Fig. 3.

Mutations in Glt_Ph alter the substrate selectivity to prefer neutral amino acids L-[³H]aspartate (100 nM; green triangles), L-[³H]serine (1 µM; red circles), L-[³H]alanine (1 µM; blue squares) and L-[³H]glutamine (1 µM; purple diamonds) transport by wild-type Glt_Ph a, Glt_Ph-R397C c and Glt_Ph-G396S/R397C e in the presence of an inwardly directed Na⁺ gradient at pH 7.5. Uptake of each substrate in the absence of a Na⁺ gradient is shown in open, black symbols, of which multiple are overlayed. b L-[³H]aspartate concentration–response for wild-type Glt_Ph. L-[³H]serine (red circles) and L-[³H]alanine (blue squares) concentration responses are shown for Glt_Ph-R397C d and Glt_Ph-G396S/R397C f. Values presented are mean ± S.E.M, (n ≥ 3)