title: Conformational study of insect adipokinetic hormones using NMR constrained molecular dynamics.
abstract: Mem-CC (pGlu-Leu-Asn-Tyr-Ser-Pro-Asp-Trp-NH2), Tem-HrTH (pGlu-Leu-Asn-Phe-Ser-Pro-Asn-Trp-NH2) and Del-CC (pGlu-Leu-Asn-Phe-Ser-Pro-Asn-Trp-Gly-Asn-NH2) are adipokinetic hormones, isolated from the corpora cardiaca of different insect species. These hormones regulate energy metabolism during flight and so are intimately involved in an insect's mobility. Secondary structural elements of these peptides and the N7 analogue, [N7]-Mem-CC (pGlu-Leu-Asn-Tyr-Ser-Pro-Asn-Trp-NH2), have been determined in dimethylsulfoxide solution using NMR restrained molecular mechanic simulations. The neuropeptides were all found to have an extended structure for the first 4 residues and a beta-turn between residues 4-8. For Tem-HrTH and Del-CC, asparagine (N7) which is postulated to be involved in receptor binding and/or activation, projects outward form the beta-turn. Mem-CC does not have an asparagine at position 7 while, for [N7]-Mem-CC, the N7 sidechain folds inside the beta-turn preventing its interaction with the receptor.
authors: Department of Chemistry, University of Cape Town, South Africa.
authors: M M
authors: MM
authors: Nair
authors: G E
authors: GE
authors: Jackson
authors: G
authors: G
authors: Gäde
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D006860:Hydrogen Bonding; D066298:In Vitro Techniques; D007301:Insect Hormones / Q000737:chemistry* / Q000378:metabolism; D019476:Insect Proteins; D009682:Magnetic Resonance Spectroscopy; D008958:Models, Molecular; D009842:Oligopeptides / Q000737:chemistry* / Q000378:metabolism; D011487:Protein Conformation; D017433:Protein Structure, Secondary; D011761:Pyrrolidonecarboxylic Acid / Q000031:analogs & derivatives; D011956:Receptors, Cell Surface / Q000378:metabolism; D013816:Thermodynamics
chemical_list: D007301:Insect Hormones; D019476:Insect Proteins; D009842:Oligopeptides; D011956:Receptors, Cell Surface; C044833:adipokinetic hormone; D011761:Pyrrolidonecarboxylic Acid