Effects of TM2 L9′T mutation on the functional effects of ACh on HS α 4β 2 nAChRs

Oocytes were injected with a 1:10 α4/β2 cDNA ratio to produce HS α4β2 nAChRs. EC50 values are the means of EC50 estimates obtained by fitting separately each concentration-response curve with a one-component sigmoidal equation, which gave the best fit for all data sets. Potency ratios were calculated from fits in which curves were constrained to slope equal to 1 and are expressed in relation to receptors containing 5 L9′ (which therefore have dose ratio values of 1). Results are from four or five independent experiments (n).

EC50 (95% CI) Potency Ratio 2 Embedded Image 3 Embedded Image 5 Embedded Image n
α4β2wt 4 (3.3-4.8) 1 5
α4LTβ2 1 (0.8-1.1) 4.18 2.1 4
α4β2LT 0.2 (0.1-0.3) 18.05 2.6 4
α4LTβ2LT 0.03 (0.02-0.04) 136.89 2.7 4
  • CI, confidence interval; HS, high sensitivity.