Lehman W, Head J F, Grant P W
Biochem J. 1980 May 1;187(2):447-56. doi: 10.1042/bj1870447.
Localization and quantification studies were carried out on bay-scallop (Aequipecten irradians) striated-muscle troponin C- and troponin I-like proteins. Indirect immunofluorescence microscopy of scallop myofibrils stained with either rabbit anti-(scallop troponin I) or anti-(scallop troponin C) antibodies shows staining of all I-bands observed. The results of quantification studies using sodium dodecyl sulfate poly-acrylamide-gel electrophoresis of untreated scallop myofibrils, washed scallop myofibrils, and isolated scallop thin filaments indicate an actin/tropomyosin/troponin-C molar rationn of 7:1:1. The molar ratio for troponin I could not be determined in untreated myofibrils because of interfering bands; in washed myofibrils a value of 0.6 mol of troponin I/mol of tropomyosin was found. Purified scallop troponin C binds Ca2+ and interacts with scallop troponin I to relieve troponin I-induced inhibition of actomyosin ATPase. Although scallop troponin C is an acidic protein, it appears to be less acidic than troponin C from higher organisms. A calmodulin-like protein has been isolated from scallop striated muscle that activates bovine brain phosphodiesterase to the same extent as does brain calmodulin. Its amino acid composition and its electrophoretic mobility on alkaline 6 M-urea/polyacrylamide gels differs from that of scallop troponin C, and it appears not to be associated with thin filaments.
对海湾扇贝（Aequipecten irradians）横纹肌肌钙蛋白C和肌钙蛋白I样蛋白进行了定位和定量研究。用兔抗（扇贝肌钙蛋白I）或抗（扇贝肌钙蛋白C）抗体对扇贝肌原纤维进行间接免疫荧光显微镜观察，结果显示所有观察到的I带均有染色。使用十二烷基硫酸钠聚丙烯酰胺凝胶电泳对未处理的扇贝肌原纤维、洗涤后的扇贝肌原纤维和分离的扇贝细肌丝进行定量研究的结果表明，肌动蛋白/原肌球蛋白/肌钙蛋白C的摩尔比为7:1:1。由于存在干扰条带，未处理的肌原纤维中无法确定肌钙蛋白I的摩尔比；在洗涤后的肌原纤维中，发现肌钙蛋白I与原肌球蛋白的摩尔比为0.6 mol/mol。纯化的扇贝肌钙蛋白C结合Ca2+并与扇贝肌钙蛋白I相互作用，以解除肌钙蛋白I对肌动球蛋白ATP酶的抑制作用。尽管扇贝肌钙蛋白C是一种酸性蛋白，但它的酸性似乎比高等生物的肌钙蛋白C弱。已从扇贝横纹肌中分离出一种钙调蛋白样蛋白，它激活牛脑磷酸二酯酶的程度与脑钙调蛋白相同。它的氨基酸组成及其在碱性6M尿素/聚丙烯酰胺凝胶上的电泳迁移率与扇贝肌钙蛋白C不同，并且它似乎与细肌丝无关。
