REVERSE CATALYSIS OF ELASTASE FROM PORCINE PANCREAS IN FROZEN AQUEOUSSYSTEMS

The reverse action of a trypsin-free elastase isolated from porcine pa ncreas was studied in frozen aqueous systems. Under frozen state condi tions, porcine pancreatic elastase was able to catalyse peptide bond f ormation more effectively than in solution at room temperature. The ac ceptance of free amino acids as nucleophilic amino components indicate s a changed specificity of the endoprotease in frozen reaction mixture s. In elastase-catalysed formation of Ser-, Ile- and Val-X-bonds in fr ozen aqueous reaction mixtures, peptide yields obtained depended on th e P-1 amino acid and the acyl donor chain length.