Table 1.

Effects of Side Chain Mutation in the Membrane Domain on the H,K ATPase^a

location	mutant	Ki[SCH] (nM)	type of inhibition	Vmax (μmol mg−1 h−1)	Km,app[NH4+] (mM ± SE)
	wtd	64 ± 11	comp	132 ± 3	2.4 ± 0.1
M1	M113L	86	comp	36	0.26 ± 0.04
	M113C	98	comp	31	2.7 ± 0.2
	I119L			31	2.8 ± 0.2
	I119A			inactive
M2	L141C	261	comp	11	2.2 ± 0.9
	L145F	ND		1–2	3.6 ± 0.4
	Q159E	132	mixed	12	6.0 ± 1.7
	Q159N	233	comp	34	3.6 ± 0.8
	E160Q	23	comp	35	0.3 ± 0.1
	E160D	168	comp	45	1.1 ± 0.1
M4	R328E/Y324Cd	493	mixed	22	0.7 ± 0.3
	V331Fd	48	mixed	68	1.0 ± 0.1
	F332Id	4000	mixed	14	4.5 ± 1.4
	A335Gd	16	comp	31	3.4 ± 0.3
	A335Sd	1200	comp	30	3.5 ± 0.4
	A335Cd		none	67	2.5 ± 0.3
	A335C/C813Ad	40000	comp	69	3.8 ± 0.3
M5	K791Sb	1325	comp	7	4.7 ± 0.3
	E795Db	700	comp	10	8.1 ± 2.6
	Y799S			inactive
M5/6 loop	L809Fc	6150	noncomp	89	1.9 ± 0.3
	P810Gc	563	comp	109	2.4 ± 0.2
	L811Fc	625	mixed	113	2.0 ± 0.1
	G812I			inactive
M6	C813Tc	586	comp	40	6.6 ± 1.8
	I816Lc	309	noncomp	31	1.4 ± 0.4

^aStandard errors for the V_max and K_i calculated from assay data were proportional to those given for the K_m,app. V_max was normalized to protein expression.

^bFrom ref 25.

^cFrom ref 50.

^dFrom ref 11.