title: Silver-induced conformational changes of polypeptides: a CD study.
abstract: The role of silver ions in various pathologies, as well as their effect on peptide conformation and properties are less understood. Consequently, we synthesized several peptides with various residues in their sequence to investigate silver-induced conformational changes at various pH values by Circular Dichroism spectroscopy. Uniquely, the glycine-based, histidine-containing peptide showed a severe change from a random coil and β-turn conformation to large α-helices during silver binding. When comparing the effect of silver ions on the conformation of bradykinin a similar tendency was found. Besides, silver ions reduced the amyloid-β peptide tendency to aggregation. Our results suggest a specific and protective role for silver ions in brain pathologies, which is related to their high affinity toward physiologically and pharmacologically active peptides. Fourier transform infrared spectroscopy studies as well as the mass spectrometric ones support our conclusions.
authors.affiliation: Petru Poni Institute of Macromolecular Chemistry, 41a Grigore Ghica Voda Alee, Iasi -700487, Romania.
authors.forename: Manuela
authors.initials: M
authors.lastname: Murariu
authors.forename: Ecaterina
authors.initials: E
authors.lastname: Stela Dragan
authors.forename: Adriana
authors.initials: A
authors.lastname: Adochitei
authors.forename: Gheorghita
authors.initials: G
authors.lastname: Zbancioc
authors.forename: Gabi
authors.initials: G
authors.lastname: Drochioiu
mesh_terms: D000595:Amino Acid Sequence; D016229:Amyloid beta-Peptides / Q000737:chemistry; D001920:Bradykinin / Q000737:chemistry; D002942:Circular Dichroism / Q000379:methods*; D006863:Hydrogen-Ion Concentration; D013058:Mass Spectrometry / Q000379:methods; D008969:Molecular Sequence Data; D010455:Peptides / Q000138:chemical synthesis / Q000737:chemistry* / Q000235:genetics; D017433:Protein Structure, Secondary; D012834:Silver / Q000737:chemistry*; D017550:Spectroscopy, Fourier Transform Infrared
chemical_list: D016229:Amyloid beta-Peptides; D010455:Peptides; D012834:Silver; D001920:Bradykinin