Kuroda M, Masaki T
J Biochem. 1980 Aug;88(2):605-8. doi: 10.1093/oxfordjournals.jbchem.a133009.
Extractability of 42,000 dalton components (42 K component) from myosin-removed myofibrils (called I-Z-I segments in this paper) under low-salt conditions was compared at pH 6.5 and pH 8.0. Kinetic and isoelectric focusing analysis of the 42 K components revealed that the 42 K component extracted at pH 8.0 was actin, which depolymerized from the end of the I-filaments of the I-Z-I segments. On the other hand, isoelectric focusing of the 42 K component extracted at pH 6.5 indicated two protein bands. The relative mobility of the minor band was virtually identical to that of actin. While the isoelectric point of the major band was more acidic than that of skeletal muscle actin. Therefore, it is concluded that there are at least two kinds of 42,000 dalton components in the myosin-removed myofibrils.
在低盐条件下，于pH 6.5和pH 8.0时比较了从去除肌球蛋白的肌原纤维（本文中称为I-Z-I节段）中提取42,000道尔顿组分（42K组分）的能力。对42K组分进行动力学和等电聚焦分析表明，在pH 8.0提取的42K组分是肌动蛋白，它从I-Z-I节段的I丝末端解聚。另一方面，对在pH 6.5提取的42K组分进行等电聚焦显示出两条蛋白带。次要条带的相对迁移率与肌动蛋白几乎相同。而主要条带的等电点比骨骼肌肌动蛋白的等电点更偏酸性。因此，得出结论：在去除肌球蛋白的肌原纤维中至少存在两种42,000道尔顿的组分。
