FIG. 2.
(A) Schematic representations of the HTLV-1 Envecto fragment and the HTLV-1 Envecto C225A mutant. The membrane-proximal Trp (W), the codon of which has been mutated into a stop codon, is shown in full-length Env. Arrow, cleavage between SU and TM; box, TM region. (B and C) Secretion of HTLV-1 Envectos. wt and C225A Envectos were produced and labeled with [35S]Cys for 18 h at indicated pH values and temperatures in transfected BHK-21 cells. The media were collected and released SU-TMecto complexes and free SU was captured for nonreducing SDS-PAGE using anti-HTLV-1 pAb. (B) wt Envectos. (C) C225A Envectos. Covalently linked and free SU subunits are indicated. Note that the anti-HTLV-1 pAb did not react with free TM. The analyses shown represent phosphorimages of the gels. Molecular masses are indicated to the left.