Broad-Spectrum Antiviral Therapeutics
(A) DRACOs with PTD or TAT tags entered H1-HeLa cells more readily than DRACO without a transduction tag. 400 nM PKR-Apaf DRACO was added to medium for 1 hour, and then cells were trypsinized and washed to remove any DRACO on the cell surface. Cells were lysed and analyzed for DRACO by westerns using anti-His6 antibodies. Lysate from approximately 105 cells was loaded in each lane. A known amount of purified PKR-Apaf DRACO was used as a standard as indicated. (B) DRACOs entered HeLa cells within 10 minutes and reached a maximum after 1.5 hours. 400 nM TAT-PKR-Apaf DRACO was added to medium for the specified time, and then cells were analyzed as in (A). (C) DRACOs persisted within HeLa cells for at least 8 days. 500 nM PTD-PKR-Apaf DRACO was added to cell medium for 1 hour, and then cells were put into DRACO-free medium. After the specified number of days, cells were analyzed as in (A).