Figure 2.

Saturation analysis of L-glutamate uptake into induced HEK/EAAT2 cells. Cells were incubated in the presence of increasing concentrations of substrate and the Na⁺-dependent L-glutamate uptake was measured and expressed as nmol min⁻¹ mg⁻¹ protein with correction for the activity observed in the absence of extracellular Na⁺. Inset: Eadie-Hofstee transformation of the saturable uptake data was used to estimate the kinetic parameters K_m and V_max which were 73.8 μM and 6.2 nmol min⁻¹ mg⁻¹ protein, respectively, for the experiment shown. Data from three independent experiments generated values of 52.7±7.5 μM for Km and 3.8±0.9 nmol min⁻¹ mg⁻¹ protein for V_max.