Abstract: The optimal pH and temperature of autolysis enzymes from Antarctic krill were investigated in this paper. Meanwhile, the effects of inhibitors and metal ions on the activities of autolysis enzymes from Antarctic krill were also explored. The results showed that autolysis enzymes from Antarctic krill were mainly composed of three enzymes with respective optimal reaction pH of 3.0, 6.0 and 8.0. In addition, the optimal reaction temperatures of the three enzymes were determined to be 40, 50 ℃ and 50－60 ℃, respectively. phenylmethyl sulfonyl fluoride (PMSF) and soybean trypsin inhibitor (SBTI) exhibited an obvious inhibition effect on autolysis enzymes from Antarctic krill at a pH ranging from 3.0 to 9.0 and from 6.0 to 10.5, respectively. Moreover, Cu2+ and Ba2+ could strongly inhibit the activities of the autolysis enzymes although Ca2+ did not reveal inhibition effect. In contrast, the autolysis enzymes were activated by Mg2+.

Key words: Antarctic krill, autolysis enzyme, characterization