Table 1 Biophysicals properties of WT, R1451C and R1451L channels at 22 °C.

From: Substitutions of the S4DIV R2 residue (R1451) in NaV1.4 lead to complex forms of paramyotonia congenita and periodic paralyses

 

WT

R1451C

R1451L

Mean ± sem

n

Mean ± sem

n

Mean ± sem

n

Steady-state activation

 

9

 

8

 

15

  V 1/2

−27.5 ± 1.8

 

−28.8 ± 2.8

 

−30.7 ± 2.5

 

  k v

−5.8 ± 0.3

 

−7.6 ± 0.5**

 

−7.9 ± 0.3***

 

Steady-state inactivation

 

7

 

8

 

9

  V 1/2

−72.2 ± 1.4

 

−78.2 ± 2.1*

 

−91.8 ± 3.3***

 

  k v

4.2 ± 0.1

 

5.9 ± 0.2***

 

9.4±0.3***

 

Recovery from fast inactivation

 

5

 

8

 

6

τ

1.1 ± 0.1

 

1.1 ± 0.1

 

1.3 ± 0.1

 

Onset of slow inactivation

 

10

 

7

 

8

τfast

39 ± 9.5

 

36 ± 11

 

38 ± 16

 

  Afast

6.4 ± 1.5

 

10 ± 1.4

 

7.9 ± 0.8

 

τslow

3810 ± 465

 

4193 ± 376

 

3085 ± 345

 

Recovery from slow inactivation (4-s cond. pulse)

 

7

 

6

 

7

τfast

3.3 ± 0.5

 

4.2 ± 1.8

 

2 ± 0.2

 

  Afast

47 ± 5.4

 

43 ± 4.9

 

41 ± 5.5

 

τslow

243 ± 43

 

291 ± 79

 

420 ± 105

 

Recovery from slow inactivation (30-s cond. pulse)

 

8

 

5

 

7

τfast

24 ± 12

 

59 ± 16

 

162 ± 46**

 

  Afast

46 ± 6.5

 

54 ± 12

 

41 ± 8.9

 

τslow

382 ± 64

 

726 ± 97**

 

1978 ± 206***

 
  1. V1/2, midpoint for activation or inactivation (mV); k, slope factor for activation or inactivation; τ, time constant (ms); A, fraction of the τ components (%); n, number of cells. Values are means ± sem, *P < 0.05, **P < 0.001, ***P < 0.001, data were significantly different for mutant channels when compared to WT at 22 °C.
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