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

---

Query: EC:3.4.24.3 (collagenase)
18,340 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

It has been demonstrated immunohistologically using cryostat sections that the lectins PHA and Con A bind to human placentae. Both lectins stain trophoblastic basement membrane (TBM), perivascular tissue and stroma. No staining of trophoblasts was observed. It has been shown by blocking experiments that the lectin binding sites on placental TBM are glycoproteins, whereas experiments involving pretreatment of placental sections with anti-collagen antisera or highly purified bacterial collagenase have indicated that lectin binding to stromal and perivascular structures is collagen-associated. The possible relation of TBM lectin-binding sites to immune response gene products is briefly discussed.
...
PMID:Immunological studies of human placentae. Lectin binding to villous stroma and to trophoblastic basement membrane. 18 Nov 90

Prostaglandins, especially PGE2 and PGI2, appear to participate in the development of inflammatory reactions. While these PGs may act to promote inflammation, they may also inhibit immune reactions; this effect is largely related to stimulation of adenylate cyclase. Human rheumatoid synovial tissue explants and derived adherent synovial cells (ASC) in vitro produce large amounts of PG, primarily PGE2, which may participate in the pathogenesis of rheumatoid inflammation and promote the osteoclastic resorption of juxtaarticular bone. Rheumatoid synovial organ cultures are unusual in that they derive a significant proportion of archidonic acid substrate for the PGE2 synthesis from triglycerides, while ASC utilize primarily phospholipids. Aspirin-like, nonsteroidal anti-inflammatory drugs inhibit PGE2 synthesis by rheumatoid synovial organ cultures at concentrations similar to those achieved in plasma during therapy. Glucocorticoids are also potent inhibitors of PGE2 synthesis, and evidence from experiments with tissue labeled with 1-[14C]arachidonic acid indicates that glucocorticoids do not act to inhibit arachidonic acid release, as has been postulated for other tissues. Human peripheral blood mononuclear cells produce a factor (MCF) that regularly stimulates the production of PGE2 and collagenase from resting ASC often by over 100-fold. The MCF appears to be produced by monocytes, and its production by monocytes is enhanced by lectin-stimulated T-cells. The ability of ASC to respond to exogenous PGE2 stimulation of cAMP synthesis is inhibited or stimulated by factors that increase or decrease PGE2 levels, respectively, in the cultures. The MCF augments the responsiveness of cAMP response to PGE2 in indomethacin-treated cultures. These in vitro experiments suggest that the pathogenesis of rheumatoid inflammation involves interactions between monocyte-macrophages, lymphocytes, and synovial cells regulating the production of PGE2, cAMP, and other factors.
...
PMID:Prostaglandins and their regulation in rheumatoid inflammation. 23 4

Connective tissue destruction is a major characteristic of chornic rheumatoid arthritis (RA). This process is accompanied by local cellular and humoral inflammatory reactions. Long-term cultures of adherent synovial cells (ASC) from patients with RA produce large amounts of collagenase and prostaglandin (PGE2), two substances that play a role in the degradation of joint structures. Lvels of collagenase and PGE2 can be stimulated (up to several hundred-fold) with a soluble factor (MCF) from cultured peripheral blood mononuclear cells (MW approximately 14,000). The monocyte-macrophages alone produce MCF but can be stimulated directly with Fc fragments of immunoglobulin or concanavalin A to increase MCF production. Addition of T lymphocytes in the presence of lectin or antigen significantly enhances the production of MCF. MCF affects other biological processes in synovial cells such as the rate of collagen synthesis, cell proliferation and sensitivity to PGE2 as well as collagen itself can further modulate collagenase release by the synovial cells and function in an amplificative loop. The understanding of these interactions between cells, mediator-effector substances and connective tissue substrates may provide a basis for devising more rational approaches to therapy of the destructive lesions which characterize RA.
...
PMID:Collagenase and prostaglandin in connective tissue destruction: cell-cell and humoral interactions. 23 69

The concanavalin A (Con A)-induced agglutinability of normal, preneoplastic, and neoplastic mouse mammary epithelial cells was examined. Cells freshly dissociated from normal mammary glands, hyperplastic alveolar nodules, or primary mammary adenocarcinomas by collagenase digestion in the presence of bovine serum albumin were strongly agglutinated by low concentrations of Con A. After short-term culture in vitro, however, cells from all three types of tissue were only weakly agglutinated by Con A, as measured by both suspension and hemadsorption assays. By comparison, cells of three established mammary tumor culture lines agglutinated strongly in the presence of the lectin. Treatment of the normal, preneoplastic, and neoplastic mammary cells in primary cultures with either trypsin or collagenase had little or no effect on their agglutinability, whereas hyaluronidase significantly increased their reactivity. Studies with fluorescein-tagged Con A indicated that all three cell types were capable of binding the lectin. The results were consistent with previous evidence suggesting that neoplastic transformation of mouse mammary epithelial cells is not manifested in vitro by several of the alterations in growth patterns, intercellular interactions, and surface properties that usually accompany transformation of fibroblastic cells.
...
PMID:Concanavalin A-induced agglutinability of normal, preneoplastic, and neoplastic mouse mammary cells. 28 51

