title: NVP-DPP728 (1-[[[2-[(5-cyanopyridin-2-yl)amino]ethyl]amino]acetyl]-2-cyano-(S)- pyrrolidine), a slow-binding inhibitor of dipeptidyl peptidase IV.
abstract: Inhibition of dipeptidyl peptidase IV (DPP-IV) has been proposed recently as a therapeutic approach to the treatment of type 2 diabetes. N-Substituted-glycyl-2-cyanopyrrolidide compounds, typified by NVP-DPP728 (1-[[[2-[(5-cyanopyridin-2-yl)amino]ethyl]amino]acetyl]-2-cyano-(S )-p yrrolidine), inhibit degradation of glucagon-like peptide-1 (GLP-1) and thereby potentiate insulin release in response to glucose-containing meals. In the present study NVP-DPP728 was found to inhibit human DPP-IV amidolytic activity with a K(i) of 11 nM, a k(on) value of 1.3 x 10(5) M(-)(1) s(-)(1), and a k(off) of 1.3 x 10(-)(3) s(-)(1). Purified bovine kidney DPP-IV bound 1 mol/mol [(14)C]-NVP-DPP728 with high affinity (12 nM K(d)). The dissociation constant, k(off), was 1.0 x 10(-)(3) and 1.6 x 10(-)(3) s(-)(1) in the presence of 0 and 200 microM H-Gly-Pro-AMC, respectively (dissociation t(1/2) approximately 10 min). Through kinetic evaluation of DPP-IV inhibition by the D-antipode, des-cyano, and amide analogues of NVP-DPP728, it was determined that the nitrile functionality at the 2-pyrrolidine position is required, in the L-configuration, for maximal activity (K(i) of 11 nM vs K(i) values of 5.6 to >300 microM for the other analogues tested). Surprisingly, it was found that the D-antipode, despite being approximately 500-fold less potent than NVP-DPP728, displayed identical dissociation kinetics (k(off) of 1.5 x 10(-)(3) s(-)(1)). NVP-DPP728 inhibited DPP-IV in a manner consistent with a two-step inhibition mechanism. Taken together, these data suggest that NVP-DPP728 inhibits DPP-IV through formation of a novel, reversible, nitrile-dependent complex with transition state characteristics.
authors.affiliation: Metabolic and Cardiovascular Diseases Research, Novartis Institute for Biomedical Research, 556 Morris Avenue, Summit, New Jersey 07901-1398, USA. thomase.hughes@pharma.novartis.com
authors.forename: T E
authors.initials: TE
authors.lastname: Hughes
authors.forename: M D
authors.initials: MD
authors.lastname: Mone
authors.forename: M E
authors.initials: ME
authors.lastname: Russell
authors.forename: S C
authors.initials: SC
authors.lastname: Weldon
authors.forename: E B
authors.initials: EB
authors.lastname: Villhauer
mesh_terms: D000818:Animals; D018938:Caco-2 Cells; D002417:Cattle; D018819:Dipeptidyl Peptidase 4; D004355:Drug Stability; D006801:Humans; D009570:Nitriles / Q000737:chemistry / Q000493:pharmacokinetics / Q000494:pharmacology*; D011480:Protease Inhibitors / Q000737:chemistry / Q000493:pharmacokinetics / Q000494:pharmacology*; D011759:Pyrrolidines / Q000737:chemistry / Q000493:pharmacokinetics / Q000494:pharmacology*
chemical_list: C121834:1-(((2-((5-cyanopyridin-2-yl)amino)ethyl)amino)acetyl)-2-cyano-(S)-pyrrolidine; D009570:Nitriles; D011480:Protease Inhibitors; D011759:Pyrrolidines; D018819:Dipeptidyl Peptidase 4