Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:3.4.24.11 (CD10)
 9,792 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Neutral endopeptidase (EC 3.4.24.11, NEP) is a type-II integral membrane protein found in a wide variety of cell types. We previously produced a secreted form of the enzyme by deletion of the cytoplasmic and transmembrane domains and in-frame fusion of the cleavable signal peptide of pro-opiomelanocortin [Lemay, Waksman, Roques, Crine and Boileau (1989) J. Biol. Chem. 264, 15620-15623]. Here we have used this secreted form of NEP and fused to it the glycosylphosphatidylinositol (GPI)-anchor attachment signal of decay-accelerating factor to produce a GPI-anchored form. Expression of this chimeric form in Cos-1 cells resulted in cell-surface activity. This activity could be released from the cell surface by phosphatidylinositol-specific phospholipase C and radiolabelling studies showed that the protein could incorporate [3H]ethanolamine, indicating that the enzyme was GPI-anchored. The Km value, using [D-Ala2,Leu5]enkephalin as substrate, of GPI-anchored NEP (62 +/- 5 microM) was comparable with that of wild-type NEP (70 +/- 4 microM), as were the sensitivities to the inhibitors phosphoramidon and thiorphan. However, pulse-chase studies showed that the biosynthesis and cell-surface delivery of GPI-anchored NEP was delayed compared with that of the wild-type transmembrane form of NEP. These results suggest a lower rate of biosynthesis and/or cellular transport for GPI-anchored NEP compared with its transmembrane counterpart.
 ...
PMID:Expression of an enzymically active glycosylphosphatidylinositol-anchored form of neutral endopeptidase (EC 3.4.24.11) in Cos-1 cells. 816 36

Due to its physiological and pharmacological action ANF could be an ideal diuretic and vasorelaxation product in the treatment of oedema and essential hypertension. Experimental and clinical investigations in oedematous conditions revealed a very slight diuretic and natriuretic effect of ANF, as compared with healthy subjects. This is due to the reduced renal perfusion pressure, the increased RAAS activity, enzymatic degradation of ANF by endopeptidase and also its inactivation via C-receptors. Moreover the use of ANF is very limited due to its short half-life and peptide structure. In recent years therefore new possibilities are sought how to influence the metabolism of endogenous ANF and thus increase its activity. Neutral endopeptidase inhibitors (NEP) inhibit ANF degradation, increase thus its plasma level and in cardiac weakntlakess have a marked diuretic and natriuretic effect. The administration of NEP inhibitors in patients with essential hypertension did not reveal so far an adequate effect on blood pressure. Inhibitors of C-receptors potentiate also the effect of endogenous ANF. In experiments they enhance Na excretion and lead to a drop of blood pressure. Recently another natriuretic peptide was detected--urodilatine. In experimental and clinical studies in cardiac failure urodilatine administration leads to an increase of diuresis and natriuresis greater than after ANF. Haemodynamic effects after urodilatine are also greater than after ANF whereby urodilatine does not cause reflex tachycardia and is resistant to peptidase degradation. Its therapeutic administration is a new perspective in the treatment of oedematous conditions and essential hypertension.
 ...
PMID:[Use of natriuretic peptides in clinical practice]. 818 76

