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)

The production of collagenase by human skin explants in culture is prevented by 10(-8) M dexamethasone, 5 . 10(-4) M dibutyryl cyclic AMP, or 2.5 . 10(-3) M theophylline. Decreases in collagenase activity are paralleled by reductions in the degradation of explant collagen during the culture period. Progesterone, which effectively inhibits collagenase production in rat uterine explant cultures, has no effect on human skin explants. The inhibition by cyclic AMP is nucleotide specific. When partially inhibitory concentrations of dexamethasone and dibutyryl cyclic AMP, or dexamethasone and theophylline, are added to culture medium together, the resultant inhibition is that predicted by additivity. Synergistic inhibition, as observed in rat uterus between progesterone and dibutyryl cyclic AMP, fails to occur. Dexamethasone inhibits the production of collagenase by cultured explants of rat uterus, with complete inhibition occurring at 10(-7) M steroid. Synergism between glucocorticoids and dibutyryl cyclic AMP or between dexamethasone and progesterone could not be demonstrated in the uterine culture system. These results suggest the existence of three regulatory systems for the control of collagenase production in mammalian tissues, and that cooperativity between systems may occur on a tissue-specific basis.
...
PMID:Hormonal interactions in mammalian collagenase regulation. Comparative studies in human skin and rat uterus. 624 13

The collagen substrate specificity of rat uterus collagenase was studied as a function of both collagen type and species of substrate origin. For each collagen examined, values for the basic kinetic parameters, Km and Vmax (kcat), were determined on collagen in solution at 25 degrees C. In all cases, Lineweaver-Burk plots were linear and rat uterus collagenase behaved as a normal Michaelis-Menten enzyme. Collagen types I, II, and III of all species tested were degraded by rat uterus collagenase. Collagen types IV and V were resistant to enzymatic attack. Both enzyme-substrate affinity and catalytic rates were very similar for all susceptible collagens (types I-III). Values for Km ranged from 0.9 to 2.5 X 10(-6) M. Values for kcat varied from 10.7 to 28.1 h-1. The homologous rat type I collagen was no better a substrate than the other animal species type I collagens. The ability of rat uterus collagenase to degrade collagen types I, II, and III with essentially the same catalytic efficiency is unlike the action of human skin fibroblast collagenase or any other interstitial collagenase reported to date. The action of rat uterus collagenase on type I collagen was compared to that of human skin fibroblast collagenase, with regard to their capacity to cleave collagen as solution monomers versus insoluble fibrils. Both enzymes had essentially equal values for kcat on monomeric collagen, yet the specific activity of the rat uterus collagenase was 3- to 6-fold greater on collagen fibrils than the skin fibroblast enzyme. Thus, in spite of their similar activity on collagen monomers in solution, the rat uterus collagenase can degrade collagen aggregated into fibrils considerably more readily than can human skin fibroblast collagenase.
...
PMID:The collagen substrate specificity of rat uterus collagenase. 631 21

The purification and properties of an estradiol-sensitive hydrolytic activity from mouse uterus which fits several criteria for being an induced protein are described. The activity in the uteri of immature animals can be stimulated 2--4-fold by estradiol to that approaching the adult level. Stimulation is blocked by puromycin. The enzyme which we have designated hydrolase II, was purified approx. 400-fold to apparent homogeneity by chromatography on Affigel Blue, DEAE-cellulose and octyl-Sepharose. Hydrolase II is a single chain polypeptide with an estimated mol. wt = 65,000 daltons and has an N-terminal serine residue. A variety of N-blocked L-amino acid nitrophenyl esters are cleaved by the enzyme. Km's at pH 7.2 were all approx. 40 microns. Of substrates tested, phenylalanine nitrophenyl ester had the highest Vmax. Cbz-beta-alanine nitrophenyl ester, which is not a normal protease substrate was cleaved with a Km of 145 microM. The enzyme had no detectable activity against peptide nitroanilide substrates for trypsin-, chymotrypsin- or elastase-like enzymes. It is inhibited by ZPCK and DIFP but not by TLCK and Ala-Ala-Pro-Ala chloromethyl ketone, a potent inhibitor of elastase-like enzymes. Mouse plasma protein protease inhibitors were without effect as was SBTI. Our results rule out hydrolase II being a carnosinase, non-serine esterase, plasminogen activator, collagenase or collagenase activator and suggest that it is a chymotrypsin-like protease.
...
PMID:Properties of an estrogen-induced hydrolytic enzyme from mouse uterus. 635 Jul 23

