Removal of sodium channel inactivation in squid axon by the oxidant chloramine-T
Removal of sodium channel inactivation in squid axon by the oxidant chloramine-T
复制标题
氧化剂氯胺-T消除鱿鱼轴突钠通道失活
DOI：
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发表时间：
1985
期刊：
影响因子：
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通讯作者：
D. Eaton
中科院分区：
文献类型：
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作者：
G. Wang;M. Brodwick;D. Eaton
我们研究了一种温和的氧化剂氯胺- t （CT）在电压箝位条件下对鱿鱼轴突钠钾电流的影响。中性ph下CT可完全去除鱿鱼巨轴突钠通道失活，CT内外处理均有效。CT显然以不可逆、全有或全无的方式消除失活。从钠离子电流峰值的电压依赖性、钠离子电流上升相和尾电流复极后的时间过程来看，对钠离子通道的激活过程影响不大。CT去除失活是ph依赖性的；较高的pH降低了去除率，而较低的pH则提高了去除率。内部焦亚硫酸盐是一种强还原剂，它不能防止外部CT的失活，也不能防止内部CT的应用。CT稍微降低了钾电流的峰值，但对其动力学没有明显的影响。我们的研究结果表明，中性形式的CT修饰嵌入的蛋氨酸残基，参与钠通道失活。
We have investigated the effects of a mild oxidant, chloramine-T(CT), on the sodium and potassium currents of squid axons under voltage-clamp conditions. Sodium channel inactivation of squid giant axons can be completely removed by CT at neutral pH. Internal and external CT treatment are both effective. CT apparently removes inactivation in an irreversible, all-or-none manner. The activation process of sodium channels is little affected, as judged from the voltage dependence of peak sodium currents, the rising phase of sodium currents, and the time course of tail currents following the repolarization. The removal of inactivation by CT is pH-dependent; higher pH decreases the removal rate, whereas lower pH increases it. Internal metabisulfite, a strong reductant, does not protect inactivation from the action of external CT, nor does external metabisulfite protect from internal CT application. CT slightly depresses the peak potassium currents at comparable concentrations but has no apparent effects on their kinetics. Our results suggest that the neutral form of CT modifies an embedded methionine residue that is involved in sodium channel inactivation.
cAMP 依赖性蛋白激酶选择性磷酸化钠通道的 α 亚基。
DOI：
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发表时间：
1982
期刊：
The Journal of biological chemistry
影响因子：
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作者：
Costa,MR;Casnellie,JE;Catterall,WA
通讯作者：
Catterall,WA