title: Design, Synthesis, and Characterization of Cyclic Peptidomimetics of the Inducible Nitric Oxide Synthase Binding Epitope That Disrupt the Protein-Protein Interaction Involving SPRY Domain-Containing Suppressor of Cytokine Signaling Box Protein (SPSB) 2 and Inducible Nitric Oxide Synthase.
abstract: SPRY domain-containing suppressor of cytokine signaling box protein (SPSB) 2-deficient macrophages have been found to exhibit prolonged expression of inducible nitric oxide synthase (iNOS) and enhanced killing of persistent pathogens, suggesting that inhibitors of the SPSB2-iNOS interaction have potential as novel anti-infectives. In this study, we describe the design, synthesis, and characterization of cyclic peptidomimetic inhibitors of the SPSB2-iNOS interaction constrained by organic linkers to improve stability and druggability. SPR, ITC, and (19)F NMR analyses revealed that the most potent cyclic peptidomimetic bound to the iNOS binding site of SPSB2 with low nanomolar affinity (KD 29 nM), a 10-fold improvement over that of the linear peptide DINNN (KD 318 nM), and showed strong inhibition of SPSB2-iNOS interaction in macrophage cell lysates. This study exemplifies a novel approach to cyclize a Type II β-turn linear peptide and provides a foundation for future development of this group of inhibitors as new anti-infectives.
authors.affiliation: Medicinal Chemistry, Monash Institute of Pharmaceutical Sciences, Monash University , Parkville, Victoria 3052, Australia.
authors.forename: Jitendra R
authors.initials: JR
authors.lastname: Harjani
authors.affiliation: Medicinal Chemistry, Monash Institute of Pharmaceutical Sciences, Monash University , Parkville, Victoria 3052, Australia.
authors.forename: Beow Keat
authors.initials: BK
authors.lastname: Yap
authors.affiliation: Medicinal Chemistry, Monash Institute of Pharmaceutical Sciences, Monash University , Parkville, Victoria 3052, Australia.
authors.forename: Eleanor W W
authors.initials: EW
authors.lastname: Leung
authors.affiliation: Medicinal Chemistry, Monash Institute of Pharmaceutical Sciences, Monash University , Parkville, Victoria 3052, Australia.
authors.forename: Andrew
authors.initials: A
authors.lastname: Lucke
authors.affiliation: The Walter and Eliza Hall Institute of Medical Research , Parkville, Victoria 3052, Australia.|The Department of Medical Biology, University of Melbourne , Parkville, Victoria 3052, Australia.
authors.forename: Sandra E
authors.initials: SE
authors.lastname: Nicholson
authors.affiliation: Medicinal Chemistry, Monash Institute of Pharmaceutical Sciences, Monash University , Parkville, Victoria 3052, Australia.
authors.forename: Martin J
authors.initials: MJ
authors.lastname: Scanlon
authors.affiliation: Medicinal Chemistry, Monash Institute of Pharmaceutical Sciences, Monash University , Parkville, Victoria 3052, Australia.
authors.forename: David K
authors.initials: DK
authors.lastname: Chalmers
authors.affiliation: Medicinal Chemistry, Monash Institute of Pharmaceutical Sciences, Monash University , Parkville, Victoria 3052, Australia.
authors.forename: Philip E
authors.initials: PE
authors.lastname: Thompson
authors.affiliation: Medicinal Chemistry, Monash Institute of Pharmaceutical Sciences, Monash University , Parkville, Victoria 3052, Australia.
authors.forename: Raymond S
authors.initials: RS
authors.lastname: Norton
authors.affiliation: Medicinal Chemistry, Monash Institute of Pharmaceutical Sciences, Monash University , Parkville, Victoria 3052, Australia.
authors.forename: Jonathan B
authors.initials: JB
authors.lastname: Baell
mesh_terms: D000818:Animals; D000071197:B30.2-SPRY Domain / Q000187:drug effects*; D001665:Binding Sites / Q000187:drug effects; D015195:Drug Design; D008264:Macrophages / Q000187:drug effects / Q000378:metabolism; D051379:Mice; D008958:Models, Molecular; D008968:Molecular Conformation; D056004:Molecular Dynamics Simulation; D052247:Nitric Oxide Synthase Type II / Q000037:antagonists & inhibitors* / Q000378:metabolism; D010455:Peptides / Q000138:chemical synthesis / Q000737:chemistry / Q000494:pharmacology*; D057786:Peptidomimetics / Q000138:chemical synthesis / Q000737:chemistry / Q000494:pharmacology*; D011485:Protein Binding / Q000187:drug effects; D050826:Suppressor of Cytokine Signaling Proteins / Q000037:antagonists & inhibitors* / Q000378:metabolism
chemical_list: D010455:Peptides; D057786:Peptidomimetics; D050826:Suppressor of Cytokine Signaling Proteins; D052247:Nitric Oxide Synthase Type II