title: Reversible ketomethylene-based inhibitors of human neutrophil proteinase 3.
abstract: Neutrophil serine proteases, proteinase 3 (PR3) and human neutrophil elastase (HNE), are considered as targets for chronic inflammatory diseases. Despite sharing high sequence similarity, the two enzymes have different substrate specificities and functions. While a plethora of HNE inhibitors exist, PR3 specific inhibitors are still in their infancy. We have designed ketomethylene-based inhibitors for PR3 that show low micromolar IC50 values. Their synthesis was made possible by amending a previously reported synthesis of ketomethylene dipeptide isosteres to allow for the preparation of derivatives suitable for solid phase peptide synthesis. The best inhibitor (Abz-VADnV[Ψ](COCH2)ADYQ-EDDnp) was found to be selective for PR3 over HNE and to display a competitive and reversible inhibition mechanism. Molecular dynamics simulations show that the interactions between enzyme and ketomethylene-containing inhibitors are similar to those with the corresponding substrates. We also confirm that N- and C-terminal FRET groups are important for securing high inhibitory potency toward PR3.
authors.affiliation: Department of Chemistry and Centre for Pharmacy, University of Bergen , Allégaten 41, 5007 Bergen, Norway.
authors.forename: Adnan
authors.initials: A
authors.lastname: Budnjo
authors.forename: Shailesh
authors.initials: S
authors.lastname: Narawane
authors.forename: Cédric
authors.initials: C
authors.lastname: Grauffel
authors.forename: Anne-Sophie
authors.initials: AS
authors.lastname: Schillinger
authors.forename: Torgils
authors.initials: T
authors.lastname: Fossen
authors.forename: Nathalie
authors.initials: N
authors.lastname: Reuter
authors.forename: Bengt Erik
authors.initials: BE
authors.lastname: Haug
mesh_terms: D001667:Binding, Competitive; D020134:Catalytic Domain; D002626:Chemistry, Pharmaceutical / Q000379:methods; D004151:Dipeptides / Q000737:chemistry; D015195:Drug Design; D004791:Enzyme Inhibitors / Q000737:chemistry*; D031541:Fluorescence Resonance Energy Transfer / Q000379:methods; D006801:Humans; D007249:Inflammation; D020128:Inhibitory Concentration 50; D007659:Ketones / Q000737:chemistry; D008958:Models, Molecular; D056004:Molecular Dynamics Simulation; D053146:Myeloblastin / Q000037:antagonists & inhibitors* / Q000737:chemistry*; D010455:Peptides / Q000737:chemistry; D013379:Substrate Specificity
chemical_list: D004151:Dipeptides; D004791:Enzyme Inhibitors; D007659:Ketones; D010455:Peptides; D053146:Myeloblastin