The myosin head can bind two actin monomers.
The myosin head can bind two actin monomers.
复制标题
肌球蛋白头可以结合两个肌动蛋白单体。
DOI：
10.1016/0006-291x(91)91990-t
复制
发表时间：
1991
影响因子：
3.1
通讯作者：
J. Borejdo
中科院分区：
文献类型：
--
作者：
O. Andreev;J. Borejdo
肌球蛋白头（S-1）虽然与肌动蛋白丝结合较弱，但发生取向变化，与肌动蛋白形成强（刚性）键，从而在肌肉中产生力脉冲。有充分的证据表明，这种键涉及1个肌球蛋白头与1个肌动蛋白单体的相互作用。然而，用S-1修饰的肌肉的X射线衍射数据，以及最近提出的细丝模型，表明每个S-1分子与两个肌动蛋白单体相互作用。我们重新研究了这一争论，发现acto-S-1键的化学计量取决于滴定过程中存在的肌动蛋白和肌球蛋白的相对量：当增加量的肌动蛋白加入到固定量的S-1中时（即当肌球蛋白头最初超过肌动蛋白时），饱和的化学计量为每摩尔肌动蛋白1摩尔S-1。然而，当逐渐增加量的S-1缓慢加入到固定量的F-肌动蛋白中时（即当肌动蛋白最初超过S-1时），饱和时的化学计量为每2摩尔肌动蛋白1摩尔S-1。S-1结合一个或两个肌动蛋白单体的能力表明，肌肉收缩期间可能会产生力。
Force impulse is thought to be generated in muscle when myosin head (S-1), while weakly bound to actin filament, undergoes orientational change to form a strong (rigor) bond with actin. There is ample evidence that this bond involves interaction of 1 myosin head with 1 actin monomer. However, X-ray diffraction data of muscle decorated with S-1, as well as recently proposed model of the thin filaments, suggested that each S-1 molecule interacted with two actin monomers. We reinvestigated this controversy and found that the stoichiometry of acto-S-1 bond depended on the relative amounts of actin and myosin present during titrations: when increasing amounts of actin were added to a fixed amount of S-1 (i.e. when myosin heads were initially in excess over actin), the saturating stoichiometry was 1 mol of S-1 per 1 mol of actin. However, when increasing amounts of S-1 were added slowly to a fixed amount of F-actin (i.e. when actin was initially in excess over S-1), the stoichiometry at saturation was 1 mol of S-1 per 2 mols of actin. The ability of S-1 to bind either one or two actin monomers suggests a way that force could be generated during muscle contraction.
胰蛋白酶消化对肌球蛋白亚片段 1 及其肌动蛋白激活的腺苷三磷酸酶的影响。
影响因子：
2.9
作者：
Botts,J;Muhlrad,A;Takashi,R;Morales,MF
通讯作者：
Morales,MF
acrylodan 标记的原肌球蛋白和原肌球蛋白-肌动蛋白的荧光特性：肌球蛋白亚片段 1 诱导原肌球蛋白和肌动蛋白之间几何形状变化的证据。
影响因子：
2.9
作者：
Lehrer,SS;Ishii,Y
通讯作者：
Ishii,Y
高 subfragment-1 浓度下骨骼 actosubfragment-1 的生化动力学。
影响因子：
3.4
作者：
Stein,LA;Harwalkar,VA
通讯作者：
Harwalkar,VA