中国对虾蛋白酶性质的研究

Study on the Characterization of Protease from Penaeus chinensis

采用酶学分析方法研究了中国对虾蛋白酶的性质。结果表明，该酶最适温度为60℃，最适pH为9．0，是一种碱性蛋白酶。此酶在50℃以T．KpH7．O-10．O稳定性较好。以酪蛋白为底物，蛋白酶的最适底物浓度为2％。60℃时，该酶的半衰期为22min，70℃时则为7min。低浓度的EDTA对酶活有抑制作用，Mn外、Ca2＋、Mg2＋对蛋白酶有一定的激活作用，而Cu2＋、Zn2＋、Fe2＋、Pb2＋对酶活有不同程度的抑制作用，可推断该酶是一种金属蛋白酶。

The characterization of protease was investigated existing in the Penaeus chinensis using enzymology analysis method. The results showed that the optimal temperature for the enzyme was 60℃ and the optimal pH was 9.0, so it was a kind of alkaline protease. The enzymes were stabled at temperature lower than over 50℃ and over a broad pH range（7.0-10.0）. With casein as the substrate, the optimal substrate concentration for protease was 2%. When 60℃, the half-life period of the enzyme was 22 min, compared with 7 min for 70℃. Low concentration of EDTA could inhibite the enzymes. Mn2＋, Ca2＋ and Mg2＋ could activate the protease, but Zn2＋, Cu2＋, Fe2＋, Pb2＋ inhibite the enzymes to different extents depending on the ions used, indicating that the protease was probably metalloproteinase.