Motion of the Ca2+-pump captured
Motion of the Ca2+-pump captured
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DOI：
10.1111/j.1742-4658.2011.08222.x
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发表时间：
2011-09-01
期刊：
影响因子：
5.4
通讯作者：
Takeyasu, Kunio
中科院分区：
文献类型：
--
作者：
Yokokawa, Masatoshi;Takeyasu, Kunio
对ATP合成酶和Ca ~（2+）-ATP酶等离子泵的研究历史悠久。解析了几种离子泵的晶体结构，并提供了离子输运机理的静态图像。在这项研究中，使用快速扫描原子力显微镜，我们已经可视化的构象变化，肌浆网Ca 2 +-ATP酶（SERCA）在真实的时间在单分子水平。在ATP和游离Ca 2+存在下对单个SERCA分子的分析揭示了对应于Albers-Post方案的上下结构变化。这种波动受到ATP和Ca 2+浓度的强烈影响，并被抑制剂毒胡萝卜素阻止。有趣的是，在生理ATP浓度下，上下运动完全消失。这些结果表明，SERCA不通过最短的结构，并有一个催化途径不同于普通的Albers-Post方案在生理条件下。
Studies of ion pumps, such as ATP synthetase and Ca2+-ATPase, have a long history. The crystal structures of several kinds of ion pump have been resolved, and provide static pictures of mechanisms of ion transport. In this study, using fast-scanning atomic force microscopy, we have visualized conformational changes in the sarcoplasmic reticulum Ca2+-ATPase (SERCA) in real time at the single-molecule level. The analyses of individual SERCA molecules in the presence of both ATP and free Ca2+ revealed up-down structural changes corresponding to the Albers-Post scheme. This fluctuation was strongly affected by the ATP and Ca2+ concentrations, and was prevented by an inhibitor, thapsigargin. Interestingly, at a physiological ATP concentrations, the up-down motion disappeared completely. These results indicate that SERCA does not transit through the shortest structure, and has a catalytic pathway different from the ordinary Albers-Post scheme under physiological conditions.