title: A photoinducible beta-hairpin.
abstract: A photochromic azobenzene linker was incorporated as a turn element into an amino acid sequence known to fold into a beta-hairpin structure in aqueous solution. Oligomer formation when the linker was in its thermodynamically favored trans form prohibited structure determination. Light-induced conformational change of the linker to the cis form led to the formation of monomers which exhibited a well-defined beta-hairpin structure as determined by (1)H NMR. The rate of the light-induced cis-to-trans isomerization of the azobenzene-containing peptide was 30% slower compared to the unsubstituted chromophore. These results suggest that suitably substituted azobenzenes can be used as photoinducible turn elements to investigate and control the folding and stability of beta-sheets.
authors.affiliation: Laboratorium für Organische Chemie and Laboratorium für Physikalische Chemie, Swiss Federal Institute of Technology, ETH-Hönggerberg, CH-8093 Zürich, Switzerland. hilvert@org.chem.ethz.ch
authors.forename: Andreas
authors.initials: A
authors.lastname: Aemissegger
authors.forename: Vincent
authors.initials: V
authors.lastname: Kräutler
authors.forename: Wilfred F
authors.initials: WF
authors.lastname: van Gunsteren
authors.forename: Donald
authors.initials: D
authors.lastname: Hilvert
mesh_terms: D001391:Azo Compounds / Q000737:chemistry; D001426:Bacterial Proteins / Q000737:chemistry; D003432:Cross-Linking Reagents / Q000737:chemistry; D005998:Glycine / Q000737:chemistry; D008958:Models, Molecular; D019906:Nuclear Magnetic Resonance, Biomolecular; D009842:Oligopeptides / Q000138:chemical synthesis / Q000737:chemistry*; D010446:Peptide Fragments / Q000138:chemical synthesis / Q000737:chemistry; D010777:Photochemistry; D011392:Proline / Q000737:chemistry; D017510:Protein Folding; D017433:Protein Structure, Secondary; D013816:Thermodynamics
chemical_list: D001391:Azo Compounds; D001426:Bacterial Proteins; D003432:Cross-Linking Reagents; C034284:IgG Fc-binding protein, Streptococcus; D009842:Oligopeptides; D010446:Peptide Fragments; D011392:Proline; C009850:azobenzene; D005998:Glycine