Adenovirus-mediated PPT1 in fibroblasts and neurons. (A) Adenovirus-mediated PPT1 was expressed in mouse fibroblasts and neurons. Cell lysates (5 μg of total protein) were treated with PNGaseF to remove the N-glycans from the polypeptides. Proteins were separated with SDS-PAGE and analyzed by immunoblotting. Antibody internalization assay was performed in adenovirus infected mouse fibroblasts (B) and neurons (D) with both AGA and PPT1 (green). Double staining with the lysosomal marker LAMP-1 (red) is shown for internalized PPT1 in fibroblasts (C). Co-localization is shown in yellow.