Continuous production of kyotorphin

The continuous α‐chymotrypsin‐catalyzed peptide synthesis of kyotorphin, tyrosyl‐arginine, via the N α formyltyrosyl‐arginine propyl ester is described. For continuous process development, two reaction systems were studied: immobilized α‐chymotrypsin covalently bound to Eupergit C packed in a column, and soluble α‐chymotrypsin utilizing an enzyme membrane reactor. Selectivities and kinetic parameters are discussed. The use of soluble enzyme in an enzyme membrane reactor proved superior to the covalently immobilized enzyme. A significant loss of enzyme activity and a certain decrease of selectivity was observed during immobilization. It was shown that the addition of organic solvent, in this case n ‐propanol, causes a severe diminuation of the enzyme activity.