FIG. 6.

OptiPrep velocity gradient centrifugation. HIV-like particles concentrated from the culture supernatants of metabolically labelled 293T cells coexpressing Wt-EGFR plus HIV-like particles (A) or Tr-EGFR plus HIV-like particles (B) were centrifuged on 6 to 18% iodixanol gradients as described previously (5). Lanes P, gel electrophoresis of the starting materials; lane P*, a longer exposure of lane P, done to visualize more weakly labelled bands at the positions of HIV MA and reverse transcriptase; lanes 1 to 11 (from the top to the bottom of the gradient), gel electrophoresis of the radioactive proteins in the gradient fractions. The positions of Wt-EGFR, Tr-EGFR, CA, and MA are shown.