Unwinding of the C-Terminal Residues of Neuropeptide Y is critical for Y₂ Receptor Binding and Activation.
Despite recent breakthroughs in the structural characterization of G-protein-coupled receptors (GPCRs), there is only sparse data on how GPCRs recognize larger peptide ligands. NMR spectroscopy, molecular modeling, and double-cycle mutagenesis studies were integrated to obtain a structural model of the peptide hormone neuropeptide Y (NPY) bound to its human G-protein-coupled Y2 receptor (Y2R). Solid-state NMR measurements of specific isotope-labeled NPY in complex with in vitro folded Y2R reconstituted into phospholipid bicelles provided the bioactive structure of the peptide. Guided by solution NMR experiments, it could be shown that the ligand is tethered to the second extracellular loop by hydrophobic contacts. The C-terminal α-helix of NPY, which is formed in a membrane environment in the absence of the receptor, is unwound starting at T(32) to provide optimal contacts in a deep binding pocket within the transmembrane bundle of the Y2R.
Institut für Biochemie, Universität Leipzig, Brüderstraße 34, 04103 Leipzig (Germany).
Anette
A
Kaiser
Institut für Medizinische Physik und Biophysik, Universität Leipzig, Härtelstraße 16-18, 04107 Leipzig (Germany).
Paul
P
Müller
Institut für Biochemie, Universität Leipzig, Brüderstraße 34, 04103 Leipzig (Germany).|Center for Structural Biology, Vanderbilt University, 465 21stAve South, Nashville, TN 37203 (USA).
Tristan
T
Zellmann
Institut für Medizinische Physik und Biophysik, Universität Leipzig, Härtelstraße 16-18, 04107 Leipzig (Germany).
Holger A
HA
Scheidt
Institut für Medizinische Physik und Biophysik, Universität Leipzig, Härtelstraße 16-18, 04107 Leipzig (Germany).
Lars
L
Thomas
Institut für Medizinische Physik und Biophysik, Universität Leipzig, Härtelstraße 16-18, 04107 Leipzig (Germany).
Mathias
M
Bosse
Institut für Biochemie, Universität Leipzig, Brüderstraße 34, 04103 Leipzig (Germany).
Rene
R
Meier
Center for Structural Biology, Vanderbilt University, 465 21stAve South, Nashville, TN 37203 (USA).
Jens
J
Meiler
Institut für Medizinische Physik und Biophysik, Universität Leipzig, Härtelstraße 16-18, 04107 Leipzig (Germany).
Daniel
D
Huster
Institut für Biochemie, Universität Leipzig, Brüderstraße 34, 04103 Leipzig (Germany).
Annette G
AG
Beck-Sickinger
Institut für Medizinische Physik und Biophysik, Universität Leipzig, Härtelstraße 16-18, 04107 Leipzig (Germany). peter.schmidt@medizin.uni-leipzig.de.
Peter
P
Schmidt
D000595:Amino Acid Sequence; D001665:Binding Sites; D006801:Humans; D062105:Molecular Docking Simulation; D008969:Molecular Sequence Data; D009478:Neuropeptide Y / Q000737:chemistry / Q000378:metabolism*; D019906:Nuclear Magnetic Resonance, Biomolecular; D011485:Protein Binding; D017433:Protein Structure, Secondary; D017476:Receptors, Neuropeptide Y / Q000737:chemistry / Q000378:metabolism*
D009478:Neuropeptide Y; D017476:Receptors, Neuropeptide Y; C095889:neuropeptide Y2 receptor
GPCRs; NMR spectroscopy; neuropeptide Y; peptide structure; receptors