Figure_4.tif (2.02 MB)
Download file

Divalent ion inhibition in mutants of the nonregulatory sites Spore and Sin.

Download (0 kB)
figure
posted on 20.11.2012, 00:11 by Iwan Zimmermann, Alessandro Marabelli, Carlo Bertozzi, Lucia G. Sivilotti, Raimund Dutzler

Dose–response relationships of the ELIC point mutant R91A (A) activated by cysteamine at different concentrations of Ca2+. (B) Anomalous difference electron density (calculated at 5 Å and contoured at 5 σ) from data of the mutant N251A in complex with Ba2+ superimposed on a model of ELIC in ribbon representation. Ion-binding sites are indicated. Dose–response relationships of the ELIC point mutants N251A (C), S84A (D), and D86A (E) activated by cysteamine at different concentrations of Ca2+. The data presented in panels (A), (B), (D), and (E) are averages from at least 5 oocytes; errors are SD. The solid lines show fits to a Hill equation. Currents were recorded at −40 mV. A dose–response curve of WT in the absence of Ca2+ (dashed line) is shown for comparison. (F) Schild plots quantifying the inhibition of ELIC mutants by Ca2+. EC50 values were obtained from fits to data shown in panels (A), (B), (D), and (E). Potencies of the antagonists (pA values) were obtained by linear regression; the intersection with the x-axis is indicated (•). WT is shown for comparison.

History

Usage metrics

Licence

Exports