An NAD(+) with Dually Modified Adenine for Labeling ADP-Ribosylation-Specific Proteins.

Protein adenosine diphosphate (ADP)-ribosylation participates in various pivotal cellular events. Its readers and erasers play key roles in modulating ADP-ribosylation-based signaling pathways. Unambiguous assignments of readers and erasers to individual ADP-ribosylated proteins provide insightful knowledge on ADP-ribosylation biology and require the development of tools and technologies for this goal. Herein, we report the design and the synthesis of a nicotinamide adenine dinucleotide (NAD(+)) carrying a photoactive and a clickable group. Functioning as a substrate for poly-ADP-ribosylation (PARylation), this NAD(+) mimic with dually modified adenine enables covalent crosslinking and labeling of proteins bound to PARylation, representing a new photoaffinity probe for studying this critical post-translational modification.