TABLE 1

Equilibrium binding parameters for [3H]methoxyPEPy and MPEP at mGlu5 mutations

Data represent the mean ± S.E.M. of a minimum of three independent determinations.

Mutation[3H]methoxyPEPy pKDaBmaxbMPEP pKIc
Mpmol/mgM
R5-wt (low)8.24 ± 0.090.6 ± 0.0*#7.87 ± 0.04#
R5-wt (poly)8.23 ± 0.103.8 ± 0.87.77 ± 0.03
F585I7.91 ± 0.191.8 ± 0.67.93 ± 0.09
R647A8.22 ± 0.081.6 ± 1.3N.D.
I650A8.43 ± 0.111.0 ± 0.1*8.34 ± 0.11*
G651FNo appreciable binding
P654SNo appreciable binding
P654FNo appreciable binding
S657C8.35 ± 0.280.8 ± 0.3 *8.12 ± 0.09
Y658VNo appreciable binding
V739M8.19 ± 0.021.6 ± 0.37.91 ± 0.07
P742S7.71 ± 0.290.4 ± 0.2*7.67 ± 0.14
L743V7.92 ± 0.091.1 ± 0.2*7.23 ± 0.10*
N746A7.72 ± 0.051.2 ± 0.4*7.60 ± 0.08
G747V8.37 ± 0.071.9 ± 0.67.88 ± 0.06
T779A8.17 ± 0.130.8 ± 0.2*
T780ANo appreciable binding
W784ANo appreciable binding
V788A8.13 ± 0.081.0 ± 0.3*7.71 ± 0.13
F792A8.11 ± 0.211.7 ± 0.67.90 ± 0.13
S806A7.71 ± 0.071.2 ± 0.1*7.21 ± 0.07*
S808ANo appreciable binding
S808TNo appreciable binding
A809VNo appreciable binding
A809GNo appreciable binding
T810A7.86 ± 0.152.0 ± 0.47.28 ± 0.09*
C815A8.00 ± 0.190.8 ± 0.1*7.57 ± 0.02

  • N.D., not determined.

  • ↵a Negative logarithm of the equilibrium dissociation constant of [3H]methoxyPEPy.

  • ↵b Maximal number of binding sites.

  • ↵c Negative logarithm of the equilibrium dissociation constant of MPEP.

  • ↵* P < 0.05 vs. wild-type (polyclonal) value, one-way analysis of variance (ANOVA), Dunnett’s post-test; #Data previously reported (Gregory et al., 2012).