Table I.

The effect of phosphorylation on the interaction between MBD-ank and the ankyrin-binding motif of sodium channels

Immobilized constructMBDCK2 phosphorylationkonkoffKD
M−1s−1s−1M
GST-Nav1.2 1,080–1,203ankGNANA1.7 ± 0.5 × 10−6a
ankBNANA1.2 ± 0.4 × 10−6a
ankG+42.4 ± 41.6 × 1052.1 ± 0.8 × 10−30.9 ± 0.7 × 10−9
ankB+28.0 ± 11.0 × 1053.0 ± 0.1 × 10−31.2 ± 0.4 × 10−9
GST-Nav1.2 989–1,133ankBNANA1.3 ± 0.2 × 10−6a
+60.1 ± 39.8 × 1052.3 ± 0.1 × 10−30.5 ± 0.2 × 10−9
GST-Nav1.2 1,080–1,203 E1111AankBNDNDND
+1.4 ± 0.3 × 1053.2 ± 0.6 × 10−32.4 ± 0.8 × 10−8
  • Mean values ± SD were obtained from three to six experiments. ankB and ankG, ankyrin B and G, respectively; NA, not applicable; ND, no binding detected.

  • a KD values were calculated using steady-state analysis (see Materials and methods).