Purification of Tetracysteine-Tagged Proteins by Affinity Chromatography Using a Non-Fluorescent, Photochemically Stable Bisarsenical Affinity Ligand

The use of genetically encoded small peptide tags such as polyhistidine and tetracysteine tags has become important for protein purification and enrichment. An improved affinity purification of tetracysteine (CCXXCC) tagged proteins has been achieved using a nonfluorescent, photochemically stable bisarsenical affinity ligand SplAsH. The photochemical stability of the SplAsH-biotin, shown in compound 5, is superior to FlAsH-EDT2 and ReAsH-EDT2. An application of the SplAsH tag for affinity purification of tetracysteine-tagged proteins is reported.