[Synthesis of peptides in organic solvents catalyzed by pepsin].

The porcine pepsin immobilized on inorganic supports catalyzes the peptide bond formation in organic solvents. Dependence of the peptide bond formation between Z-Ala-Ala-Phe-OH and H-Leu-Ala-Ala-OCH3 upon the porous material, organic solvent, reaction time, enzyme concentration, ionic strength and pH was studied. Syntheses of peptides of the general formula Z-Ala-Ala-Xaa-Yaa-Ala-Ala-OCH3, where Xaa = Phe, Tyr, Trp; Yaa = Leu, Phe, Tyr, Trp, were carried out.