Development of DNA Aptamer as a β-Amyloid Aggregation Inhibitor.

Developing a strategy of modulating β-amyloid (Aβ) aggregation with low cost, easy synthesis, high efficiency, and biosafety is significant and a challenge for Alzheimer's disease (AD) therapy. Herein, DNA aptamer (Aβ-Apt) against Aβ 42 obtained by in vitro selection was developed as a potent inhibitor of Aβ 42 aggregation for the first time. Indeed, the Aβ 42 monomer fibrillation was inhibited completely by Aβ-Apt. Notably, the inhibition effect of Aβ-Apt on the Aβ 42 oligomer aggregation was more obvious than that on the Aβ 42 monomer aggregation. It was presumed that the distinguishing effect may be attributed to different binding behaviors of Aβ-Apt with Aβ 42 monomer and Aβ 42 oligomer. Surface plasmon resonance analysis demonstrated that Aβ-Apt specifically recognized Aβ 42 monomer and Aβ 42 oligomer. Furthermore, the binding affinity of Aβ-Apt with Aβ 42 oligomer was larger than that of Aβ-Apt with Aβ 42 monomer. This work provided a promising platform with high efficiency for manipulating Aβ aggregation.