Xenbase Image ID: 124586

Figure 4. Kinetics of depolarization-induced recovery from CNGA1 block by extracellular PhTx. (A) Current transient elicited by stepping the membrane voltage from −200 to −50 mV in the presence of 0.1 µM of extracellular PhTx. The superimposed curve is a single-exponential fit. (B) Natural logarithm of the reciprocal of the time constant (mean ± SEM; n = 4–6) for channel unblock (1/τoff, an estimate of the apparent off-rate constant koff) at four voltages, obtained from fits as shown in A, is plotted against the concentration of extracellular PhTx. Lines through the data represent averages over the three concentrations tested at each voltage. (C) Natural logarithm of koff from B is plotted against membrane voltage. The plot is fitted with the equation ln koff = ln koff (0 mV) + zoffVF/RT, yielding koff (0 mV) = 9.65 ± 0.35 × 103 s−1 and zoff = 1.31 ± 0.02. Image published in: Martínez-François JR and Lu Z (2010) © 2010 Martínez-François and Lu. This image is reproduced with permission of the journal and the copyright holder. This is an open-access article distributed under the terms of the Creative Commons Attribution-NonCommercial-ShareAlike license Larger Image Printer Friendly View

Return to previous page