Table IV.

Summary of Charge Neutralization Mutation Effects on Fast Inactivation

Channel		v1/2 shift*		ah change*
		mV
1R1Q‡		−0.8		−0.2
1R1Q§		−5.0		−0.8
1R2Q		−5.1‖		−1.0‖
1R2Q§		−6.0		−0.5
1R3Q‡		−5.8		−1.1‖
1R3Q§		+6.0		+1.4
1K4Q		−3.7‖		−0.4‖
1K4Q§		−6.0		+0.9
2R1Q‡		+8.2‖		−0.4
2R2Q		−8.1		−0.8‖
2R3Q‡		−9.6‖		−1.1‖
2K4Q		−5.7‖		−0.6‖
2K5Q§		−9.0		−0.8
3K1Q‡		−21.0‖		−0.8‖
3R2Q		−8.5‖		−0.9‖
3R3Q‡		−10.6‖		−0.6
3R4Q		−3.2‖		0.0
4R1Q‡		+4.7‖		−2.0‖
4R2Q		−0.6		−0.5‖
4R3Q‡		−57.5‖		−2.6‖
4R4Q		+0.2		+0.3

^*v_1/2 and a_h are the half-maximal voltage and slope factor for fast inactivation. Data from Stühmer et al. (1989) did not include an assessment of statistical significance.  

^‡Data from Chen et al. (1966).  

^§Data from Stühmer et al. (1989). These data were acquired using a 100-ms prepulse, whereas all other data were acquired using a 500-ms prepulse.  

^‖Values statistically significant, with a probability <0.05 resulting from random variation.