title: Kinetic study of neuropeptide Y (NPY) proteolysis in blood and identification of NPY3-35: a new peptide generated by plasma kallikrein.
abstract: There is little information on how neuropeptide Y (NPY) proteolysis by peptidases occurs in serum, in part because reliable techniques are lacking to distinguish different NPY immunoreactive forms and also because the factors affecting the expression of these enzymes have been poorly studied. In the present study, LC-MS/MS was used to identify and quantify NPY fragments resulting from peptidolytic cleavage of NPY(1-36) upon incubation with human serum. Kinetic studies indicated that NPY(1-36) is rapidly cleaved in serum into 3 main fragments with the following order of efficacy: NPY(3-36) >> NPY(3-35) > NPY(2-36). Trace amounts of additional NPY forms were identified by accurate mass spectrometry. Specific inhibitors of dipeptidyl peptidase IV, kallikrein, and aminopeptidase P prevented the production of NPY(3-36), NPY(3-35), and NPY(2-36), respectively. Plasma kallikrein at physiological concentrations converted NPY(3-36) into NPY(3-35). Receptor binding assays revealed that NPY(3-35) is unable to bind to NPY Y1, Y2, and Y5 receptors; thus NPY(3-35) may represent the major metabolic clearance product of the Y2/Y5 agonist, NPY(3-36).
authors.affiliation: Division of Clinical Pharmacology and Toxicology, Centre Hospitalier Universitaire Vaudois (CHUV), 1011 Lausanne, Switzerland.
authors.forename: Karim
authors.initials: K
authors.lastname: Abid
authors.forename: Bertrand
authors.initials: B
authors.lastname: Rochat
authors.forename: Paul-Gerhard
authors.initials: PG
authors.lastname: Lassahn
authors.forename: Reto
authors.initials: R
authors.lastname: Stöcklin
authors.forename: Sophie
authors.initials: S
authors.lastname: Michalet
authors.forename: Noureddine
authors.initials: N
authors.lastname: Brakch
authors.forename: Jean-Francois
authors.initials: JF
authors.lastname: Aubert
authors.forename: Bilgin
authors.initials: B
authors.lastname: Vatansever
authors.forename: Patricia
authors.initials: P
authors.lastname: Tella
authors.forename: Ingrid
authors.initials: I
authors.lastname: De Meester
authors.forename: Eric
authors.initials: E
authors.lastname: Grouzmann
mesh_terms: D000218:Adamantane / Q000031:analogs & derivatives / Q000494:pharmacology; D000328:Adult; D002853:Chromatography, Liquid / Q000379:methods; D005260:Female; D006801:Humans; D007700:Kinetics; D008297:Male; D013058:Mass Spectrometry / Q000379:methods; D009478:Neuropeptide Y / Q000737:chemistry / Q000378:metabolism*; D009570:Nitriles / Q000494:pharmacology; D010446:Peptide Fragments / Q000737:chemistry* / Q000378:metabolism; D010455:Peptides / Q000737:chemistry / Q000494:pharmacology; D020842:Plasma Kallikrein / Q000737:chemistry / Q000378:metabolism*; D011480:Protease Inhibitors / Q000494:pharmacology; D017434:Protein Structure, Tertiary; D011759:Pyrrolidines / Q000494:pharmacology; D013379:Substrate Specificity; D000077597:Vildagliptin
chemical_list: D009478:Neuropeptide Y; D009570:Nitriles; D010446:Peptide Fragments; D010455:Peptides; D011480:Protease Inhibitors; D011759:Pyrrolidines; C544461:neuropeptide Y (3-35); D020842:Plasma Kallikrein; D000077597:Vildagliptin; C097277:apstatin; D000218:Adamantane