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)

Activation of bovine plasma prekallikrein was investigated with several proteinases. Highly purified bovine plasma prekallikrein was rapidly activated to kallikrein [EC 3.4.21.8] by bovine activated Hageman factor, trypsin [EC 3.4.21.4] and Pronase P (proteinases from Streptomyces griseus) and more gradually by papain [EC 3.4.22.2] and ficin [EC 3.4.22.3]. Activation of prekallikrein was also observed with bovine plasmin [EC 3.4.21.7], but not with bovine clotting factors Xa (Stuart factor) [EC 3.4.21.6] and IXa (Christmas factor) or thrombin [EC 3.4.21.5]. Urokinase [EC 3.4.99.26], Reptilase, collagenase [EC 3.4.24.3], elastase [EC 3.4.21.11], alpha-chymotrypsin [EC 3.4.21.1], Nagarse [EC 3.4.21.14], and stem bromelain [EC 3.4.22 4] did not convert prekallikrein to kallikrein. Plasma kallikrein activated to Hageman factor released kinin rapidly from bovine high molecular weight (HMW) kininogen. However, from bovine low molecular weight (LMW) kininogen, liberation of kinin was extremely slow. The kallikrein activity was inhibited by soybean trypsin inhibitor (SBTI), Trasylol, diisopropylfluorophosphate (DFP), and N-alpha-tosyl-L-lysine chloromethylketone (TLCK), but not by egg-white trypsin inhibitor (EWTI), lima bean trypsin inhibitor (LBTI), heparin or hexadimethrine bromide (Polybrene). The kallikrein formed an enzyme-inhibitor complex with SBTI and Trasylol, but not with LBTI. Prekallikrein did not react with SBTI. Prekallikrein consists of a single polypeptide chain of molecular weight about 90,000, as estimated by sodium dodecyl sulfate (SDS)-polyacrylamide gel electrophoresis. Activation of prekallikrein by Hageman factor was found to involve cleavage of the single peptide bond on the disulfide-bridged polypeptide chain, and no change of molecular weight was observed during the activation. The peptide bond cleaved in prekallikrein by the activation was an Arg-X peptide bond on a disulfide-bridged polypeptide chain.
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PMID:Studies on prekallikrein of bovine plasma. II. Activation of prekallikrein with proteinases and properties of kallikrein activated by bovine Hageman factor. 676 24

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

Cultured pulmonary artery smooth muscle cells derived from the medial vessel layer of weanling rabbits were grown in the presence or absence of sodium ascorbate. The connective tissue elements insoluble elastin and collagen were identified and quantified. Formation and accumulation of alpha-aminoadipic acid gamma-semialdehyde (allysine) and the intermolecular cross-links desmosine (Des), isodesmosine (Ides), and aldol condensation product (Aldol) were evaluated from [14C]lysine pulse-chase experiments. [14C]Des, [14C]Ides, peptide-bound [14C]lysine, [14C]allysine, and [14C]Aldol were determined from amino acid analysis. The latter two components were determined after reduction with NaBH4. [14C]Proline conversion to hydroxy[14C]proline and collagenase susceptibility were used to identify and quantify collagen synthesis. Ascorbate dramatically affects insoluble elastin synthesis, accumulation, and cross-link formation. Cells grown in the presence of ascorbate synthesize and accumulate significantly less insoluble elastin than non-ascorbate cultures. Those elastin molecules which do become incorporated into the extracellular matrix in the presence of ascorbate contain a slightly elevated content of hydroxyproline and lysine and, most importantly, are turned over more rapidly.
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PMID:Effects of ascorbate on insoluble elastin accumulation and cross-link formation in rabbit pulmonary artery smooth muscle cultures. 681 21

Chick embryo epiphyseal cartilage has been shown to contain three different proteoglycan species (PG-H, PG-Lb, and PG-Lt). This report is concerned with the purification and characterization of the third proteoglycan, PG-Lt. The proteoglycan can be separated from the other two by virtue of its low buoyant density in a CsCl density gradient and further purified by consecutive ion exchange and gel chromatography. The final preparation is composed of PG-Lt monomer and PG-Lt oligomer. The amino acid composition of PG-Lt is quite different from that of PG-H and PG-Lb and rather resembles that of collagens with respect to high content of glycine and high degrees of hydroxylation of proline and lysine. PG-Lt monomer is composed of disulfide-bonded subunits of Mr congruent to 120,000 and 190,000 as demonstrated by its gel electrophoretic behavior after reduction with 2-mercaptoethanol. The latter, but not the former, contains dermatan sulfate chains with glucuronic acid/iduronic acid residues and yields a protein-enriched core molecule of Mr congruent to 100,000 after digestion with chondroitinase ABC. Both of the protein subunits are completely digestible with bacterial collagenase. Immunofluorescence microscopic examination of cartilage tissues, using an antibody against PG-Lt, shows that this proteoglycan exists in both the cartilage matrix and perichondrial noncartilagenous region. When chondrocytes are plated onto tissue culture dishes, the antibody stains strands found on the cell surfaces and in the intercellular space of substrate-attached cell layers, suggesting that PG-Lt mediates cell-to-cell and cell-to-substrate contacts.
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PMID:Isolation and characterization of a third proteoglycan (PG-Lt) from chick embryo cartilage which contains disulfide-bonded collagenous polypeptide. 687 91

