title: Conformational calculations on gastrin C-terminal tetrapeptide.
abstract: Energy optimizations were performed on some typical conformations of the gastrin C-terminal peptide amide NAc-Trp-Met-Asp-Phe-NH2. Two families of lowest energy conformations were found corresponding to: (a) alpha-helical structures; (b) conformations having beta-structure at the level of Trp residue, and C7-structure at the level of Asp residue. The two aromatic rings were folded on the peptide backbone and ca. 5 A distant from each other (centre to centre). The last family, favoured by energy and population probability, can better account for conformational experimental results and biological activity observations.
mesh_terms: D000595:Amino Acid Sequence; D005755:Gastrins; D008958:Models, Molecular; D009842:Oligopeptides; D011487:Protein Conformation; D013329:Structure-Activity Relationship
chemical_list: D005755:Gastrins; D009842:Oligopeptides