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)

Synthesis and secretion of basement membrane proteins by 3T3-L1 adipocytes were studied by metabolic labeling of the cells with [35S]methionine. Enhanced synthesis and secretion of many polypeptides of high molecular weight were observed by stimulating the adipose conversion of 3T3-L1 fibroblasts with dexamethasone, 1-methyl-3-isobutylxanthine, and insulin. Among these polypeptides, alpha 1(IV) and alpha 2(IV) chains of collagen were identified based on specific immunoprecipitation and digestion with bacterial collagenase. Synthesis and secretion of alpha 1(IV) and alpha 2(IV) chains were negligible in the fibroblasts, but remarkably enhanced in adipocytes. Based on specific immunoprecipitation of a sulfated polypeptide of 150 kDa, enhanced (6-fold) synthesis and secretion of entactin were also demonstrated. Immunoprecipitation with anti-laminin antiserum showed synthesis of three polypeptides with sizes corresponding to B subunits but failed to demonstrate synthesis of the A subunit. Synthesis of these laminin-related polypeptides remained constant during the conversion. Nonreducing sodium dodecyl sulfate electrophoresis showed intracellular assembly of three laminin-related polypeptides into binary and ternary complexes in a similar sequence of AB1B2 formation via B1B2 in embryonal carcinoma F9 (Morita, A., Sugimoto, E., and Kitagawa, Y. (1985) Biochem. J. 229, 259-264). The ternary complex of laminin in 3T3-L1 cells had a size significantly smaller than AB1B2 complex in F9 cells. In this complex, a novel subunit appears to take the place of the A subunit. Thus, a novel laminin complex is produced by 3T3-L1 cells.
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PMID:Enhanced synthesis and secretion of type IV collagen and entactin during adipose conversion of 3T3-L1 cells and production of unorthodox laminin complex. 246 Apr 44

Apamin, a bee venom polypeptide, is reported to block the Ca2+-dependent K+ channel in smooth muscle, hepatocyte, and neuroblastoma cells. In embryonic chick hearts, it was found to block the Ca2+ channel. We report here that apamin (10(-9)-10(-7) M) hyperpolarizes the resting membrane potential and shortens the duration of the action potential (AP) in the fast response of adult guinea pig ventricular papillary muscles. This peptide also depresses the isoproterenol or Ba2+-induced slow response APs in the presence of high K+ (21.6 mM) Tyrode solution, without affecting the resting potential. The most striking effect of apamin on the slow response was to shorten the duration of AP with only slight decreases in the maximal rate of increase (Vmax) of the AP, a nonlinear measure of Ca2+ currents. These findings suggest that apamin increases membrane K+ conductance in the mammalian ventricular myocardium. However, in enzymatically isolated single ventricular cells and at wide range of concentrations (10(-7)-10(-11) M), apamin did not affect the AP configuration and did not alter the membrane Ca2+ or K+ current, perhaps because of a loss of apamin sensitivity secondary to enzymatic digestion of the tissue with collagenase.
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PMID:Possible increases in potassium conductance by apamin in mammalian ventricular papillary muscles: a comparison with the effects on enzymatically isolated ventricular cells. 247 13

We report the complete primary and secondary structures of a metastasis-associated Mr 34,000 galactoside-binding lectin. The polypeptide sequence (264 amino acids) was derived from the nucleotide sequence of three overlapping complementary DNA clones isolated from lambda gt11 and lambda gt10 phage libraries of UV-induced murine fibrosarcomas. Striking features of the polypeptide sequence are two distinct regions of beta-sheet and globular structures at the amino and carboxy terminals, respectively. Homology search suggests that the polypeptide is a chimeric gene product formed by fusion of the 5'-end of an Mr approximately 14,000 galactoside-binding lectin with an internal domain of the collagen alpha gene. Enzymatic treatment with collagenase confirmed the presence of a collagen-like structure in the polypeptide. Unexpectedly, the entire sequence is greater than 85% homologous to a rat low affinity IgE-binding protein.
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PMID:Identification of the metastasis-associated, galactoside-binding lectin as a chimeric gene product with homology to an IgE-binding protein. 252 69

