摘要
本实验分别以牛肉肌束和分化为肌细胞的L6成肌细胞为研究对象,研究钙离子对离体肌束中钙激活蛋白酶活性、蛋白分解以及活体肌肉(肌细胞)中钙激活蛋白酶mRNA水平表达的影响。结果表明500μmol/L以内的钙离子处理肌束,可以提高肌束中μ-钙激活蛋白酶的活性,当高于此浓度时,μ-钙激活蛋白酶因发生自动降解而失活。但是钙离子对m-钙激活蛋白酶活性影响不大,只有钙离子浓度达到10mmol/L时才会导致自动降解而失活。钙离子可以加速肌肉中蛋白质的降解,且浓度越高,降解越明显;钙离子处理活体肌细胞,在没有产生明显细胞死亡的情况下,可导致μ-钙激活蛋白酶和m-钙激活蛋白酶mRNA水平表达的增加。由本研究的结果初步推断钙离子不仅可以激活钙激活蛋白酶的酶活性,提高分解肌肉蛋白的能力,在刚刚屠宰的肉(肌肉未死亡)中进行钙离子嫩化也可以导致钙激活蛋白酶表达量的增加。
In order to evaluate the effects of calcium ion on calpains mRNA expression and proteolysis activity, and muscle protein degradation, L6 myoblast and beef fascicle were used in vivo and in vitro samples respectively in this study. The results indicated that μ-calpains activity increases when the calcium ions concentration is less than 500μmol/L, otherwise, the μ-calpalns activity disappeares due to autolysis. The effects of calcium ion on m-calpain are less effective than on μ-calpain. Furthermore, calcium ion also accelerates the degradation of beef muscle proteins/n vitro experiments, mRNA expressions of μ-, and m-calpain both increases in L6 myoblast during the L6 had low death rate/n vivo experiment. Therefore, it could be deduced that the calcium ion can not only activate calpains proteolysis activity and accelerate the degradation of muscle proteins, but also lead to mRNA expression of μ-, and m-calpain when the muscle cell is still alive.
出处
《食品科学》
EI
CAS
CSCD
北大核心
2007年第5期25-28,共4页
Food Science
基金
国家自然科学基金(30371016)
