Changes in enzymatic and structural properties of grass carp fast skeletal myosin induced by the laboratory-conditioned thermal acclimation and seasonal acclimatization
Changes in enzymatic and structural properties of grass carp fast skeletal myosin induced by the laboratory-conditioned thermal acclimation and seasonal acclimatization
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DOI：
10.1111/j.1444-2906.2005.00948.x
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发表时间：
2005-02
影响因子：
1.9
通讯作者：
Y. Tao;Makito Kobayashi;H. Fukushima;S. Watabe
中科院分区：
文献类型：
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作者：
Y. Tao;Makito Kobayashi;H. Fukushima;S. Watabe
采用2003年1月（冬季）和2002年5月（春季）、8月（夏季）和11月（秋季）采集的草鱼快速骨骼肌，在实验室热驯化10、20和30℃条件下制备肌球蛋白。10℃和冬草鱼肌凝蛋白活化Mg2+- atp酶活性的最大初始速度（Vmax）是30℃和夏草鱼肌凝蛋白的1.7 ~ 1.8倍。10℃草鱼肌球蛋白Ca2+- atp酶的失活速率常数（KD）是20℃和30℃草鱼肌球蛋白的3 ~ 4倍，而冬草鱼肌球蛋白的失活速率常数（KD）是夏鱼肌球蛋白的7倍左右。春、秋鱼肌球蛋白的KD值分别与驯化于30°C和10°C的鱼相当。在差示扫描量热分析中，大多数肌球蛋白的转变温度（Tm）在38°C和45-46°C附近。然而，在32-33°C时，最低的Tm是10°C驯化的秋冬鱼肌球蛋白的主要恒温温度之一。草鱼对环境温度变化的这些反应与之前报道的普通鲤鱼几乎相似。
Myosins were prepared from fast skeletal muscles of grass carp thermally acclimated to 10, 20 and 30°C in the laboratory as well as from those seasonally acclimatized and collected in January (winter) 2003 and May (spring), August (summer) and November (autumn) 2002. The maximal initial velocities (Vmax) of actin-activated Mg2+-ATPase activity for myosins from the 10°C-acclimated and winter grass carp were 1.7–1.8-fold as high as those from the 30°C-acclimated and summer fish. The inactivation rate constant (KD) of Ca2+-ATPase for myosin from the 10°C-acclimated grass carp was three to fourfold higher than those for myosins from the fish acclimated to 20°C and 30°C, whereas myosin from winter grass carp was about sevenfold as high as that for myosin from summer fish. Myosins from spring and autumn fish showed KD values comparable to those of the fish acclimated to 30°C and 10°C, respectively. In differential scanning calorimetry analysis, the transition temperature (Tm) was observed near 38°C and 45–46°C with most myosins. However, the lowest Tm at 32–33°C was given as one of the major endotherms in myosins from the 10°C-acclimated, autumn and winter fish. These responses of grass carp to changed environmental temperatures were almost similar to those for common carp reported previously.