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-140 mV to -80 mV
-140 mV to -60 mV -140 mV to -50 mV
-140 mV to -100 mV(n=12 ) (n=9)
(n=20 )(n=26 )
0 2000 4000 6000 8000 100000.0
0.2
0.4
0.6
0.8
1.0
pope
n
Time (ms)
0 2000 4000 6000 8000 100000.0
0.2
0.4
0.6
0.8
1.0
pope
n
Time (ms)
0 2000 4000 6000 8000 100000.0
0.2
0.4
0.6
0.8
1.0
pope
n
Time (ms)
0 2000 4000 6000 8000 100000.0
0.2
0.4
0.6
0.8
1.0
pope
n
Time (ms)
(n=12 )
𝑝𝑜𝑝𝑒𝑛=𝑇𝑜𝑡𝑎𝑙𝐶𝑢𝑟𝑟𝑒𝑛𝑡 (𝑝𝐴)
𝑐𝑢𝑟𝑟𝑒𝑛𝑡 𝑗𝑢𝑚𝑝 (𝑝𝐴 )×𝑡𝑟𝑖𝑎𝑙𝑠× ¿𝑜𝑓 h𝑐 𝑎𝑛𝑛𝑒𝑙𝑠 ¿ # of channels = 8
-140 mV to -40 mV-140 mV to +30 mV
-140 mV to +40 mV -140 mV to +60 mV
(n=18 ) (n=12 )
(n=13 ) (n=13 )
0 2000 4000 6000 8000 100000.0
0.2
0.4
0.6
0.8
1.0
pope
n
Time (ms)
0 2000 4000 6000 8000 100000.0
0.2
0.4
0.6
0.8
1.0
pope
n
Time (ms)
popen
0 2000 4000 6000 8000 100000.0
0.2
0.4
0.6
0.8
1.0
pope
n
Time (ms)
0 2000 4000 6000 8000 100000.0
0.2
0.4
0.6
0.8
1.0
pope
n
Time (ms)
-140 mV to +80 mV -140 mV to +90 mV
-140 mV to +100 mV-140 mV to +110 mV
(n=23 ) (n=21 )
(n=15 )(n=14 )
0 2000 4000 6000 8000 100000.0
0.2
0.4
0.6
0.8
1.0
pope
n
Time (ms)
0 2000 4000 6000 8000 100000.0
0.2
0.4
0.6
0.8
1.0
pope
n
Time (ms)
0 2000 4000 6000 8000 100000.0
0.2
0.4
0.6
0.8
1.0
pope
n
Time (ms)
0 2000 4000 6000 8000 100000.0
0.2
0.4
0.6
0.8
1.0
pope
n
Time (ms)
-140 mV
-100 mV
-80 mV
+40 mV
+ 80 mV+ 100 mV
-40 mV
-140 mV
0 2000 4000 6000 8000 100000.0
0.2
0.4
0.6
0.8
1.0
pope
n
Time (ms)
+40 mV +80 mV +100 mV
0 2000 4000 6000 8000 100000.0
0.2
0.4
0.6
0.8
1.0
pope
n
Time (ms)
-100 mv -80 mV -40 mV
-150 -100 -50 0 50 100 1500
0.10.20.30.40.50.60.70.80.9
1
Voltage (mV)
pop
en_s
s
V (V) I (pA) theoretical-0.14 -5.9 -8.0-0.1 -5 -5.6
-0.08 -4 -4.4-0.06 -3.2-0.05 -2.5 -2.6-0.04 -2.1 -2.00.03 2.30.04 3 2.90.06 4 4.10.08 6.2 5.30.09 6.6 5.90.1 7.8 6.50.11 8 7.1
-0.15 -0.1 -0.05 0 0.05 0.1 0.15
-8
-6
-4
-2
0
2
4
6
8
f(x) = 60.7008086253369 x + 0.448247978436658R² = 0.998671982935847
Voltage (V)
Cu
rren
t (p
A)
Previously reported as 89pS (20140827), we find out it is closer to be 60.7 pS (20150423). This discrepancy can be somewhat explained by the program algorithm in Clampfit which requires two consecutive flat lines. With high amount of NaChBac channels, this is difficult to observe, and when it is observed, it is generally when two channels are closed at the same time.
what the program looks for what tends to be the case
Studer (2009) reports 120 pS with 150 mM NaCl, 20mM NaCH3CO2. His bilayer was POPE:POPC (3:7).
pAms
pAms
150 mM NaCl in Cis and Trans
0 10 20 30 40 50 60 70 80 90 100
40
50
60
70
40
50
60
70
20
30
40
50
60
20
30
40
50
10
20
30
40
50
0
10
20
30
40
-30
-20
-10
0
-40
-30
-20
-10
0
-30
-20
-10
0
10
0 10 20 30 40 50 60 70 80 90 100
-30
-20
-10
0
cu
rre
nt (p
A)
Time (ms)
+110 mV
pA pA
cu
rre
nt (p
A)
+100 mV
pA
+90 mV
cu
rre
nt (p
A)
pA
pA
cu
rre
nt (p
A)
+80 mV
pApA
cu
rre
nt (p
A)
+60 mV
cu
rre
nt (p
A)
+40 mV
pA
cu
rre
nt (p
A)
-50 mV -80 mV
cu
rre
nt (p
A)
pA
cu
rre
nt (p
A)
-100 mV
pA
cu
rre
nt (p
A)
Time (ms)
-140 mV
Filter: 8 pole Bessel 1000 Hz cutoffSampling interval: 50µs
-20pA/-2.5pA = 8 protein channels
0 10 20 30 40 50-40
-20
0
20
40
60
0 10 20 30 40 50-40
-20
0
20
40
60curr
ent (p
A)
Time (ms)
NaCl +60 mV NaCl +40 mV NaCl -40 mV
curr
ent (p
A)
Time (ms)
KCL +60 mV KCl +40 mV KCl -40 mV
Cis and trans chamber are filled with either1) 150 mM NaCl, 10mM Tris 7.42) 150 mM KCl, 20 mM HEPES 7.4
Recorded 1 second after voltage was set
P Na/P K = 171 ± 16 (n = 8)from Ren et al., 2001
40
50
60
70
0 50 100
20
30
40
50
0 50 100
-40
-30
-20
= 3.9 pA
cu
rre
nt
(pA
) +60 mV
= 5.9 pA
cu
rre
nt
(pA
) +40 mV
= - 3.4 pA
cu
rre
nt
(pA
)
Time (ms)
-40 mV
-0.06 -0.04 -0.02 0 0.02 0.04 0.06 0.08
-4
-2
0
2
4
6
8
f(x) = 92.5 x + 0.283333333333333R² = 0.999756572541383
150 mM KCl in Cis and Trans
~ 60.8pA/5.9pA = 10.3 channels
0 10 20 30 40 500
7
14
22
29
36
43
50
58
65
0.5mM/0mM
curr
en
t (p
A)
Time (ms)
0 10 20 30 40 500
7
14
22
29
36
43
50
58
65
0.5mM/0.5mMcurr
en
t (p
A)
Time (ms)
0 10 20 30 40 500
7
14
22
29
36
43
50
58
65
10.3mM/10.3mM
curr
en
t (p
A)
Time (ms)
0 10 20 30 40 500
5
10
15
20
25
30
35
40
45
50
55
60
65
10.3mM/10.3mM
curr
en
t (p
A)
Time (ms)
150 mM KCl Cis/TransCis / trans blocker: Ni+recorded 1 second after voltage
150 mM KCl Cis/Trans+60 and -60 mV voltage appliedover 10 seconds
