Electrostatic interactions in the SH1-SH2 helix of human cardiac myosin modulate the time of strong actomyosin binding.
Electrostatic interactions in the SH1-SH2 helix of human cardiac myosin modulate the time of strong actomyosin binding.
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人心肌肌凝蛋白SH1-SH2螺旋的静电相互作用可调节肌动球蛋白强结合的时间。
DOI：
10.1007/s10974-020-09588-1
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发表时间：
2021-06
影响因子：
2.7
通讯作者：
Nesmelov YE
中科院分区：
文献类型：
--
作者：
Gargey A;Iragavarapu SB;Grdzelishvili AV;Nesmelov YE
在人心肌肌球蛋白的β亚型中引入了两个单一突变，R694N和E45Q，以消除肌球蛋白头部SH1-SH2螺旋上的永久性盐桥E45：R694和E98：R694。在对α和β肌球蛋白亚型的分子动力学模拟中发现了β亚型特异性桥E45：R694和E98：R694。α和β亚型表现出不同的动力学，ADP与含有β肌球蛋白亚型的肌球蛋白解离较慢，因此，β肌球蛋白与肌动蛋白强结合的时间更长。我们假设，SH1-SH2螺旋上的静电相互作用调节了ADP对肌动球蛋白的亲和力，从而调节了肌动球蛋白强结合的时间。在分化的C2C12细胞中表达了野生型和突变型肌球蛋白头部结构(1-843个氨基酸残基)，并用瞬时动力学分光光度法表征了肌球蛋白强结合状态的持续时间。所有肌球蛋白结构都表现出与肌球蛋白快速结合的速率和缓慢的ADP解离速度，表明ADP的释放限制了肌球蛋白强结合状态的时间。与野生型和E45Q突变体相比，突变体R694N从肌动球蛋白释放ADP的速度更快，这表明人心肌肌球蛋白SH1-SH2螺旋区域内的静电相互作用调节了ADP的释放，从而调节了肌动球蛋白强结合状态的持续时间。
Two single mutations, R694N and E45Q, were introduced in the beta isoform of human cardiac myosin to remove permanent salt bridges E45:R694 and E98:R694 in the SH1-SH2 helix of the myosin head. Beta isoform-specific bridges E45:R694 and E98:R694 were discovered in the molecular dynamics simulations of the alpha and beta myosin isoforms. Alpha and beta isoforms exhibit different kinetics, ADP dissociates slower from actomyosin containing beta myosin isoform, therefore, beta myosin stays strongly bound to actin longer. We hypothesize that the electrostatic interactions in the SH1-SH2 helix modulate the affinity of ADP to actomyosin, and therefore, the time of the strong actomyosin binding. Wild type and the mutants of the myosin head construct (1–843 amino acid residues) were expressed in differentiated C2C12 cells, and the duration of the strongly bound state of actomyosin was characterized using transient kinetics spectrophotometry. All myosin constructs exhibited a fast rate of ATP binding to actomyosin and a slow rate of ADP dissociation, showing that ADP release limits the time of the strongly bound state of actomyosin. The mutant R694N showed a faster rate of ADP release from actomyosin, compared to the wild type and the E45Q mutant, thus indicating that electrostatic interactions within the SH1-SH2 helix region of human cardiac myosin modulate ADP release and thus, the duration of the strongly bound state of actomyosin.
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影响因子：
5.6
作者：
MARSTON, SB;TAYLOR, EW
通讯作者：
TAYLOR, EW
DOI：
10.1016/j.bbrc.2019.01.045
发表时间：
2019-02-19
影响因子：
3.1
作者：
Gargey, Akhil;Ge, Jinghua;Nesmelov, Yuri E.
通讯作者：
Nesmelov, Yuri E.
影响因子：
5.7
作者：
Koppole, Sampath;Smith, Jeremy C.;Fischer, Stefan
通讯作者：
Fischer, Stefan
DOI：
10.1073/pnas.250289597
发表时间：
2000-12-19
影响因子：
11.1
作者：
Martinsson, T;Oldfors, A;Wahlström, J
通讯作者：
Wahlström, J
影响因子：
2.9
作者：
Sasaki, N;Ohkura, R;Sutoh, K
通讯作者：
Sutoh, K