鸡肉钙激活酶与其它畜禽肉中钙激活酶 对钙离子浓度敏感性的比较

 【目的】研究鸡肉中钙激活酶的种类和性质,并与其它畜禽肉以及鱼肉中钙激活酶对钙离子浓度敏感性进行比较。【方法】提取宰后0 d鸡胸肉中的钙激活酶，通过硫酸铵沉淀和透析的方法对鸡肉钙激活酶进行纯化，采用活性电泳的方法检测钙激活酶种类和活性。通过设置0、0.01、0.03、0.05、0.10、0.50和5.00 mmol·L-1的钙离子浓度，比较鸡肉、鱼肉、鸭肉、兔肉、猪肉、牛肉在宰后0 d肉样中不同种类的钙激活酶对钙离子的敏感性。【结果】禽肉鸡肉、鸭肉中μ-钙激活酶的电泳迁移率小于哺乳类兔肉、猪肉、牛肉，当Ca2+浓度从0.01 mmol·L-1升到0.03 mmol·L-1时，兔肉、猪肉和牛肉μ-钙激活酶活性增加，但鸡肉和鸭肉钙激活酶活性没有改变（P>0.05），说明禽类μ-钙激活酶对钙离子的敏感程度高于哺乳类；在禽类鸡肉、鸭肉中存在另外一种钙激活酶，其对钙离子的敏感性介于哺乳动物中的m-钙激活酶和μ-钙激活酶之间，并且它在禽肉中的活性分别占67.4%和88.4%。【结论】鸡肉中的钙激活酶对钙离子浓度敏感性高于哺乳类。

Calpains in Chicken Muscle and Comparison of Calcium Sensitivity with Other Animals

【Objective】The objective of this experiment was to investigate the variety and characteristics of calpains in chicken muscle and compare calcium sensitivity of calpains with other animals. 【Method】Calpains were extracted from chicken breast muscle and purified by dialysis after ammonium sulfate precipitation. After slaughter immediately, calpains were also extracted from fish, duck, rabbit, pig and bovine, respectively, and calpain activity was detected by casein zymography. The gels were incubated with an increasing concentration of 0 mmol·L-1, 0.01 mmol·L-1, 0.03 mmol·L-1, 0.05 mmol·L-1, 0.10 mmol·L-1, 0.50 mmol·L-1 and 5.00 mmol·L-1 CaCl2 in order to test their calcium sensitivity. 【Result】μ-calpain of chicken and duck had a lower electrophoretic mobility than that from rabbit, pork and beef. When the calcium concentration increased from 0.01 mmol·L-1 to 0.03 mmol·L-1, the activity of μ-calpain in rabbit, pork and beef was enhanced, while the activity of chicken and duck had no change (P＞0.05), indicating that μ-calpain in bird species had a greater calcium sensitivity than that from mammalian; another calpain in chicken muscle with a calcium sensitivity between that of mammalian μ-calpain and the m-calpain was named μ/m-calpain. The μ/m-calpain in chicken and duck accounted for 67.4% and 88.4% of the total activity.【Conclusion】Calpains in chicken muscle have a greater calcium sensitivity than that from mammalian.