title: Reversible photocontrol of peptide helix content: adjusting thermal stability of the cis state.
abstract: Cross-linking reagents based on an azobenzene core can be used to reversibly photoregulate secondary structure when introduced as intramolecular bridges in peptides and proteins. Photoisomerization of the azobenzene core in the trans to cis direction is triggered by photon absorption but isomerization from cis to trans occurs thermally as well as photochemically. The rate of the thermal process effectively determines the half-life of the cis form as well as the extent to which the trans form can be recovered. We designed and characterized a series of methanethiosulfonate (MTS)-bearing thiol-reactive azo-benzene-based cross-linkers. These cross-linkers are shown to permit photoregulation of helix content in a test peptide with half-lives for the cis conformation ranging from 11 s to 43 h at 25 degrees C. The cross-linkers described here thus broaden the range of reagents available for reversible photocontrol of peptide and protein conformation.
authors.affiliation: Department of Chemistry, University of Toronto, 80 Saint George Street, Toronto M5S 3H6, Canada.
authors.forename: Nina
authors.initials: N
authors.lastname: Pozhidaeva
authors.forename: Marie-Eve
authors.initials: ME
authors.lastname: Cormier
authors.forename: Anita
authors.initials: A
authors.lastname: Chaudhari
authors.forename: G Andrew
authors.initials: GA
authors.lastname: Woolley
mesh_terms: D003432:Cross-Linking Reagents / Q000032:analysis / Q000737:chemistry*; D010455:Peptides / Q000032:analysis / Q000737:chemistry*; D010775:Photic Stimulation / Q000379:methods*; D010777:Photochemistry / Q000379:methods; D017433:Protein Structure, Secondary; D013237:Stereoisomerism; D013816:Thermodynamics
chemical_list: D003432:Cross-Linking Reagents; D010455:Peptides