TABLE 2

Dissociation constant (Kd) and thermodynamics parameters (enthalpy change ΔH, and entropy change ΔS) as determined by isothermal titration calorimetry

CompoundsKdHS
Wild-TypeGln55Arg MutantWild-TypeGln55Arg MutantWild-TypeGln55Arg Mutant
μMμMkcal/molkcal/molcal/mol/Kcal/mol/K
Imidacloprid0.530 ± 0.023a0.514 ± 0.053−10.33 ± 0.11−10.50 ± 0.21−5.93 ± 0.39−6.38 ± 0.89
Clothianidin1.79 ± 0.051.27 ± 0.15−9.85 ± 0.09−6.28 ± 0.41−6.74 ± 0.33+5.97 ± 1.61
Thiacloprid0.297 ± 0.0120.294 ± 0.015−6.87 ± 0.09−11.49 ± 0.06+6.84 ± 0.37−8.62 ± 0.24
CH-IMI0.092 ± 0.0040.100 ± 0.003−12.93 ± 0.92−13.28 ± 0.46−7.45 ± 0.61−15.00 ± 1.47
DN-IMI0.091 ± 0.0040.119 ± 0.003−12.84 ± 0.22−10.74 ± 0.30−10.78 ± 0.69−4.32 ± 1.05
(–)-Nicotine0.114 ± 0.0170.609 ± 0.012−15.07 ± 0.07−14.45 ± 0.19−18.97 ± 0.26−20.03 ± 0.64
  • a Data are presented as means ± S.E.M. from three replicates.