Interleukin-1 is a polypeptide factor with profound effects on several cell types, such as chondrocytes, fibroblasts, and T-cells. The ability of interleukin-1 to induce the synthesis of matrix-degradative enzymes, as well as prostaglandin E2, suggests a pivotal role for this mediator in chronic inflammation. Previous studies have shown that the effect of human monocyte interleukin-1 on the synthesis of collagenase and neutral proteases by chondrocytes was enhanced by basic fibroblast growth factor. Using recombinant human interleukin-1B, we have examined whether the potentiation of interleukin-1 effects by fibroblast growth factor is related to changes in the number or affinity of interleukin-1 receptors. Our studies confirm that rabbit articular chondrocytes in culture contain a single class of high-affinity receptors for interleukin-1 with a Ka of 0.9-1.1 x 10(-13) M-1. While the untreated chondrocytes contain approximately 1,620 receptors per cell, fibroblast growth factor-treated cells exhibit a higher number of receptors (approximately 2,960 per cell) with no apparent change in the affinity. The increase in receptor number can be abolished by inhibitors of lysosomal function, indicating a requirement for intracellular processing of the fibroblast growth factor. Our results suggest that the potentiation of interleukin-1 catabolic effects by fibroblast growth factor may be related to its ability to induce additional interleukin-1 receptors on the chondrocyte cell surface.
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PMID:Induction of interleukin-1 receptors on chondrocytes by fibroblast growth factor: a possible mechanism for modulation of interleukin-1 activity. 253 23

The effect of human TNF on cultured human microvascular endothelial (HME) cells was examined. Incubation with TNF alone transformed the morphology of HME cells from a cobblestone-like appearance into a disordered array of criss-crossed, elongated, spindle-shaped cells. Coadministration of epidermal growth factor (EGF) and TNF caused even more dramatic morphologic changes than TNF alone. Addition of basic fibroblast growth factor or insulin-like growth factor-I showed rather weak effects on cell morphology than EGF. Cell growth of HME cells was stimulated up to two-fold by TNF whereas addition of EGF additively enhanced the growth rate. Treatment of HME cells with 10 ng/ml EGF increased the binding of 125I-TNF, and Scatchard analysis showed increased TNF-R number by EGF treatment. Cellular response to TNF in the absence or presence of EGF was assessed by analyzing SDS-PAGE patterns of secreted proteins from HME cells. TNF enhanced the secretion of a protein of molecular weight 25,000 Da (25 kDa) which was found to be IL-6. In contrast, secretion of a polypeptide of 29 kDa was significantly increased when HME cells were treated with EGF, but not with TNF. Coadministration of TNF and EGF synergistically increased the secretion of the 29-kDa protein. This 29-kDa protein was found to be tissue inhibitor of metalloproteinases when assayed with antitissue inhibitor of metalloproteinases antibody. TNF and EGF also enhanced secretion of collagenase with Mr of approximately 55 kDa. Increased steady state levels of the inhibitor mRNA were observed when HME cells were treated with EGF, and coadministration of TNF further increased the levels. The morphologic transformation of HME cells by TNF and/or EGF is discussed in relation to their expression of the secreted proteins.
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PMID:Effects of tumor necrosis factor and epidermal growth factor on cell morphology, cell surface receptors, and the production of tissue inhibitor of metalloproteinases and IL-6 in human microvascular endothelial cells. 254 71

Comparison of the proteins secreted by early and late passage cell cultures of human fibroblasts revealed a high level of immunoreactive collagenase (Mr = 55,000 Da and 58,000 Da) in the late passage cell culture conditioned medium. Both molecular weight species reacted with a monoclonal anticollagenase antibody and were apparently glycosylation varaents of the same protein. The question of whether the apparent age-dependent differences in collagenase synthesis reflected changes in protein synthesis or secretion was addressed by assaying immunoreactive collagenase and collagenase mRNA. Immunofluorescence microscopy of cellular collagenase revealed that the percentage of collagenase positive cells ranged from 1 to 6% (early passage) to 35 to 46% (late passage) indicating that the late passage cells had higher basal levels of collagenase synthesis. Later passage cultures also secreted higher levels of immunoprecipitable collagenase into the culture medium and Northern analysis established that the basal level of collagenase mRNA was also 10 times greater in late passage cells. High basal levels of collagenase were also observed in fibroblasts cultured from an in vivo aged donor and from donors with Werner's syndrome. Collagenase production was induced in both early and late passage cell cultures by exposure to fibroblast extracellular matrix, fibroblast conditioned media, polypeptide growth factors, or phorbol esters. The induced levels were always greater in the late passage cell cultures than in the early passage cell cultures.
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PMID:Collagenase production by early and late passage cultures of human fibroblasts. 256 Nov 5

