Figure 5.

Sphingopeptides strongly bind and accumulate in the cell membrane and in the viral membrane. A) Sphingopeptides are strongly anchored to the membrane and sustain a potent inhibitory effect on washing. C34, enfuvirtide, and sphing-N17 were preincubated with TZM-bl cells, followed by washing to remove unbound peptides and the addition of fully infectious viruses to start the infection. IC₅₀ of the peptide with or without washing the cells (IC₅₀ 1 or 2, respectively) was calculated. Results are presented as the mean ± sd ratio of IC₅₀ 1/2 (n≥2), which reflects the fold increase in IC₅₀ after cell washing. B) Infectivity of purified viruses that were pretreated with sphing-N17 or DMSO. Infectivity of the purified viruses was measured by luciferase activity in TZM-bl cells and is expressed in relative light units. C) Antiviral activity of sphing-N17 when it is preincubated with TZM-bl cells before the addition of fully infectious virus or when it is added to a mixture of the virus with cells.