Stereochemistry of the peptide α-amidation reaction involving two enzymes, peptidylglycine α-hydroxylating monooxygenase (PHM) and peptidylhydroxyglycine N–C lyase (PHL)

Peptidylglycine α-hydroxylating monooxygenase (PHM), the first enzyme involved in the peptide α-amidation, has been shown to convert N-benzoylglycine, a model substrate, stereoselectively to S-N-benzoyl-α-hydroxyglycine, whereas peptidylhydroxyglycine N–C lyase (PHL), the second enzyme, has been found to react exclusively with S-form of the intermediate.