title: A parallel semisynthetic approach for structure-activity relationship studies of peptide YY.
abstract: The gut hormone peptide YY (PYY) is postprandially secreted from enteroendocrine L cells and is involved in the regulation of energy homeostasis. The N-terminal truncated version PYY(3-36) decreases food intake and has potential as an anti-obesity agent. The anorectic effect of PYY(3-36) is mediated through Y₂ receptors in the hypothalamus, vagus, and brainstem regions, and it is well known that the C-terminal tetrapeptide sequence of PYY(3-36) is crucial for Y2 receptor activation. The aim of this work was to develop a semisynthetic methodology for the generation of a library of C-terminally modified PYY(3-36) analogues. By using an intein-based expression system, PYY(3-29) was generated as a C-terminal peptide α-thioester. Heptapeptides bearing an N-terminal cysteine and modifications at one of the four C-terminal positions were synthesized in a 96-well plate by parallel solid-phase synthesis. In the plate format, an array of [Ala30]PYY(3-36) analogues were generated by ligation, desulfurization, and subsequent solid-phase extraction. The generated analogues, in which either Arg33, Gln34, Arg35, or Tyr36 had been substituted with proteinogenic or non-proteinogenic amino acids, were tested in a functional Y₂ receptor assay. Generally, substitutions of Tyr36 were better tolerated than modifications of Arg33, Gln34, and Arg35. Two analogues showed significantly improved Y₂ receptor selectivity; therefore, these results could be used to design new drug candidates for the treatment of obesity.
authors.affiliation: Department of Drug Design & Pharmacology, University of Copenhagen, Universitetsparken 2, 2100 Copenhagen, Denmark.
authors.forename: Louise
authors.initials: L
authors.lastname: Albertsen
authors.forename: Søren
authors.initials: S
authors.lastname: Østergaard
authors.forename: Johan F
authors.initials: JF
authors.lastname: Paulsson
authors.forename: Jens Chr
authors.initials: JC
authors.lastname: Norrild
authors.forename: Kristian
authors.initials: K
authors.lastname: Strømgaard
mesh_terms: D000595:Amino Acid Sequence; D004926:Escherichia coli / Q000378:metabolism; D008969:Molecular Sequence Data; D009842:Oligopeptides / Q000138:chemical synthesis / Q000737:chemistry*; D019894:Peptide YY / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism; D011485:Protein Binding; D017476:Receptors, Neuropeptide Y / Q000737:chemistry / Q000378:metabolism; D011993:Recombinant Fusion Proteins / Q000096:biosynthesis / Q000737:chemistry / Q000235:genetics; D060327:Solid-Phase Synthesis Techniques; D013329:Structure-Activity Relationship
chemical_list: D009842:Oligopeptides; D017476:Receptors, Neuropeptide Y; D011993:Recombinant Fusion Proteins; D019894:Peptide YY
keywords: peptide modifications; peptide YY; protein ligation; solid-phase peptide synthesis; structure-activity relationships