Xenbase Image ID: 120862
Figure 2. Effects of ATP on wtKir6.2ΔC26 and Kir6.2ΔC26-C166S macroscopic currents. (A) Macroscopic currents recorded from an inside-out patch on an oocyte injected with mRNA encoding Kir6.2ΔC26-C166S. ATP was added to the internal solution as indicated by the bar. Currents were elicited in response to a series of voltage ramps from −110 to +100 mV. The patch was excised at the point indicated by the arrow. The dashed line indicates the zero current level. (B) Macroscopic wtKir6.2ΔC26 (i) or Kir6.2ΔC26-C166S (ii) currents. ATP was added to the internal solution as indicated by the bar. Currents were elicited in response to a series of voltage ramps from −110 to +100 mV. The dashed line indicates the zero current level. (C) Mean ATP dose–response relationships for wtKir6.2ΔC26 currents (○, n = 7) and Kir6.2ΔC26-C166S currents (•, n = 10). Test solutions were alternated with control solutions and the slope conductance (G) is expressed as a fraction of the mean (Gc) of that obtained in control solution before and after exposure to ATP. Conductance was measured between −20 and −100 mV and is the mean of five voltage ramps. The dotted and solid lines are the best fit of the data to the Hill equation (Eq. 1) using the mean values for Ki and h given in the text. The dashed line has been fit to the Kir6.2ΔC26-C166S data using a modified form of the Hill equation (Eq. 2) in which it is not assumed that ATP block at saturating concentrations is complete. Mean values for Ki and h are given in the text.
Image published in: Trapp S et al. (1998)
Image downloaded from an Open Access article in PubMed Central. Image reproduced on Xenbase with permission of the publisher and the copyright holder.
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