Knowledge of the dynamics of collagen turnover requires information regarding rates of synthesis of this group of connective-tissue proteins. The relationship of various amino acid pools to the tRNA precursor pool used for protein synthesis is known to vary between different cell types and tissues, even for essential amino acids. We studied extracellular, intracellular and tRNA-proline pools in cultured human lung IMR-90 fibroblasts to determine the relationship between them as candidate proline precursor pools for total protein and collagen synthesis. Time-course experiments showed that the three proline pools attained distinctly different steady-state specific radioactivities (extracellular greater than intracellular greater than tRNA) at the extracellular proline concentration of 0.2 mM. The kinetics of radioisotope incorporation into cell protein and collagenase-digestible protein indicated that the intracellular free proline pool could not be used reliably as a precursor for calculating synthetic rates. However, tRNA-proline behaved isotopically as if it were the precursor and provided synthesis rates 2-3-fold higher than those calculated by using either free proline pool. The incorporation of labelled lysine and leucine was constant over a wide range of extracellular proline concentrations. Fractional rates of protein synthesis based on tRNA-amino acid were the same with [3H]phenylalanine as with [3H]proline. The specific radioactivity of cell-associated hydroxyproline reached a steady-state value 8-10h after radioisotope administration which matched the mean tRNA-proline specific radioactivity, suggesting that tRNA-proline is not isotopically compartmentalized. A model of cellular proline-pool relationship is presented and discussed.
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PMID:Prolyl-tRNA-based rates of protein and collagen synthesis in human lung fibroblasts. 691 81

Mouse thyroid tissue was dissociated with collagenase, fixed in periodate-lysine-paraformaldehyde (PLP), and further dissociated with EDTA and trypsin to yield cell suspensions containing mainly follicle epithelial cells and vascular endothelial cells. H-2 complex antigens were detected on the vascular endothelial cells at about the same high density as on peritoneal macrophages, and at a lower concentration on the laterobasal membranes of follicle epithelial cells. Neither of these cell types expressed detectable Ia antigens, but a minor cell type was presented that showed dense expression of Ia antigens. This cell type was probably a passenger leukocyte. It showed ultrastructural characteristics closely resembling those of spleen dendritic cells, which are known to express Ia antigens and to be potent stimulator cells in mixed lymphocyte culture. Dissociation of thyroid glands that had been cultured in vitro for 14 days yielded only follicle epithelium, and these cells showed the same labeling density of H-2 complex antigens as on uncultured cells. Dissociation of islets of Langerhans yielded capillary endothelial cells and beta cells, neither of which expressed detectable Ia antigens. The labeling results are discussed in relation to the cellular changes that occur during culture in vitro and the altered behavior of cultured allografts.
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PMID:H-2 complex and Ia antigens on cells dissociated from mouse thyroid glands and islets of Langerhans. 701 Jul 10

Insoluble elastins were isolated from control and aneurytic aortas by a sequential extraction procedure involving the use of purified collagenase. Marked differences in amino acid analyses and susceptibilities to pancreatic elastase were observed between normal and pathological samples. The incorporation of either 14C-lysine or 14C-glucosamine into proteins of the vessel wall was also studied. In addition, high amounts of elastase-type activity was extractable from pathological aorta specimens which may contribute significantly to the loss of elastic tissue evidenced by ultra-structural studies and confirmed by the biochemical technics. We propose therefore that increased elastase-type protease activity in these pathological aortas does significantly contribute to the weakening of the aortic wall and also may well be the main cause of the rupture of aneurysms observed occasionally.
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PMID:Studies on elastic tissue of aorta in aortic dissections and Marfan syndrome. 703 99

