Differently selected D-enantiomeric peptides act on different Abeta species.

Aging is the most significant risk factor for Alzheimer disease (AD). The pathological hallmark of AD is the accumulation of aggregated amyloid-beta (Abeta) forms and insoluble plaques, mainly composed of Abeta, in the brain of the patient. Recently, we reported on the selection of D-enantiomeric, Abeta-binding peptides D1 and D3. D1 was selected against aggregated Abeta species to address diagnosis by in vivo imaging of amyloid plaques, whereas D3 was selected using low-molecular-weight Abeta species, therefore addressing therapeutical studies. Here, we use a surface plasmon resonance method to confirm that both peptides show the desired binding specificities.