title: Conformational study on an insect neuropeptide of the AKH/RPCH-family by combined 1H NMR spectroscopy and molecular mechanics.
abstract: Peptides of the AKH/RPCH family are mainly involved in influencing energy metabolism in insects, i.e., regulating carbohydrate and/or lipid breakdown in the fat body. We have studied the solution conformation of a member of this family, the peptide Emp-AKH from praying mantis. It has been characterized by use of two dimensional nuclear magnetic resonance spectroscopy and molecular modelling. The proton spectrum of the Emp-AKH peptide was assigned by sequential assignment procedure. Proton-proton distances were derived from the volumes of cross-peaks in two dimensional nuclear Overhauser enhancement spectra. The three dimensional structure was built using Evans & Sutherland molecular modelling station. Our data indicate that the Emp-AKH peptide has adopted a beta-sheet structure for amino acids 1 to 5 and a beta-turn for amino acids at positions 5 to 8. The type of turn appears to be a Non-specific beta-turn.
authors.affiliation: Zoology Department, University of Cape Town, Rondebosch, South Africa.
authors.forename: I Z
authors.initials: IZ
authors.lastname: Zubrzycki
authors.forename: G
authors.initials: G
authors.lastname: Gäde
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D006859:Hydrogen; D007301:Insect Hormones / Q000737:chemistry*; D009682:Magnetic Resonance Spectroscopy / Q000379:methods; D008958:Models, Molecular; D008969:Molecular Sequence Data; D009036:Moths; D009479:Neuropeptides / Q000737:chemistry; D009842:Oligopeptides / Q000138:chemical synthesis / Q000737:chemistry*; D011487:Protein Conformation; D017433:Protein Structure, Secondary; D011761:Pyrrolidonecarboxylic Acid / Q000031:analogs & derivatives
chemical_list: D007301:Insect Hormones; D009479:Neuropeptides; D009842:Oligopeptides; C044833:adipokinetic hormone; D006859:Hydrogen; D011761:Pyrrolidonecarboxylic Acid