Yazawa Y, Kamidochi M
Department of Nutritional Physiology, Hokkaido University of Education at Asahikawa, Japan.
Mol Cell Biochem. 1999 Jan;190(1-2):63-6.
We found out a new protein from natural actomyosin prepared from adductor muscle of Hokki clam, bivalve shell. We isolated this protein and determined some properties. It has a large molecular weight (230 kDa) and the star diagram of amino acid composition was very similar to that of paramyosin (110 kDa). When this protein was added to Hokki clam myosin, the Mg2+ -ATPase activity was more activated in the presence of 10(-7) M Ca2+ and further inhibited in the presence of 10(-4) M Ca2+ as compared with those of myosin. From these results, we suggest that Hokki clam adductor muscle contains another myosin-linked regulatory protein, myonin, which is different from the myosin-linked system, the myosin light chain-linked system. We named this protein 'myonin'.
我们从双壳贝类鸟蛤闭壳肌制备的天然肌动球蛋白中发现了一种新蛋白质。我们分离出这种蛋白质并测定了一些特性。它具有较大的分子量（230 kDa），氨基酸组成的星形图与副肌球蛋白（110 kDa）非常相似。当将这种蛋白质添加到鸟蛤肌球蛋白中时，与肌球蛋白相比，在10^(-7) M Ca2+存在下Mg2+-ATP酶活性被进一步激活，而在10^(-4) M Ca2+存在下则被进一步抑制。基于这些结果，我们认为鸟蛤闭壳肌含有另一种与肌球蛋白相关的调节蛋白——肌宁蛋白，它不同于与肌球蛋白相关的系统和与肌球蛋白轻链相关的系统。我们将这种蛋白质命名为“肌宁蛋白”。
