TABLE 2

Ligand-binding affinities of wild-type and mutants of mGluR8

Specific [3H]LY341495 binding and competition by l-AP4 were measured as described under Materials and Methods. Each binding was expressed as the mean ± range of two independent experiments performed in duplicate.



[3H]LY341495
Binding
Inhibition of Binding by l-AP4 (IC50)

Bmax
Kd

pmol/mg nM μM
WT 63 ± 20 33 ± 4 8.5 ± 0.5
L625A 60 ± 13 40 ± 7 7.7 ± 0.6
Y663A 59 ± 7 32 ± 1 4.7 ± 1.3*
Y663W 55 ± 6 35 ± 7 4.2 ± 0.2*
L667A 49 ± 7 30 ± 8 5.8 ± 0.6*
T764A 57 ± 5 34 ± 1 3.6 ± 0.1*
T764W 40 ± 10 42 ± 3 3.8 ± 0.2*
M787A 77 ± 3 40 ± 1 4.5 ± 1.1*
Y788A 59 ± 12 35 ± 8 8.1 ± 0.9
T789A 71 ± 3 32 ± 6 7.3 ± 0.1
C791A
60 ± 11
35 ± 1
5.2 ± 0.7*
  • * Significant decrease of IC50 compared with wild-type (P < 0.05; Student's t test, two-tailed).