Properties of single potassium channels in vesicles formed from the sarcolemma of frog skeletal muscle.
Properties of single potassium channels in vesicles formed from the sarcolemma of frog skeletal muscle.
复制标题
青蛙骨骼肌肌膜形成的囊泡中单一钾通道的特性。
DOI：
10.1113/jphysiol.1985.sp015749
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发表时间：
1985
期刊：
影响因子：
--
通讯作者：
T. A. Ward
中科院分区：
文献类型：
--
作者：
N. Standen;P. Stanfield;T. A. Ward
采用膜片钳技术研究了蛙骨骼肌膜大泡中的单位延迟整流钾通道。通道被去极化脉冲激活。单通道电导在生理[K+]o中约为15 pS，并且通过将[K+]o升高至120 mM而加倍。TEA+引起单通道电流的明显降低，我们将其归因于快速阻断。当以短暂的间隔重复去极化时，有和没有通道开口的记录是非随机排序的，这为可能是失活的缓慢过程提供了证据。在多通道贴片中，方差与平均电流之间的关系、二项式分析以及单次和双次开口的时间分布都与通道独立行为一致。开放时间呈指数分布。平均开放时间，τ 0，增加与去极化，使1/τ 0是电压的指数函数。第一潜伏期直方图峰值时间晚于零，不能拟合的方案只有两个封闭的状态。通道开放发生在爆发和关闭时间直方图可以拟合的三个指数之和。我们的结果意味着一个计划，至少有三个封闭的状态，开放和失活状态。
The patch‐clamp method was used to study unitary delayed rectifier K+ channels in large vesicles formed from the membrane of frog skeletal muscle. Channels were activated by depolarizing pulses. Single‐channel conductance was about 15 pS in physiological [K+]o and was doubled by raising [K+]o to 120 mM. TEA+ caused an apparent reduction in single‐channel current, which we attribute to a rapid block. When depolarizations were repeated at brief intervals, records with and without channel openings were ordered non‐randomly, providing evidence for a slow process which was probably inactivation. In multichannel patches the relation between variance and mean current, binomial analysis, and the distribution of times for single and double openings were all consistent with channels behaving independently. Open times were distributed exponentially. Mean open time, tau o, increased with depolarization so that 1/tau o was an exponential function of voltage. First latency histograms peaked at times later than zero and could not be fitted by a scheme having only two closed states. Channel openings occurred in bursts and closed time histograms could be fitted by the sum of three exponentials. Our results imply a scheme with at least three closed states, an open and an inactivated state.
影响因子：
3.4
作者：
HORN, R;LANGE, K
通讯作者：
LANGE, K