FIG 1.

(A) GS-5806 inhibits pre- to posttriggered conformational changes of RSV F protein. Pre- to posttriggered conformational change was initiated by dialyzing ΔTM-RSV F protein overnight at 4°C in low-ionic-strength buffer (10 mM HEPES, pH 8.0) in the presence of a 5-fold molar excess of GS-5806, GSC-1 (an inactive analog), or DMSO (∼0.1%). The mean number of rosettes observed per grid view for different samples was calculated from at least 6 randomly selected EM images. The plot shows the mean values, with error bars representing the standard deviation. (B) The formation of rosettes in GS-5806-containing samples decreased in a dose-dependent manner. The mean number of rosettes observed per grid view for different samples containing various concentrations of GS-5806 was calculated from 6 to 10 randomly selected EM images and plotted as a function of GS-5806 concentration. The error bars represent the standard deviation of the mean values. (C) The ΔTM-RSV F protein containing the T400A amino acid change is associated with reduced susceptibility to GS-5806. The effects of GS-5806 on ΔTM-RSV F T400A protein rosette formation were evaluated. The mean number of rosettes observed per grid view for different samples was calculated from 6 randomly selected EM images. The plot shows the mean values, with error bars representing the standard deviation.