Büsselberg D, Evans M L, Rahmann H, Carpenter D O
Wadsworth Center for Laboratories and Research, New York State Department of Health, Albany 12209-0509.
Neurosci Lett. 1990 Sep 4;117(1-2):117-22. doi: 10.1016/0304-3940(90)90129-w.
We have investigated the effect of Zn2+ on voltage-activated calcium currents of Aplysia neurons, using conventional two-electrode voltage-clamp techniques. The peak of these currents was reversibly reduced by Zn2+ (50% reduction at 3.75 mM; total block at 20 mM), while the current-voltage relation and the activation and inactivation curves were shifted to depolarized voltages. The effects of Zn2+ were concentration-dependent. The Hill coefficient was 1.62. The high concentrations required, the shift of the current-voltage relation and the effects on activation and inactivation are best explained by a charge-screening effect combined with a specific binding site for Zn2+ near the entrance of the channel.
我们使用传统的双电极电压钳技术，研究了Zn2+对海兔神经元电压激活钙电流的影响。这些电流的峰值被Zn2+可逆性降低（在3.75 mM时降低50%；在20 mM时完全阻断），而电流-电压关系以及激活和失活曲线则向去极化电压方向移动。Zn2+的作用呈浓度依赖性。希尔系数为1.62。所需的高浓度、电流-电压关系的移动以及对激活和失活的影响，最好用电荷筛选效应结合通道入口附近Zn2+的特异性结合位点来解释。
