title: Synthesis and biological activity of human neuropeptide S analogues modified in position 5: identification of potent and pure neuropeptide S receptor antagonists.
abstract: Neuropeptide S (NPS), the endogenous ligand of a previously orphan receptor now named NPSR, regulates various biological functions in the brain, including arousal, locomotion, anxiety, and food intake. Here we report on a focused structure-activity study of Gly5, which has been replaced with L and D amino acids. Fifteen NPS related peptides were synthesized and pharmacologically tested for intracellular calcium mobilization using HEK293 cells stably expressing the mouse NPSR. The results of this study demonstrated that peptide potency is inversely related to the side chain size, while peptide efficacy strongly depends on the relative L and D configuration, with the L amino acids favoring agonist while D amino acids display antagonist pharmacological activity. [D-Val5]NPS behaved as NPSR pure antagonist in HEK293(mNPSR) cells showing the highest potency (pK(B) 7.56) among this series of peptides. The antagonist action of [D-Val5]NPS was confirmed in vivo in mice, where the peptide at a dose of 10 nmol completely blocked the stimulatory effect of 0.1 nmol NPS on locomotor activity.
authors.affiliation: Department of Pharmaceutical Sciences and Biotechnology Center, Section of Pharmacology and National Institute of Neuroscience, University of Ferrara, via Fossato di Mortara 19, 44100 Ferrara, Italy. r.guerrini@unife.it
authors.forename: Remo
authors.initials: R
authors.lastname: Guerrini
authors.forename: Valeria
authors.initials: V
authors.lastname: Camarda
authors.forename: Claudio
authors.initials: C
authors.lastname: Trapella
authors.forename: Girolamo
authors.initials: G
authors.lastname: Calò
authors.forename: Anna
authors.initials: A
authors.lastname: Rizzi
authors.forename: Chiara
authors.initials: C
authors.lastname: Ruzza
authors.forename: Stella
authors.initials: S
authors.lastname: Fiorini
authors.forename: Erika
authors.initials: E
authors.lastname: Marzola
authors.forename: Rainer K
authors.initials: RK
authors.lastname: Reinscheid
authors.forename: Domenico
authors.initials: D
authors.lastname: Regoli
authors.forename: Severo
authors.initials: S
authors.lastname: Salvadori
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D002460:Cell Line; D004305:Dose-Response Relationship, Drug; D006801:Humans; D008124:Locomotion / Q000187:drug effects; D008297:Male; D051379:Mice; D008969:Molecular Sequence Data; D009479:Neuropeptides / Q000138:chemical synthesis / Q000737:chemistry* / Q000494:pharmacology*; D043562:Receptors, G-Protein-Coupled / Q000037:antagonists & inhibitors*; D013329:Structure-Activity Relationship
chemical_list: C484532:NPSR1 protein, human; D009479:Neuropeptides; D043562:Receptors, G-Protein-Coupled; C506531:neuropeptide S, human