Figure 2

DesBP weakly interacts with monomeric Aβ42. (a) ¹H-¹⁵N-HSQC spectrum of 15 μM ¹⁵N-labeled Aβ42 monomers in the absence (blue) and presence (red) of 240 μM DesBP. 32 scans were taken for each spectra at 5 °C on a 500 MHz NMR. (b) Chemical shift differences (bar graph) and normalised intensity (dotted line) of Aβ42 in the presence of DesBP suggest minimal interaction of DesBP with monomeric Aβ42. (c) BLI binding assay showing the dynamic association and dissociation processes between the Aβ42 and DesBP at the concentrations of 50 μM (black) and 100 μM (blue). The dashed line represents the time at which the BLI sensor was transferred to the control buffer. The kinetic profile of association and dissociation were well fitted by single-exponential functions (red line). The dissociation constant was estimated to be 640 ± 260 μM (association rate k_a = 0.102 ± 0.003 M^-1 s⁻¹, dissociation rate k_d = 0.060 ± 0.002 s⁻¹).