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:2.7.10.1 (ERK)
95,504 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The effects of Met-enkephalinamide (MET-ENKamide) on brain temperature (Tb) and metabolic rate (MR) were assessed following direct administration into the preoptic/anterior hypothalamus (PO/AH) of freely moving rats. Bilateral microinjections of saline or MET-ENKamide (1-25 micrograms/microliter) were delivered through cannula guide tubes previously implanted in nine animals. Thiorphan, an enkephalinase inhibitor, was microinjected into the PO/AH of two of the animals. All injections were made remotely at an ambient temperature of 22 +/- 1 degree C in a volume of 1 microliter. Measurements of Tb (via a brain-dwelling thermistor) and MR were recorded continuously. The ability of naloxone to antagonize the effects of MET-ENKamide was investigated by fashioning a double-barreled injection cannula to fit within each guide tube; 1 microliter of saline or naloxone (1-10 micrograms) was delivered bilaterally into the PO/AH followed by 1 microliter of MET-ENKamide (25 micrograms) 5-10 min later. PO/AH administration of MET-ENKamide (1-25 micrograms) produced dose-dependent increases in Tb preceded by dose-dependent increases in MR, with a characteristic time course of approximately 30 min. Naloxone antagonized the rise in Tb and MR, either partially or completely, depending on dose. When administered alone, naloxone had no effect on Tb or MR. Microinjection of thiorphan (10 micrograms) into the PO/AH evoked increases in Tb and MR that were similar to those responses induced by MET-ENKamide. These results support a role for endogenous Met-enkephalin in the regulation of Tb in the rat.
...
PMID:Changes in body temperature and metabolic rate following microinjection of Met-enkephalinamide in the preoptic/anterior hypothalamus of rats. 386 98

Membrane metallo-endopeptidase (NEP; neutral endopeptidase, kidney-brush-border neutral proteinase, enkephalinase, EC 3.4.24.11) cleaves peptides at the amino side of hydrophobic amino acids. While the enzyme is known to be in organs such as kidney and brain, we found it in human neutrophils. These cells cleaved the NEP substrate glutaryl (Glut)-Ala-Ala-Phe-(4-methoxynaphthylamine) (Glut-Ala-Ala-Phe-MNA) at a rate of 9.5 nmol X hr-1 per 10(6) cells, and phosphoramidon (1 microM) inhibited the hydrolysis by 90%. Intact neutrophils from donors who smoked had NEP activities about twice that of nonsmokers. Subcellular fractionation and sucrose density gradient centrifugation of lysed neutrophils showed that most of the NEP activity was membrane bound. A washed membrane fraction from human neutrophils rapidly cleaved 0.5 mM Glut-Ala-Ala-Phe-MNA (96 nmol X min-1 X mg-1) and the hydrolysis was inhibited by phosphoramidon and by specific antiserum to human renal NEP. The washed membrane fraction also rapidly cleaved 0.1 mM bradykinin (34 nmol X min-1 mg-1) and 0.1 mM fMet-Leu-Phe (49 nmol X min-1 X mg-1). The membrane-bound enzyme cleaved the peptide substrates at the same site as the homogeneous human renal NEP, and phosphoramidon and thiorphan inhibited the hydrolysis. Kinetic studies with pure human renal NEP showed that the chemotactic peptide fMet-Leu-Phe was one of the best biologically active substrates (Km, 59 X 10(-6) M; kcat, 3654 min-1). Immunocytochemistry at the light microscopic level revealed a high concentration of NEP on the cell membrane of neutrophils. This was confirmed with electron microscopy using the immunogold technique on ultrathin cryosections. These studies indicate that NEP in neutrophils may have important functions in inflammation and chemotaxis.
...
PMID:Neutral endopeptidase 24.11 in human neutrophils: cleavage of chemotactic peptide. 390 53

