Inhibition of ATP-regulated K(+)-channels by a photoactivatable ATP-analogue in mouse pancreatic beta-cells.
Inhibition of ATP-regulated K(+)-channels by a photoactivatable ATP-analogue in mouse pancreatic beta-cells.
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小鼠胰腺 β 细胞中光活化 ATP 类似物对 ATP 调节的 K( ) 通道的抑制。
DOI：
10.1016/s0167-4889(97)90011-2
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发表时间：
1991
期刊：
影响因子：
--
通讯作者：
P. Rorsman
中科院分区：
文献类型：
--
作者：
C. Ammälä;K. Bokvist;S. Galt;P. Rorsman
应用膜片钳技术的内面向外膜片钳构型，研究了一种光活化的（DMNPE笼状）ATP类似物对小鼠胰腺β细胞ATP调节的K+通道（KATP通道）的影响。笼状前体导致通道活性的浓度依赖性降低，aKi为17 μM;与标准Mg-ATP获得的11 μM相似。前体和ATP之间的阻断能力的微小差异可能是为什么在笼状分子的光解和ATP的释放后没有观察到通道活性变化的原因。这表明，参与KATP通道阻断反应的ATP分子的一部分在DMNPE笼状ATP中没有得到充分的保护，使得该化合物不适合用于研究ATP诱导的KATP通道抑制的快速动力学。
The effects of a photoactivatable (DMNPE-caged) ATP-analogue on ATP-regulated K+-channels (KATP-channel) in mouse pancreatic β-cells were investigated using the inside-out patch configuration of the patch-clamp technique. The caged precursor caused a concentration-dependent reduction of channel activity with aKiof 17 μM; similar to the 11 μM obtained for standard Mg-ATP. The small difference in the blocking capacity between the precursor and ATP is probably the reason why no change in channel activity was observed upon photolysis of the caged molecule and liberation of ATP. It is suggested that the part of the ATP molecule involved in the blocking reaction of the KATP-channel is not sufficiently protected in DMNPE-caged ATP making this compound unsuitable for studying the rapid kinetics of ATP-induced KATP-channel inhibition.