| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
|
|
|
|||||||
|
|||||||||
Electrophysiology Laboratory, Wyeth Research, Taplow, Berkshire, UK.
1. This study used the whole-cell patch clamp technique to investigate the action of a 28-mer 'inactivation peptide' based on part of the N-terminal sequence of the human Kv3.4 K+ channel (hKv3.4 peptide) on the cloned mouse brain K+ channel mKv1.1 expressed in Chinese hamster ovary (CHO) cells, and compared this with the inactivation produced by Shaker B inactivation peptide (ShB peptide). 2. Inclusion of the hKv3.4 peptide in the patch electrode (320 microM) transformed non-inactivating mKv1.1 into a rapidly inactivating current. The voltage dependence of time constants of decay and steady-state inactivation induced by hKv3.4 peptide were characteristic of an 'A-type' K+ current. 3. The hKv3.4 peptide had no effect on the voltage dependence of activation of mKv1.1, with a mid-point of activation of -8 mV, and a slope factor of 15 mV. Steady-state inactivation curves had a mid-point of inactivation of -36 mV and a slope factor of -7 mV; the time constant of recovery from inactivation at -90 mV was 1.3 s. 4. The chemical modification reagents N-bromoacetamide (NBA, 100 microM) and chloramine-T (CL-T, 500 microM) had no effect on the fast inactivation of mKv1.1 induced by ShB peptide. In contrast, the inactivation caused by hKv3.4 peptide was removed by brief exposure to NBA and CL-T. 5. Chemical modification resulted in a hyperpolarizing shift of -8 mV (CL-T) and -11 mV (NBA) in the voltage dependence of activation of mKv1.1 in the presence of hKv3.4 peptide. 6. Chemical modification was critically dependent on the presence of a cysteine residue at position 6, and not position 24, of hKv3.4 peptide. 7. NBA and CL-T caused only a slight inhibition of unmodified mKv1.1 current with no significant effect on the voltage dependence of mKv1.1 activation, and also had no effect on channel deactivation at -90 mV. 8. Chemical modification experiments were consistent with a selective action on the hKv3.4 peptide itself, specifically at the cysteine residue at position 6.
This article has been cited by other articles:
|
|
 |
|
  G. W. Abbott, M. H. Butler, and S. A. N. Goldstein Phosphorylation and protonation of neighboring MiRP2 sites: function and pathophysiology of MiRP2-Kv3.4 potassium channels in periodic paralysis FASEB J, February 1, 2006; 20(2): 293 - 301. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 W. Ulbricht Sodium Channel Inactivation: Molecular Determinants and Modulation Physiol Rev, October 1, 2005; 85(4): 1271 - 1301. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 R. Wissmann, W. Bildl, D. Oliver, M. Beyermann, H.-R. Kalbitzer, D. Bentrop, and B. Fakler Solution Structure and Function of the "Tandem Inactivation Domain" of the Neuronal A-type Potassium Channel Kv1.4 J. Biol. Chem., April 25, 2003; 278(18): 16142 - 16150. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
R. Wissmann, T. Baukrowitz, H. Kalbacher, H. R. Kalbitzer, J. P. Ruppersberg, O. Pongs, C. Antz, and B. Fakler NMR Structure and Functional Characteristics of the Hydrophilic N Terminus of the Potassium Channel beta -Subunit Kvbeta 1.1 J. Biol. Chem., December 10, 1999; 274(50): 35521 - 35525. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 H. Satoh, H. Katoh, P. Velez, M. Fill, and D. M. Bers Bay K 8644 Increases Resting Ca2+ Spark Frequency in Ferret Ventricular Myocytes Independent of Ca Influx : Contrast With Caffeine and Ryanodine Effects Circ. Res., December 14, 1998; 83(12): 1192 - 1204. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
M. Salinas, J. de Weille, E. Guillemare, M. Lazdunski, and J.-P. Hugnot Modes of Regulation of Shab K+ Channel Activity by the Kv8.1 Subunit J. Biol. Chem., March 28, 1997; 272(13): 8774 - 8780. [Abstract] [Full Text] [PDF]
|
|
| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
