Figure 1.

Copper-mediated TTR-Aβ interactions. (A) Overall scenario for bio-layer interferometry (BLI) using a streptavidin (SA) coated optical sensor. Biotinylated Aβ(1–28) was loaded on the BLI bio-sensor tip surface (100 nM). A single biotin is present at the N-terminal position of the Aβ peptide. The tip was then plunged in solutions containing TTR and copper at different concentrations to analyze the interactions. (B) Sensorgram curves colored according to TTR concentration (0 μM–1.56 μM). Inset on the right, represents the specific time dependent binding of TTR on immobilized Aβ(1–28) in the presence of 1% of BSA at pH 5.5, corresponding to the total binding for each TTR concentration minus the nonspecific binding found without TTR in presence of 1.56 mM Aβ and 1% of BSA. (C) Time dependent binding of TTR on immobilized Aβ peptide at a concentration of 1.56 μM of TTR in presence of various CuCl₂ concentrations at pH 5.5 with 1% of BSA without CuCl₂ during the dissociation. The sensorgram curves are colored according to CuCl₂ concentration (0 mM–12.5 mM). Inset on the right, shows the dissociation step using buffer added by various CuCl₂ concentrations (0 to 12.5 mM).