Conformation of naturally-occurring peptides in surfactant solution: Its relation to the structure-forming potential of amino acid sequence

Short polypeptides are unordered in aqueous solution. Surfactants provide a proteinaceous environment in which ordered conformation of the peptides can be induced if they have a structure-forming potential. Ten peptides studied are classified into four types: (I) helix-forming, (II) β-forming, (III) either helix- or β-forming, and (IV) neither structure-forming. At low molar ratio, R, of sodium dodecyl sulfate to peptide (residue) (R < 10), type II peptides appear to be aggregated, but they dissociate at R ≅ 100 or more.