Fractionation of exopeptidase from viscera of Argentina shortfin squid, Illex argentinus

Abstract

For the effective use of exopeptidase from squid viscera as food processing aids, the viscera of Argentina shortfin squid (Illex argentinus) were fractionated by various methods such as acetone treatment, ammonium sulfate treatment, anion exchange chromatography, and gel filtration. The positive exopeptidase fractions were obtained from the fraction II treated by cold acetone (30~40%, w/w), the fraction V by ammonium sulfate (60~70% saturation), the fraction II (0.2 M NaCl) by anion exchange chromatography, and the fraction I (30~50 kDa) by gel filtration. The specific activities of positive fractions from viscera of Illex argentinus against substrates were higher to LeuPNA than to ArgPNA. Total activity and recovery against LeuPNA of positive fraction by gel filtration were 1,867 U and 30.69%, respectively, which were the highest among those of positive fraction. The results suggested that the gel filtration chromatography method was the most efficient method for the fractionation of exopeptidase from viscera of Illex argentinus.