title: Discovery, structure-activity relationship studies, and crystal structure of nonpeptide inhibitors bound to the Shank3 PDZ domain.
abstract: Shank is the central scaffolding protein of the postsynaptic density (PSD) protein complex found in cells of the central nervous system. Cellular studies indicate a prominent role of the protein in the organization of the PSD, in the development of neuronal morphology, in neuronal signaling, and in synaptic plasticity, thus linking Shank functions to the molecular basis of learning and memory. Mutations in the Shank gene have been found in several neuronal disorders including mental retardation, typical autism, and Asperger syndrome. Shank is linked to the PSD complex via its PDZ domain that binds to the C-terminus of guanylate-kinase-associated protein (GKAP). Here, small-molecule inhibitors of Shank3 PDZ domain are developed. A fluorescence polarization assay based on an identified high-affinity peptide is established, and tetrahydroquinoline carboxylates are identified as inhibitors of this protein-protein interaction. Chemical synthesis via a hetero-Diels-Alder strategy is employed for hit optimization, and structure-activity relationship studies are performed. Best hits possess K(i) values in the 10 μM range, and binding to the PDZ domain is confirmed by ¹H,¹⁵N HSQC NMR experiments. One of the hits crystallizes with the Shank3 PDZ domain. The structure, analyzed at a resolution of 1.85 Å, reveals details of the binding mode. Finally, binding to PDZ domains of PSD-95, syntrophin, and DVL3 was studied using ¹H,¹⁵N HSQC NMR spectroscopy.
authors.affiliation: Leibniz-Institut für Molekulare Pharmakologie (FMP), Robert-Rössle-Str. 10, 13125 Berlin, Germany.
authors.forename: Jörn
authors.initials: J
authors.lastname: Saupe
authors.forename: Yvette
authors.initials: Y
authors.lastname: Roske
authors.forename: Christian
authors.initials: C
authors.lastname: Schillinger
authors.forename: Nestor
authors.initials: N
authors.lastname: Kamdem
authors.forename: Silke
authors.initials: S
authors.lastname: Radetzki
authors.forename: Anne
authors.initials: A
authors.lastname: Diehl
authors.forename: Hartmut
authors.initials: H
authors.lastname: Oschkinat
authors.forename: Gerd
authors.initials: G
authors.lastname: Krause
authors.forename: Udo
authors.initials: U
authors.lastname: Heinemann
authors.forename: Jörg
authors.initials: J
authors.lastname: Rademann
mesh_terms: D000595:Amino Acid Sequence; D001665:Binding Sites; D002352:Carrier Proteins / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism; D018360:Crystallography, X-Ray; D004353:Drug Evaluation, Preclinical; D006801:Humans; D009419:Nerve Tissue Proteins; D054731:PDZ Domains / Q000187:drug effects; D010455:Peptides / Q000138:chemical synthesis / Q000737:chemistry; D054730:Protein Interaction Domains and Motifs; D011804:Quinolines / Q000138:chemical synthesis / Q000737:chemistry* / Q000494:pharmacology; D011994:Recombinant Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D013329:Structure-Activity Relationship
chemical_list: D002352:Carrier Proteins; D009419:Nerve Tissue Proteins; D010455:Peptides; D011804:Quinolines; D011994:Recombinant Proteins; C492357:SHANK3 protein, human; C542964:1,2,3,4-tetrahydroquinoline