Figure 1. Purified pdg proteins retain activity in vitro after addition of NLS and TAT peptides to enhance cellular delivery.
a. Human keratinocytes and skin fibroblasts were transfected with expression vectors for GFP, pdg-GFP, or pdg-NLS-GFP and GFP localization was visualized by direct immunofluoresence microscopy. DAPI (blue) indicates nuclei. Scale bar = 10 μm. b. Coomassie blue stained 15% SDS-PAGE gel showing the purity of pdg, pdg-NLS, or pdg-NLS-TAT enzymes after protein expression and purification. c. Plasmid nicking assay on UVC-irradiated DNA showing in vitro activity of the purified pdg enzymes after addition of NLS and TAT peptides. I = covalently closed circular, supercoiled plasmid DNA; II = nicked duplex DNA; III = linear duplex DNA; (-) = plasmid not treated with a pdg.