Kyuto Tashiro

Abstract ADP-ribosylation (ADPr) is a regulatory post-translational modification targeting nine amino acid residues, but glutamate/aspartate-linked ADPr (Glu/Asp-ADPr) is labile and remains challenging to detect using conventional mass spectrometry (MS)-based workflows. Using synthetic peptides, we show that ester-linked Glu/Asp-ADPr is lost under alkaline conditions, elevated temperatures, and by hydrolysis via wildtype Af1521.

We report here chemoenzymatic and fully synthetic methodologies to modify aspartate and glutamate side chains with ADP-ribose at specific sites on peptides. Structural analysis of aspartate and glutamate ADP-ribosylated peptides reveals near-quantitative migration of the side chain linkage from the anomeric carbon to the 2″- or 3″-ADP-ribose hydroxyl moieties.