The surface saccharide composition of collagenase-dispersed pancreatic cells from adult guinea pig and rat glands was examined by using eight lectins and their ferritin conjugates: Concanavalin A (ConA); Lens culinaris (LCL); Lotus tetragonolobus (LTL); Ricinus communis agglutinins I and II (RCA I, RCA II); Soybean agglutinin (SBA); Ulex europeus lectin (UEL); and wheat germ agglutinin (WGA). Binding studies of iodinated lectins and lectin-ferritin conjugates both revealed one population of saturable, high-affinity receptor sites on the total cell population (approximately 95% acinar cells). Electron microscopy, however, revealed differences in lectin-ferritin binding to the plasmalemma of acinar, centroacinar, and endocrine cells. Whereas acinar cells bound heavily all lectin conjugates, endocrine and centroacinar cells were densely labeled only by ConA, LCL, WGA, and RCA I, and possessed few receptors for LTL, UEL, and SBA. Endocrine and centroacinar cells could be differentiated from each other by using RCA II, which binds to centroacinar cells but not to endocrine cells. Some RCA II receptors appeared to be glycolipids because they were extracted by ethanol and chloroform-methanol in contrast to WGA receptors which resisted solvent treatment but were partly removed by papain digestion. RCA I receptors were affected by neither treatment. The apparent absence of receptors for SBA on endocrine and centroacinar cells, and for RCA II on endocrine cells, was reversed by neuraminidase digestion, which suggested masking of lectin receptors by sialic acid. The absence of LTL and UEL receptors on endocrine and centroacinar cells was not reversed by neuraminidase. We suggest that the differential lectin-binding patterns observed on acinar, centroacinar, and endocrine cells from the adult pancreas surface-carbohydrate-developmental programs expressed during morphogenesis and cytodifferentiation of the gland.
...
PMID:Distribution of cell surface saccharides on pancreatic cells. II. Lectin-labeling patterns on mature guinea pig and rat pancreatic cells. 42 54

Erythrocytes of different species (chicken, sheep, man, mouse, rat, guinea pig) except rabbit erythrocytes strongly adhere to the marginal zone of mouse spleen follicles in frozen sections. This adherence reaction (AR) is not restricted to red blood cells but is also observed with human lymphocytes. Pretreatment of the tissue sections with trypsin, mercaptoethanol, periodate, chloroform/methanol, acetone, and heating the sections abolishes AR whereas neuraminidase (VCN) treatment of the sections has an amplifying effect. AR is inhibited by preincubation of the neuraminidase- or untreated sections with neuraminic acid (NA). Treatment of the erythrocytes with VCN completely abolishes AR whereas treatment with other enzymes (hyaluronidase, collagenase) is ineffective in this respect. Determination of NA in the erythrocyte membrane before and after VCN treatment reveals a positive correlation between the amount of NA and AR. Rabbit red blood cells have the lowest NA content in their membranes and, in addition, there is little effect of VCN treatment in further reducing it. It is possible that a lectin-like substance is responsible for AR. The biologic significance of AR is hypothetical, but since AR occurs in an area of the spleen playing a role in antigen trapping it is conceivable that this trapping may be mediated by interaction of NA and NA receptor(s).
...
PMID:Erythrocyte adherence to the marginal zone of mouse spleen follicle mediated by receptor(s) for neuraminic acid. 46 83

The submandibular glands of 4-week-old rats were dissociated by a procedure involving digestions with collagenase and hyaluronidase, chelation of divalent cations and mechanical force. A suspension of single cells was obtained in low yield by centrifugation in a Ficoll-containing medium. Immediately after dissociation and after a culture period of 16-18 hr the dissociated cells were tested for agglutinability by concanavalin A (Con A). Using ferritin (tfer)-conjugated Con A the lectin binding by the isolated acinar cells was also studied. The dissociated cells were agglutinated by low concentrations of Con A and bound Fer-Con A molecules on their entire surface without any indication of polarization of the cell membrane. There was a considerable cell to cell variation in the amount of Fer-Con A binding which was, in general, sparse and patchy. The contact surfaces between agglutinated cells revealed a dense binding of Fer-Con A molecules irrespective of the types of cells participating in the agglutination reaction. Cells cultured for 16-18 hr were no longer agglutinated by Con A. As compared to the freshly dissociated cells the cultured acinar cells revealed a more uniform and denser binding of Fer-Con A molecules. Furthermore, there were more lectin molecules bound to the cell surface corresponding to the basal part of the cell, where the nucleus and most of the rough surface endoplasmic reticulum were located, than to the apical cell surface. It is suggested that the higher density of lectin-binding sites on the cell surface in the vicinity of the cisternae of the rough endoplasmic reticulum indicates insertion sites of newly synthesized membrane glycoproteins.
...
PMID:Distribution of concanavalin A binding sites on the surface of dissociated rat submandibular gland acinar cells. 115 94

