TABLE 1

Equilibrium and kinetic parameter estimates for [3H]NMS at the WT and N410K+T423K M2 mAChRs

Values represent the mean ± S.E. from at least three experiments performed in duplicate.

WTN410K+T423Kna
Equilibrium pKDb10.18 ± 0.1010.27 ± 0.215
koff (min−1)c0.037 ± 0.0020.007 ± 0.001*3
t1/2 (min)d18.71053
kon (M−1.min−1)e2.91 ± 0.26 × 1080.90 ± 0.17 × 108*3
Kinetic pKDf9.93 ± 0.2810.36 ± 0.22n.a.
  • n.a., not applicable, as kinetic pKD values were calculated from kinetic rate constants kon and koff.

  • a Number of experiments performed for each assay.

  • b Negative logarithm of [3H]NMS equilibrium dissociation constant derived from saturation binding assays.

  • c Dissociation rate constant of [3H]NMS derived from dissociation binding assays.

  • d Half-life dissociation estimate of [3H]NMS calculated from koff estimates.

  • e Association rate constant of [3H]NMS derived from association binding assays.

  • f Negative logarithm of [3H]NMS equilibrium dissociation constant calculated from koff/kon.

  • * Significantly different from the corresponding value at the wild type (P < 0.05), Student’s t test.