넙치( Paralichthys olivaceus ) 알로부터 Serine Protease Inhibitors의 분획 특성

Abstract

Protease inhibitors (PI) of trypsin and papain as target proteases from the roe of bastard halibut Paralichthys olivaceus were fractionated out using ammonium sulfate precipitation (A), DEAE 650M anion exchange chromatography (D), and Sephacryl S-300 gel filtration (S). The recovery percentages of the fractions with the strongest inhibitory activity for each fractionation method were 13% for the A4 fraction, 21.2% for the D3 fraction, and 21.3% for the S2 fraction, with specific inhibitory activities of the fractions toward trypsin and casein of 168, 139, and 218 U/mg, respectively, while no inhibition of papain was observed. The IC50 for the trypsin-specific substrate Nα-benzoyl-l-arginine-pnitroanilide (BAPNA) was 0.65, 1.55, 2.26, and 2.85 mg/mL for the A4, S2, A3, and D3 fractions, respectively. These results suggest that chromatographic fractionation methods (D and S) based on the molecular mass and charge of the protein were more effective at fractionating PI than was ammonium sulfate precipitation based on protein solubility, and that the bastard halibut roe extract acts as a serine protease inhibitor. Therefore, the PI fraction from fish roe might be useful for inhibiting proteases in foodstuffs, and could constitute an alternative food-grade inhibitor for the surimi industry.