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)

Periportal and perivenous hepatocytes from rat liver were isolated by combined digitonin-collagenase perfusion, and gluconeogenesis, urea synthesis and fatty acid synthesis was measured both in freshly isolated cells and in primary culture. A periportal zonation of gluconeogenesis and urea synthesis of about 3 and 1.5 fold, respectively, was observed. This zonation persisted unchanged for 23 hours in culture under identical conditions of incubation for periportal and perivenous cells. Fatty acid synthesis was not zonated.
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PMID:Periportal and perivenous hepatocytes retain their zonal characteristics in primary culture. 302 Nov 46

A superfusion technique was adapted to collagenase-dispersed renal medullary and cortical tubular cells to study prostaglandin (PG) synthesis in response to arginine vasopressin (AVP), angiotensin II (ANG II), bradykinin (BK), Ca2+ ionophore A23187, and to changes in osmolality. Medullary and cortical cells promptly responded to the stimuli by an increase in PGE2 and PGF2 alpha production, whereas 6-keto-PGF1 alpha was not detected. AVP and BK were active on medullary cells, and ANG II was active mainly on cortical cells. A23187 stimulated PG synthesis in both cells but predominantly in the medulla. PG synthesis was dependent on the presence of extracellular Ca2+. The Ca2+ entry blocking agents verapamil and lanthanum did not inhibit the PG response to AVP, BK, and ANG II. Thus peptide hormone-stimulated PG synthesis in renal tubular cells did not depend on Ca2+ influx through channels blocked by these agents. Hyperosmolar NaCl or mannitol stimulated PG synthesis in cortical and, more markedly, in medullary cells. Hyperosmolar urea inhibited PGE2 synthesis stimulated by peptide hormones, NaCl, and A23187 in both cell preparations. In conclusion, the superfusion of isolated tubular cells is a useful method to study the dynamic aspects of renal PG release in response to various sequentially applied stimuli.
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PMID:Dynamic response of PG synthesis to peptide hormones and osmolality in renal tubular cells. 308 19

We investigated the role of intracellular calcium in epithelial cell volume regulation using cells isolated from the toad urinary bladder. A suspension of cells was prepared by treatment of the bladder with collagenase followed by ethyleneglycol-bis(beta-aminoethylether)-N,N'-tetraacetic acid. The cells retained their ion-transporting capabilities: ouabain (1 mM) and amiloride (10 microM) inhibited cellular uptake of 86Rb and 22Na, respectively. Using a Coulter counter to measure cellular volume, we found that we could swell cells either by reducing the extracellular osmolality or by adding the permeant solute urea (45 mM) isosmotically. Under both conditions, cells first swelled and then returned to their base-line volume, in spite of the continued presence of the stimulus to swell. Volume regulation was inhibited when cells were swelled at low extracellular [Ca] (100 nM) and was retarded in cells preloaded with the calcium buffer quin 2. Swelling increased the intracellular free calcium concentration ([Ca]i), as measured by quin 2 fluorescence: [Ca]i increased 35 +/- 9 nM (n = 6) after hypotonic swelling and 42 +/- 3 nM (n = 3) after urea swelling. Reducing extracellular [Ca] to less than 100 nM prevented the swelling-induced increase in [Ca]i, suggesting that the source of the increase in [Ca]i was extracellular. This result was confirmed in measurements of cellular uptake of 45Ca: the rate of uptake was significantly higher in swollen cells compared with control (1.1 +/- 0.2 vs. 0.4 +/- 0.1 fmol . cell-1 X 5 min-1). Our experiments provide the first demonstration that cellular swelling increases [Ca]i. This increase is likely to play a critical role in cellular volume regulation.
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PMID:Role of intracellular calcium in cellular volume regulation. 308 13

The glycosaminoglycans (GAG), glycoproteins and collagen in bovine aorta and venous tissue have been studied. The concentration of hyaluronic acid and dermatan sulphate was significantly more in the venous tissue while chondroitin sulphates were higher in the aorta. Sequential extraction with phosphate buffered saline (PBS) collagenase, hyaluronidase and urea was also carried out with the two tissues. The GAG extractable by PBS and collagenase digestion were more in the aorta. The total aortic glycoproteins had significantly lower hexose and higher sialic acid. The PBS extractable glycoproteins of the venous tissue had more hexose and fucose. The glycoproteins released by collagenase digestion of the venous tissue had lower sialic acid and higher fucose, while glycoprotein released by hyaluronidase digestion had lower sialic acid and higher hexose and fucose. Urea extractable glycoproteins had lower fucose and sialic acid in the venous tissue. Venous tissue had higher total collagen and acid and salt soluble collagen while insoluble collagen was more in the aorta. The total GAG in the venous tissue had greater anticoagulant activity while the aortic GAG bound significantly more serum lipoproteins.
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PMID:Studies on the macromolecular components of the bovine aortic and venous tissue. 309 9

