title: Molecular modeling of the binding of pheromone biosynthesis activating neuropeptide to its receptor.
abstract: Moth sex-pheromone biosynthesis follows a circadian cycle, which is cued by the release of the neurohormone pheromone biosynthesis activating neuropeptide (PBAN) to the hemolymph. PBAN binds to a G protein-coupled receptor (GPCR), in pheromone glands, (PG) initially identified by us in Helicoverpa zea moths (HezPBAN-R). In this study, the sequences of the seven transmembrane helices of HezPBAN-R were identified, built, packed and oriented correctly after multiple sequence alignment of the HezPBAN-R and several other GPCRs using the X-ray structure of rhodopsin as a template. Molecular dynamics simulations were run on three different beta-turn types of the C-terminal hexapeptide of PBAN and the results clustered into 12 structurally distinct groups. The lowest energy conformation from each group was used for computer-simulated docking with the model of the HezPBAN-R. Highest scoring complexes were examined and putative binding sites were identified. Experimental studies, using in vitro PG, revealed lower levels of pheromonotropic activity when challenged with pyrokinin-like peptides than with HezPBAN as ligand. Thus, the Drosophila melanogaster pyrokinin-1 receptor (CG9918) was chosen to create chimera receptors by exchanging between the three extracellular loops of the HezPBAN-R and the CG9918 for in silico mutagenesis experiments. The predicted docking model was validated with experimental data obtained from expressed chimera receptors in Sf9 cells.
authors.affiliation: Chemical Physics Department, Weizmann Institute of Science, 76100 Rehovot, Israel.
authors.forename: Peter S
authors.initials: PS
authors.lastname: Stern
authors.forename: Lian
authors.initials: L
authors.lastname: Yu
authors.forename: Man-Yeon
authors.initials: MY
authors.lastname: Choi
authors.forename: Russell A
authors.initials: RA
authors.lastname: Jurenka
authors.forename: Liron
authors.initials: L
authors.lastname: Becker
authors.forename: Ada
authors.initials: A
authors.lastname: Rafaeli
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D001665:Binding Sites; D008958:Models, Molecular; D008969:Molecular Sequence Data; D009036:Moths / Q000378:metabolism*; D009479:Neuropeptides / Q000737:chemistry / Q000378:metabolism*; D017434:Protein Structure, Tertiary
chemical_list: D009479:Neuropeptides; C079709:pheromone biosynthesis activating neuropeptide, Helicoverpa zea