title: Optimization of on-resin palladium-catalyzed Sonogashira cross-coupling reaction for peptides and its use in a structure-activity relationship study of a class B GPCR ligand.
abstract: Class B G protein-coupled receptors are activated by their cognate ligands following a two-step binding model involving a specific network of ligand-receptor intermolecular interactions. In particular, a N-capping structure present in the ligand would contribute significantly to position the N-terminal segment of the ligand once bound to its receptor. The aim of the current study was to implement the use of Pd-catalyzed Sonogashira coupling for the investigation of this structural motif. First, we have developed and evaluated various Sonogashira-based procedures for on-resin post-synthesis modification using a Leu-enkephalin derivative as a model peptide. Next, we have prepared a small library of PACAP-based analogs and evaluated the pharmacological profile of a few of them using a competitive binding assay, as well as functional and survival assays. Notably, our results suggest that the modification of the N-capping region could alter the binding specificity of PACAP without altering its biological activity, thereby opening the way for the design of more selective compounds. Finally, the possibility to achieve sequential multiple point substitutions via the Sonogashira cross-coupling method, during solid phase peptide synthesis, was also evaluated. Altogether, we demonstrated the versatility of such a procedure for the incorporation of various mono- and multiple alkyne-derived modifications during solid phase peptide synthesis and confirmed its usefulness for the structure-activity study of a class B GPCR ligand.
authors.affiliation: INRS - Institut Armand-Frappier, Laboratoire d'études moléculaires et pharmacologiques des peptides, Université du Québec, 531 boul. des Prairies, Ville de Laval, Québec, H7V 1B7, Canada.
authors.forename: Ngoc-Duc
authors.initials: ND
authors.lastname: Doan
authors.affiliation: INRS - Institut Armand-Frappier, Laboratoire d'études moléculaires et pharmacologiques des peptides, Université du Québec, 531 boul. des Prairies, Ville de Laval, Québec, H7V 1B7, Canada; INRS - Institut Armand-Frappier, Groupe de Recherche en Ingénierie des Peptides et en Pharmacothérapie (GRIPP), Université du Québec, 531 boul. des Prairies, Ville de Laval, Québec, H7V 1B7, Canada.
authors.forename: Mathilde
authors.initials: M
authors.lastname: Poujol de Molliens
authors.affiliation: INRS - Institut Armand-Frappier, Laboratoire d'études moléculaires et pharmacologiques des peptides, Université du Québec, 531 boul. des Prairies, Ville de Laval, Québec, H7V 1B7, Canada; INRS - Institut Armand-Frappier, Groupe de Recherche en Ingénierie des Peptides et en Pharmacothérapie (GRIPP), Université du Québec, 531 boul. des Prairies, Ville de Laval, Québec, H7V 1B7, Canada.
authors.forename: Myriam
authors.initials: M
authors.lastname: Létourneau
authors.affiliation: INRS - Institut Armand-Frappier, Laboratoire d'études moléculaires et pharmacologiques des peptides, Université du Québec, 531 boul. des Prairies, Ville de Laval, Québec, H7V 1B7, Canada. Electronic address: alain.fournier@iaf.inrs.ca.
authors.forename: Alain
authors.initials: A
authors.lastname: Fournier
authors.affiliation: INRS - Institut Armand-Frappier, Groupe de Recherche en Ingénierie des Peptides et en Pharmacothérapie (GRIPP), Université du Québec, 531 boul. des Prairies, Ville de Laval, Québec, H7V 1B7, Canada. Electronic address: david.chatenet@iaf.inrs.ca.
authors.forename: David
authors.initials: D
authors.lastname: Chatenet
mesh_terms: D000818:Animals; D016466:CHO Cells; D002384:Catalysis; D045744:Cell Line, Tumor; D002470:Cell Survival / Q000187:drug effects; D003412:Cricetulus; D004305:Dose-Response Relationship, Drug; D006801:Humans; D008024:Ligands; D015394:Molecular Structure; D009942:Organometallic Compounds / Q000737:chemistry*; D010165:Palladium / Q000737:chemistry*; D010455:Peptides / Q000138:chemical synthesis / Q000737:chemistry* / Q000494:pharmacology*; D043562:Receptors, G-Protein-Coupled / Q000378:metabolism*; D013329:Structure-Activity Relationship
chemical_list: D008024:Ligands; D009942:Organometallic Compounds; D010455:Peptides; D043562:Receptors, G-Protein-Coupled; D010165:Palladium
keywords: Class B GPCR ligands; G protein-coupled receptors; Neuroprotection; Pituitary adenylate cyclase-activating polypeptide; Sonogashira cross-coupling