Neutral endopeptidase (E.C.3.4.24.11, enkephalinase, NEP) is a potentially important enzyme capable of regulating the activity of neuropeptides released in the respiratory mucosa. In order to confirm the existence of NEP in the human respiratory mucosa, inferior nasal turbinate mucosae obtained at surgery and nasal secretions induced by topical provocations with methacholine, histamine, and allergen were analyzed for: (1) NEP activity (pmol product/min/ml) by enzymatic degradation of [3H]leu-enkephalin, (2) the presence of NEP-immunoreactive material by Western blot analysis, and (3) cellular localization of NEP distribution by immunohistochemistry. NEP activity in human nasal secretions obtained after normal saline challenge was 0.15 +/- 0.06 pmol/min/ml. Secretion increased to 0.86 +/- 0.26 pmol/min/ml after methacholine provocation and 1.69 +/- 0.74 pmol/min/ml after histamine provocation. The increase in NEP activity in methacholine-induced secretions was prevented by atropine (0.13 +/- 0.06 pmol/min/ml). After methacholine, histamine, and antigen nasal provocation, the kinetics of NEP appearance correlated more closely to the glandular marker, lactoferrin, than with the vascular markers albumin and IgG. In homogenates of nasal mucosa, the membrane fraction contained significantly more NEP on a per mg protein basis than did the soluble fraction (227.6 +/- 50.52 versus 9.61 +/- 3.18 pmol/min/mg protein, respectively, P < 0.01, n = 6). NEP in the membrane fraction was detected as a single band migrating at 97 kD on Western blots using antibodies specific for NEP and the common acute lymphoblastic leukemia antigen (CALLA). Immunoreactive NEP was localized to serous cells of the submucosal glands, epithelial cells, and endothelial and myoepithelial cells of small vessels. Staining for NEP in the serous cells was of the same intensity as that in epithelial cells. These results indicate that 97 kD NEP-immunoreactive material exists in discrete locations in the nasal mucosa, including the epithelium, serous cells of the submucosal glands, and vessel walls, and that NEP activity is detected as a minor component in nasal secretions enriched by glandular products. In addition to the modulating functions of NEP on neuropeptide-mediated activities on vessels and glands, it is possible that NEP in secretions plays a role in regulating mucosal responses to luminal neuropeptides or other as yet uncharacterized NEP substrates.
 ...
PMID:Human nasal mucosal neutral endopeptidase (NEP): location, quantitation, and secretion. 821 97

The presence of neutral endopeptidase 24.11 was demonstrated in human umbilical vein endothelial cells by immunostaining. Enzymatic activity of neutral endopeptidase was determined as 0.167 +/- 0.02 mU/mg protein in the membrane fraction of human umbilical vein endothelial cells, using the fluorogenic peptide substrate, dansyl-D-Ala-Gly-Phe(pNO2)-Gly. No activity was found in the cytosolic fraction of endothelial cells. The role of this peptidase in the degradation of the endogenous vasodilator bradykinin was investigated by incubating human umbilical vein endothelial cell monolayers with bradykinin (10(-8) mol/l). The inhibitor of neutral endopeptidase, phosphoramidon (10(-8) mol/l), decreased the degradation of bradykinin in the supernatant of endothelial cells; the half-life of bradykinin was then increased from 29 +/- 1 to 46 +/- 2 minutes. The angiotensin-converting enzyme inhibitor, lisinopril (10(-8) mol/l), increased the half-life of bradykinin to 244 +/- 20 minutes; the combination of both inhibitors increased the half-life of bradykinin to 381 +/- 51 minutes. Inhibitors of aminopeptidase (amastatin) and carboxypeptidase (2-mercaptomethyl-3-guanidinoethyl-thiopropionic acid) caused no significant effect. The effect of phosphoramidon was small in comparison with that of lisinopril, but was pronounced in combination with lisinopril. Neutral endopeptidase activity is localized in the membranes of human endothelial cells and seems to be involved in the degradation of bradykinin by the vascular endothelium, particularly during angiotensin converting enzyme inhibition.
 ...
PMID:Degradation of bradykinin by neutral endopeptidase (EC 3.4.24.11) in cultured human endothelial cells. 839 30