Several small collagenous apatite binding (SCAB) proteins have been extracted from the mineralized matrix of fetal porcine calvarial bone. One protein (SCAB 3), released on demineralization of bone with 0.5 M EDTA, appears to represent the alpha 1 pN-propeptide that is normally released during proteolytic processing of type I procollagen. The 28 Kd protein, which stains blue with "Stains-all", is reduced to a 19 Kd fragment by bacterial collagenase digestion, but is not susceptible to cyanogen bromide. The amino acid composition, blocked amino-terminus and immunological properties are all consistent with properties of alpha 1 (I) pN-propeptide. Fractionation on hydroxylapatite in the presence of urea has revealed a nonbinding (SCAB 3a) and a binding (SCAB 3b) form. Extraction of the demineralized matrix of bone with 4 M GuHCl revealed a third form (G2-28) which was similar to SCAB 3a on hydroxylapatite chromatography but showed differences on FPLC "Mono Q" resin. The occurrence of these different forms of pN-propeptide in bone may be of significance in collagen fibril-associated hydroxylapatite formation and in the regulation of osteoblastic function during bone resorption.
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PMID:Identification of small collagenous proteins with properties of procollagen alpha 1 (I) pN-propeptide in fetal porcine calvarial bone. 339 4

The formation of collagen IV dimers in the extracellular space requires the association of two C-terminal globular domains giving rise to a large hexameric structure NC1 (Mr = 170,000). NC1 hexamer was purified from collagenase digests of a mouse tumor and several human tissues. It was shown by electrophoresis to consist of two kinds of cross-linked, dimeric segments, Da and Db (Mr about 50,000), and monomeric segments in a molar ratio of about 3:1. In the native hexamers free SH groups were detectable by N-[14C]ethylmaleimide and other sulfhydryl reagents. They account for 4-11% of the total number of cysteine residues with some variations between preparations from different sources and in the distribution between monomers and dimers. Reduction with 10 mM dithioerythritol under non-denaturing condition completely converted dimers into monomers and allowed the alkylation of all twelve cysteine residues present in each monomeric NC1 segment. A monomeric intermediate with four to six free SH groups and a higher electrophoretic mobility than the final product was observed. Generation of this intermediate from dimers Da and Db follows apparently different routes proceeding either directly or through a dimeric intermediate respectively. The time course of conversion is best described by a mechanism consisting of two (Db) or three (Da) consecutive steps with pseudo-first-order rate constants ranging from 0.14 ms-1 to 0.5 ms-1. Glutathione-catalyzed reoxidation of completely reduced NC1 in the presence of 2 M urea results in a product indistinguishable from native material by ultracentrifugation and electrophoresis pattern. The data suggest that in situ formation of NC1 structures is catalyzed by a small fraction (5-10%) of intrinsic SH groups leading to the formation and stabilization of dimers by rearrangement of disulfide bonds.
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PMID:Reductive cleavage and reformation of the interchain and intrachain disulfide bonds in the globular hexameric domain NC1 involved in network assembly of basement membrane collagen (type IV). 340 52

We describe a unique mesangial matrix component of the rat glomerulus identified by a murine monoclonal antibody. The antigen is present exclusively in the glomerular mesangium and cannot be detected in other rat tissues by indirect immunofluorescence techniques or following pretreatment of tissue sections with acid urea or other nonionic detergents. Specific immunoprecipitation of the solubilized antigen yields a single peptide with an apparent m.w. of 81,000 when analyzed by discontinuous SDS-PAGE. This mesangial matrix component is collagenase resistant and trypsin sensitive. Perfusion of an isolated kidney preparation with this antibody results in direct binding of the mouse immunoglobulin to its mesangial antigen. Passive administration of the monoclonal antibody to Lewis rats results in characteristic electron dense deposits within the mesangial matrix that can be visualized ultrastructurally as early as 3 days. The immune deposits form without the activation of rat complement and persist for longer periods than those that develop after the planting of aggregated proteins or preformed immune complexes. Experimental animals that received either a monoclonal antibody specific for laminin or a non-kidney binding preparation did not develop such immune deposits at any time during the course of the autologous phase of the immune process. The results obtained in this study indicate that electron dense immune deposits can develop in the mesangium with the participation of a unique intrinsic matrix component and specific circulating monoclonal antibodies by an in situ mechanism of immune complex formation.
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PMID:Immune deposits formed in situ by a monoclonal antibody recognizing a new intrinsic rat mesangial matrix antigen. 352 86

