Fractionation and enzymatic characterization of endoprotease and exopeptidase from crude extracts of cuttlefish Sepia officinalis hepatopancreas

Abstract

This study examines the optimal fractionation method and conditions for the isolation of endoprotease and exopeptidase-active fractions from crude extracts of cuttlefish hepatopancreas (HP) using four fractionation methods: ammonium sulfate fractionation (ASF), polyethylene glycol fractionation (PGF), ion exchange chromatography (IEC), and gel filtration chromatography (GFC). Total endoprotease activity highest in the fraction II (concentrate of fractions 34-42; 842.60 U) of GFC, followed by fraction III (40-60% ammonium sulfate fraction; 670.25 U) of ASF, fraction I (concentrate of fractions 8-12; 436.89 U) of IEC, and fraction II (10-20% polyethylene glycol; 307.31 U) of PGF. Total exopeptidase activity of these fractions was highest in fraction II (2,704.70 U) of GFC, fraction III (2,110.50 U) of ASF, fraction III (1,605.60 U) of PGF, and fraction II (concentrate of fractions 38-44; 1,196.22 U) of IEC. These results showed that fraction II of GFC had the highest activity toward both exopeptidase and endoprotease, with exopeptidase activity being 3.21 times higher than of endoprotease. These results suggest cuttlefish HP could be used as a potential source for the extraction of exopeptidase, an enzyme capable of catalyzing the cleavage of N- and C-terminal amino acids in polypeptides, Like endoprotease, the most efficient method for separating exopeptide-active fractions was GFC. ? The Korean Society of Fisheries and Aquatic Science.