Figure 4.

Effect of reducing and oxidizing agents on hASCT2 transport activity. The reconstitution was performed as described in Section 4.5. Transport was started by adding 50 μM [³H]Gln and 50 mM external Na-gluconate at time zero to proteoliposomes containing 10 mM Gln in the presence of 5 mM GSH, 100 µM NaHS (H₂S donor), 1 mM GSNO (NO donor), 1 mM Cys, 5 mM GSSG, 5 mM CySS, 1 mM Hydrogen Peroxide or 100 µM Cu-Phenanthroline. Transport activity was calculated as percent of residual activity with respect to condition without any addition. The transport reaction was stopped after 30 min, as described in Section 4.6. Results are means ± S.D. from three experiments. Student’s two tailed unpaired t-test was performed on the sample without any addition (none) in the transport buffer; p values were symbolized as follows: * p < 0.05; ** p < 0.01.