Automated multi-step purification protocol for Angiotensin-I-Converting-Enzyme (ACE)

► Detergent free solubilisation of Angiotensin-I-Converting-Enzyme (ACE). ► Development of an automated multi-step purification protocol for ACE. ► ACE purification about 300-fold to a specific activity of 37 U mg−1 in less than 8 h. ► Development of a novel activity staining protocol for ACE. ► The automated protein purification protocol can be easily applied to other proteins.