Enzyme-catalysed deprotection of N-acetyl and N-formyl amino acids

To investigate the full potential of hydrolases for the removal of two amine-protecting groups, 15 different, commercially available lipases, acylases, proteases and esterases were studied for the hydrolyses of N-acetyl and N-formyl protecting groups. In addition to the well-known acylases from porcine kidney and Aspergillus melleus, this screening revealed that porcine liver esterase and the lipases from Rhizomucor miehei and Pseudomonas stutzeri are also catalysts for the hydrolysis of N-acetylalanine. The activity of lipases in this reaction was unexpected, since lipases are commonly believed not to hydrolyse amides. In addition, from these 15 enzymes, three were found to be active in the hydrolysis of N-formylalanine, i.e. porcine liver esterase and the two acylases. This is the first example where esterase is employed to deprotect N-formyl amides.