Creatine kinase (CK) activity was measured in human endometrium as a function of the normal menstrual cycle. The specific activity of CK was consistently higher in the secretory endometrium than in the proliferative tissue (proliferative, 0.9 U/mg of protein; secretory, 3.3 U/mg of protein). The relative distribution of CK activity in isolated glands and stromal cells was determined following collagenase digestion of the endometrial specimen according to our previously described procedure. These studies show an enrichment of CK activity in the glands that is greater than fivefold that present in the stromal cells. Electrophoretic mobility of CK activity on cellulose acetate further indicates that the endometrial enzyme is a BB (brain type) isoenzyme. In the rat uterus, CK has been shown to be an estrogen-induced protein. In contrast, the activity of this enzyme may be modulated by progesterone in human endometrium.
...
PMID:Creatine kinase activity in human endometrium: relative distribution in isolated glands and stroma. 684 32

Normal mammary epithelial cells from BALB/cfC3H midpregnant mice were freed from stromal cell types by Percoll density gradient centrifugation after collagenase digestion and were then embedded within collagen gels. Sustained growth leading to an increase in cell number was accomplished in response to cholera toxin and high concentrations of horse serum. The extent of growth was found to be dependent on the horse serum concentration, the maximum growth being attained at 50%. A serum concentration of 12.5% horse serum and 2.5% fetal calf serum, along with cholera toxin at 0.01 mug/ml, allowed maintenance but failed to cause any significant increase in cell number during the experimental period of 2 weeks. This same maintenance medium was used to determine the effects of various exogenously added steroids, protein hormones, and organ extracts on the proliferation of mammary epithelial cells in culture. Hormones failed to elicit any proliferative response, but extracts of kidney, brain, uterus, and spleen produced proliferative responses equal to or greater than the response obtained with 50% horse serum and cholera toxin. Kidney extracts prepared from midpregnant mice, virgin mice, and virgin mice given pituitary isografts all showed comparable activities, suggesting that the concentration of stimulatory factor(s) was not influenced by the hormonal status of the donor. Normal mammary epithelial cells that had undergone a 10- to 15-fold increase in cell number over initial values during 2-3 weeks in culture were passaged to secondary gel cultures. Outgrowth similar to those seen in primary culture were seen again in secondary culture. The present system provides a method for sustaining growth in culture of primary mammary epithelial cells from normal tissues.
...
PMID:Sustained growth in primary culture of normal mammary epithelial cells embedded in collagen gels. 692 40

A new hydrolase activity has been identified by its capability of cleaving t-boc-Ala-Ala-Pro-Ala-AMC, the released 7-amino-4-methylcoumarin (AMC) being quantified fluorometrically. The activity in the 28,000 X g supernatant fraction of homogenates of weanling mouse uterus was about one fifth that of the adult mouse. The administration of estradiol to the weanling mouse caused a prompt increase in uterine hydrolase, the response being biphasic with peaks at 2 and 6 h. Stimulation was dose responsive and effectively blocked by cycloheximide and puromycin. Estrogen stimulation of hydrolase activity was also observed in the kidney (one fourth that of in the uterus), but not in the heart or liver. Progesterone and testosterone were poor stimulators, but estriol was as effective as estradiol. According to its elution profile in gel filtration, a molecular weight for the hydrolase of about 60,000 is suggested. Inhibition studies in vitro with crude enzyme preparations indicate a serine protease with a SH group essential for maximal activity. The natural substrate for the hydrolase has not been elucidated. It does not solubilize [3H]elastin, and the properties seem to eliminate plasminogen or latent collagenase as possible substrates.
...
PMID:A new hormone-response hydrolase activity in the mouse uterus. 700 May

A simple method of preparing single cell suspensions for radioligand binding studies is described. The method involves incubating tissues in the presence of collagenase and elastase for 90 min in physiological solution with 1 mM calcium chloride and the mechanical disruption of the tissue by pipetting. The tissues examined were atria, ventricle, bladder, uterus, and taenia coli removed from mature guinea pigs. Viability of the cells by trypan blue exclusion showed 60-88% viable cells and receptor binding studies using (3H]-1-quinuclidinyl benzilate (QNB) yield KD values of approximately equal to 0.1 nM. The receptor numbers for each tissue were (receptors/cell): atria, 5700; ventricle, 11,000; uterus, 31,000; bladder, 44,000; taenia coli, 68,000.
...
PMID:A simple method for preparing single cell suspensions of heart and smooth muscle for radioreceptor labeling studies. 709 98