The objectives of this investigation were to characterize neuropeptide-degrading enzymes on the surface of gastric muscle cells and to determine their physiological function. Neutral endopeptidase (NEP, EC 3.4.24.11) activity was measured using the fluorogenic substrate glutaryl-Ala-Ala-Phe-4-methoxy-2-naphthylamine. The NEP inhibitors phosphoramidon and DL-thiorphan (1 microM) inhibited degradation of the substrate by gastric muscle membranes by 100% and by freshly dispersed gastric muscle cells by 55-60%. The phosphoramidon or DL-thiorphan-inhibitable activity, attributed to NEP, of membranes was 112 +/- 4.0 pmol h-1 (micrograms protein)-1 and of cells was 4.2 +/- 0.8 nmol h-1 (10(6) cells)-1. This activity was associated with membranes prepared from cells and was not detected in the cytoplasm or in the cell incubation solution. Gastric muscle membranes were fractionated by electrophoresis and analysed by Western blotting using two NEP antisera. Both antisera recognized a protein in membranes with an electrophoretic mobility identical to that of recombinant human NEP and an apparent molecular mass of approximately 95 kDa. Neuropeptides were degraded by membranes with specific activities in the order of [Leu5]enkephalin > [Met5]enkephalin > gastrin-releasing peptide-10 (GRP-10) > [D-Ala2][Leu5]enkephalin > somatostatin-14. Phosphoramidon and DL-thiorphan similarly inhibited the degradation of GRP-10 (mean of 35% inhibition), somatostatin-14 (57%) and the aminopeptidase-resistant analogue, [D-Ala2][Leu5]enkephalin (75%). When aminopeptidases were inhibited with amastatin (10 microM) phosphoramidon inhibited degradation of [Leu5]enkephalin (54%) and [Met5]enkephalin (100%). Phosphoramidon increased the potency of the contractile effects of neuropeptides on muscle cells by > 280-fold for somatostatin-14, 17-fold for GRP-10, 18-fold for [Met5]enkephalin and 14-fold for [Leu5]enkephalin. The results show that an NEP-like enzyme on the surface of gastric muscle cells degrades and inactivates enkephalins, GRP-10 and somatostatin-14 and acts in a manner analogous to that of acetylcholinesterase in the neuromuscular junction of skeletal muscle.
 ...
PMID:Neutral endopeptidase (EC 3.4.24.11) modulates the contractile effects of neuropeptides on muscle cells from the guinea-pig stomach. 844 12

Neutral endopeptidase (NEP; also known as neprilysin and enkephalinase; EC 3.4.24.11) is a cell-surface metallopeptidase that is present in many mammalian tissues. It is particularly abundant on the brush-border membranes of the kidney proximal tubule. In this paper, the presence of NEP in purified glomeruli from dog kidney was assessed by measuring phosphoramidon- and thiorphan-sensitive [D-Ala2,Leu5]enkephalin-degrading activity. Using this assay, the Km and kcat. of the glomerular enzyme were found to be identical to those of the tubular enzyme. By Western blotting the apparent M(r) of the glomerular enzyme was found to be 104,000, compared with 94,000 for the tubular enzyme. This might be due to a different glycosylation pattern, since endoglycosidase F treatment of NEP obtained from both tissues yielded deglycosylated enzymes with similar electrophoretic mobilities. The glomerular enzyme also appears to be membrane-bound, since it was retained in the detergent-rich phase after phase separation with Triton X-114. Autoradiography experiments performed with RB104, a new highly selective and potent NEP inhibitor, showed that NEP was expressed in both glomeruli and proximal tubules. The presence in glomeruli of NEP and some other brush-border peptidases (dipeptidyl-dipeptidase IV, aminopeptidase N and angiotensin I-converting enzyme) suggests that cell-surface peptidases might play an important role as regulators of plasma-derived peptides in this part of the nephron.
 ...
PMID:Characterization of neutral endopeptidase 24.11 in dog glomeruli. 848 5