Sera from two patients with primary anti-tubular-basement-membrane-mediated tubulointerstitial nephritis, one a renal allograft recipient and the other with spontaneous anti-tubular-basement-membrane disease, were analyzed for the specificity of their autoantibodies. Both sera had circulating antibodies that reacted by ELISA with extracts of tubular basement membrane from several species, but failed to react significantly with extracts of glomerular basement membrane. Reactive antigen was solubilized with 6 M guanidine-HCl, 6 M urea, with reduction and alkylation, and with sodium dodecylsulfate. Digestion of the basement membrane with collagenase released relatively small quantities of antigen from the membrane, and trypsin and pepsin destroyed its antigenicity. The antigenic activity was characterized with respect to its size distribution by gel filtration and by immuno-overlay analysis of protein blots. Collectively, the results indicate that the major reactivity of both sera is directed towards a Mr 58,000 component that is unique to the tubular basement membrane. Minor reactivities toward high molecular weight components common to both glomerular and tubular basement membranes were detected by immuno-overlay analysis. This study identifies an antigen that is involved in human anti-tubular-basement-membrane-mediated tubulointerstitial nephritis, and demonstrates an advantage of the use of denaturing extraction over proteolytic methods to prepare the antigen.
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PMID:Identification of a target antigen in human anti-tubular basement membrane nephritis. 355 4

Using human kidney cortical homogenates and long-term cultured glomerular cells as antigens, the author produced three monoclonal antibodies to glomerular components; 25C reacted with the glomerular basement membrane (GBM) and the wall of blood vessels but with neither the tubular basement membrane (TBM) nor the Bowman's capsule, 33G reacted predominantly with the mesangium, and 34F reacted with glomeruli and the tubular brush border in a granular pattern. Both 25C and 33G exhibited the species-restricted property, and 34F reacted with glomeruli and tubular brush border of all the species examined. Overnight incubation of the kidney sections with 4.0 M urea revealed the reactivity of 25C to the TBM and Bowman's capsule. Dot immunobinding assay revealed that 25C did not react with the known extracellular matrices examined in this study, but rather with collagenase-digested GBM fraction. Also, 33G recognized fibronectin. Western blotting revealed the binding of 34F to the 145-kDa polypeptide solubilized from the kidney with 0.5 M NaCl, and also showed the binding of 25C to 210-kDa polypeptide of collagenase-digested GBM. These findings revealed structural variations in the basement membrane and the existence of a common antigen between the glomeruli and tubular brush border in the human kidney.
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PMID:Monoclonal antibodies to human glomerular antigens. II. Using human adult kidney components as antigens. 378 54

NC1 subunits were purified from gel filtration pools of acid-extracted, collagenase-digested human glomerular basement membranes (hGBM). This methodology, which enriches 28-kDa monomers (M28) in the total digest, allowed purification of these monomers and 24-kDa (M24) and 26-kDa (M26) monomers free from dimers. Reactivity of these subunits with Goodpasture autoantibodies using immunoblotting of sodium dodecyl sulfate-polyacrylamide gel electrophoresis and two-dimensional nonequilibrium pH gradient electrophoresis gels showed strong reactivity with the purified M28 subunits. Inhibition enzyme-linked immunosorbent assay, used to quantitate the reactivity of the purified NC1 subunits, indicated that M28 had a greater than 10-fold increase in ability to inhibit binding to NC1 than NC1 itself. Comparison of hGBM NC1 components were made with those obtained from collagenase digests of salt and acid-extracted bovine and sheep GBM and Englebreth-Holm-Swarm tumor similarly purified by gel filtration and reverse-phase high performance liquid chromatography. Two-dimensional gel analysis of these NC1 isolates revealed absence of the very cationic M28 monomers. Reactivity with antibodies eluted from diseased kidneys of sheep immunized with hGBM (Steblay nephritis) was compared with Goodpasture autoantibody reactivity by immunoblotting two-dimensional gels of hGBM NC1. We conclude that a very cationic M28 monomer (M28 ) found only in hGBM is the probable target in Goodpasture syndrome, that the epitope is present on most NC1 components from extracted and unextracted hGBM, and is exposed by urea denaturation which is enhanced by acid treatment. A weakly cationic M28 monomer (M28+) is present in GBM from other species and is the probable target in Steblay nephritis. Differential recognition of the two M28 components by these antibodies points to different genetic origins or possibly distinct post-translational modifications for these components. This is supported by their presence or absence in different species and tissues, as well as biochemical differences from the M24/26 monomers which presumably are derived from alpha 1(IV) and alpha 2(IV) collagen chains.
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PMID:Antibody specificity of human glomerular basement membrane type IV collagen NC1 subunits. Species variation in subunit composition. 378 34


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