Chung S H, Kuyucak S
Department of Chemistry, Australian National University, Canberra.
Neurosci Lett. 1995 Mar 10;187(3):181-4. doi: 10.1016/0304-3940(95)11369-8.
Single channel currents activated by N-methyl-D-aspartate (NMDA) were recorded in inside-out membrane patches from hippocampal pyramidal cells. The effects of temperature on the conductance level and the kinetics of single channels were accurately determined by using a digital signal processing technique based on hidden Markov models. With increasing temperature, the probability of the channel being in the open state increases steeply, as does the amplitude of channel currents. The proportional change in channel conductance with increasing temperature is greater than the corresponding change in bulk conductivity of 150 mM electrolyte solutions. From the temperature dependence of channel conductance and kinetics, we derived several thermodynamical properties of the NMDA-receptor activated channel. Among these are the height of the energy barrier V presented to an ion traversing the pore, the activation energy Ea and the enthalpy delta H of the channel.
在海马锥体细胞的内向外膜片中记录了由N-甲基-D-天冬氨酸（NMDA）激活的单通道电流。通过使用基于隐马尔可夫模型的数字信号处理技术，精确测定了温度对单通道电导水平和动力学的影响。随着温度升高，通道处于开放状态的概率急剧增加，通道电流的幅度也随之增加。通道电导随温度升高的比例变化大于150 mM电解质溶液本体电导率的相应变化。根据通道电导和动力学的温度依赖性，我们推导了NMDA受体激活通道的几个热力学性质。其中包括离子穿越孔道时所面临的能垒V的高度、通道的活化能Ea和焓变ΔH。
