Table IV

Summary of Charge-neutralizing Mutation Effects on Activation

Mutantv1/2 shift*zm change (e0)*
mV
1R1Q‡+3.3−0.6
1R1Q§−2.00.0
1R2Q−1.0+0.4
1R2Q§−8.0−1.8‖
1R3Q‡+4.7176−1.7176
1R3Q§+12.0−1.5‖
1K4Q+18.5176−1.2176
1K4Q§+19.0−0.9‖
2R1Q‡+13.3176−1.2176
2R2Q+4.4176−1.1176
2R3Q‡+0.4176−1.6176
2K4Q+14.9176−0.7
2K5Q§+10.00.0
3K1Q‡−10.4176−0.5
3R2Q−0.3+0.4
3R3Q‡+5.9176−2.1176
3R4Q−18.1176+0.3
4R1Q‡+2.3−1.6176
4R2Q+3.6176−0.5
4R3Q‡+8.6176−1.6176
4R4Q+0.4+0.9
• * v1/2 and zm are the half-maximal voltage and gating valence of activation. Data from Stühmer et al. (1989) did not include an assessment of statistical significance.

• Data from Chen et al. (1996).

• § Data from Stühmer et al. (1989).

• The values for zm from Stühmer et al. (1989) were multiplied by three for comparison because those values were based on three identical gating charges (m3).

• 176 Values statistically significant, with a probability <0.05 resulting from random variation.