Conglutinin and mannose-binding protein (MBP) are members of the C-type lectins which are widely present in mammalian plasma. Serum amyloid P-component (SAP) is a member of the pentraxin family with lectin properties. A scheme for the partial purification of all three lectins by carbohydrate affinity chromatography and selective elution was developed. The purification was monitored by SDS-PAGE, Western blotting and electron microscopy. Binding of the lectins to Sephadex-iC3b, their collagenase sensitivity, and the size and antibody reactivity of their subunits was investigated. The demonstration, by SDS-PAGE, of 25-kDa subunits, which were unaffected by collagenase treatment but bound to Sephadex-iC3b and antibodies to human SAP, indicated the existence of bovine SAP. Bovine conglutinin (BK) also showed calcium-dependent binding to Sephadex-iC3b, whereas bovine MBP did not. The binding of BK was inhibitable with GlcNAc. A 3000-fold increase in BK activity (ELISA) was obtained in eluates from Sephadex-iC3b. SDS-PAGE analyses of BK and MBP revealed subunits with an Mr of 43 kDa and 30 kDa, respectively. These subunits were sensitive to collagenase treatment which reduced the Mr to 20 kDa. Electron micrographs revealed a prominent flexible tetramer molecule (diameter 96 nm) in the BK preparations, a predominantly hexameric structure (diameter 30 nm) in the MBP preparations, and single annular pentameric disc-like molecules (diameter 11 nm) in the SAP preparations.
...
PMID:Purification, subunit characterization and ultrastructure of three soluble bovine lectins: conglutinin, mannose-binding protein and the pentraxin serum amyloid P-component. 131 9

A forty-kilodalton (40-kDa) protein was extracted from alveolar bone of young adult rabbit with 0.5 M EDTA after extraction with 4 M GuHCl, and purified by gel-filtration, anion-exchange and hydroxyapatite columns using a high-pressure liquid chromatography system under denaturing conditions. The purified 40-kDa protein was not susceptible to bacterial collagenase and thrombin, but was cleaved by cyanogen bromide. The protein was stained blue with Stains-all. Among various lectins, concanavalin A and lentil lectin agglutinin bound to this protein, but peanut agglutinin, Ricinus communis agglutinin, phytohemagglutinin-E and wheatgerm lectin agglutinin did not. Lectin binding assays showed that the protein is a glycoprotein containing large amounts of mannose and/or glucose residues, but is not a fragment of proteoglycan. The amino acid composition of the protein shows a characteristically high content of acidic amino acids. Therefore, the mineral-binding 40-kDa glycoprotein is considered to be osteonectin/secreted protein acidic and rich in cysteine (SPARC), in terms of similarities to bovine and porcine osteonectins with regard to molecular weight and contents of glycoses and amino acids.
...
PMID:Characterization of mineral-binding 40-kDa glycoprotein extracted from young adult rabbit alveolar bone. 132 44

Activated macrophages (M phi s) have terminal alpha-D-galactosyl (alpha D-Gal) residues on their membranes that are not apparent on resting cells. Ligation of these epitopes with Griffonia simplicifolia I-B4 (GSI-B4), a lectin that has specificity for alpha-D-Gal residues, alters selected M phi functions. To explore the mechanism(s) that may be responsible for some of the functional changes, alterations in the secretory pattern of [35S]methionine-labeled proteins were assessed when cells were cultured with or without this ligand. The proteins were identified by Western blots and quantitated. Interestingly, alpha-D-Gal ligation proved to decrease the secretion of some proteins while increasing the secretion of others. Some of the most significant changes were observed in four proteins: fibronectin and transglutaminase were down-regulated by 55 and 66% respectively, while plasminogen activator inhibitor type 2 was increased by 259% and collagenase was increased 1000-fold. These observations show that the emergence of new oligosaccharide epitopes, such as alpha-D-Gal, concomitant with M phi activation may serve to mediate the transduction of signals that cause quantitative changes in the elaboration of diverse M phi products. The biologic significance of the four identified proteins has been well established. Fluctuations in their levels are likely to play a role at sites of chronic inflammation.
...
PMID:Specific ligation of surface alpha-D-galactosyl epitopes markedly affects the quantity of four major proteins secreted by macrophages. 137 96


1 2 3 4 5 6 7 8 9 10 Next >>

---