Biochemical Studies on Changes in Fish Muscle Proteins Following Temperature Acclimation

由于鱼类肌原纤维蛋白占总肌肉蛋白的50%以上，因此人们认为，肌原纤维蛋白的特性极大地影响了各种鱼类肉类食品加工的可行性和储存的稳定性。本研究旨在回答在温度驯化过程中，哪些成分和部位对鲤鱼和金鱼肌原纤维蛋白的变化最为关键的问题，从而为渔业提供有关鱼类肌肉作为食用材料的有价值的基础信息。几只鲤鱼在10或30的浓度下驯化至少1个月，并进行肌原纤维的制备。在相同的反应温度下，10个驯化的鱼的肌纤维Mg^<2+>- atp酶活性显著高于30个驯化的鱼。在40ºC温度下，10ºC驯化的鲤鱼肌原纤维Ca^<2+->- atp酶的热稳定性比30ºC驯化的鲤鱼低几倍。对驯化后的金鱼进行同样的实验，也得到了类似的结果。在肌动蛋白激活的Mg^<2+>-ATPase活性方面，10个驯化的鲤鱼肌球蛋白及其亚片段-1 （Sl）的最大初速度（Vmax）分别高于30个驯化的鲤鱼，这与两驯化组间肌纤维Mg^<2+>-ATPase活性的差异一致。3.经30 - c驯化的肌球蛋白和Sl的热稳定性均优于10 - c驯化的肌球蛋白。当使用α -凝乳胰蛋白酶对肌球蛋白的丝状部分棒状蛋白进行有限的蛋白水解时，SDS-PAGE分析显示，10个氨基苯胺驯化的鲤鱼显示出一条l -肌球蛋白带。另一方面，30只驯化的鲤鱼出现了3条l -肌球蛋白条带。其中一个与10c驯化的l -meromyosin相同。sds -凝胶分析结果显示，温度驯化10次和30次的鲤鱼肌球蛋白、Sl重链和棒的肽图存在明显差异，表明温度驯化过程中鲤鱼肌球蛋白分子的初级结构发生了改变。少

Since fish myofibrillar proteins account for over 50% in total muscle proteins, the feasibility of various kinds of fish meat for food processing and their stability during storage are regarded to be greatly influenced by the properties of myofibrillar proteins. This study was performed to answer the questions on which components and parts are most critical in changes of myofibrillar proteins of carp and goldfish during temperature acclimation, thus providing fisheries industry with valuable and foundamental information on fish muscles as food materials.1. Several individuals of carp were acclimated to either 10 or 30ﾟC for a minimum of 1 month and subjected to the preparation of myofibrils. Myofibrillar Mg^<2+>-ATPase activity of 10ﾟC-acclimated carp was significantly higher than that of 30ﾟC-acclimated fish when assayed at the same reaction temperatures. In contrast, the thermal stability at 40ﾟC of myofibrillar Ca^<2+->-ATPase of 10ﾟC-acclimated carp was several times lower than tha … More t of 30ﾟC-acclimated one. The similar results were obtained when acclimated goldfish were subjected to the same experiments.2. Myosin and its subfragment-1 (Sl) from 10ﾟC-acclimated carp showed a higher maximal initial velocity (Vmax) in actin-activated Mg^<2+>-ATPase activity than the 30ﾟC-acclimated counterparts, respectively, in a good agreement with the differences observed in myfibrillar Mg^<2+>-ATPase activity between the two acclimated groups. The 30ﾟC-acclimated myosin and Sl were again more thermostable than the 10ﾟC-acclimated counterparts, respectively.3. When a filamentous part of the myosin molecule, rod, was subjected to a limited proteolysis using alpha-chymotrypsin, the 10ﾟC-acclimated carp exhibited one L-meromyosin band in SDS-PAGE analysis. On the other hand, the 30ﾟC-acclimated carp gave three L-meromyosin bands. one of which was identical to the 10ﾟC-acclimated L-meromyosin.4. Peptide maps of myosin and Sl heavy chains and rod performed in SDS-gels were clearly different between 10ﾟC-and 30ﾟC-acclimated carp, suggesting that the primary structure of carp myosin molecule is altered during temperature acclimation. Less