Fig. 4

Effect on local HDX upon dopamine binding to dDAT. a Chart showing differences in the average deuterium uptake (ΔHDX) between the Na⁺-bound state and the Na⁺- and DA-bound state for the 85 identified peptides at the five sampled time points (orange—0.25 min; red—1 min; cyan—10 min; blue—1 h; black—8 h). The individual dDAT peptides are arranged along the x-axis starting from the N-terminal and ending on the C-terminal. The peptide number refers to Supplementary Table 2. Positive and negative values indicate reduced and increased HDX, respectively, upon binding of DA. Values represent means of either three (Na⁺ + DA state) or six (Na⁺ state) independent measurements. Structural motifs in dDAT are marked along the x-axis together with regions showing correlated exchange kinetics (EX1) in at least one of the two states. The dotted lines (±0.20 D) mark a threshold value for significant differences in HDX corresponding to the 95% confidence interval, calculated from the pooled standard deviations for all time points. b, c Regions showing significant differences (Student’s t-test p-value < 0.01) in deuterium uptake between the Na⁺-bound state and the Na⁺- and DA-bound state for at least two consecutive time points are mapped onto the crystal structure (b) (PDB ID: 4XP1) and snake diagram (c) of dDAT. Regions are colored red and blue to indicate dDAT segments becoming destabilized (increased HDX) or stabilized (decreased HDX), respectively, upon binding of DA. Regions colored light gray displayed unchanged HDX while regions in dark gray were uncovered by peptide sequences. Wild-type dDAT regions including part of EL2 (residue 162–202) and the N- and C-termini (residue 1–24 and 601–645, respectively) are only marked on the snake diagram in c as they were not resolved in the crystal structure (b) or were truncated in the construct used for crystallization. Source data are provided as a Source Data file