Human kidney "enkephalinase", a neutral metalloendopeptidase that cleaves active peptides

Gafford, John T.; Skidgel, Randal A.; Erdös, Ervin G.; Hersh, Louis B.

doi:10.1021/bi00282a035

Cited by 274 publications

(132 citation statements)

References 40 publications

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“…14 - 15 Our findings suggest that this endopeptidase also influences the metabolism of Ang I by decreasing hydrolysis of Ang II and facilitating conversion of Ang I into Ang-(l-7). Inhibition of Ang II degradation appears to be an important action of SCH 39,370.…”

Section: Discussionmentioning

confidence: 75%

“…In our experiments, SCH 39,370 caused both baseline and peak plasma levels of Ang II to double in both WKY and SHR. Gafford et al 15 have reported that NEP 24.11 hydrolyzes Ang II at the Tyr'.Ile 5 to yield Ang-(l-4). Therefore, the observation that SCH 39,370 did not reduce blood pressure in SHR may reflect the opposing effects that NEP 24.11 has on the various peptidergic systems that regulate vascular resistance.…”

Section: Discussionmentioning

confidence: 99%

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In vivo metabolism of angiotensin I by neutral endopeptidase (EC 3.4.24.11) in spontaneously hypertensive rats.

et al. 1992

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We investigated the processing enzymes involved in the formation of circulating angiotensin-(l-7) after intravenous administration of angiotensin I to conscious spontaneously hypertensive and Wistar-Kyoto rats. Immunoreactive products, including angiotensin I, angiotensin II, and angiotensin-(l-7), were measured in arterial blood by three specific radioimmunoassays. Angiotensin I infusion (2 nmol) induced a rapid increase in immunoreactive angiotensin II and angiotensin-(l-7). Pretreatment with the angiotensin converting enzyme inhibitor enalaprilat (2 mg/kg) eliminated angiotensin II formation and augmented circulating levels of angiotensin I and angiotensin-(l-7) in spontaneously hypertensive and Wistar-Kyoto rats. The elevated levels of angiotensin-(l-7) in enalaprilat-treated rats were blocked by concurrent treatment with the neutral endopeptidase (EC 3.4.24.11) inhibitor SCH 39,370 (15 mg/kg) in both strains. Administration of SCH 39,370 alone decreased angiotensin-(l-7) levels in spontaneously hypertensive rats, whereas angiotensin II levels increased in both strains (p<0.01). Comparisons of the metabolism of angiotensin I in the two rat strains showed increased formation of angiotensin-(l-7) in spontaneously hypertensive rats not given any of the enzyme inhibitors. In addition, levels of angiotensin I were higher after administration of SCH 39,370 in hypertensive rats. These novel findings reveal that neutral endopeptidase EC 3.4.24.11 participates in the conversion of angiotensin I to angiotensin-(l-7) and in the metabolism of angiotensin II in the circulation of both spontaneously hypertensive and Wistar-Kyoto rats. Our results suggest that neutral endopeptidase EC 3.4.24.11 is a major enzymatic constituent of the circulating renin-angiotensin system. (Hypertension 1992;19:692-696) KEY WORDS • angiotensin I • angiotensin II • angiotensin converting enzyme • enalaprilat • enzyme inhibitors • peptide peptidohydrolases • spontaneously hypertensive rats A ngiotensin-(l-7) ] is the first member / \ of the angiotensin peptide family to cause cells -Z \ -to secrete hormones and release autacoids without eliciting accompanying changes in blood pressure, water intake, and aldosterone secretion. Incubation of hypothalamic explants with Ang-(l-7) stimulates a dose-dependent release of vasopressin.

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Section: Discussionmentioning

confidence: 75%

Section: Discussionmentioning

confidence: 99%

In vivo metabolism of angiotensin I by neutral endopeptidase (EC 3.4.24.11) in spontaneously hypertensive rats.

et al. 1992

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“…Its activity is highest on the epithelial cells of kidneys. 30 NEP activity has also been found in the cardiovascular system, on the plasma membranes of vascular endothelial cells, 31 and on cultured rat myocytes. 29 …”

