Miyanishi T, Maita T, Matsuda G, Tonomura Y
J Biochem. 1982 Jun;91(6):1845-53. doi: 10.1093/oxfordjournals.jbchem.a133881.
Our laboratory has presented strong evidence for the nonidentical two-headed structure of skeletal muscle myosin. We previously showed that each of the two kinds of heads, i.e., the burst head, which forms the myosin-P-ADP complex, and the nonburst head, which forms the myosin-ATP complex upon reaction with ATP, contains 1 mol of reactive lysine residue per mol which is modified rapidly with TNBS. We also found that in the presence of PPi only the reactive lysine residue in the burst head is modified with TNBS. Utilizing this phenomenon, we presented evidence [(1981) J. Biochem. 89, 831-839] indicating that the chemical structures around the reactive lysine residues in the burst and the nonburst head are different. In this study, we determined the amino acid sequence around the reactive lysine residues to demonstrate the nonidentical chemical structure of the two heads of skeletal muscle myosin. We found that the sequence around the reactive lysine residue in the burst head was ....Pro-Met-Asn-Pro-Pro-Lys-Tyr.... and the sequence in the nonburst head was ....Ser-Met-Asn-Pro-Pro-Lys-Tyr..... Thus, a proline residue located ner the reactive lysine residue in the burst head was found to be replaced by a serine residue in the nonburst head.
我们实验室已提供有力证据，证明骨骼肌肌球蛋白具有不同的双头结构。我们先前表明，两种头部，即形成肌球蛋白 - P - ADP复合物的爆发头，以及与ATP反应时形成肌球蛋白 - ATP复合物的非爆发头，每摩尔均含有1摩尔可快速被TNBS修饰的活性赖氨酸残基。我们还发现，在焦磷酸存在的情况下，只有爆发头中的活性赖氨酸残基会被TNBS修饰。利用这一现象，我们提供了证据[（1981年）《生物化学杂志》89卷，831 - 839页]，表明爆发头和非爆发头中活性赖氨酸残基周围的化学结构不同。在本研究中，我们确定了活性赖氨酸残基周围的氨基酸序列，以证明骨骼肌肌球蛋白两个头部的化学结构不同。我们发现，爆发头中活性赖氨酸残基周围的序列是....脯氨酸 - 甲硫氨酸 - 天冬酰胺 - 脯氨酸 - 脯氨酸 - 赖氨酸 - 酪氨酸....，非爆发头中的序列是....丝氨酸 - 甲硫氨酸 - 天冬酰胺 - 脯氨酸 - 脯氨酸 - 赖氨酸 - 酪氨酸.....。因此，发现爆发头中位于活性赖氨酸残基附近的一个脯氨酸残基在非爆发头中被一个丝氨酸残基取代。
