title: Reconstructing the discontinuous and conformational β1/β3-loop binding site on hFSH/hCG by using highly constrained multicyclic peptides.
abstract: Making peptide-based molecules that mimic functional interaction sites on proteins remains a challenge in biomedical sciences. Here, we present a robust technology for the covalent assembly of highly constrained and discontinuous binding site mimics, the potential of which is exemplified for structurally complex binding sites on the "Cys-knot" proteins hFSH and hCG. Peptidic structures were assembled by Ar(CH2 Br)2-promoted peptide cyclizations, combined with oxime ligation and disulfide formation. The technology allows unprotected side chain groups and is applicable to peptides of different lengths and nature. A tetracyclic FSH mimic was constructed, showing >600-fold improved binding compared to linear or monocyclic controls. Binding of a tricyclic hCG mimic to anti-hCG mAb 8G5 was identical to hCG itself (IC50 =260 vs. 470 pM), whereas this mimic displayed an IC50 value of 149 nM for mAb 3468, an hCG-neutralizing antibody with undetectable binding to either linear or monocyclic controls.
authors.affiliation: Van't Hoff Institute for Molecular Sciences, University of Amsterdam, Science Park 904, 1098 XH Amsterdam (Netherlands).
authors.forename: Linde E J
authors.initials: LE
authors.lastname: Smeenk
authors.forename: Drohpatie
authors.initials: D
authors.lastname: Timmers-Parohi
authors.forename: Joris J
authors.initials: JJ
authors.lastname: Benschop
authors.forename: Wouter C
authors.initials: WC
authors.lastname: Puijk
authors.forename: Henk
authors.initials: H
authors.lastname: Hiemstra
authors.forename: Jan H
authors.initials: JH
authors.lastname: van Maarseveen
authors.forename: Peter
authors.initials: P
authors.lastname: Timmerman
mesh_terms: D000595:Amino Acid Sequence; D000911:Antibodies, Monoclonal / Q000737:chemistry; D000936:Antigen-Antibody Complex / Q000737:chemistry; D001665:Binding Sites; D040761:Biomimetic Materials / Q000138:chemical synthesis / Q000737:chemistry*; D002384:Catalysis; D006063:Chorionic Gonadotropin / Q000737:chemistry*; D003500:Cyclization; D004220:Disulfides / Q000737:chemistry; D005640:Follicle Stimulating Hormone / Q000737:chemistry*; D006801:Humans; D007700:Kinetics; D008958:Models, Molecular; D008969:Molecular Sequence Data; D010091:Oximes / Q000737:chemistry; D010456:Peptides, Cyclic / Q000138:chemical synthesis / Q000737:chemistry*; D011485:Protein Binding; D017433:Protein Structure, Secondary
chemical_list: D000911:Antibodies, Monoclonal; D000936:Antigen-Antibody Complex; D006063:Chorionic Gonadotropin; D004220:Disulfides; D010091:Oximes; D010456:Peptides, Cyclic; D005640:Follicle Stimulating Hormone
keywords: constrained peptides; discontinuous epitope; multicyclic peptides; protein mimicry