Figure 3
From: Structural changes in the cytoplasmic pore of the Kir1.1 channel during pHi-gating probed by FRET
Effects of the pH i on the FRET efficiency. A. Bright field image of a pipette containing a oocyte membrane patch (right panel) and currents recorded at +50 mV from a holding potential of -80 mV at pHi 7.4 (left panel) or pHi 10.0 (center panel). B. Fluorescence images acquired with the ECFP, EYFP, and FRET filter cubes at the indicated pHi. Fluorescence intensities were measured in the area of the membrane patch indicated by the dotted circle. Scale bar, 20 μm. C. Averaged FRET efficiency of ECFP-S219R-EYFP in the open state (pHi 10.0, n = 6) and closed state (7.4, n = 8) and FRET efficiency of ECFP + EYFP. n = 6 – 8. *** indicates p < 0.005 compared to the pHi 10.0 value.