Figure 2.

Interaction of 5-Helix with cell-surface gp41 and gp160. Cells (293T) expressing HIV-1 Env_HXB2 were incubated with biotin-tagged 5-Helix (1 μM) in the presence and absence of sCD4 (5 μg/ml) and C-peptide C37-H6 (2 μM). After cell washing and lysis, protein was precipitated on monomeric avidin beads and subsequently analyzed by SDS/PAGE and Western blotting. The primary detection antibody, Chessie 8, recognizes an epitope found in the cytoplasmic tail of gp41 (and, hence, gp160). The labeling above each lane refers to the initial culture-incubation conditions, and the numbers on the right refer to protein standard molecular masses. Note that no 5-Helix is added to lane 1 (leftmost) and that mock-transfected cells are used in lane 5.