An X-ray diffraction study on a single frog skinned muscle fiber in the presence of vanadate.
An X-ray diffraction study on a single frog skinned muscle fiber in the presence of vanadate.
复制标题
在钒酸盐存在下对单个青蛙皮肌纤维进行的 X 射线衍射研究。
DOI：
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发表时间：
1995
期刊：
影响因子：
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通讯作者：
N. Yagi
中科院分区：
文献类型：
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作者：
S. Takemori;M. Yamaguchi;N. Yagi
使用的技术，以获得一个详细的X射线衍射图案从一个单一的青蛙皮肤肌肉纤维与同步辐射和成像板，我们研究了安排的肌球蛋白头ADP和钒酸盐绑定。1 mM钒酸盐的存在下收缩引起捕获的ADP和钒酸盐的肌球蛋白头。无论是在存在和不存在的Ca 2+，赤道反射的强度表明，大多数的头与ADP和钒酸盐位于靠近骨干的粗丝。在43 nm-1处的第一条肌球蛋白层线的存在也表明，头形成了一个螺旋周围的粗丝轴。肌动蛋白层线强度弱，表明肌球蛋白头已从细丝上脱落。结果表明，肌球蛋白-ADP-钒酸盐复合物对肌动蛋白的亲和力较弱，与细丝上的调节系统的状态无关。
Using a technique to obtain a detailed X-ray diffraction pattern from a single frog skinned muscle fiber with synchrotron radiation and an imaging plate, we studied the arrangement of myosin heads to which ADP and vanadate are bound. The presence of 1 mM vanadate during contraction caused trapping of ADP and vanadate on the myosin head. Both in the presence and absence of Ca2+, the intensities of the equatorial reflections indicated that most of the heads with ADP and vanadate were located close to the backbone of the thick filament. The presence of the first myosin layer-line at 43 nm-1 also suggested that the heads formed a helix around the shaft of the thick filament. Weak intensity of actin layer-lines suggested that the myosin heads were detached from the thin filament. The results suggest that the myosin-ADP-vanadate complex has a weak affinity toward actin regardless of the state of the regulatory system on the thin filament.