FIG. 3.

Radioimmunoprecipitation analysis of α-helix 2 deletion mutants. CEM (12D-7) cells were infected with wt or mutant NL4-3 virions pseudotyped with VSV-G. Infected cells were metabolically labeled overnight with [³⁵S]Cys. Virion-associated material was obtained by pelleting the infected cell supernatant in an ultracentrifuge; lysates derived from cell- and virion-associated material were immunoprecipitated with AIDS patient sera (see Materials and Methods). The positions of the Env precursor gp160, the mature surface glycoprotein gp120, p66 (RT), the Gag precursor Pr55^Gag, p32 (IN), and p24 (CA) are indicated; the sizes of molecular mass markers are shown in kilodaltons (K). The results are representative of two independent experiments.