Thapsigargin affinity purification of intracellular P2A-type Ca2+ ATPases

► The ubiquitous Ca2+ ATPases SERCA2b and SPCA1a so far evaded purification. ► A new purification strategy was developed biasing towards properly folded protein. ► This method uses thapsigargin and reactive dye as ligands. ► Elution of WT hSERCA2b was hampered by its nM affinity for thapsigargin. ► Thapsigargin mutant hSERCA2b-I765A could be easily purified.