Biarsenical-tetracysteine method

The biarsenical-tetracysteine method was first introduced more than 7 years ago, and further refinements and development of novel applications are still appearing. Within the last few years, biologists have started to exploit the unique features of this system for probing protein trafficking, turnover, localization, and dynamics. This review aims to describe the conception and development of this protein tag and its applications in the biological sciences. 

I would like to thank all my coworkers over the years in the Tsien and Ellisman labs who have contributed to the development of the biarsenical-tetracysteine method, particularly Roger Tsien for devising the original concepts and for continual input into their improvement. 

Of increasing utility have been the tetracysteine tags specific for fluorogenic, biarsenical ligands (e.g., FlAsH, Table 12.2, Fig. 12.3, method 11 [72, 113, 114]). The latter bind with high affinity and selectivity to very short peptide sequences incorporating two dicysteine elements separated by 2 or more residues. The variety of dyes... 

Fig. 12.3. Some expression systems involving noncovalent (binding) linkages. Numbers correspond to entries (methods) in Table 12.2 (5) labeling with methotrexate derivatives that recognize a dihydrofolatereductase segment, and (11) labeling with biarsenical derivatives binding to a 6-12 tetracysteine...

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