PURIFICATION AND CHARACTERIZATION OF PANCREATIC ELASTASE FROM NORTH-ATLANTIC SALMON (SALMO-SALAR)

An elastase I-like enzyme was purified to homogeneity from the pyloric caeca of North Atlantic salmon (Salmo salar) and compared with porcin e elastase I. The molecular weight and isoelectric point were estimate d to be 27 kDa and over 9.3, respectively. The pH optimum was between 8.0 and 9.5, and the enzyme was unstable at pH values below 4. Kinetic properties examined using Suc-(Ala)(3)-p-nitroanilide showed that the catalytic efficiency of salmon elastase was about 2.5 times higher th an that of porcine elastase. Furthermore, the salmon enzyme was less s table at lower pH values and temperatures than the porcine enzyme. The preference for amino acids at the primary binding site was found to b e different from that of the porcine elastase. The salmon elastase bin ding pocket seems to prefer more branched aliphatic residues than the porcine elastase.