title: Global chain properties of an all l-α-eicosapeptide with a secondary α-helix and its all retro d-inverso-α-eicosapeptide estimated through the modeling of their CZE-determined electrophoretic mobilities.
abstract: Several global chain properties of relatively long peptides composed of 20 amino acid residues are estimated through the modeling of their experimental effective electrophoretic mobilities determined by CZE for 2 < pH < 6. In this regard, an all l-α-eicosapeptide, including a secondary α-helix (Peptide 1) and its all retro d-inverso-α-eicosapeptide (Peptide 2), are considered. Despite Peptides 1 and 2 are isomeric chains, they do not present similar global conformations in the whole range of pH studied. These peptides may also differ in the quality of BGE components chain interactions depending on the pH value. Three Peptide 1 fragments (Peptides 3, 4, and 5) are also analyzed in this framework with the following purposes: (i) visualization of the effects of initial and final strands at each side of the α-helix on the global chain conformations of Peptide 1 at different pHs and (ii) analysis of global chain conformations of Peptides 1 and 2, and Peptide 1 fragments in relation to their pI values. Also, the peptide maximum and minimum hydrations predicted by the model, compatible with experimental effective electrophoretic mobilities at different pHs, are quantified and discussed, and needs for further research concerning chain hydration are proposed. It is shown that CZE is a useful analytical tool for peptidomimetic designs and purposes.
authors.affiliation: Instituto de Desarrollo Tecnológico para la Industria Química (INTEC), Universidad Nacional del Litoral (UNL), Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Santa Fe, Argentina.
authors.forename: Julio A
authors.initials: JA
authors.lastname: Deiber
authors.forename: Maria V
authors.initials: MV
authors.lastname: Piaggio
authors.forename: Marta B
authors.initials: MB
authors.lastname: Peirotti
mesh_terms: D000595:Amino Acid Sequence; D019075:Electrophoresis, Capillary / Q000379:methods*; D007536:Isomerism; D008956:Models, Chemical; D008969:Molecular Sequence Data; D010191:Pancreatic Polypeptide / Q000032:analysis / Q000737:chemistry*; D010446:Peptide Fragments / Q000032:analysis / Q000737:chemistry*; D010455:Peptides / Q000737:chemistry*; D011487:Protein Conformation
chemical_list: D010446:Peptide Fragments; D010455:Peptides; C040734:pancreatic eicosapeptide; D010191:Pancreatic Polypeptide
keywords: Peptide effective electrophoretic mobility; Peptide global chain properties; Peptidomimetic structure function; Retro-d-inverso-α-eicosapeptide; l-α-Eicosapeptide