| Abstract: | Biochemical studies of cellular processes involving polyubiquitin have gained increasing attention. More tools are needed to identify ubiquitin (Ub)‐binding proteins. We report diazirine‐based photoaffinity probes that can capture Ub‐binding proteins in cell lysates, and show that diazirines are preferable to aryl azides as the photo‐crosslinking group, since they decrease non‐selective capture. Photoaffinity probes containing at least two Ub units were required to effectively capture Ub‐binding proteins. Different capture selectivity was observed for probes containing diubiquitin moieties with different types of linkages, thus indicating the potential to develop linkage‐dependent probes for selectively profiling Ub‐binding proteins under various cellular conditions. |
