Thiol-selective fluorogenic probes for labeling and release.

ABSTRACT: Thiol alkylation is a powerful technique for the labeling of proteins. We report a new class of highly reactive, selective, and fluorogenic probes for thiols in aqueous solution at neutral pH, based on the 7-oxanorbornadiene (OND) framework. The maleate moiety in 7-oxabicyclo[2.2.1]hept-2,5-diene-2,3-dicarboxylic acid esters serves as both a tunable electrophile and an intramolecular quencher of an attached dansyl fluorophore. Thiols have been found to add with high rates (second-order rate constants of 40-200 M(-1) s(-1)) to give adducts that exhibit enhancements of fluorescence intensity up to 180-fold. The resulting adducts are also versatile with respect to cleavage (release) reactions by two mechanisms. First, retro-Diels-Alder fragmentation occurs with half-lives from days to weeks a

SUBMITTER: Hong V 

PROVIDER: S-EPMC3166955 | biostudies-literature | 2009 Jul

REPOSITORIES: biostudies-literature