Synthesis of Arylazide‐ and Diazirine‐Containing CrAsH‐EDT(2) Photoaffinity Probes

Two photo‐crosslinking biarsenical (CrAsH‐EDT(2))‐modified probes were synthesized that are expected to be useful tools for tetracysteine‐labeled proteins to facilitate the co‐affinity purification of their DNA binding sequences and interacting proteins. In addition, improvements for the synthesis of CrAsH‐EDT(2) and N (1)‐(4‐azido‐2‐nitrophenyl)hexane‐1,6‐diamine are reported. Both photoprobes effectively entered HeLa cells (and the nucleus) and were dependent on the tetracysteine motif in recombinant DMRT1 (doublesex and Mab3‐related transcription factor) to induce fluorescence, suggesting that their crosslinking abilities can be exploited for the identification of nucleic acids and proteins associated with a protein of interest.