Lowy J, Poulsen F R
Nature. 1982 Sep 23;299(5881):308-12. doi: 10.1038/299308a0.
The intensities of three regions of the low-angle X-ray diffraction pattern from a molluscan unstriated muscle have been followed during tension generation at a time resolution of 0.5-1 s using synchrotron radiation. The observed intensity changes can be reasonably interpreted in terms of myosin cross-bridge movements during the contractile cycle. A model that accounts for the intensity changes suggests that myosin heads move out from the thick filament during activation and attach to actin sites to produce tension with a small delay. During relaxation from both phasic and tonic contractions the heads remain attached to actin sites longer than it takes for tension to decay.
利用同步辐射，以0.5 - 1秒的时间分辨率，跟踪了软体动物无横纹肌低角度X射线衍射图谱三个区域在张力产生过程中的强度变化。观察到的强度变化可以根据收缩周期中肌球蛋白横桥的运动得到合理的解释。一个解释强度变化的模型表明，在激活过程中，肌球蛋白头部从粗肌丝伸出，并附着在肌动蛋白位点上，稍有延迟后产生张力。在相位收缩和张力收缩的松弛过程中，头部附着在肌动蛋白位点上的时间比张力衰减所需的时间更长。
