Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UNIPROT:P20366 (substance P)
 21,176 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

A recent study determined that cultured human skeletal muscle adult myoblasts, myotubes, and fibroblasts degraded angiotensins and kinins via neutral endopeptidase-24.11 (NEP-24.11: EC 3.4.24.11) and aminopeptidase N (APN: EC 3.4.11.2). Due to the possible importance of other peptides to skeletal muscle blood flow and function, the present study looked specifically at the metabolism of the neurokinins substance P (SP) and neurokinin A (NKA) by skeletal muscle peptidases. The results show that SP is degraded not only by NEP-24.11, but also sequentially by dipeptidyl(amino)peptidase IV (DAP IV: EC 3.4.14.5)/APN. NKA is unaffected by DAP IV but is metabolized by NEP-24.11 and APN. NEP-24.11 was inhibited by phosphoramidon (IC50 = 80 nM), thiorphan and ZINCOV, DAP IV by diprotin A (IC50 = 8 microM), and APN by amastatin (IC50 = 50 nM) and bestatin (IC50 = 100 microM). Skeletal muscle myocyte and fibroblast metabolism of SP and NKA may regulate local skeletal muscle vascular and extravascular functions including SP- and NKA-mediated nerve-induced vasodilation. Inhibition of both NEP-24.11 and DAP IV/APN may increase skeletal muscle blood flow and decrease peripheral vascular resistance via potentiation of local neurokinin levels.
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PMID:Substance P and neurokinin A metabolism by cultured human skeletal muscle myocytes and fibroblasts. 897 37

Two enzymes with substance P degrading activity were purified from the membrane bound fraction of the rat spinal cord. The purified enzymes were characterized with regard to biochemical and kinetic properties. One of the enzymes exhibited close similarity to neutral endopeptidase 24.11 (NEP, EC 3.4.24.11), while the other resembled a substance P converting endopeptidase (SPE), which has previously been identified and purified from human cerebrospinal fluid (CSF). Detergent treated spinal cord homogenates from male Sprague Dawley rats were purified by anion-exchange chromatography (DEAE-sepharose CL-6B), hydrophobic-interaction chromatography (phenyl-sepharose CL-4B) and molecular sieving (Sephadex G-50). Two fractions with enzymes differing in size were recovered and allowed for further purification to apparent homogeneity by ion-exchange chromatography and molecular sieving on a micro-purification system (SMART). The enzyme activities were monitored by following the conversion of synthetic substance P using a radioimmunoassay specific for the heptapeptide product, substance P (1-7). By SDS-polyacrylamide gel electrophoresis of the purified enzymes molecular weights of 43 and 70 kDa were estimated for the SPE-like and NEP-like activity, respectively. A K(m) of 5 microM was determined for the conversion of substance P to its (1-7) fragment by the SPE-like activity. Reversed-phase HPLC together with mass spectrometry permitted identification of all fragments released from substance P by the peptidases. The released fragments were for both enzymes identified as substance P (1-7), substance P (8-11), substance P (1-8), substance P (9-11). The NEP-like enzyme preparation also gave substance P (1-6) as a major product.
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PMID:Purification and characterization of substance P endopeptidase activities in the rat spinal cord. 909 Jul 24

Neutral endopeptidase (NEP, E.C. 3.4.24.11), a widely distributed ectoenzyme, cleaves and inactivates a variety of biologically active peptides, including the tachykinin, substance P (SP). This study was undertaken to determine whether the modulation of SP airway smooth muscle contraction by NEP is age-dependent. We studied the contractile response of isolated tracheal rings from newborn and 120 day old New Zealand white rabbits. We measured NEP activity and determined immunoreactive NEP content in tracheal membrane preparations. NEP activity was then localized histochemically in sections of rabbit tracheas. In the presence of the NEP inhibitor, SCH 32615, the contractile response of isolated tracheal rings to SP was increased both in the newborn and 120 day old rabbits. However, the increase was greatest in the newborn animals. NEP activity in tracheal membrane preparations increased fivefold between the newborn and 120 day old rabbits. Western blot analysis also revealed a significant increase in the immunoreactive NEP content of these tracheal membrane preparations between the newborn and 120 day old rabbits. NEP activity, localized histochemically, was most intense in the epithelial region of the newborn animals, with a shift of activity to the subepithelial region with age. The prominent epithelial localization of neutral endopeptidase in the tracheas of these 1 day old rabbits, which we have shown to have relatively low neutral endopeptidase activity, suggests that the location of neutral endopeptidase in the airway, including proximity to relevant substance P receptors, may be critical to its function.
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PMID:Neutral endopeptidase activity in newborn and adult rabbit tracheas. 927 29

