XB-IMG-159282
Xenbase Image ID: 159282
|
Figure 2. Longitudinal Φ value gradient extends from catalytic site 2 to the extracellular surface.(A, F) Inward unitary currents of the cut-ΔR(D1370N) CFTR background construct, and of channels bearing mutations at either position 555 (A) or position 117 (F), in the same background. Letters to the left of the traces indicate the amino acid present in the target position; the native residue is marked by red. Currents were recorded in symmetrical 140 mM Cl-, at −80 mV in (A) but at −100 mV in (F); dashes on the left mark zero-current level. (B–D) and (G–I), Mean burst (B, G, τb) and interburst (C, H, τib) durations and open probabilities (D, I, Po) of the constructs in A and F, respectively. Red horizontal lines highlight the respective control values of the background construct which is identified by the red letter representing the native target residue. All data are shown as mean ± SEM (n = 6 for data in B–D, n = 5–7 for data in G–I). (E, J) Brønsted plots for position 555 (E) and 117 (J). Red symbol and letter identifies the background construct. Solid lines are linear regression fits with slope Φ indicated.Figure 2—figure supplement 1. All tested constructs are saturated by 10 mM ATP.(A) Representative macroscopic inward current of CFTR channels bearing mutation T460A in the cut-ΔR(D1370N) background, recorded in an inside-out patch at −80 mV in response to alternating exposures to 3 and 10 mM MgATP (green bars). (B) Fractional macroscopic currents in 3 mM ATP, normalized to the mean of the currents in the presence of bracketing applications of 10 mM ATP, for cut-ΔR(D1370N) channels harbouring the indicated amino-acid substitutions (letters) at the respective target positions (numbers above groups of bars). Bars are grouped by target position, color coding as in Figures 1 and 6. All data are shown as mean ± SEM (n = 3–11). For the background construct I3 ATP / I10 ATP=1.00 ± 0.07 (n = 6) (cf., Sorum et al., 2015). Image published in: Sorum B et al. (2017) © 2017, Sorum et al. 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 license Larger Image Printer Friendly View |