Section: Bradykinin Metabolism Of the Heartmentioning

confidence: 94%

Kallidin- and Bradykinin-Degrading Pathways in Human Heart

et al. 1999

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Background-Since kinins kallidin (KD) and bradykinin (BK) appear to have cardioprotective effects ranging from improved hemodynamics to antiproliferative effects, inhibition of kinin-degrading enzymes should potentiate such effects. Indeed, it is believed that this mechanism is partly responsible for the beneficial effects of angiotensin-converting enzyme (ACE) inhibitors. In the heart, enzymes other than ACE may contribute to local degradation of kinins. The purpose of this study was to investigate which enzymes are responsible for the degradation of KD and BK in human heart tissue. Methods and Results-Cardiac membranes were prepared from the left ventricles of normal (nϭ5) and failing (nϭ10) hearts. The patients had end-stage congestive heart failure as the result of coronary heart disease or idiopathic dilated cardiomyopathy. Heart tissue was incubated with KD or BK in the presence or absence of enzyme inhibitors. We found no difference in the enzymes responsible for kinin metabolism or their activities between normal and failing hearts. Thus KD was mostly converted into BK by the aminopeptidase M-like activity. When BK was used as substrate, it was converted into an inactive metabolite BK-(1-7) mostly (80% to 90%) by the neutral endopeptidase (NEP) activity, with ACE unexpectedly playing only a minor role. The low enzymatic activity of ACE in the cardiac membranes, compared with that of NEP, was not due to chronic ACE inhibitor therapy, because the cardiac ACE activities of patients, whether receiving ACE inhibitors or not, and of normal subjects were all equal. Conclusions-The present in vitro study shows that in human cardiac membranes, the most critical step in kinin metabolism, that is, inactivation of BK, appears to be mediated mostly by NEP. This observation suggests a role for NEP in the local control of BK concentration in heart tissue. Thus inhibition of cardiac NEP activity could be cardioprotective by elevating the local concentration of BK in the heart. (Circulation. 1999;99:1984-1990.)

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“…Thereafter, it was shown to hydrolyze a number of biologically active peptides into inactive fragments in vitro, such as tachykinins (17), bradykinin (18), and atrial natriuretic peptides (19,20). The physiological implication of NEP in the inactivation of these messenger peptides was confirmed in vivo by the design and use of selective and potent inhibitors, e.g.…”

mentioning

confidence: 99%

A Three-dimensional Model of the Neprilysin 2 Active Site Based on the X-ray Structure of Neprilysin

Voisin

Rognan

Gros

et al. 2004

Journal of Biological Chemistry

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Neprilysin 2 (NEP2), a recently identified member of the M13 subfamily of metalloproteases, shares the highest degree of homology with the prototypical member of the family neprilysin. Whereas the study of the in vitro enzymatic activity of NEP2 shows that it resembles that of NEP as it cleaves the same substrates often at the same amide bonds and binds the same inhibitory compounds albeit with different potencies, its physiological role remains elusive because of the lack of selective inhibitors. To aid in the design of these novel compounds and better understand the different inhibitory patterns of NEP and NEP2, the x-ray structure of NEP was used as a template to build a model of the NEP2 active site. The results of our modeling suggest that the overall structure of NEP2 closely resembles that of NEP. The model of the active site reveals a 97% sequence identity with that of NEP with differences located within the S 2 subsite of NEP2 where Ser 133 and Leu 739 replace two glycine residues in NEP. To validate the proposed model, site-directed mutagenesis was performed on a series of residues of NEP2, mutants expressed in AtT20 cells, and their ability to bind various substrates and inhibitory compounds was tested. The results confirm the involvement of the conserved Arg 131 and Asn 567 in substrate binding and catalytic activity of NEP2 and further show that the modifications in its S 2 pocket, particularly the presence therein of Leu 739 , account for a number of differences in inhibitor binding between NEP and NEP2.Neprilysin 2 (SEP and NL-1) is a recently identified type II membrane-bound zinc-dependent metalloprotease (1-3). It is part of the M13 family of metalloproteases, which also comprises neprilysin (NEP, 1 EC 3.4.24.11) (4 -6), the endothelinconverting enzymes, ECE-1 (EC 3.4.24.71) (7) and ECE-2 (8), the Kell blood group antigen (9), the phosphate-regulating neutral endopeptidase on the X chromosome (10) and X-converting enzyme (11). Not only do all of the members of this family of metalloproteases share considerable sequence identities, suggesting a common ancestor as well as a common fold, NEP2, by far the closest homologue of NEP displays over 50% of overall protein sequence identity with NEP, a degree of homology that also suggests a common function (12).The best characterized member of the family, NEP (13, 14), was first identified as a kidney brush-border neutral endopeptidase slowly hydrolyzing [ 125 I]iodoinsulin B chain (15) and rediscovered as an "enkephalinase" of cerebral membranes hydrolyzing the Gly 3 -Phe 4 bond of enkephalins (16). Thereafter, it was shown to hydrolyze a number of biologically active peptides into inactive fragments in vitro, such as tachykinins (17), bradykinin (18), and atrial natriuretic peptides (19,20). The physiological implication of NEP in the inactivation of these messenger peptides was confirmed in vivo by the design and use of selective and potent inhibitors, e.g. thiorphan (21-24). These functions of NEP and the design of specific inhibitors thereof are of ...

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Human kidney "enkephalinase", a neutral metalloendopeptidase that cleaves active peptides

Cited by 274 publications

References 40 publications

In vivo metabolism of angiotensin I by neutral endopeptidase (EC 3.4.24.11) in spontaneously hypertensive rats.

In vivo metabolism of angiotensin I by neutral endopeptidase (EC 3.4.24.11) in spontaneously hypertensive rats.

Kallidin- and Bradykinin-Degrading Pathways in Human Heart

A Three-dimensional Model of the Neprilysin 2 Active Site Based on the X-ray Structure of Neprilysin

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