Regulatory and catalytic domain dynamics of smooth muscle myosin filaments.
Regulatory and catalytic domain dynamics of smooth muscle myosin filaments.
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平滑肌肌球蛋白丝的调节和催化域动力学。
DOI：
10.1021/bi060037h
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发表时间：
2006
期刊：
影响因子：
2.9
通讯作者：
Fajer,PiotrG
中科院分区：
文献类型：
--
作者：
Li,Hui-Chun;Song,Likai;Salzameda,Bridget;Cremo,ChristineR;Fajer,PiotrG
Domain dynamics of the chicken gizzard smooth muscle myosin catalytic domain (heavy chain Cys-717) and regulatory domain (regulatory light chain Cys-108) were determined in the absence of nucleotides using saturation-transfer electron paramagnetic resonance. In unphosphorylated synthetic filaments, the effective rotational correlation times, τr, were 24 ± 6 μs and 441 ± 79 μs for the catalytic and regulatory domains, respectively. The corresponding amplitudes of motion were 42 ± 4° and 24 ± 9° as determined from steady-state phosphorescence anisotropy. These results suggest that the two domains have independent mobility due to a hinge between the two domains. Although a similar hinge was observed for skeletal myosin (Adhikari and Fajer (1997)Proc. Natl. Acad. Sci. U.S.A.94, 9643−9647. Brown et al. (2001)Biochemistry40, 8283−8291), the latter displayed higher regulatory domain mobility, τr= 40 ± 3 μs, suggesting a smooth muscle specific mechanism of constraining regulatory domain dynamics. In the myosin monomers the correlation times for both domains were the same (∼4 μs) for both smooth and skeletal myosin, suggesting that the motional difference between the two isoforms in the filaments was not due to intrinsic variation of hinge stiffness. Heavy chain/regulatory light chain chimeras of smooth and skeletal myosin pinpointed the origin of the restriction to the heavy chain and established correlation between the regulatory domain dynamics with the ability of myosin toswitch offbut not toswitch onthe ATPase and the actin sliding velocity. Phosphorylation of smooth muscle myosin filaments caused a small increase in the amplitude of motion of the regulatory domain (from 24 ± 4° to 36 ± 7°) but did not significantly affect the rotational correlation time of the regulatory domain (441 to 408 μs) or the catalytic domain (24 to 17 μs). These data are not consistent with a stable interaction between the two catalytic domains in unphosphorylated smooth muscle myosin filaments in the absence of nucleotides.
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DOI：
10.1042/bj20020099
发表时间：
2002
期刊：
The Biochemical journal.
影响因子：
--
作者：
Nyitrai,Miklos;Szent-Gyorgyi,AndrewG;Geeves,MichaelA
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Geeves,MichaelA
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DOI：
10.1016/s0022-2836(02)00191-2
发表时间：
2002
期刊：
Journal of molecular biology.
影响因子：
--
作者：
Tonino,Paola;Simon,Martha;Craig,Roger
通讯作者：
Craig,Roger
影响因子：
2.2
作者：
FAJER, P;MARSH, D
通讯作者：
MARSH, D
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DOI：
--
发表时间：
--
期刊：
影响因子：
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作者：
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嵌合调节轻链作为平滑肌肌球蛋白功能的探针。
DOI：
--
发表时间：
1993
期刊：
The Journal of biological chemistry
影响因子：
--
作者：
Trybus,KM;Chatman,TA
通讯作者：
Chatman,TA