Blatz A L, Magleby K L
Biophys J. 1986 May;49(5):967-80. doi: 10.1016/S0006-3495(86)83725-0.
Interpretation of currents recorded from single ion channels in cellular membranes or lipid bilayers is complicated by the necessarily limited time resolution of the recording and detection systems. All intervals less than a certain duration, depending on the frequency response of the system, are not detected. Such missed events produce increases in the durations of observed open and shut intervals. In order to obtain the true kinetic scheme and rate constants underlying the observed activity, it is necessary to take into account missed events. We develop methods to correct for missed events for models with two or more states, including models with multiple open and shut states, compound states, and loops. Our methods can be used in a forward direction to predict observed distributions of open and shut intervals for a given kinetic scheme and time resolution. They can also be used in a backwards direction with iterative methods to determine rate constants consistent with the observed distributions. While a given kinetic scheme with rate constants predicts unique observed distributions of open and shut intervals, rate constants determined from observed distributions are not necessarily unique. Using these correction methods, we examine the effects of missed events for a five-state model consistent with some properties of large conductance Ca-activated K channels.
对细胞膜或脂质双分子层中单个离子通道记录的电流进行解读很复杂，这是因为记录和检测系统的时间分辨率必然有限。所有小于特定持续时间（取决于系统的频率响应）的间隔都无法检测到。这些未检测到的事件会导致观察到的开放和关闭间隔持续时间增加。为了获得观察到的活动背后的真正动力学机制和速率常数，有必要考虑未检测到的事件。我们开发了针对具有两个或更多状态的模型（包括具有多个开放和关闭状态、复合状态和环的模型）校正未检测到事件的方法。我们的方法可以向前用于预测给定动力学机制和时间分辨率下观察到的开放和关闭间隔分布。它们也可以与迭代方法一起向后用于确定与观察到的分布一致的速率常数。虽然具有速率常数的给定动力学机制可预测开放和关闭间隔的唯一观察到的分布，但从观察到的分布确定的速率常数不一定是唯一的。使用这些校正方法，我们研究了与大电导钙激活钾通道的某些特性一致的五态模型中未检测到事件的影响。
