Table 2.

Electrophysiological effects of mutating the S2 HC

Construct	Location	G-V		SSI		n
		V1/2	dx	V1/2	dx
WT	n/a	−26.3 ± 0.5	3.0 ± 0.1	−52.9 ± 0.5	5.7 ± 0.1	17
Tyr168Leu	DI S2 HC	−26.9 ± 0.6	2.7 ± 0.2	−52.8 ± 0.5	4.7 ± 0.1a	4
Phe621Leu	DII S2 HC	−29.7 ± 1.1a	4.4 ± 0.1a	−59.7 ± 0.4a	4.1 ± 0.1a	6
Phe1076Leu	DIII S2 HC	−21.6 ± 0.5a	2.8 ± 0.1	−50.3 ± 0.7a	4.6 ± 0.2a	8
Phe1396Leu	DIV S2 HC	−37.7 ± 1.3a	2.2 ± 0.3	−57.8 ± 0.9a	4.9 ± 0.2a	5
Tyr168TAG + F3-Phe	DI S2 HC	−23.5 ± 0.9	3.8 ± 0.1	−54.6 ± 1.0	5.0 ± 0.4	4
Phe621TAG + F3-Phe	DII S2 HC	−24.2 ± 0.9	2.6 ± 0.1	−52.6 ± 0.2	4.4 ± 0.1a	3
Phe1076TAG + F3-Phe	DIII S2 HC	−23.5 ± 1.7	2.8 ± 0.2	−52.3 ± 1.2	4.8 ± 0.3a	4
Phe1396TAG + F3-Phe	DIV S2 HC	−26.6 ± 1.1	2.9 ± 0.1	−47.6 ± 1.1a	7.3 ± 0.2a	6
Tyr168Trp	DI S2 HC	−11.6 ± 1.3a	5.8 ± 0.3a	−58.9 ± 0.6a	6.9 ± 0.3a	5
Phe621Trp	DII S2 HC	−29.1 ± 0.8	3.1 ± 0.2	−51.3 ± 1.4	6.4 ± 0.6	4
Phe1076Trp	DIII S2 HC	−23.7 ± 0.9a	2.2 ± 0.3	−46.5 ± 0.7a	4.6 ± 0.2a	8
Phe1396Trp	DIV S2 HC	−27.8 ± 0.5	2.7 ± 0.4	−39.1 ± 1.0a	6.5 ± 0.3a	4
Tyr168TAG + Ind	DI S2 HC	−16.5 ± 1.5a	3.8 ± 0.3	−51.4 ± 0.6	6.8 ± 0.3a	3

Displayed are the values for the midpoints (V_1/2) and the slope factors (dx) of the G-V relations and the SSI, as well as the number of experiments conducted (n).

^aStatistical difference to WT values in an unpaired t test (P < 0.01).