TABLE III.

Biophysical Properties of Individual Substitutions in hKv1.5

hKv1.5	K	G	L	Q	I	L	G	K	T	L	Q	A	S	M	R	E
	I		I		I		I		I		I		I		I
position	418		420		422		424		426		428		430		432
	(380)		(382)		(384)		(386)		(388)		(390)		(392)		(392)
	Activation														Deactivation					Inactivation
	V1/2 (mV)					k (mV)			τa (ms)					τd (ms)					V1/2,i (mV)					ki (mV)			n
K418T	1.5 ± 1.5					7.3 ± 0.6			4.5 ± 0.4					22.8 ± 3.0					−8.2 ± 0.7					4.9 ± 0.3			6
I422S	−26.4 ± 1.9					6.9 ± 0.6			12.6 ± 0.9					475 ± 27					−38.9 ± 1.0					4.5 ± 0.2			5
I422A	−24.1 ± 2.3					7.0 ± 0.7			5.7 ± 0.4					277 ± 52					−33.7 ± 1.7					5.8 ± 0.3			7
I422W	no current
I422R	no current
K425E	−10.1 ± 1.9					6.0 ± 0.3			4.3 ± 0.3					18.9 ± 3.2					−16.4 ± 1.4					3.6 ± 0.3			5
K425F	−5.2 ± 2.7					6.2 ± 1.3			7.8 ± 1.0					ND					ND					ND			3
K425A	12.2 ± 1.6					7.0 ± 0.3			5.7 ± 0.8					19.2 ± 1.9					2.9 ± 1.5					5.5 ± 0.3			6
T426A	−1.5 ± 2.0					6.6 ± 0.3			3.6 ± 0.2					6.6 ± 0.8					−13.9 ± 2.6					4.5 ± 0.4			5
T426W	no current
T426R	no current
Q428R	−9.7 ± 1.4					6.5 ± 0.2			5.0 ± 0.8					22.0 ± 5.2					−19.3 ± 0.6					5.0 ± 0.1			5
A429R	−8.2 ± 1.8					7.1 ± 0.5			7.0 ± 0.6					4.4 ± 0.5					−16.2 ± 2.6					5.2 ± 0.3			5
M431F	−11.1 ± 1.4					5.9 ± 0.3			5.5 ± 0.9					16.1 ± 1.4					−16.3 ± 0.9					4.9 ± 0.3			6
R432E	−9.4 ± 0.6					4.9 ± 0.3			3.0 ± 0.3					13.7 ± 0.3					−14.0 ± 1.5					4.1 ± 0.2			4
R432N	−1.6 ± 1.2					5.8 ± 0.2			4.4 ± 0.5					57.0 ± 5.3					−7.5 ± 1.4					4.5 ± 0.2			8
R432F	17.4 ± 1.3					7.0 ± 0.5			5.9 ± 0.7					12.5 ± 0.5					2.0 ± 1.1					4.3 ± 0.3			7
V514I	−5.1 ± 1.7					5.4 ± 0.7			4.5 ± 0.5					223 ± 19					−12.4 ± 1.4					3.6 ± 0.3			5
Y521E	−14.9 ± 1.4					5.3 ± 0.4			3.5 ± 0.3					11.9 ± 1.1					−22.8 ± 2.1					3.7 ± 0.4			5
H524K	−5.0 ± 1.6					4.6 ± 0.4			4.0 ± 0.4					26.6 ± 2.7					−11.5 ± 1.3					4.0 ± 0.1			5
R525E	−16.5 ± 0.9					5.6 ± 0.4			3.5 ± 0.2					25.8 ± 2.1					−26.4 ± 0.9					3.2 ± 0.1			6
E526Q	−9.6 ± 0.3					5.1 ± 0.3			4.8 ± 0.6					13.8 ± 1.8					−16.8 ± 1.2					4.5 ± 0.2			4
T527K	−7.1 ± 0.3					5.1 ± 0.2			4.2 ± 0.5					17.9 ± 3.2					−12.3 ± 1.4					3.8 ± 0.3			5
D528R	−10.9 ± 1.5					5.3 ± 0.5			4.7 ± 0.4					26.6 ± 2.6					−18.4 ± 0.6					4.0 ± 0.2			7
H529Q	−3.7 ± 1.2					5.0 ± 0.4			4.2 ± 0.5					18.8 ± 2.3					−9.0 ± 2.0					4.1 ± 0.4			6
E531K	−9.9 ± 2.8					5.6 ± 0.6			4.9 ± 0.5					20.4 ± 1.6					−17.0 ± 1.1					3.5 ± 0.2			5

Sequence of L45 from hKv1.5 on top with Shaker numbering between parentheses. All mutations were done in an hKv1.5 background, and V_1/2, k, and t were obtained as in Table I. ND, not determined.