Abstract:

【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.