Fig. 2
From: A single NaK channel conformation is not enough for non-selective ion conduction
K+/Rb+-favored and ion-free state observed in ssNMR. Comparison of 2D NCA (a, c) and NCO (b, d) spectral closeups of SF residues in sample A (<1 µM ions; gray), B (50 mM Na+; blue), C (50 mM K+; red), and D (50 mM Rb+; purple)