Synthesis and secretion of blood coagulation factor X was studied during incubations of hepatocytes prepared by perfusion of rat livers with collagenase. The apparent molecular weight of factor X isolated from the incubation medium was about 14,000 less than factor X isolated from rat plasma. The extracellular form of factor X was a two-chain polypeptide and the observed difference in molecular weight was reflected in the heavy chain. Since these properties were more characteristic of factor Xa than factor X, experiments were designed to determine if factor X activation occurred during the incubations. Clotting factor assays indicated that factor X secreted by hepatocytes was present as factor Xa. Also, when purified plasma factor X was added to incubations of hepatocytes the added factor X was converted to factor Xa. Plasma membranes prepared from isolated hepatocytes or from liver homogenates contained an enzyme that converted factor X to factor Xa in a calcium-dependent reaction. The results suggest that the activity is due to the presence of thromboplastin (tissue factor) and factor VII in the membrane preparations.
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PMID:The activation of factor X by hepatocyte plasma membranes. 261 30

A high molecular weight extracellular protein has been purified from cell culture medium of Ewing's sarcoma cell lines, by high performance liquid chromatography and electroelution from SDS-PAGE electrophoresis. This protein has an apparent molecular mass of about 500,000 Da on SDS-PAGE. Immunoprecipitation studies with several extracellular matrix glycoproteins (laminin, fibronectin) specific antisera indicate it is a separate protein. Reduction of disulphide bonds with 2-ME or DTT fails to significantly alter its migration on SDS-PAGE gels, other than a slight apparent increase in molecular mass, indicating an apparent single polypeptide chain structure. The slightly greater mobility observed in unreduced gels suggests one or more regions of intrachain disulfide bonding. It is sensitive to pepsin and trypsin, but resistant to bacterial collagenase indicating that it does not contain collagenous domains. Metabolic labelling with 3H-proline, 3H-leucine, and 35S-methionine indicate that this protein is proline-poor, but leucine, and especially methionine, rich. Sodium 35S-sulfate incorporation is totally negative and treatment with glycosaminoglycan degrading enzymes has no effect on the mobility of the protein on gels, unlike typical proteoglycans. This protein appears by rotary shadowing electron microscopy as a long, thin, filamentous molecule at least 500 nm (0.5 um) in length. The tissue localization and function are unknown at this time, but are under active investigation.
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PMID:A novel 500,000 Da, linear, single chain extracellular protein synthesized by several childhood tumors. 263 60

An enzymic method for recovering primordial follicles from the pig ovary consists of incubating cortical slices for 2 h with 0.025% collagenase 1A. An average of 185,000 or 419,000 primordial follicles per ovary were recovered from ovaries collected in Cambridge and Kansas, respectively. Following a discontinuous Percoll gradient, primordial follicles can be separated from contaminating somatic cells by mouth pipette or a micromanipulator to collect 100-1500 follicles but for large scale recovery of approximately 30,000 follicles flow cytometry is recommended. Two types of primordial follicles can be distinguished by electron microscopy: peripheral clusters of small oocytes with an incomplete investment of pregranulosa cells and a deeper region of individual oocytes surrounded by a complete layer of pregranulosa cells. The viability of the purified primordial follicles is attested by their ability to synthesize proteins for at least 12 h after incubation with [35S]methionine. Moreover, the primordial follicles showed several polypeptide bands in common with mature oocytes especially with Mr of 60,000-90,000 but with considerable differences from somatic cells.
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PMID:Isolation and preliminary characterization of pig primordial follicles. 268 42

Inflammatory and 'non-inflammatory' forms of arthritis affect a large proportion of the population and these diseases can often lead to disability. Although the pain of arthritis can be relieved to some extent by the peripherally acting aspirin-like drugs, the progression of disease leading to joint destruction is largely resistant to current drug therapy. The synovial joints of patients with rheumatoid arthritis are infiltrated with neutrophils, macrophages and lymphocytes and the resident cells become activated to degrade the cartilage and bone. The inflammatory and destructive changes that occur are brought about by the action of mediators or local hormones which are produced by a variety of cell-types. Lipid mediators, such as prostaglandins, contribute to the symptoms of arthritis while polypeptide cytokines, such as interleukin 1 and tumour necrosis factor, play a key role in joint destruction by activating the synovial cells and chondrocytes to release metalloproteinases, such as collagenase. Aspirin-like drugs inhibit the production of prostaglandins from inflamed tissues and thereby blunt the symptoms of arthritis. However, these drugs do not suppress the production of collagenase from connective tissue cells and, therefore, do not halt the degeneration of joint tissues.
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PMID:Pathogenesis and treatment of chronic arthritis. 269 74


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