Fluorogenic probes for detecting deacylase and demethylase activity towards post-translationally-modified lysine residues

Reversible enzymatic post-translational modification of the ε-amino groups of lysine residues (e.g. N-acylation reactions) plays an important role in regulating the cellular activities of numerous proteins. This study describes how enzyme catalyzed N-deprotection of lysine residues of non-fluorescent peptide-coumarin probes can be used to generate N-deprotected peptides that undergo spontaneousO- toN-ester transfer reactions (uncatalyzed) to generate a highly fluorescentN-carbamoyl peptide. This enables detection of enzyme catalyzedN-deacetylation,N-demalonylation,N-desuccinylation andN-demethylation reactions activities towards the N-modified lysine residues of these probes using simple ‘turn on’ fluorescent assays.