Scale-up of enzymatic solid-to-solid peptide synthesis and enzyme recovery

The feasibility of scale-up for applications of enzymatic solid-to-solid synthesis of dipeptides was investigated by using Thermoase catalyzed synthesis of Z-Asp-Phe-OMe as a model reaction. The reaction system involves typically only 10% (w/w) enzyme suspension added to dry solid substrates. Enzymatic solid-to-solid biocatalysis combines the main advantages of aqueous media, high catalytic activity, low water media, and high yields. A flow sheet for the whole process is described, as well as the use of a jacketed reactor with an anchor stirrer for various steps of the process, including the neutralization reaction to adjust the acid-base condition of the reaction mixture. A solution for enzyme recycling, an important issue for scale-up applications, is also suggested.