Fig. 4.

Effect of various concentrations of aspartate on α-KGA-derived glutamate uptake into isolated synaptic vesicles. Two preparations of rat synaptic vesicle fraction SV-A′ (50 μg protein) were combined and incubated at 30° C for 15 min with 30 μM [¹⁴C]α-KGA in the medium containing 100 mM sucrose described in Materials and Methods, in the absence (○) or presence (●) of 2 mM ATP with various concentrations of L-aspartate. Values are the mean ± SEM of triplicate determinations. Glu, glutamate; v, the initial velocity of vesicular uptake of α-KGA-derived Glu uptake expressed in pmol^·min^−1·mg⁻¹.