Recent developments on neutral endopeptidase (NEP, EC 3.4.24.11) are described. These include (1) the development of a novel colorimetric assay with a chromogenic substrate (Glutaryl-Gly-Gly-Phe-2-naphthylamide) coupled with aminopeptidase M (EC 3.4.11.2). (2) A detergent form of the pig kidney enzyme has been purified by immuno-adsorbent chromatography and its molecular properties compared with other forms of the enzyme from rabbit kidney and pig intestine. (3) Rat kidney microvilli contain two endopeptidases of about equal activity when assayed with [125I]iodo-insulin B chain as substrate. One is similar to the rabbit and pig endopeptidases in being sensitive to inhibition by phosphoamidon. The other is insensitive to the inhibitor, though susceptible to chelating agents. The two enzymes are resolvable and have been partially characterized. (4) Endopeptidases of the phosphoramidon-sensitive type are present in various tissues in addition to the principal locations in brush borders of kidney and intestine.
...
PMID:Microvillar membrane neutral endopeptidases. 612 11

Angiotensin I converting enzyme (ACE) and neutral endopeptidase ("enkephalinase"; NEP), were purified to homogeneity from human kidney. NEP cleaved substance P (SP) at Gln6-Phe7,-Phe8, and Gly9-Leu10 and neurotensin (NT) at Pro10-Tyr11 and Tyr11-Ile12. NEP hydrolyzed 0.1 mM SP, NT and their C-terminal fragments at the following rates (mumol/min/mg): SP1-11 = 7.8, SP4-11 = 11.7, SP5-11 = 15.4, SP6-11 = 15.6, SP8-11 = 6.7, NT1-13 = 2.9, and NT8-13 = 4.0. Purified ACE rapidly inactivated SP as measured in bioassay. HPLC analysis showed that ACE cleaved SP at Phe8-Gly9 and Gly9-Leu10 to release C-terminal tri- and dipeptide (ratio = 4:1). The hydrolysis was Cl- dependent and inhibited by captopril. ACE released mainly C-terminal tripeptide from SP methyl ester, but only dipeptide from SP free acid. Modification of arginine residues in ACE with cyclohexanedione or butanedione similarly inhibited hydrolysis of SP, bradykinin and Bz-Gly-Phe-Arg (80-93%) indicating an active site arginine is required for hydrolysis of SP. ACE hydrolyzed NT at Tyr11-Ile12 to release Ile12-Leu13. SP, NT and their derivatives (0.1 mM) were cleaved by ACE at the following rates (mumol/min/mg): SP1-11 = 1.2, SP methyl ester = 0.7, SP free acid = 8.5, SP4-11 = 2.4, SP5-11 = 0.9, SP6-11 = 1.4, SP8-11 = 0, NT1-13 = 0.2, and NT8-13 = 1.3. Peptide substrates were used as inhibitors of ACE (substrate = FA-Phe-Gly-Gly) and NEP (substrate = Leu5-enkephalin).(ABSTRACT TRUNCATED AT 250 WORDS)
...
PMID:Hydrolysis of substance p and neurotensin by converting enzyme and neutral endopeptidase. 620 35

The purpose of this study was to identify the presence of placental neutral metalloendopeptidase (NEP; enkephalinase; EC 3.4.24.11) in human normotensive and pre-eclamptic pregnancy. The localization of NEP in placentae from normotensive, chronic hypertensive and pre-eclamptic pregnancies was carried out on fresh frozen tissues by using a monoclonal primary antibody developed against human common acute lymphoblastic leukaemia antigen (CD10) together with the avidin-biotin-peroxidase method. In placentae from normotensive, chronic hypertensive and superimposed pre-eclamptic pregnancies, intense staining was found in the extravillous trophoblast, and also in fibroblasts of the chorionic plate and stem villi. Light to moderate staining was noted in the villous-associated trophoblast and in some cells from the villous core. In cases of pre-eclampsia, very intense staining was detected not only on the surface, but also in the cytoplasm of the villous-associated trophoblast. The increased expression of placental NEP in pre-eclampsia suggests that this enzyme may be involved in the regulation of the local concentration of circulating biologically active peptides at the fetomaternal interface, and thus could be implicated in the pathophysiological changes of this syndrome.
...
PMID:Increased immunohistochemical expression of neutral metalloendopeptidase (enkephalinase; EC 3.4.24.11) in villi of the human placenta with pre-eclampsia. 747 14

