Nanolithography of Amyloid Precursor Protein Cleavage with beta-Secretase by Atomic Force Microscopy

Cleavage of the amyloid precursor protein (APP) by secretases is critical in neural cell processes including the pathway for neural cell proliferation and that underlying the pathogenesis of Alzheimer's disease (AD). Understanding the mechanism of APP cleavage and development of a convenient tool for the accurate evaluation of APP cleavage intensity by secretases are very important in the development of new AD therapeutic targets. In this study, we developed a sophisticated technology to evaluate the APP cleavage mechanism at the nano-molecular level by atomic force microscopic (AFM) nanolithography. APP was modified on a glass substrate; nanolithography of APP cleavage by beta-secretase-modified AFM probe scanning was achieved. APP cleavage was verified by the AFM imaging and the fluorescent immunostaining. The present method will be very useful in understanding the molecular level of the APP cleavage mechanism by beta-secretase in vitro; this method will facilitate inhibitor screening for the therapeutic target of AD.