title: Light-Switchable Peptides with a Hemithioindigo Unit: Peptide Design, Photochromism, and Optical Spectroscopy.
abstract: This Minireview focuses on the hemithioindigo photoswitch and its use for the reversible control of three-dimensional peptide structure and related biological functions. Both the general design aspects and biophysical properties of various hemithioindigo-based chromopeptides are summarized. Hemithioindigo undergoes reversible Z→E photoisomerization after absorption of visible light. The unique ultrafast switching mechanism of hemithioindigo combines picosecond isomerization kinetics with strong double-bond torsion after light absorption, making it the ideal tool for instantaneous modulation of biological structure. Various inhibitors and model peptides based on hemithioindigo are described that can directly regulate biological signaling or allow the fastest events in peptide folding to be studied. Finally, a diverse range of chromopeptides with photoswitchable β-hairpin structures based on azobenzenes, stilbenes, and hemithioindigo are compared to emphasize the unique properties of hemithioindigo.
authors.affiliation: Institut für Chemie, Technische Universität Berlin, Str. des 17. Juni 135, 10623, Berlin, Germany.
authors.forename: S
authors.initials: S
authors.lastname: Kitzig
authors.affiliation: Institut für Chemie, Technische Universität Berlin, Str. des 17. Juni 135, 10623, Berlin, Germany.
authors.forename: M
authors.initials: M
authors.lastname: Thilemann
authors.affiliation: Molecular Microscopy Research Group, Zernike Institute for Advanced Materials, University of Groningen, Nijenborgh 4, 9747 AG, Groningen, The Netherlands.
authors.forename: T
authors.initials: T
authors.lastname: Cordes
authors.affiliation: Institut für Chemie, Technische Universität Berlin, Str. des 17. Juni 135, 10623, Berlin, Germany. Karola.Rueck-Braun@tu-berlin.de.
authors.forename: Karola
authors.initials: K
authors.lastname: Rück-Braun
mesh_terms: D007203:Indigo Carmine / Q000031:analogs & derivatives* / Q000737:chemistry; D008027:Light; D008954:Models, Biological; D010455:Peptides / Q000737:chemistry*; D013057:Spectrum Analysis / Q000379:methods*
chemical_list: D010455:Peptides; C527420:hemithioindigo; D007203:Indigo Carmine
keywords: chromophores; peptides; photochromism; protein folding; time-resolved spectroscopy