Type II integral membrane proteins are anchored by a signal-peptide/membrane-anchor domain (SA domain) located near their N-terminus, whereas type I membrane proteins are anchored by stop-transfer sequences usually located near the C-terminus. In this study we have attempted to transform neutral endopeptidase-24.11 (EC 3.4.24.11; NEP), a type II membrane protein, into a type I membrane protein. Three type I mutant proteins were constructed by fusion of topogenic sequences to the C-terminus of SecNEP, a soluble form of NEP. The first two type I mutants, SecNEP-TMC and SecNEP-TMIC, were constructed by fusing in frame the cytosolic and SA domains of NEP to the C-terminus of SecNEP. These two fusion proteins differ only in the orientation of the cytosolic tail. The third type I mutant, SecNEP-ACE, was constructed by fusing in frame the stop-transfer and cytosolic domains of angiotensin I-converting enzyme (EC 3.4.15.1; ACE) to the C-terminus of SecNEP. Our results suggest that: (1) the NEP ectodomain can be anchored with a type I topology in the endoplasmic reticulum (ER) membrane by both NEP and ACE topogenic sequences; (2) SecNEP-TMC and SecNEP-TMIC were transport-incompetent and needed proteolytic cleavage in the C-terminal region to leave the ER, whereas SecNEP-ACE was transported out of the ER as a type I membrane protein. Therefore we concluded that the nature of topogenic sequences determines the transport-competence of topological mutants of neutral endopeptidase-24.11.
...
PMID:The nature of topogenic sequences determines the transport competence of topological mutants of neutral endopeptidase-24.11. 749 41

Analysis of SP and NKA metabolism by human vascular endothelium, relative to that in human plasma, identified integrative, multiple pathways for the processing of circulating SP (but not NKA) by angiotensin-converting enzyme (ACE; EC 3.4.15.1), dipeptidyl(amino)peptidase IV (DAP IV; EC 3.4.14.5), and aminopeptidase M (AmM; EC 3.4.11.2). In contrast, SP and NKA, which may diffuse into or be neurally released within the vessel wall, were both metabolized by smooth muscle neutral endopeptidase-24.11 (NEP-24.11; EC 3.4.24.11). Collectively, these studies indicate peptide-specific and site-specific differential processing of SP and NKA by human plasma and vasculature.
...
PMID:Metabolism of substance P and neurokinin A by human vascular endothelium and smooth muscle. 752 48

The effects of retinoic acid (RA) on the expression of osteoblastic-related cell markers was examined. A marrow stromal osteogenic cell line, MBA-15, was analyzed by Northern blotting for the expression of bone matrix proteins. These cells constitutively express mRNA encoding for procollagen alpha 2 (I), osteonectin, osteopontin, biglycan, and alkaline phosphatase (ALK-P). Gene expression was unchanged in response to RA triggering for 24 hr. Furthermore, cell growth and enzymatic activities of ALK-P and neutral endopeptidase (CD10/NEP) were studied. These parameters were examined in MBA-15 and clonal populations representing different stages of differentiation. The cell's growth rate was unchanged, while ALK-P activity was greatly increased during the culture period under RA treatment in MBA-15 and in the clonal cell lines examined while CD10/NEP activity displayed a different pattern. MBA-15.4, a preosteoblast cell line, exhibited an inhibition in CD10/NEP activity at the beginning of the culture period, reaching basal level with time. This activity was greatly increased over control level in MBA-15.6, a mature stage of osteoblasts. Furthermore, the response of cell lines to various growth factors was tested subsequent to priming the cultures with RA. A synergistic effect was monitored for ALK-P activity in MBA-15.4 and MBA-15.6 cells under rh-bone morphogenic protein (BMP-2) and purified osteogenin (BMP-3), and an antagonist effect was measured when cells were exposed to transforming growth factor beta (TGF beta). Contrarily, BMP-2 and BMP-3 inhibited the CD10/NEP activity that had remained unchanged following priming of the cell with RA. Insulin-like growth factor I (IGF-I) and basic fibroblast growth factors (bFGF) did not affect either ALK-P nor CD10/NEP activities in both cloned cells. Cellular response to bone-seeking hormone, parathyroid hormone (PTH), and prostaglandin E2 (PGE2) was monitored by activation of intracellular cAMP. Treatment with RA caused a dramatic decrease in MBA-15.6 cell responses to PTH and PGE2, but no significant effects could be observed in other clonal lines.
...
PMID:Differential effects of retinoic acid and growth factors on osteoblastic markers and CD10/NEP activity in stromal-derived osteoblasts. 752 53

