Rapid affinity purification of retinal arrestin (48 kDa protein) via its light‐dependent binding to phosphorylated rhodopsin

Arrestin (also named ‘48 kDa protein’ or ‘S‐antigen’) is a soluble protein involved in controlling light‐dependent cGMP phosphodiesterase activity in retinal rods, and is also known for its ability to induce autoimmune uveitis of the eye. We report a rapid and simple purification method based on the property of arrestin to bind specifically and reversibly to illuminated and phosphorylated rhodopsin [(1984) FEBS Lett. 176, 473–478]. This method does not require column chromatography and yields about 2–4 mg purified arrestin from 15 bovine retinas. Pure arrestin can be resolved by isoelectric focusing into at least 10 distinct bands, all of which stain with a monoclonal antibody specific for S‐antigen.