FIG. 6.

Efficacy of C34 peptide at sequential intermediate stages of fusion induced by HXB2 WT (open circles) and ΔCT (filled circles). Varied concentrations of C34 were added either at the beginning of E-T cell coincubation (A), at the TAS (B), or at the LAS (C). Fusion was then triggered by incubating the cells at 37°C for 2.5 h (A) or for 1 h (B and C). The IC₅₀s obtained by curve fitting (see Materials and Methods) are given in parentheses in the insets. Fusion was quantified by fluorescence microscopy.