High-Resolution AFM Imaging of Prestin Purified and Reconstituted into an Artificial Lipid Bilayer

In the present study, purified prestin was observed by atomic force microscopy (AFM). First, the lipid bilayer was formed on a freshly cleaved mica disk by the deposition of small unilamellar lipid vesicles. Such bilayer was destabilized by incubation with a detergent. Afterward, purified prestin was added to the destabilized lipid bilayer. Finally, a high resolution image of the prestin-reconstituted lipid bilayer was acquired by AFM. As a result, densely embedded prestin with a diameter of 11.0 +/- 1.3 nm was visualized. From the obtained image, cytoplasmic side of prestin was found to form a ring-like structure with four peaks and one valley at its center.