Department of Animal Science, Purdue University 901 W. State Street, West Lafayette, IN 47907-2054, USA.
Meat Sci. 2010 Mar;84(3):364-70. doi: 10.1016/j.meatsci.2009.09.003.
The kinetics of myosin dissociation from actin was investigated and also the impact of salt, MgPPi, and myosin heavy chain isoform on myosin subfragment 1 (S1) dissociation from actin using purified proteins and fluorescence spectroscopy. Both NaCl and MgPPi increased myosin S1 dissociation rate. When salt concentrations increased from 0.1 to 1.0 M, the dissociation rate of S1 from bovine masseter (slow) and cutaneous trunci (fast) muscle increased 38 and 78 fold, respectively. MgPPi had an even greater effect on S1 dissociation from actin. With the addition of MgPPi to the mixture of pyrene actin and S1, the fluorescence increased about 85% within the dead time of the mixing approach.. Unlike salt, MgPPi had no apparent difference in its ability to dissociate slow or fast S1 isoforms from actin. The results reveal that salt and MgPPi increase myosin extraction and functionality in meat by weakening the actomyosin interaction and that some of the difference in the functionality of red and white muscle may be related to actomyosin dissociation.
肌球蛋白从肌动蛋白上的解离动力学，以及盐、MgPPi 和肌球蛋白重链同工型对肌球蛋白亚基 1（S1）从肌动蛋白上解离的影响，使用纯化蛋白和荧光光谱进行了研究。NaCl 和 MgPPi 均增加肌球蛋白 S1 的解离速率。当盐浓度从 0.1 M 增加到 1.0 M 时，来自牛咬肌（慢）和腹外斜肌（快）的 S1 解离速率分别增加了 38 倍和 78 倍。MgPPi 对肌动蛋白上 S1 的解离有更大的影响。在向 pyrene 肌动蛋白和 S1 的混合物中加入 MgPPi 后，在混合过程的死时间内，荧光增加了约 85%。与盐不同，MgPPi 对从肌动蛋白上解离慢或快 S1 同工型的能力没有明显差异。结果表明，盐和 MgPPi 通过削弱肌球蛋白肌动蛋白相互作用来增加肉中的肌球蛋白提取和功能，并且红肌和白肌功能的一些差异可能与肌球蛋白肌动蛋白解离有关。
