title: Probing alpha-helical and beta-sheet structures of peptides at solid/liquid interfaces with SFG.
abstract: We demonstrated that sum frequency generation (SFG) vibrational spectroscopy can distinguish different secondary structures of proteins or peptides adsorbed at solid/liquid interfaces. The SFG spectrum for tachyplesin I at the polystyrene (PS)/solution interface has a fingerprint peak corresponding to the B1/B3 mode of the antiparallel beta-sheet. This peak disappeared upon the addition of dithiothreitol, which can disrupt the beta-sheet structure. The SFG spectrum indicative of the MSI594 alpha-helical structure was observed at the PS/MSI594 solution interface. This research validates SFG as a powerful technique for revealing detailed secondary structures of interfacial proteins and peptides.
authors.affiliation: Department of Chemistry, University of Michigan, Ann Arbor, Michigan 48109, USA.
authors.forename: Xiaoyun
authors.initials: X
authors.lastname: Chen
authors.forename: Jie
authors.initials: J
authors.lastname: Wang
authors.forename: Jason J
authors.initials: JJ
authors.lastname: Sniadecki
authors.forename: Mark A
authors.initials: MA
authors.lastname: Even
authors.forename: Zhan
authors.initials: Z
authors.lastname: Chen
mesh_terms: D010455:Peptides / Q000737:chemistry*; D044367:Phase Transition; D017433:Protein Structure, Secondary; D013057:Spectrum Analysis
chemical_list: D010455:Peptides