Compound | Ki | Concentration | Exchange rate (pmol/mg protein/ 2 min) |
---|---|---|---|
μM | |||
l-Glutamate | 4.9 ± 1 | 100 | 362 ± 12 |
50 | 344 ± 16 | ||
10 | 316 ± 22 | ||
2,4-MPDC | 6.8 ± 3 | 100 | 282 ± 28 |
75 | 280 ± 30 | ||
l-Aspartate | 1.7 ± 0.6 | 100 | 278 ± 16 |
20 | 266 ± 22 | ||
cis-ACBD | 30 ± 2 | 100 | 266 ± 4 |
300 | 270 ± 8 | ||
l-cis-2,4-PDC | 66 ± 6 | 100 | 206 ± 16 |
500 | 260 ± 22 | ||
l-trans-2,4-PDC | 1.5 ± 0.5 | 100 | 250 ± 28 |
15 | 208 ± 28 | ||
l-β-THA | 2.0 ± 1 | 100 | 172 ± 24 |
20 | 162 ± 16 | ||
l-trans-2,3-ADC | 78 ± 6 | 100 | 146 ± 14 |
800 | 156 ± 26 | ||
l-anti-endo-3,4-MPDC | 4.9 ± 2 | 100 | 120 ± 20 |
50 | 120 ± 18 | ||
Kainate | 59 ± 6 | 100 | 0 ± 1.5 |
600 | 0 ± 0 | ||
cis-5-Me-l-trans-2,3-PDC | 37 ± 6 | 100 | 3 ± 6 |
350 | 0 ± 0 | ||
DHK | 28 ± 2 | 100 | 0 ± 3 |
300 | 11.4 ± 6 | ||
DHK+ | 300 | 60 ± 12 | |
l-Glutamate | 10 | ||
l-trans-2,3-PDC | 33 ± 6 | 100 | 3 ± 6 |
300 | 19 ± 6 | ||
l-trans-2,3-PDC +l-Glutamate | 300 10 | 76 ± 16 |
K i values ± S.D. reported in this table represent the average of at least three separate Lineweaver-Burk analyses that were carried out as described in Figure 2. The synaptosomal efflux of d-[3H]aspartate induced by the inhibitors was quantified over a 2-min period at 37°C and was corrected for the efflux that occurred in the absence of added compound (228 ± 8 pmol/mg protein/2 min). Inhibitors were tested both at 100 μM and, to ensure comparable levels of transporter binding, at concentrations approximately 10 times greater than theK i values for which they inhibitedd-[3H]aspartate uptake. Values represent mean ± S.E. from at least four separate determinations conducted in duplicate.