鸭肉中组织蛋白酶B的特性研究

Study on enzymatic properties of the cathepsin B in the duck muscle

从樱桃谷肉鸭腿肌中提取组织蛋白酶B,研究了pH值、温度、蛋白酶激活剂和抑制剂对其酶活的影响。结果表明:组织蛋白酶B的最适反应pH值为5.5,最适反应温度为40℃,在30℃下和pH 5.0～5.5范围内有较好的稳定性。激活剂二硫苏糖醇(DTT)和L-半胱氨酸(L-cys-teine)对组织蛋白酶B有一定的激活作用;抑制剂E-64对组织蛋白酶B有明显抑制作用;金属蛋白酶抑制剂已二胺四乙酸(EDTA)和丝氨酸蛋白酶抑制剂苯甲基磺酸氟(PMSF)对组织蛋白酶B无抑制作用。

Cathepsin B was extracted from the muscle of cherry valley ducks by biochemical techniques. The influence of pH, temperature, activators and inhibitors on the activity of the cathepsin B was studied. The results showed that the activity of the cathepsin B with the optimum pH and temperature were 5.5 and 40℃, respectively. It were stable under 30℃ and within a pH range of 5.0 - 5.5, but unstable when the temperature was higher. L-cysteine and DTT could increase the activity of the cathepsin B in various degrees. On the contrary, the activity of the cathepsin B was completely inhibited by E-64. It was not inhibited by EDTA and PMSF.