Additional file 4: Figure S4. of The human Na+/H+ exchanger 1 is a membrane scaffold protein for extracellular signal-regulated kinase 2

Affinity of the hNHE1cdt to iaERK2. (a) Peak behaviour for residues of the D3-domain, the F1-site, and the F2-site upon titration with iaERK2. Q815 is shown as a negative example. (b) Plotted peak intensity changes (top) and chemical shifts (bottom) for residues of the D3-domain, the F1-site, and the F2-site upon titration with iaERK2. The D3-domain has the highest apparent affinity, and single residue non-linear least squares fittings reveals a Kd app of 35 ± 13 μM, 11 ± 2 μM, and 8 ± 1 μM for L684, T685, and V686, respectively. Global fitting results in a Kd app of 16 ± 2 μM for the hNHE1 D3-domain. The affinities for the F1- and the F2-sites are lower (>50 μM). (PDF 304 kb)