The interaction of the calcium-binding protein (troponin C) with bivalent cations and the inhibitory protein (troponin I).
The interaction of the calcium-binding protein (troponin C) with bivalent cations and the inhibitory protein (troponin I).
复制标题
钙结合蛋白（肌钙蛋白 C）与二价阳离子和抑制蛋白（肌钙蛋白 I）的相互作用。
DOI：
10.1042/bj1370145
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发表时间：
1974
期刊：
影响因子：
--
通讯作者：
S. Perry
中科院分区：
文献类型：
--
作者：
J. Head;S. Perry
1. 经十二烷基硫酸钠沉淀平衡和电泳，估计兔白色骨骼肌钙结合蛋白的分子量为18500。2. 在每个分子中加入2个Ca（2+）离子会在紫外吸收光谱中产生可逆的变化，这种变化被解释为由蛋白质结构的构象变化引起的。3. Cd（2+）与Ca（2+）在产生光谱变化方面几乎一样有效。其他二价金属离子，特别是Mg(2+)，效果较差。4. 在pH8.6的6m尿素中，钙结合蛋白与Ca（2+）的结合使其向阳极的迁移率增加。钙（2+）饱和形式的蛋白质比钙（2+）不饱和形式的蛋白质在凝胶过滤时更迟钝。5. 在Ca（2+）存在下，钙结合蛋白与抑制蛋白形成等摩尔复合物。该络合物在8m尿素和7.0 ~ 8.6 pH范围内稳定。6. 本文描述了一种测量全肌肉中钙结合蛋白含量的同位素稀释法。在兔腰肌中，肌动蛋白单体与钙结合蛋白分子的比例约为。7:1。红色骨骼肌和心肌也得到了类似的结果。7. 有证据表明，兔红色骨骼肌和心肌肌钙蛋白复合物的抑制蛋白与白色骨骼肌的抑制蛋白不同。
1. The molecular weight of the calcium-binding protein of rabbit white skeletal muscle was estimated to be 18500 by sedimentation equilibrium and electrophoresis in sodium dodecyl sulphate. 2. Addition of 2 Ca(2+) ions per molecule produced reversible changes in the u.v.-absorption spectrum that are interpreted as arising from conformational changes in the structure of the protein. 3. Cd(2+) was almost as effective as Ca(2+) in producing the spectral changes. Other bivalent metal ions, particularly Mg(2+), were less effective. 4. Binding of Ca(2+) by the calcium-binding protein produced an increase in mobility to the anode on electrophoresis in 6m-urea at pH8.6. The Ca(2+)-saturated form of the protein was more retarded on gel filtration than the Ca(2+)-free form. 5. In the presence of Ca(2+) the calcium-binding protein formed an equimolar complex with the inhibitory protein. This complex was stable in 8m-urea and in the pH range 7.0-8.6. 6. An isotope-dilution method for the measurement of the content of calcium-binding protein in whole muscle is described. In rabbit psoas muscle the ratio of actin monomers to molecules of calcium-binding protein was approx. 7:1. Similar values were obtained for red skeletal and cardiac muscle. 7. Evidence is presented indicating that in the rabbit the inhibitory protein of the troponin complex of red skeletal and cardiac muscles is different from the inhibitory protein of white skeletal muscle.