Peptides containing proline residue at C-terminus (Xaa-Pro) are valuable compounds because of their 

antihypertensive activity or antidiabetic activity.  Thus, they could be used as pharmaceuticals and 

functional foods.  We previously established the synthetic method of Xaa-Pro using adenylation 

domain of nonribosomal peptide synthetase.  However, the supply of expensive ATP is an obstacle to 

practical application.  For the inexpensive supply of ATP from AMP released after the reaction, we 

focused class III polyphosphate kinase 2 (PPK2) which efficiently synthesizes ATP synthesis from AMP 

and polyphosphate by single enzyme and constructed a novel ATP regeneration system from AMP.  

Although synthesis of Xaa-Pro requires equivalent ATP, production of Xaa-Pro was more than initial 

concentration of ATP in the case of the ATP regeneration system was introduced.  Therefore, it was 

indicated that ATP was successfully regenerated form AMP by class III PPK2.  From this result, 

economic production method of Xaa-Pro which reduces addition of ATP is applicable to industrial 

process.