Kienker P
Department of Biophysics, Johns Hopkins University, Baltimore, Maryland 21218.
Proc R Soc Lond B Biol Sci. 1989 Apr 22;236(1284):269-309. doi: 10.1098/rspb.1989.0024.
One cannot always distinguish different Markov models of ion-channel kinetics solely on the basis of steady-state kinetic data. If two generator (or transition) matrices are related by a similarity transformation that does not combine states with different conductances, then the models described by these generator matrices have the same observable steady-state statistics. This result suggests a procedure for expressing the model in a unique form, and sometimes reducing the number of parameters in a model. I apply the similarity transformation procedure to a number of simple models. When a model specifies the dependence of the rates of transition on an experimentally variable parameter such as the concentration of a ligand or the membrane potential, the class of equivalent models may be further restricted, but a model is not always uniquely determined even under these conditions. Voltage-step experiments produce non-stationary data that can also be used to distinguish models.
人们不能总是仅根据稳态动力学数据来区分离子通道动力学的不同马尔可夫模型。如果两个生成器（或转移）矩阵通过不将具有不同电导的状态组合在一起的相似变换相关联，那么由这些生成器矩阵描述的模型具有相同的可观测稳态统计量。这一结果提示了一种将模型以唯一形式表示的方法，有时还能减少模型中的参数数量。我将相似变换方法应用于一些简单模型。当一个模型指定转变速率对诸如配体浓度或膜电位等实验可变参数的依赖性时，等效模型的类别可能会进一步受限，但即使在这些条件下，一个模型也并非总是能被唯一确定。电压阶跃实验产生的非平稳数据也可用于区分模型。
