日本鲟肌动球蛋白热变性和冷冻变性

THERMOSTABILITY AND FREEZE DENATURATION OF CHARYBDIS JAPONICA

研究了日本鲟肌动球蛋白经变性和冷冻后ATPase活性、总流基数和不饱和巯基数及蛋白质浓度的变化。结果表明，热变性后肌动球蛋白Ca2+—ATPase和Mg2+—ATPase活性下降，且Ca2+—ATPase活性有明显转折。低温热变性后对总流基数影响较小，温度增高时，流基数逐渐下降，而不饱和流基数在30℃之前，呈动态变化，之后又逐渐减少。热变性后，肌动球蛋白浓度也降低。冷冻变性后，肌动球蛋白ATPase活性和总巯基数随冷藏时间而明显下降，冷藏温度越低，ATPase活性下降越慢。

The thermostability and freeze denaturation of ATPase activity, total-SH and actomyosin(AM) from Charybdis japonica were studied. The results indicate that Ca2+-or Mg2+-ATPase activity of Am decreased due to thermai denaturation and Ca2+-ATPase activity of AM showed an inflecting point. Low temperature made less effect on total-SH which decreased gradually with the increase of incubating temperature. However, Un-SH showed an irregular change curve before 30℃, after then decreased gradually- The concentration of AM (AM solubility) decreased with thermostability. ATPase activity and total-SH of AM decreased with the time of frozen storage. The lower the frozen temperature was, the slower the decrease in ATPase activity would be.