Calcium and voltage dependence of single Ca2+-activated K+ channels from cultured hippocampal neurons of rat.
Calcium and voltage dependence of single Ca2+-activated K+ channels from cultured hippocampal neurons of rat.
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来自培养的大鼠海马神经元的单个 Ca2 激活的 K 通道的钙和电压依赖性。
DOI：
10.1016/0005-2736(88)90373-2
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发表时间：
1988
期刊：
影响因子：
--
通讯作者：
Franciolini,F
中科院分区：
文献类型：
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作者：
Franciolini,F
在培养的大鼠海马神经元上，在单通道水平上研究了钙激活的钾通道（K（Ca））的钙依赖性和电压依赖性。K（Ca）通道具有约。220 pS电导在对称的150 mM K+，并门控电压和Ca2+离子。对于在内膜表面处的固定的Ca 2+浓度，[Ca]i，通道开放概率Po对于膜电位的14mV正变化增加e倍。在固定的膜电位（0 mV）下，在[Ca]i= 10− 6 M时首次观察到通道活性，并随着Ca2+浓度的增加而增加，接近吸附等温线，幂为1.4。半激活（Po= 0.5）通道所需的[Ca] i为4 · 10−6M。与其他制备物相比，本文报道的来自海马神经元的K（Ca）通道显示出最低的Ca 2+敏感性和最高的电压敏感性。这些发现是从进化的角度来解释的。
Calcium and voltage dependence of the Ca2+-activated K+channel, K(Ca), was studied at the single-channel level in cultured hippocampal neurons from rat. The K(Ca) channel has approx. 220 pS conductance in symmetrical 150 mM K+, and is gated both by voltage and by Ca2+ions. For a fixed Ca2+concentration at the inner membrane surface, [Ca]i, channel open probability,Po, increases e-fold for 14 mV positive change in membrane potential. At a fixed membrane potential (0 mV), channel activity is first observed at [Ca]i= 10−6M, and increases with Ca2+concentration approximating an adsorption isotherm with power 1.4. The [Ca]irequired to half activate (Po= 0.5) the channel is 4 · 10−6M. When compared to other preparations, the K(Ca) channel from hippocampal neurons reported here shows the lowest Ca2+sensitivity and the highest voltage sensitivity. These findings are interpreted in evolutionary terms.