Several endogenous peptides, including bradykinin and substance P, have potent inflammatory effects in the joint. Levels of these peptides are regulated by plasma and cell-associated peptide degrading enzymes. One of these peptidases, neutral endopeptidase-24.11 (NEP-24.11), is expressed constitutively and in high density on human synovial cells and is presumed to play a critical role in local regulation of peptide levels in the joint. We examined the role of endogenous NEP-24.11 in regulating bradykinin-mediated effects in an articular model, and investigated the ability of soluble, recombinant human NEP-24.11 to augment the effects of the endogenous enzyme. Our studies demonstrate that endogenous synovial NEP-24.11 does not significantly modulate inflammatory peptide effects on cells when competing with colocalizing peptide receptors expressed in high density. Administration of excess, soluble recombinant NEP-24.11 can overcome this problem, however. Furthermore, the activity of the recombinant enzyme was not compromised in the presence of oxidants or inflammatory joint fluids. Recombinant NEP-24.11 holds promise as a novel therapeutic strategy for the treatment of inflammatory arthritis.
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PMID:Soluble recombinant neutral endopeptidase (CD10) as a potential antiinflammatory agent. 948 54

Membrane metalloendopeptidase EC 3.4.24.11 (Enkephalinase, neutral endopeptidase, NEP) is a cellular ectoenzyme, immunophenotypically identified as the leukocyte cluster of differentiation CD10 or CALLA (common acute lymphoblastic leukemia antigen). Immunological, biochemical and molecular biology techniques have identified tis cell membrane feature in various organs: brain, cardiovascular system, lung, placenta, kidney etc. The CD10 immunophenotype is a common feature of lymphoblasts in acute lymphoid leukemia not expressing the T- or B-markers. The enzymatic activity of CD10/NEP possibly influences normal lymphocyte ontogeny by proteolytic cleavage of the regulatory peptides. The substrates of CD10/NEP in the kidneys are (see the list of abbreviations) ANP, adrenomedullin and PAMP; in the brain, the substrates are enkephalins and oxytocin; in the lung, bombesin, BLP, GRP, neuromedin C, substance P and neurokinin A; in the cardiovascular system, angiotenisin II, bradykinin and CGRP; in the gut, VIP; on the neutrophil membrane, fMLP etc. Some substrates are not strictly tissue-specific, e.g. substance P. Preclinical and clinical trials explore possibilities of therapeutic application of the inhibitors of neutral endopeptidase, such as thiorphan in the management of pain, diarrhoea, depression, arterial hypertension and asthma. Other possibilities of application include the treatment of hyalinomembranous disease and prevention of neurotoxicosis in tetanus and botulism.
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PMID:[Membrane metalloendopeptidase (CD10/CALLA): distribution, physiologic and pathophysiologic functions and its inhibitors]. 974 92

Neutral endopeptidase is a mammalian type II integral membrane zinc-containing endopeptidase, which degrades and inactivates a number of bioactive peptides. The range of substrates cleaved by neutral endopeptidase in vitro includes the enkephalins, substance P, endothelin, bradykinin and atrial natriuretic factor. Due to the physiological importance of neutral endopeptidase in the modulation of nociceptive and pressor responses there is considerable interest in inhibitors of this enzyme as novel analgesics and anti-hypertensive agents. Here we describe the crystal structure of the extracellular domain (residues 52-749) of human NEP complexed with the generic metalloproteinase inhibitor phosphoramidon at 2.1 A resolution. The structure reveals two multiply connected folding domains which embrace a large central cavity containing the active site. The inhibitor is bound to one side of this cavity and its binding mode provides a detailed understanding of the ligand-binding and specificity determinants.
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PMID:Structure of human neutral endopeptidase (Neprilysin) complexed with phosphoramidon. 1066 92

Toxin A (TxA) of Clostridium difficile induces acute inflammation of the intestine initiated by release of substance P (SP) and activation of the neurokinin-1 receptor. However, the mechanisms that terminate this response are unknown. We determined whether the SP-degrading enzyme neutral endopeptidase (NEP, EC 3.4.24.11) terminates TxA-induced enteritis. We used both genetic deletion and pharmacological inhibition of NEP to test this hypothesis. In wild-type mice, instillation of TxA (0.5-5 microg) into ileal loops for 3 h dose dependently increased ileal fluid secretion, stimulated granulocyte transmigration determined by myeloperoxidase activity, and caused histological damage characterized by depletion of enterocytes, edema, and neutrophil accumulation. Deletion of NEP reduced the threshold secretory and inflammatory dose of TxA and exacerbated the inflammatory responses by more than twofold. This exacerbated inflammation was prevented by pretreatment with recombinant NEP. Conversely, pretreatment of wild-type mice with the NEP inhibitor phosphoramidon exacerbated enteritis. Thus NEP terminates enteritis induced by C. difficile TxA, underlying the importance of SP degradation in limiting neurogenic inflammation.
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PMID:Deletion of neutral endopeptidase exacerbates intestinal inflammation induced by Clostridium difficile toxin A. 1144 35