We have isolated and characterized the human cardiac mast cell (CMC) and compared this novel mast cell (MC type with MC obtained from uterus, skin, and lung. Heart tissue was obtained from 14 patients with cardiomyopathy (CMP, heart transplantation). CMC were isolated by enzymatic digestion using collagenase, pronase-E, hyaluronidase, and DNAse. Substantial amounts of CMC (0.5% to 1.5% of isolated cells) were found in the atrial appendages but not in ventricular digests or other sites of the heart (< 0.1%). In situ staining of atrial tissue revealed the presence of CMC in the myocardium (2.16 +/- 0.7 MC/mm2), endocardium (2.24 +/- 0.9 MC/mm2), and epicardium. As assessed by combined toluidine blue/immunofluorescence staining with monoclonal antibodies (MoAbs), isolated CMC expressed surface IgE, the receptor for stem cell factor (c-kit receptor/CD117), the p24 antigen (CD9), the Pgp-1 homing receptor (CD44), the pan leukocyte antigen (CD45), and the ICAM-1 antigen (CD54). CMC were not recognized by MoAbs to lymphocyte function associated antigen 2 (LFA-2; CD2), T-cell receptor (TcR; CD3), T4 antigen (CD4), LFA-1 alpha-chain (CD11a), C3biR alpha-chain (CD11b), CR4 alpha-chain (CD11c), LPS-R related Ag (CD14), 3-FAL/x-hapten (CD15), Fc gamma RIII (CD16), lactosylceramid (CDw17), the B-cell antigen CD19, or CR1 (CD35). In situ expression of leukocyte antigens on CMC was demonstrable by indirect immunoperoxidase staining technique and double-labeling immunohistochemistry. Almost all CMC (90%) reacted with MoAbs against tryptase and chymase and thus were MCTC. Cardiac mast cells were also stained by the heparin-binding dye Berberine sulfate and expressed measurable amounts of histamine (4.6 +/- 1.4 pg per cell). Cross linking of either IgE receptor or SCF receptor (c-kit) on CMC resulted in histamine secretion (non-specific release: < 6% of total histamine, alpha IgE induced: 12% to 52%; SCF-induced release: 9% to 18%), whereas neither substance P (a skin MC agonist) nor the basophil agonist FMLP showed an effect on CMC. Together, the CMC is an MCTC primarily located in the appendage of the atrium. This novel type of MC exhibits surface membrane antigen and functional properties similar to those of lung and uterus MC.
...
PMID:The human cardiac mast cell: localization, isolation, phenotype, and functional characterization. 752 50

Basophils and mast cells represent distinct cell lineages within the hemopoietic system. Based on the unique cell surface antigen profile of both cells, we have established methods which allow the reproducible purification to homogeneity (> 99%) of normal human basophil granulocytes from the peripheral blood and of mast cells from human dispersed tissues. Basophils (n = 9) were purified by current counterflow elutriation followed by depletion of monocytes with CD14 mAb conjugated to magnetic beads, and subsequent cell sorting for CD217+ cells. Basophil purity was 99.5 +/- 0.4% (range 98.7-99.9%). Mast cells were obtained from lung (n = 6), uterus (n = 1), mastocytosis bone marrow (n = 2), and human foreskin (n = 2). Mast cells were purified by collagenase digestion followed by current counterflow elutriation and sorting with CD117/c-kit mAb. Mast cell purity was 99.4 +/- 0.7% (range: 97.5-99.9%). Purified cells were more than 90% viable and were able to release histamine on induction with IgE plus anti-IgE. Furthermore, the PCR technique could be applied on pure cells and confirmed expression of high affinity IgE receptor (Fc epsilon R1) alpha chain mRNA. Thus, by combining isolation techniques including elutriation, magnetic cell depletion and cell sorting with mAb, functionally intact normal human basophils and mast cells can be enriched to homogeneity.
...
PMID:Purification of human basophils and mast cells by multistep separation technique and mAb to CDw17 and CD117/c-kit. 753 67

Degradation of type I collagen, the most abundant collagen, is initiated by collagenase cleavage at a highly conserved site between Gly775 and Ile776 of the alpha 1 (I) chain. Mutations at or around this site render type I collagen resistant to collagenase digestion in vitro. We show here that mice carrying a collagenase-resistant mutant Col1a-1 transgene die late in embryo-genesis, ascribable to overexpression of the transgene, since the same mutation introduced into the endogenous Col1a-1 gene by gene targeting permitted normal development of mutant mice to young adulthood. With increasing age, animals carrying the targeted mutation developed marked fibrosis of the dermis similar to that in human scleroderma. Postpartum involution of the uterus in the mutant mice was also impaired, with persistence of collagenous nodules in the uterine wall. Although type I collagen from the homozygous mutant mice was resistant to cleavage by human or rat fibroblast collagenases at the helical site, only the rat collagenase cleaved collagen trimers at an additional, novel site in the nonhelical N-telopeptide domain. Our results suggest that cleavage by murine collagenase at the N-telopeptide site could account for resorption of type I collagen during embryonic and early adult life. During intense collagen resorption, however, such as in the immediate postpartum uterus and in the dermis later in life, cleavage at the helical site is essential for normal collagen turnover. Thus, type I collagen is degraded by at least two differentially controlled mechanisms involving collagenases with distinct, but overlapping, substrate specificities.
...
PMID:A targeted mutation at the known collagenase cleavage site in mouse type I collagen impairs tissue remodeling. 779 Mar 74


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

---