A pair of pyrene groups as a conformational probe for designed two α-helix polypeptides

摘要: Peptides with two α-helix segments anchored on 2,2′-bipyridyl-4,4′-dicarboxylic acid and suberic have been designed synthesized. L-1-Pyrenylalanine (Pya) was introduced near the centre of each α-helical segment as a CD fluorescent probe to detect arrangement segments. The amphiphilic 14-peptide an amino sequence in which hydrophobic acids, Leu Pya, are deployed same manner acids coiled-coil proteins. synthesis carried out by solid-phase Kaiser's oxime resin solution coupling anchors. probing behaviour pair Pya residues examined measurements under various conditions, e.g. aqueous methanolic solutions, presence guanidine hydrochloride (GuHCl) increasing temperature. peptides showed highly pattern far-UV region solution. Furthermore, they strong split peaks positive negative maxima at longer shorter wavelengths, respectively, pyrene absorption (1La 1Bb). These signals decreased disruptions structure addition methanol, GuHCl also On other hand, excimer emission fluorescence very weak solution, but it transiently increased while helix-helix interaction relaxed some extent methanol. facts indicate that groups forced be close proximity right-handed sense between structures solution; whereas, is loosened destruction 3D structure. Thus, has demonstrated provide significant information about simple spectra.