title: Molecular modelling of beta turns in a cyclic melanotropin.
abstract: Alpha-Melanocyte stimulating hormone (alpha-MSH) is a tridecapeptide which interacts with a family of G protein-coupled receptors, the melanocortin receptors, to cause its biological effects. We have modelled the low energy conformations of the alpha-MSH derivatives as part of a project to probe the receptor binding conformation of melanocortins, and also to design ligands for targeting cytotoxic drugs to MC1 receptors expressed by melanoma cells. Here we report a molecular dynamics study of beta turns in a cyclic lactam analogue [Nle4, Asp5, D-Phe7, Lys10]alpha-MSH. The data show that it is possible for a beta turn to exist in the ring portion of this molecule which contains the melanocortin conserved sequence - His-Phe-Arg-Trp-, even though the lowest energy conformers lack a beta turn.
authors.affiliation: School of Pharmacy and Pharmacology, University of Bath, UK.
authors.forename: N C
authors.initials: NC
authors.lastname: Chan
authors.forename: S K
authors.initials: SK
authors.lastname: Branch
authors.forename: S H
authors.initials: SH
authors.lastname: Moss
authors.forename: C W
authors.initials: CW
authors.lastname: Pouton
mesh_terms: D000595:Amino Acid Sequence; D008958:Models, Molecular; D008969:Molecular Sequence Data; D011487:Protein Conformation; D018043:Receptors, Corticotropin / Q000378:metabolism; D044101:Receptors, Melanocortin; D000521:alpha-MSH / Q000031:analogs & derivatives / Q000737:chemistry*
chemical_list: D018043:Receptors, Corticotropin; D044101:Receptors, Melanocortin; D000521:alpha-MSH