Fig. 2.
Surface plasmon resonance analysis of the binding of trx-eAPP290–624 to trx-ApoE4 (A), trx-ApoE3 (B), or thioredoxin (trx) (C). The sensograms are shown in gray, and the fits are shown in red. The arrows mark the direction of increasing concentration. The effective KD (KD, eff) was calculated with a single site binding model (D). Competition between disulfiram and ApoE4 for the ectodomain of APP was demonstrated by preincubating trx-ApoE4 with varying concentrations of disulfiram and then analyzing the binding of the mixture to a flow cell treated with biotinylated MBP-eAPP19–624 (E). At saturating concentrations of disulfiram (5 µM, ∼10 times the KD of disulfiram for APP), the binding of ApoE4 is reduced by 50% (Fig. S3).