文献类型： 外文期刊

作者： Cai, Qiu-Feng ¹ ; Jiang, Yu-Kun ¹ ; Zhou, Li-Gen ² ; Sun, Le-Chang ¹ ; Liu, Guang-Ming ¹ ; Osatomi, Kyoshi ³ ; Cao, Mi ¹ ;

作者机构： 1.Jimei Univ, Coll Biol Engn, Key Lab Sci & Technol Aquaculture & Food Safety, Xiamen 361021, Peoples R China

2.Zhejiang Acad Agr Sci, Inst Food Proc, Hangzhou 310021, Zhejiang, Peoples R China

3.Nagasaki Univ, Fac Fisheries, Nagasaki 8528521, Japan

关键词： Homology;Lateolabrax japonicus;Purification;Trypsin

期刊名称：COMPARATIVE BIOCHEMISTRY AND PHYSIOLOGY B-BIOCHEMISTRY & MOLECULAR BIOLOGY （ 影响因子：2.231； 五年影响因子：2.215 ）

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收录情况： SCI

摘要： A cationic trypsin (trypsin A) and an anionic trypsin (trypsin B) were highly purified from the hepatopancreas of the Japanese sea bass (Lateolabrax japonicus) by ammonium sulfate precipitation, column chromatographies of DEAE-Sepharose and Sephacryl S-200 HR. Purified trypsins revealed single band on SDS-PAGE and their molecular masses were 21kDa and 21.5kDa, respectively. Trypsins A and B exhibited maximal activity at 40°C, and shared the same optimal pH at 9.0 using Boc-Phe-Ser-Arg-MCA as the substrate. The two trypsins were stable up to 45°C and in the pH range from 7.0 to 11.0. Trypsin inhibitors such as Pefabloc SC, PMSF and benzamidine are effective to these two enzymes and their susceptibilities were similar. Apparent K_ms of trypsins A and B were 1.12 and 0.7μM and k_(cat)s of them were 72.08 and 67.79S-1 for Boc-Phe-Ser-Arg-MCA, respectively. The N-terminal amino acid sequences of the two trypsins were determined to the 24th residues, which were highly identical to trypsins from other species of fish while trypsins A and B only shared 45.8% identity. The digestive effect of the two trypsins on native shrimp muscular proteins indicated their effectiveness in the degradation of food proteins.