The biosynthesis of collagen and fibronectin molecules by cultivated glomerular epithelial or mesangial cells was studied at confluency using radioactive proline or lysine as precursors. Collagen represented 0.5% of the total protein synthesized by the glomerular epithelial cells. About 60% of this collagenous protein were associated to the cell layer, whereas about 40% were secreted into the culture medium. Two major collagenous polypeptides were observed with apparent molecular weights of 185K and 170K, and were identified as two gene products of type IV procollagen. They exhibited ratios of 3- to 4-hydroxyproline, of total hydroxyproline to proline, and of hydroxylysine to lysine characteristic of type IV procollagen. They were degraded by bacterial collagenase. The patterns of peptides obtained after digestion of the 185K and 170K chains of this type IV procollagen with pepsin and V8 protease were identical to those obtained after digestion of type IV procollagen chains purified from a murine tumor (EHS sarcoma). Finally. a purified antibody to type IV collagen specifically immunoprecipitated the collagenous protein produced by the glomerular epithelial cells. By contrast, the mesangial cells synthesized about 5% of collagenous protein. 90% of this collagen were secreted into the cultured medium, whereas about 10% remained associated to the cell layer. Type I, III and IV procollagens were synthesized by the mesangial cells. Fibronectin was found in the medium and cell layer of both epithelial and mesangial cells. Fibronectin molecules were identified by their resistance to bacterial collagenase, their susceptibility to pepsin digestion, and their specific adherence to collagen. It was composed of disulfide-linked peptides of 220K daltons. The data therefore demonstrate that: (a) the glomerular epithelial and mesangial cells synthesize fibronectin molecules and type IV procollagen in vitro; (b) the cultivated mesangial cells also synthesize type I and III collagens. The implications of these findings in certain pathological circumstances, such as diabetes mellitus, are now being investigated.
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PMID:Synthesis of collagen and fibronectin by glomerular cells in culture. 732 12

Triacylglycerol metabolism has been studied in kidney cortex tubules from starved rats, prepared by collagenase treatment. Triacylglycerol was determined by a newly developed fully enzymic method. Incubation of tubules in the absence of fatty acids led to a decrease of endogenous triacylglycerol by about 50% in 1h. Addition of albuminbound oleate or palmitate resulted in a steady increase of tissue triacylglycerol over 2h. The rate of triacylglycerol synthesis was linearly dependent on oleate concentration up to 0.8mm, reaching a saturation at higher concentrations. Triacylglycerol formation from palmitate was less than that from oleate. This difference was qualitatively the same when net synthesis was compared with incorporation of labelled fatty acids. Quantitatively, however, the difference was less with the incorporation technique. Gluconeogenic substrates, which by themselves had no effect on triacylglycerol concentrations, stimulated neutral lipid formation from fatty acids. Glucose and lysine did not have such a stimulatory effect. Inhibition of gluconeogenesis from lactate by mercaptopicolinic acid likewise inhibited triacylglycerol formation. This inhibitory effect was seen with oleate as well as with oleate plus lactate. When [2-(14)C]lactate was used the incorporation of label into triacylglycerol was found in the glycerol moiety exclusively. Addition of dl-beta-hydroxybutyrate (5mm) to the incubation medium in the presence of oleate or oleate plus lactate led to a significant increase in triacylglycerol formation. In contrast with the gluconeogenic substrates, dl-beta-hydroxybutyrate had no stimulatory effect on fatty acid uptake. The results suggest that renal triacylglycerol formation is a quantitatively important metabolic process. The finding that gluconeogenic substrates, but not glucose, increase lipid formation, indicates that the glycerol moiety is formed by glyceroneogenesis in the proximal tubules. The effect of ketone bodies seems to be caused by the sparing action of these substrates on fatty acid oxidation. The decrease of triacylglycerol in the absence of exogenous substrates confirms previous conclusions that endogenous lipids provide fatty acids for renal energy metabolism.
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PMID:Triacylglycerol metabolism in isolated rat kidney cortex tubules. 737 17

The formation of adducts between methyltetrahydrophthalic anhydride (MTHPA), an important industrial chemical and potent allergen, and collagen from guinea pig lung tissue was investigated. Collagen peptides were obtained from the lung tissue by homogenization, defatting, washing, and digestion with collagenase. In experiments in vitro, lung tissue was exposed to 8.4 mumol (50 microCi) of 14C MTHPA. The amount of adducts was 97 nmol MTHPA/g of wet tissue as determined from the bound radioactivity. In a study in vivo, four guinea pigs were injected intratracheally with 8.4 mumol of 14C MTHPA each. The amount of adducts was 0-1.2 nmol MTHPA/g of wet tissue (determined by bound radioactivity). N epsilon-methyltetrahydrophthaloyl-L-lysine (MTHPL) was synthesized and characterized by NMR, UV, and mass spectrometry (MS). A method to analyze MTHPL, after derivatization with methanol and pentafluorobenzoyl chloride, using gas chromatography-MS was developed. Analysis of Pronase-digested MTHPA-exposed lung tissue showed a concentration of 19 nmol MTHPL/g wet lung in vitro and between 0 and 0.15 nmol MTHPL/g wet lung in vivo. Thus, 20% in vitro and 12-15% in vivo of the bound radioactivity was found as adducts with lysine. These results are a first step toward studies of allergenic epitopes in proteins and methods for biological monitoring of exposure to acid anhydrides.
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PMID:Lysine adducts between methyltetrahydrophthalic anhydride and collagen in guinea pig lung. 748 35


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