Papain catalyzed synthesis of glyceryl esters of BOC(Z)-protected amino acids and peptides was performed at 40-50 degrees C in a 50 molar excess of glycerol. Equilibrium was achieved in 6-7 h. The maximal yield of esters (50-70%) was obtained at 10% of water and pH 3.2-3.4. A lower water concentration resulted in a sharp decrease of the ester yield. The synthesized glyceryl esters of neutral amino acids are good substrates for trypsin and can be used for peptide synthesis catalyzed for trypsin. Glycerol esters are also good substrates for other enzymes possessing esterase activity.