Fig. 4.

NMR analyses of the GIRK chimera. Overlay of ¹H–¹³C HMQC spectra of {u-[²H]; Ileδ1, Metε-[¹³CH₃]} GIRK_CP (black) and {u-[²H]; Ileδ1, Metε-[¹³CH₃]} GIRK chimera (purple). The signals from the TM region are labeled with asterisks, and the signals with chemical shift differences are labeled. The close-up views of the ¹H–¹³C HMQC signals of Ile270 (A) and Ile298 (B) are shown. Cross marks denote the chemical shifts of the open and closed states, which were calculated using the exchange parameters from the MQ CPMG RD and methyl-HDR analyses.