FIG. 4.
DTT sensitivity of the intersubunit disulfide of C225A Envecto fragments. The mutant ectodomains were bound to HOS cells in duplicate and incubated for 0 to 60 min at 37°C. The cultures were then subjected to an additional incubation in TN/Ca2+, pH 7.4, for 5 min at 37°C, one series in the presence of 4 mM DTT and the other series without. An excess of NEM (40 mM) was added and the cells and the supernatants were treated under lysis conditions and subjected to immunoprecipitation using a combination of anti-HTLV-1 and anti-TM pAbs. The captured proteins were analyzed by nonreducing SDS-PAGE. The analysis shown represents a phosphorimage of the gel. Incubation times with cells and DTT addition are indicated. Analyses of control samples where the DTT was mixed with the NEM before addition to the cells are shown in lanes 10 and 11. Molecular masses are indicated to the left.