FIG. 4.

Mass spectroscopy (A) and gel retardation analysis (B) of PNA_TAR-S-S-penetratin isolated from mouse organs. Following intraperitoneal (IP) injection of the conjugate, mice were euthanized at different times, and the conjugate accumulated in kidney and liver tissue was isolated. Mass spectrometry analysis of the isolated compound from kidney following 6 h of IP administration (top panel A) was done on an Applied Biosystems 4700 Proteomics Analyzer 7000. For gel retardation (bottom panel B), 5′-³²P-labeled 82-mer TAR-DNA (5 nM) was incubated with the isolated PNA_TAR conjugate in the binding buffer (50 mM Tris.HCl, pH 7.8, and 5 mM MgCl₂) for 30 min at room temperature. Gel loading dye containing 0.25% bromophenol blue and 30% glycerol was added to it and loaded on a native 6% polyacrylamide gel. The gel was run for 3 h at 150V in 1X Tris-borate-EDTA buffer, dried, and subjected to Phosphor-Imager analysis (Molecular Dynamics).