FIG. 6.

Intracellular membrane-bound Pr55^gag is largely resistant to Brij98. (A) Analyses of transfected 293T cells. The total membrane fraction from PNS was extracted with Brij98 for 5 min at 37°C or left untreated, and the samples were subjected to flotation on iodixanol step gradients. Total Pr55^gag in gradient fractions was visualized by Western blotting. (B) Brij98 resistance of newly synthesized Pr55^gag. The wild type and ΔNC (MA-CA-p2) mutant of Pr55^gag were expressed in Jurkat cells from recombinant SFV genomes. Cells were metabolically labeled with [³⁵S]methionine for 15 min and chased for 0 min and 2 h (Pr55^gag) or for 2 h (ΔNC). The total membrane fraction from PNS was extracted with Brij98 as described above, and the extracts were fractionated on iodixanol step gradients. Aliquots of gradient fractions were analyzed by SDS-PAGE.