Misler S, Falke L C, Gillis K, McDaniel M L
Proc Natl Acad Sci U S A. 1986 Sep;83(18):7119-23. doi: 10.1073/pnas.83.18.7119.
In B cells from dispersed rat islet of Langerhans we have identified an inward rectifying voltage-independent K+ channel whose behavior parallels the metabolically regulated potassium permeability (PK) found in tracer flux and microelectrode recording studies. In cell-attached patches of membrane, the channel is closed when any one of several substrates (glucose, mannose, leucine, or glyceraldehyde) is added to the cell's bathing solution but is reopened on addition of an appropriate metabolic inhibitor, which prevents utilization of that substrate. In inside-out excised patches, a K+ channel with nearly identical kinetic features is closed by addition of micromolar concentrations of ATP to the "cytoplasmic" solution. The ATP sensitivity of channel activity is modified by addition of ADP, suggesting competition at a nucleotide binding site. These results suggest the presence of a metabolically regulated K+ channel gated by intracellular concentrations of ATP or the ratio of ATP/ADP concentrations.
在分散的大鼠胰岛B细胞中，我们鉴定出一种内向整流性非电压依赖性钾通道，其行为与示踪剂通量和微电极记录研究中发现的代谢调节钾通透性（PK）相似。在细胞膜的细胞贴附片上，当向细胞的浴液中添加几种底物（葡萄糖、甘露糖、亮氨酸或甘油醛）中的任何一种时，通道关闭，但添加适当的代谢抑制剂后通道重新开放，该抑制剂可阻止该底物的利用。在内外膜外翻的膜片上，向“细胞质”溶液中添加微摩尔浓度的ATP可关闭具有几乎相同动力学特征的钾通道。添加ADP可改变通道活性的ATP敏感性，表明在核苷酸结合位点存在竞争。这些结果表明存在一种由细胞内ATP浓度或ATP/ADP浓度比值门控的代谢调节钾通道。
