Côté A, Doucet J P, Trifaró J M
J Neurochem. 1986 Jun;46(6):1771-82. doi: 10.1111/j.1471-4159.1986.tb08495.x.
Tropomyosins have been isolated from bovine adrenal medulla. Purified from a heat-stable extract, the adrenal medullary tropomyosins show the same chromatographic patterns as platelet tropomyosin components purified under very similar conditions on ion-exchange (DEAE-Sephacel) and hydroxylapatite columns. When analyzed by polyacrylamide gel electrophoresis, the purified fraction, reduced and denatured, yielded three polypeptides with apparent molecular weights of 38,000, 35,500, and 32,000. The molar ratio of the two major polypeptides (38 kd and 32 kd) was 2:1. The predominant form of 38 kd is different from other nonmuscle tropomyosins previously isolated and with which an apparent molecular weight of 30,000 is normally associated. The three adrenal medullary tropomyosins have similar isoelectric points of about 4.7. When adrenal tropomyosins were subjected to sodium dodecyl sulfate-polyacrylamide gel electrophoresis in the presence of 8 M urea, each form showed a shift to a higher molecular weight, which is a characteristic of muscle tropomyosin. The 38,000 adrenal medullary tropomyosin exhibits a stronger affinity for F-actin than the other forms. Peptide profiles obtained after limited proteolytic digestion show some similarity between the two predominant tropomyosins of the bovine adrenal medulla and also between these and the alpha and beta forms of bovine skeletal muscle tropomyosin.
原肌球蛋白已从牛肾上腺髓质中分离出来。从热稳定提取物中纯化得到的肾上腺髓质原肌球蛋白，在离子交换（DEAE - 琼脂糖凝胶）和羟基磷灰石柱上，在非常相似的条件下纯化时，显示出与血小板原肌球蛋白组分相同的色谱模式。当通过聚丙烯酰胺凝胶电泳分析时，纯化后的组分经还原和变性后，产生了三种表观分子量分别为38,000、35,500和32,000的多肽。两种主要多肽（38kd和32kd）的摩尔比为2:1。38kd的主要形式与先前分离的其他非肌肉原肌球蛋白不同，其他非肌肉原肌球蛋白通常与表观分子量30,000相关。三种肾上腺髓质原肌球蛋白具有相似的等电点，约为4.7。当肾上腺原肌球蛋白在8M尿素存在下进行十二烷基硫酸钠 - 聚丙烯酰胺凝胶电泳时，每种形式都显示出向更高分子量的迁移，这是肌肉原肌球蛋白的一个特征。38,000的肾上腺髓质原肌球蛋白对F - 肌动蛋白的亲和力比其他形式更强。有限蛋白酶消化后获得的肽谱显示，牛肾上腺髓质的两种主要原肌球蛋白之间以及它们与牛骨骼肌原肌球蛋白的α和β形式之间存在一些相似性。
