Voltage-dependent calcium channels from brain incorporated into planar lipid bilayers
Voltage-dependent calcium channels from brain incorporated into planar lipid bilayers
复制标题
来自大脑的电压依赖性钙通道并入平面脂质双层
作者：
M. Nelson;R. French;B. Krueger
许多重要的生理过程，包括神经递质释放和肌肉收缩1-3，都受到细胞中 Ca2+ 离子浓度的调节。 Ca2+ 离子通过对 Ca2+、Ba2+ 和 Sr2+ 离子有选择性的电压依赖性通道进入4-14，可以提高细胞质 Ca2+ 的水平。我们测量了通过来自大鼠大脑的单个电压依赖性钙通道的电流，这些钙通道已被纳入平面脂质双层中。通道门控是电压依赖性的：膜去极化增加了通道开放时间并减少了关闭时间。这些通道对二价阳离子的选择性高于对一价离子的选择性。众所周知的钙通道阻滞剂，镧和镉，可产生浓度依赖性的表观单通道电导降低。与预期相反14，通过通道的二价阳离子携带电流的性质不仅影响单通道电导，还影响通道开放时间，其中钡的平均开放时间最短。
Many important physiological processes, including neurotransmitter release and muscle contraction1–3, are regulated by the concentration of Ca2+ ions in the cell. Levels of cytoplasmic Ca2+ can be elevated by the entry of Ca2+ ions through voltage-dependent channels which are selective for Ca2+, Ba2+ and Sr2+ ions4–14. We have measured currents through single, voltage-dependent calcium channels from rat brain that have been incorporated into planar lipid bilayers. Channel gating was voltage-dependent: membrane depolarization increased the channel open times and decreased the closed times. The channels were selective for divalent cations over monovalent ions. The well-known calcium channel blockers, lanthanum and cadmium, produced a concentration-dependent reduction of the apparent single-channel conductance. Contrary to expectations14, the nature of the divalent cation carrying current through the channel affected not only the single-channel conductance, but also the channel open times, with mean open times being shortest for barium.
DOI：
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发表时间：
1983
期刊：
The Journal of biological chemistry
影响因子：
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作者：
Venter,JC;Fraser,CM;Schaber,JS;Jung,CY;Bolger,G;Triggle,DJ
通讯作者：
Triggle,DJ
离子是否参与钙通道的门控？
DOI：
10.1126/science.6289432
发表时间：
1982
期刊：
Science (New York, N.Y.)
影响因子：
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作者：
Saimi,Y;Kung,C
通讯作者：
Kung,C