Calcium currents in the A7r5 smooth muscle-derived cell line. Increase in current and selective removal of voltage-dependent inactivation by intracellular trypsin.
Calcium currents in the A7r5 smooth muscle-derived cell line. Increase in current and selective removal of voltage-dependent inactivation by intracellular trypsin.
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DOI：
10.1085/jgp.98.6.1127
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发表时间：
1991-12
期刊：
影响因子：
--
通讯作者：
Scarpa A
中科院分区：
文献类型：
--
作者：
Obejero-Paz CA;Jones SW;Scarpa A
We studied the effects of trypsin on L-type calcium current in the A7r5 smooth muscle cell line. Intracellular dialysis with trypsin increased the whole-cell current up to fivefold. The effect was concentration dependent, and was prevented by soybean trypsin inhibitor. Ensemble analysis indicated an increase in the number of functional channels, and possibly a smaller increase in the open probability, with no change in the single channel current. The shape of the current-voltage curve was unaffected. Trypsin also nearly eliminated inactivation of currents carried by Ba2+, but had little or no effect on the rapid inactivation process in Ca2+, This indicates that trypsin removes voltage-dependent but not Ca(2+)-dependent inactivation, suggesting the existence of distinct protein domains for these two mechanisms of calcium channel inactivation.
