title: Interactions of AsCy3 with cysteine-rich peptides.
abstract: There is great interest in fluorogenic compounds that tag biomolecules within cells. Biarsenicals are fluorogenic compounds that become fluorescent upon binding four proximal Cys thiols, a tetracysteine (Cys(4)) motif. This work details interactions between the biarsenical AsCy3 and Cys(4) peptides. Maximal affinity was observed when two Cys-Cys pairs were separated by at least 8 amino acids; the highest affinity ligand bound in the nanomolar concentration range (K(app) = 43 nM) and with a significant (3.2-fold) fluorescence enhancement.
authors.affiliation: Department of Chemistry and ‡Department of Molecular, Cellular and Developmental Biology, Yale University , New Haven, Connecticut 06520-8107, United States.
authors.forename: Seth C
authors.initials: SC
authors.lastname: Alexander
authors.forename: Alanna
authors.initials: A
authors.lastname: Schepartz
mesh_terms: D001152:Arsenicals / Q000138:chemical synthesis* / Q000737:chemistry; D003545:Cysteine / Q000737:chemistry*; D004151:Dipeptides / Q000737:chemistry; D005456:Fluorescent Dyes / Q000737:chemistry*; D008024:Ligands; D015394:Molecular Structure; D010455:Peptides / Q000737:chemistry*; D017434:Protein Structure, Tertiary
chemical_list: D001152:Arsenicals; C000597252:AsCy3 compound; D004151:Dipeptides; D005456:Fluorescent Dyes; D008024:Ligands; D010455:Peptides; C046557:cysteinylcysteine; D003545:Cysteine