Formation of amide bond catalyzed by lipase in aqueous phase for peptide synthesis

•Lipase catalyzed amidation for peptide synthesis.•A high yield of dipeptide was obtained in aqueous solution.•RSM design for optimization of reaction parameters.•Using the kinetic model compared the catalytic efficiency.•Kinetic constants show the advantage of lipase on amidation.

A dipeptide N-acetyl-l-phenylalanyl-l-tyrosinamide (N-Ac-Phe-Tyr-NH2), with angiotensin I converting enzyme (ACE) inhibitor activity, was synthesized via porcine pancreatic lipase catalyzed amidation of N-acetyl-phenylalanine ethyl ester with l-tyrosinamide in an aqueous phase. Response surface methodology was employed to evaluate the effects of synthesis parameters. The optimum synthesis conditions obtained an 84.45% yield of N-Ac-Phe-Tyr-NH2 with a reaction time of 3.8 min, a temperature of 20.9 °C, an enzyme amount of 6.5 U, and a substrate molar ratio of 2.5:1 (Tyr:Phe). The kinetics of lipase and α-chymotrypsin catalyzed amidation was compared using the Ping-Pong mechanism. The lipase showed a lower apparent kinetic constant than α-chymotrypsin indicating that the acyl lipase intermediate had a higher affinity toward tyrosinamide in the amidation. In addition, because the lipase can avoid the secondary hydrolysis of synthesized peptide, it is expected to be an effective method for obtaining a good yield of dipeptide.

Graphical abstractFigure optionsDownload full-size imageDownload as PowerPoint slide