FIG. 6.
Receptor triggering of Env results in the formation of stable TM trimers. [35S]Cys-labeled Mo-MLV was bound by centrifugation to cultures of XC cells at 4°C and then incubated for 30 min at 37°C. NEM was added and the virus-cell samples lysed with Triton X-100-EDTA HN buffer. One sample was then mildly treated with SDS and the other one left untreated. Both samples were analyzed by 2D BN-PAGE/nonreducing SDS-PAGE. Shown are phosphorimages of the gel analyses of the untreated sample (A) and the SDS-treated sample (B). Marker lanes (1D), cutouts, and labeling as in Fig. 4. Note that A″ and B″ are shown in higher contrast to better visualize the TM subunit. (C) Relative amounts of the oligomeric forms of the SU-TM complexes and the TM subunits in the two samples as percentages of the SU-TM and TM, respectively (mean ± standard deviation; n = 4).