FIGURE 6.

Effect of MTSEA treatment of cfnt2ΔCys-K155C on inosine uptake capability. A, uptake of over 3 min was measured in triplicate by Δldnt1/Δldnt2 pALTneo-HA-cfnt2ΔCys-K155C cells under a variety of conditions. All cells were first treated or mock-treated with 2.5 mm MTSEA or 10 mm MTSES for 10 min in the absence or presence (+ ligand) of 1 mm inosine. Following three washes of the cells to remove unreacted reagent and excess unlabeled ligand, uptake of 5 μm [³H]inosine was measured. No treatment, cells not treated with thiol-modifying reagents (relative uptake set to 100%); competitive inhibitor, mock-treated cells whose uptake of 5 μm [³H]inosine was challenged with 5 mm unlabeled inosine. B, structures of MTSEA as well as MTSEA-modified cysteine (Cys adduct) and lysine side chains.