Neutral endopeptidase (NEP; also known as EC 3.4.24.11, CALLA) is a widely distributed membrane-bound enzyme that hydrolyzes many biologically important endogenous peptides. To evaluate the influence of glucocorticoids on airway epithelial cell NEP expression, we used the human airway epithelial cell line Calu-1. Cells, grown to confluency in Dulbecco's modified Eagle medium with 10% fetal bovine serum and penicillin-streptomycin, were incubated with different concentrations of dexamethasone or vehicle alone in the presence or absence of actinomycin D or cycloheximide for planned times. NEP activity was assayed at the end of treatment employing reverse-phase, high-pressure liquid chromatography. In some experiments, changes in NEP-specific mRNAs in the presence or absence of dexamethasone and/or the inhibitors were also evaluated by Northern blot analysis. We found that dexamethasone increased Calu-1 NEP activity in a dose- and time-dependent manner. Northern blot analysis indicated that NEP-specific mRNAs were also increased by dexamethasone. Furthermore, neither actinomycin D nor cycloheximide inhibited the increases in NEP activity and NEP-specific mRNAs caused by dexamethasone stimulation. We speculate, therefore, that dexamethasone increases NEP expression of these airway epithelial cells by enhancing transcription and new protein synthesis.
 ...
PMID:Dexamethasone increases airway epithelial cell neutral endopeptidase by enhancing transcription and new protein synthesis. 850 56

Enkephalinase (EC 3.4.24.11), an enzyme widely distributed in brain and peripheral tissues of human and various animal species, was measured in the intestinal fetal cells and in the intestinal epithelial cells of adult rat, where its activity was respectively 96,1 +/- 10,18 fmol/mg protein and 52,27 +/- 8,43 fmol/mg protein. The immortalized cell lines: SLC-11 (after transfection with the plasmid containing oncogene from the human adenovirus type 2-E1A), SLC-21 (plasmid containing oncogene from polyoma virus) and SLC-41 (plasmid containing oncogene from simian virus 40 large tumor antigen) presented relatively strong enkephalinase activity; it was respectively 28,3 +/- 1,7, 37,9 +/- 3,6 and 49,3 +/- 3,1 fmol/mg protein. The cells of SLC-12T and SLC-44T lines, obtained after transfection with the mutant Ha-ras-1-gene and possessing tumorigene potency have the enkephalinase activity very decreased: 1,6 +/- 0,9 and 8,7 +/- 3,2 fmol/mg protein (p < 0,001). This interesting properties of the tumorigene cells may constitute a new subject of investigations in the carcinomas therapy.
 ...
PMID:Enkephalinase activity in the intestinal epithelial cells of the fetus of 19 days and their immortalized and transformed counterparts the SLC-cell lines. 851 26

Enkephalinase-blocking agent thiorphan was added to long-term cultures of mouse bone marrow cells at the time of culture initiation (time 0) or 2 weeks thereafter, when the stromal layer appears. Cellularity, cell morphology (in cytospin smears) and the yield of granulocyte-macrophage progenitor cells (GM-CFC assay in agar) were recorded. Low concentrations of thiorphan accelerated recovery of the cultures after an initial drop of the cell count. Expansion and maturation of the granulocytic lineage was promoted, with parallel decline of the GM-CFC yield. Thiorphan probably interfered with the activity of enkephalinase (endopeptidase 24.11) in the cultures. That enzyme is the CD10 surface marker (CALLA) of lymphoid, myeloid and stromal elements.
 ...
PMID:Enkephalinase-blocking agent thiorphan affects cell growth and differentiation in long term culture of mouse bone marrow. 856 66

Neutral endopeptidase (NEP; EC 3.4.24.11) is a type-2 cell-surface metalloproteinase known by a variety of eponyms, including enkephalinase, common acute lymphoblastic leukemia antigen (CALLA), and CD10. Identified substrates are largely neural or humoral oligopeptide agonists, and the enzyme functions to terminate signaling by degrading the ligand, analogous to the acetylcholine/acetylcholinesterase system. Targeted disruption of the NEP locus in mice results in enhanced lethality to endotoxin shock with a pronounced gene-dosage effect. The site(s) of action appears downstream from release of TNF and IL-1, as NEP-deficient animals demonstrate increased sensitivity to these mediators as well. This unexpected finding indicates an important protective role for NEP in septic shock.
 ...
PMID:Neutral endopeptidase modulates septic shock. 860 28


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