Table 4. Summary of 4-fluoropropofol binding at various sites in NaChBac.

Region	Residue	STDmax	ksat	σ × 100
		%	s–1	s−1
Intrasubunit extracellular interface	S208	3.0 ± 1.0*	0.7 ± 0.5	2.1 ± 1.7
Voltage sensing domain	N36	11.4 ± 0.5***	2.0 ± 0.3**	22.3 ± 3.7**
	V40	9.1 ± 0.5***	2.8 ± 0.6**	25.5 ± 5.5**
S4–S5 linker	S129	8.4 ± 0.3***	1.9 ± 0.3**	15.8 ± 2.7**
	L150	9.5 ± 0.6***	1.6 ± 0.3**	15.5 ± 3.1**
Selectivity filter	T189	9.0 ± 0.5***	2.2 ± 0.4**	19.7 ± 3.8**
Activation gate	F227	17.4 ± 0.9***	2.5 ± 0.4**	42.6 ± 7.6**
	I223	9.7 ± 0.5***	1.4 ± 0.2**	13.3 ± 2.3**
	I223a	10.0 ± 0.4†	1.7 ± 0.2†	17.4 ± 1.5††
	I223b	8.0 ± 0.5†	1.1 ± 0.2†	8.4 ± 1.2††

Values are given as mean ± SEM. Difference from zero was evaluated individually for each parameter by the Student’s t test: *, P < 0.05; **, P < 0.01; ***, P < 0.001. Difference between parameters obtained in the absence and presence of etidocaine was evaluated by the Student’s t test: ^†, P < 0.05; ^††, P < 0.01.

^aMeasured by using 100 µM 4-fluoropropofol without the local anesthetic etidocaine.

^bMeasured by using 100 µM 4-fluoropropofol in competition with 50 µM etidocaine.