Murai S, Arata T, Inoue A
Department of Biology, Faculty of Science, Osaka University.
J Biochem. 1995 May;117(5):974-9. doi: 10.1093/oxfordjournals.jbchem.a124829.
It was shown by Miyanishi et al. [Miyanishi, T., Maita, T., Matsuda, G., and Tonomura, Y. (1982) J. Biochem. 91, 1845-1853] that the amino acid sequence around the reactive lysine residue is different between head B (Pi-burst head) and head A of the myosin molecule. Thus, we synthesized these two peptides, and prepared rabbit polyclonal antibodies against them. Each antibody bound strongly with both peptides. However, the binding of the antibodies with S-1 was inhibited by the peptide used for the antigen but unaffected by the non-antigen peptide, suggesting that only antibodies specific to each head can bind with S-1. Myosin was absorbed by either antibody A or B, which was immobilized on protein A in Staphylococcus aureus cells. However, half of S-1 was absorbed by each of the antibodies. The S-1 prepared showed about 0.5 mol of initial Pi-liberation per mol of S-1. The Pi-burst size of S-1 unbound to the immobilized anti-A antibody increased to almost 1 mol/mol S-1, while that of S-1 unbound to the anti-B antibody decreased to 0.15 mol/mol S-1. These results suggest the existence of two kinds of heads in the myosin molecule.
宫西等人[宫西敏史、间田哲、松田刚、户村洋（1982年）《生物化学杂志》91卷，1845 - 1853页]表明，肌球蛋白分子头部B（Pi爆发头部）和头部A周围反应性赖氨酸残基的氨基酸序列不同。因此，我们合成了这两种肽，并制备了针对它们的兔多克隆抗体。每种抗体都能与这两种肽强烈结合。然而，抗体与S - 1的结合受到用于抗原的肽的抑制，但不受非抗原肽的影响，这表明只有针对每个头部的特异性抗体才能与S - 1结合。肌球蛋白被固定在金黄色葡萄球菌细胞中蛋白A上的抗体A或抗体B吸附。然而，每种抗体吸附了一半的S - 1。制备的S - 1每摩尔S - 1显示约0.5摩尔的初始Pi释放。未与固定化抗A抗体结合的S - 1的Pi爆发大小增加到几乎1摩尔/摩尔S - 1，而未与抗B抗体结合的S - 1的Pi爆发大小降至0.15摩尔/摩尔S - 1。这些结果表明肌球蛋白分子中存在两种头部。
