title: Diaminoterephthalate turn-on fluorescence probes for thiols--tagging of recoverin and tracking of its conformational change.
abstract: Diaminoterephthalates with a maleimide moiety were synthesized and used as fluorescence dyes for sensing thiols. Whereas these "NiWa Blue" dyes showed no emission, the conjugate addition of a thiol to the maleimide group turned on a fluorescence at about 400 nm when irradiating the dye at 338 nm. The neuronal-calcium sensor protein recoverin possesses a single cysteine residue at position 39, which reacts with NiWa Blue, and is therefore labeled by a fluorophore with an emission at about 440 nm. In the absence of Ca(2+), irradiation at 280 nm of a tryptophan residue in close proximity to Cys-bound NiWa Blue lead to strong FRET, which was detected by emission of the dye at 440 nm. In the presence of Ca(2+), the protein holds a conformation with distal Trp and Cys residues, thus FRET of irradiated Trp to Cys-bound NiWa Blue was significantly weakened.
authors.affiliation: Institut für Chemie, Carl von Ossietzky-Universität, Postfach 2503, 26111 Oldenburg , Germany.
authors.forename: Nina
authors.initials: N
authors.lastname: Wache
authors.forename: Claudia
authors.initials: C
authors.lastname: Schröder
authors.forename: Karl-Wilhelm
authors.initials: KW
authors.lastname: Koch
authors.forename: Jens
authors.initials: J
authors.lastname: Christoffers
mesh_terms: D002851:Chromatography, High Pressure Liquid / Q000379:methods; D057930:Click Chemistry; D005456:Fluorescent Dyes / Q000737:chemistry*; D010795:Phthalic Acids / Q000737:chemistry*; D011487:Protein Conformation; D051603:Recoverin / Q000032:analysis / Q000737:chemistry*; D013050:Spectrometry, Fluorescence / Q000379:methods*; D013438:Sulfhydryl Compounds / Q000032:analysis / Q000737:chemistry*
chemical_list: D005456:Fluorescent Dyes; D010795:Phthalic Acids; D013438:Sulfhydryl Compounds; D051603:Recoverin; C011363:terephthalic acid