American lobster troponin.
American lobster troponin.
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美国龙虾肌钙蛋白。
DOI：
10.1093/oxfordjournals.jbchem.a123262
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发表时间：
1990
影响因子：
2.7
通讯作者：
T. Ojima
中科院分区：
文献类型：
--
作者：
K. Nishita;T. Ojima
从美洲龙虾（Homarus americanus）腹肌中分离肌钙蛋白的方法与提取赤坂扇贝肌钙蛋白的方法基本相同[J]。医学杂志。化学，261,16749-16754（1986）。由此分离出的肌钙蛋白与龙虾原肌球蛋白对兔重组肌动球蛋白具有较高的Ca2（+）敏感性。肌钙蛋白由Mr值约为42,000,32,000,30,000和17,000的组分组成，但不是先前报道的存在于几种甲壳类肌钙蛋白中的Mr值为52,000-59,000的组分。在6 M尿素存在下，用DEAE-Toyopearl柱层析分离这些肌钙蛋白组分。用同样的色谱法将Mr 17000组分进一步分离为一个主要组分和两个次要组分，但每个组分都被确认为Ca2+结合组分TnC。Mr 32,000和30,000组分都被认为是抑制亚基，TnIs，因为在原肌球蛋白存在下，肌动球蛋白的mg - atp酶活性被添加组分强烈抑制，并且被进一步添加TnC逆转抑制。最后，Mr 42000组分被认为是TnT，因为该组分与TnC和TnI形成化学计量复合物，并且对肌动球蛋白-原肌球蛋白系统的Ca2+调节是必不可少的。
Troponin was isolated from the abdominal muscle of the American lobster (Homarus americanus) by essentially the same method as used for akazara scallop troponin [J. Biol. Chem. 261, 16749-16754 (1986)]. The thus isolated troponin together with lobster tropomyosin confers high Ca2(+)-sensitivity to rabbit reconstituted actomyosin. The troponin consists of components having Mr of about 42,000, 32,000, 30,000, and 17,000, but not the Mr 52,000-59,000 component previously reported to be present in several crustacean troponins. These troponin components were separated from each other by DEAE-Toyopearl column chromatography in the presence of 6 M urea. The Mr 17,000 component was further separated into one major and two minor components by the same chromatography, but each of them was confirmed to be a Ca2+ binding component, TnC. The Mr 32,000 and 30,000 components were both regarded as inhibitory subunits, TnIs, since the Mg-ATPase activity of actomyosin in the presence of tropomyosin was strongly inhibited by the addition of the components, and the inhibition was reversed by the further addition of TnC. Finally, the Mr 42,000 component was regarded as TnT, since this component formed stoichiometic complex with TnC and TnI, and was indispensable for Ca2+ regulation of the actomyosin-tropomyosin system.