FIG. 4.

Analysis of incorporation mutant or wild-type Env proteins into pseudotyped virions. Virions pseudotyped with Env proteins were obtained by cotransfection of 293T cells with Env CMV plasmid constructs pCAGGS (A) or pJW4303 (tPA signal peptide) (B) with pSG3 plasmid expressing the env-minus molecular clone SG3 (HIV-1) and collected and purified after 3 days. The samples were analyzed by SDS–PAGE and Western blotting by using a polyclonal antibody from human plasma (HIV-Ig) for analysis of Gag proteins or a polyclonal anti-SIVmac251 antiserum for analysis of Env proteins. The amounts of proteins were quantitated by densitometer analysis (NIH Image version 1.54) (C). The levels of Env proteins incorporation were determined by the Env/Gag ratio and indicated as percent of wild-type Env (100%).