Structure-activity relationship analysis identifies N-alkylated tails as important for function. (A) The importance of the tail group in the activity of the alkovirs was tested by modification of the tail length in N-nonyl-DGJ. Briefly, Hep G2 2.215 cells were either left untreated (lane 1) or treated with 3TC at 1.0 μM (lane 2), N-nonyl-DGJ at 20 μM (lane 3), N-septyl-DGJ at 20 μM (lane 4), N-septyl-DGJ at 2 μM (lane 4), N-octyl-DGJ at 20 μM (lane 6), or N-octyl-DGJ at 2 μM (lane 7) for 7 days, and the amount of virus was determined in each culture medium by Southern blot hybridization. (B) Modification of the tail with an oxygen species can eliminate activity. Blots show the amount of HBV DNA secreted from untreated Hep G2 2.215 cells (lanes 1 and 2) and from those treated with 3 μM 3TC (lanes 3 and 4), 500 μM N-butyl-DGJ (lanes 5 and 6), 20 μM N-nonyl-DGJ (lanes 7 and 8), or 1,000 μM N-7-oxy-decyl-DGJ (lanes 9 and 10). Rc DNA, relaxed circular DNA.