Figure 4.
Figure 4. (A) Binding of [^3H]AMPA to the S1S2 domains of
GluR2[o] and GluR3[i]. The K[D] of binding differed by less than
twofold: 19 ± 2 nM for GluR2 and 43 ± 5 nM for
GluR3. Armstrong and Gouaux[5] reported a K[D] of 24.8 ±
1.8 nM for [^3H]AMPA binding to GluR2. (B) Structures of the
ligands used in the binding studies, (C) The inhibition of
[^3H]AMPA binding by agonists, partial agonists, and antagonist
to the S1S2 domains of GluR2[o] and GluR3[i]. Except for
willardiine, the IC[50] values were within twofold for the two
subtypes: (ligand, GluR2 IC[50]/GluR3 IC[50]; IC[50] expressed
in M)
fluorowillardiine, 0.0040 ± 0009/0.0062 ± 0.0014;
iodowillardiine, 0.46 ± 0.05/0.79 ± 0.14; Cl-HIBO,
5.0 ± 0.3/55 ± 4; willardiine, 3.1 ±
0.2/0.99 ± 0.18; UBP277, 135 ± 12/69 ± 10.
In all cases, GluR2[o] is shown with filled symbols, and
GluR3[i] is shown with open symbols.
The above figure is reprinted
by permission from John Wiley & Sons, Inc.:
Proteins
(2008,
75,
628-637)
copyright 2008.
M)
fluorowillardiine, 0.0040 ± 0009/0.0062 ± 0.0014;
iodowillardiine, 0.46 ± 0.05/0.79 ± 0.14; Cl-HIBO,
5.0 ± 0.3/55 ± 4; willardiine, 3.1 ±
0.2/0.99 ± 0.18; UBP277, 135 ± 12/69 ± 10.
In all cases, GluR2[o] is shown with filled symbols, and
GluR3[i] is shown with open symbols.