic acid (EDTA), but not by serine- and thiol-protease inhibitors, and was restored by zinc. Activity was also inhibited by tissue inhibitor of metalloproteinase-1 (TIMP-1) and alpha-2 macroglobulin. The partially purified enzyme rapidly degraded denatured collagens (gelatin) as well as native types III, IV, and V collagens, but had no activity against casein, types I and VI collagens.
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PMID:Kupffer cell-derived 95-kd type IV collagenase/gelatinase B: characterization and expression in cultured cells. 760 25

The inhibitory activity of a new peptidyl collagenase inhibitor, FN-439 or tetrapeptidyl hydroxamic acid (H2N-C6H4-CO-Gly-L-Pro-D-Leu-D-Ala-NHOH), was determined against vertebrate collagenases derived from human fibroblast, human polymorphonuclear leukocyte (PMN) and tadpole skin. In addition, the effect of FN-439 in inhibiting corneal ulceration was also investigated with alkali-burned rabbit corneas. FN-439 can block the active site of collagenase, and hydroxamic acid can chelate Zn2+ which is essential for collagenase activity. Furthermore, this compound contains D-amino acids to resist nonspecific host-derived degradative enzymes. In our experiments, corneal ulceration occurred in 5 of the 9 control eyes, but in none of the 9 eyes treated with FN-439 (P < 0.01). The only cellular elements observed at the ulcerated area were PMNs and monocytes. FN-439 appeared to act against PMN collagenase. In addition, we compared the change in the concentration of FN-439 (D-peptide) and the L-form of FN-439 (L-peptide) in aqueous humor aspirated from the rabbit eyes burned with alkali. After incubation for 3 hours, the concentration of the D-peptide was decreased by 3%, while that of the L-peptide was decreased by 60%. FN-439 may be useful for treating noninfectious corneal ulcers because of its potent activity (IC50 = 1 microM) and chemical and biological stabilities.
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PMID:Inhibition of corneal ulceration by tetrapeptidyl hydroxamic acid. 764 81

At the end of a nonconception estrous cycle, the sheep corpus luteum undergoes involution (luteolysis), a process thought to involve apoptotic deletion of cells. It is not yet clear which of the heterogeneous luteal cell types is involved or what mechanisms drive the apoptotic progression. We examined intact paraffin-embedded corpora lutea (in situ terminal dUTP nick end-labeling method) and found direct evidence for apoptotic deletion of cells during luteolysis, but not in healthy, nonregressing corpora lutea. We then sought to implement in vitro models to dissect apoptotic mechanisms in the constituent cells of the corpus luteum. Cells prepared using standard collagenase dispersion of corpus luteum were evaluated for evidence of apoptosis (DNA laddering) by direct agarose gel electrophoresis, a method that obviates the need for DNA extraction, so allowing examination of relatively few cells (< or = 0.5 x 10(6)). When cells were prepared from nonregressing corpus luteum for in vitro manipulation, a population(s) of cells undergoing spontaneous apoptosis was detected. Apoptosis was inhibited by Zn2+ (5 mM), by the tyrosine phosphatase inhibitor sodium orthovanadate (100 microM), or by maintenance at 4 degrees C. It appears that simple collagenase digestion of intact corpus luteum removes a subset of constituent cells from their survival signal, leading to rapid initiation of endonuclease activity and apoptotic cell death. Identification of the required survival factors and their actions is being pursued to facilitate development of appropriate in vitro models for this endocrine system.
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PMID:Spontaneous apoptosis of cells prepared from the nonregressing corpus luteum. 765 26

In rheumatoid and osteoarthritis, degradation of articular cartilage is mediated by the matrix metalloproteinases collagenase, stromelysin and gelatinase. The key event in this process is the cleavage of triple helical collagen by collagenase. We have determined the crystal structure of the catalytic domain of human recombinant fibroblast collagenase complexed with a synthetic inhibitor at 2.2 A resolution. The protein fold is similar to the amino termini of the zinc endopeptidases astacin thermolysin and elastase despite a lack of primary sequence homology. The conformation of the bound inhibitor provides a molecular basis for the design of inhibitors of collagenase and other matrix metalloproteinases. Such inhibitors should be useful in the treatment of a variety of diseases including arthritis and cancer.
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PMID:Structure of the catalytic domain of human fibroblast collagenase complexed with an inhibitor. 765 13


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