Neutral endopeptidase (EC3.4.24.11, NEP, enkephalinase) is a zinc-metalloendopeptidase, cleaving a variety of substrates like enkephalins, substance P, and bradykinin. In the brain, NEP is a key enzyme in the degradation of enkephalins. Pharmacological inhibition of NEP-activity causes analgesia resulting from enhanced extracellular enkephalin concentrations. Recently, transgenic mice lacking the enzyme NEP have been developed (Lu, 1995). The present study was designed to investigate the nociceptive behavior of these NEP-knockout mice. Interestingly, NEP-deficient mice did not respond with decreased pain perception, but exhibited hyperalgesia in the hot-plate jump, warm-water tail-withdrawal, and mostnotablyin theacetic-acid writhing test. Inhibition of aminopeptidase N by bestatin reduced writhing in both strains, whereas NEP-inhibition by thiorphan reduced writhing selectively in wild-type mice. Naloxone increased writhing in wild-type but not in knockouts, whereas the bradykinin B2-receptor antagonist HOE140 reduced writhing selectively in NEP-knockouts. Similarly, the nitric oxide synthase inhibitor L-NAME reduced writhing in NEP-knockouts. These results indicate that genetic elimination of NEP, in contrast to pharmacological inhibition, leads to bradykinin-induced hyperalgesia instead of enkephalin-mediated analgesia. Nitric oxide (NO) is suggested to be involved in this process.
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PMID:Neutral endopeptidase knockout induces hyperalgesia in a model of visceral pain, an effect related to bradykinin and nitric oxide. 1193 42

In this study we examined surface expression of CD26 and the corresponding enzyme activity of dipeptidyl peptidase IV (DPPIV) on the cells of immature murine T-cell line, R1.1. The data obtained have shown that R1.1 cells express high density of surface CD26 as compared to normal thymus cells. This was associated with strong enzyme activity, which, based on substrates and inhibitor specificity, corresponded to DPPIV. The DPPIV enzyme activity of R1.1 cells was 10 times stronger than that found on normal murine thymus cells (V(max) = 39 micromol/min/10(6) cells, vs 3.7 micromol/min/10(6) cells, respectively). Upon activation with anti-CD3, up-regulation of both membrane CD26, as well as of DPPIV enzyme activity on R1.1 cells were observed. The finding of strong DPPIV on R1.1 cells makes them suitable model for testing putative substrates/inhibitors of the enzyme in its natural microenvironment. Since in addition to strong DPPIV, R1.1 cells also express kappa opioid receptors (KOR) [European Journal of Pharmacology 227 (1992) 257], we tested the effect of dynorphin-A(1-17), an endogenous opioid peptide with KOR selectivity, on DPPIV of R1.1 cells. Dynorphin-A(1-17) down-regulated DPPIV in a dose-dependent manner, with the potency similar to that of substance P, a known natural DPPIV substrate [Journal of Pharmacology and Experimental Therapeutics 260 (1992) 1257]. DPPIV down-regulation was resistant to bestatin and thiorphan, the inhibitors of two cell surface peptidases (APN and NEP, respectively) with potential of dynorphin-A(1-17) degradation, suggesting that the mechanism underlying the observed effect does not involve degradative products of dynorphin-A(1-17). DPPIV down-regulation was also resistent to KOR antagonist, NBI, suggesting that the mechanism underlying the observed phenomenon involves neither cointernalization of KOR and DPPIV. Collectively, cells of immature T cell line, R1.1 exert strong DPPIV enzyme activity, which could be down-regulated in the presence of dynorphin-A(1-17) by mechanism that presumably includes non-substrate inhibition. By down-regulating DPPIV, dynorphin-A(1-17) may indirectly affect activity and/or specificity of natural substrates of DPPIV, such as substance P, RANTES, and endomorphins.
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PMID:Dipeptidyl peptidase IV (DPPIV) enzyme activity on immature T-cell line R1.1 is down-regulated by dynorphin-A(1-17) as a non-substrate inhibitor. 1273 31

Sialorphin is an exocrine and endocrine signaling mediator, which has been identified by a genomic approach. It is synthesized predominantly in the submandibular gland and prostate of adult rats in response to androgen steroids and is released locally and systemically in response to stress. We now demonstrate that the cell surface molecule to which sialorphin binds in vivo in the rat kidney is the membrane-anchored neutral endopeptidase (neprilysin; NEP, EC 3.4.24.11). NEP plays an important role in nervous and peripheral tissues, as it turns off several peptide-signaling events at the cell surface. We show that sialorphin prevents spinal and renal NEP from breaking down its two physiologically relevant substrates, substance P and Met-enkephalin in vitro. Sialorphin inhibited the breakdown of substance P with an IC50 of 0.4-1 microM and behaved as a competitive inhibitor. In vivo, i.v. sialorphin elicited potent antinociceptive responses in two behavioral rat models of injury-induced acute and tonic pain, the pin-pain test and formalin test. The analgesia induced by 100-200 mcicrog/kg doses of sialorphin required the activation of mu- and delta-opioid receptors, consistent with the involvement of endogenous opioid receptors in enkephalinergic transmission. We conclude that sialorphin protects endogenous enkephalins released after nociceptive stimuli by inhibiting NEP in vivo. Sialorphin is a natural systemically active regulator of NEP activity. Furthermore, our study provides evidence that it is a physiological modulator of pain perception after injury and might be the progenitor of a new class of therapeutic molecules.
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PMID:Sialorphin, a natural inhibitor of rat membrane-bound neutral endopeptidase that displays analgesic activity. 1283 17


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