Figure 6.

Expression of SV5 F cysteine mutants. A) Wt SV5 F and the Cys mutants were expressed in HeLa T4 cells by use of the vTF7-3 system. Three h post-transfection, cells were starved and labeled with Tran[³⁵S] for 30 min followed by a 3 h chase. Samples were immunoprecipitated, separated on a 7.5% SDS-polyacrylamide gel in the absence of a reducing agent and analyzed as above. B) Wt SV5 F and the Cys mutants were expressed in HeLa T4 cells by use of the vTF7-3 system. Three h post-transfection, cells were starved for 30 min, pulsed with Tran[³⁵S] for 30 min and chased for 1 h. Chemical cross-linking was performed on cell suspensions in the presence of 0.2% NP-40 and 1mM DTSSP. Samples were immunoprecipitated and analyzed on a 3.5% polyacrylamide gel in the absence of a reducing agent. C) Wt SV5 F and the Cys mutants were expressed in CV-1 cells by use of the vTF7-3 system. Three h post-transfection, cells were labeled overnight followed by a 2 h chase. Samples were immunoprecipitated, separated on a 15% SDS-polyacrylamide gel in the presence reducing agent and analyzed as above.