Procaine effects on single sarcoplasmic reticulum Ca2+ release channels.
Procaine effects on single sarcoplasmic reticulum Ca2+ release channels.
复制标题
普鲁卡因对单一肌浆网 Ca2 释放通道的影响。
DOI：
10.1016/s0006-3495(93)81465-6
复制
发表时间：
1993
影响因子：
3.4
通讯作者：
Palade,P
中科院分区：
文献类型：
--
作者：
Zahradnikova,A;Palade,P
钙（2+）诱导的Ca2+释放阻滞剂普鲁卡因对单个肌浆网Ca2+释放通道的影响已经在平面脂质双层中进行了研究。普鲁卡因没有降低单通道电导，也没有明显缩短通道的平均打开时间；相反，它增加了最长关闭时间。这些结果表明普鲁卡因选择性地与封闭状态的通道相互作用，而不是与开放状态的通道相互作用。肌浆网Ca2+释放通道的门控是由Ashley和Williams（1990）的改良方案描述的。J. gen Physiol. 95:981-1005)，包括一个额外的长期封闭状态。计算机模拟表明，普鲁卡因更有可能与这种长寿命的Ca（2+）结合的通道封闭状态相互作用，而不是与通道的其他状态相互作用。使用相同模型的模拟也能够重现通道“随机”和“突发”形式的门控之间的显著Ca（2+）敏感转变，其变化可能解释了在该研究和其他单通道中报告的“换档”行为。
The effects of the Ca(2+)-induced Ca2+ release blocker procaine on individual sarcoplasmic reticulum Ca2+ release channels have been examined in planar lipid bilayers. Procaine did not reduce the single channel conductance nor appreciably shorten the mean open times of the channel; rather, it increased the longest closed time. These results indicated that procaine interacted selectively with a closed state of the channel rather than with an open state. Gating of the sarcoplasmic reticulum Ca2+ release channel was described by a modified scheme of Ashley and Williams (1990. J. Gen. Physiol. 95:981–1005), including an additional long-lived closed state. Computer simulations determined that procaine was more likely to interact with this long-lived Ca(2+)-bound closed state of the channel rather than with other states of the channel. Simulations with the same model were also able to reproduce a prominent Ca(2+)-sensitive transition between "random" and "bursting" forms of gating of the channel, variations of which may account for "gearshift" behavior reported in studies with this and other single channels.