The purpose of this study was to investigate whether neutral endopeptidase (NEP; EC 3.4.24.11) modulates substance P-induced vasodilation in the oral mucosa in vivo. Using intravital microscopy, we measured the diameter of second-order arterioles (44-70 microns) in the hamster cheek pouch during suffusion of capsaicin and substance P. We found that capsaicin (0.1 and 10.0 nM) induced significant concentration-dependent vasodilations (13 +/- 4 and 39 +/- 7% increase from baseline, respectively; P < 0.05) that were significantly potentiated by phosphoramidon (10.0 nM), a selective NEP inhibitor (35 +/- 15 and 61 +/- 12% increase from baseline, respectively; P < 0.05). Substance P (0.1 and 10.0 nM) also induced significant concentration-dependent vasodilations (7 +/- 3 and 25 +/- 8% increase from baseline, respectively; P < 0.05) that were mediated by the COOH-terminal of the molecule. Substance P-induced responses were significantly potentiated by phosphoramidon (34 +/- 9 and 53 +/- 10% increase from baseline, respectively; P < 0.05) and thiorphan (10.0 microM), a selective NEP inhibitor (44 +/- 11 and 53 +/- 10% increase from baseline, respectively; P < 0.05). Substance P-(1-9) had no significant effects on arteriolar diameter. Suffusion of captopril, leupeptin, Bestatin, and DL-2-mercaptomethyl-3-guanidinoethylthiopropanoic acid together had no significant effects on substance P-induced vasodilation. Phosphoramidon did not potentiate nitroglycerin-induced vasodilation. These data indicate that NEP modulates substance P-induced vasodilation in the hamster cheek pouch in vivo. We suggest that any decrease in tissue NEP activity may amplify neurogenic vasodilation in the oral mucosa.
...
PMID:Neutral endopeptidase modulates substance P-induced vasodilation in vivo. 753 97

Capsaicin pretreatment was used to deplete tachykinins in order to study the role of tachykinins in chronic hypoxia-induced pulmonary hypertension. Forty three young Wistar rats weighing 235 +/- 4 g were randomly divided into four groups: control (n = 10); capsaicin pretreatment (n = 10); intermittent chronic hypoxia (n = 10); and capsaicin pretreatment + intermittent chronic hypoxia (n = 13). Control animals breathed room air. Rats in the capsaicin pretreatment groups were given capsaicin via subcutaneous injection over a three-day period. Hypobaric hypoxia was intermittently applied by placing animals into a hypobaric chamber with a barometric pressure of 380 Torr for two weeks. In the capsaicin pretreatment + intermittent chronic hypoxia group, rats were exposed to intermittent hypoxia for two weeks immediately after the last dose of capsaicin. Subsequently, pulmonary vascular function, as well as substance P (a tachykinin) level and neutral endopeptidase (NEP, the major degradation enzyme for tachykinins) activity in the lungs were measured. Chronic hypoxia caused significant increases in pulmonary artery pressure, right ventricle/(left ventricle + septum) weight ratio, hematocrit, and lung substance P level, as well as a significant decrease in lung NEP activity. All these chronic hypoxia-induced changes were significantly lessened by capsaicin pretreatment. Capsaicin pretreatment alone did not induce any significant alteration in vascular function. These results suggest that the chronic hypoxia causes an increase in lung tachykinin levels which, in turn, enhance the development of pulmonary hypertension.
...
PMID:Capsaicin pretreatment attenuates chronic hypoxic pulmonary hypertension. 753 34


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

---