| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
Biophysical Journal 66: 996-1010 (1994)
© 1994 the Biophysical Society
Department of Molecular Physiology and Biophysics, Baylor College of Medicine, Houston, Texas 77030.
ABSTRACT
Ionic and gating currents from noninactivating Shaker B K+ channels were studied with the cut-open oocyte voltage clamp technique and compared with the macropatch clamp technique. The performance of the cut-open oocyte voltage clamp technique was evaluated from the electrical properties of the clamped upper domus membrane, K+ tail current measurements, and the time course of K+ currents after partial blockade. It was concluded that membrane currents less than 20 microA were spatially clamped with a time resolution of at least 50 microseconds. Subtracted, unsubtracted gating currents with the cut-open oocyte voltage clamp technique and gating currents recorded in cell attached macropatches had similar properties and time course, and the charge movement properties directly obtained from capacity measurements agreed with measurements of charge movement from subtracted records. An accurate estimate of the normalized open probability Po(V) was obtained from tail current measurements as a function of the prepulse V in high external K+. The Po(V) was zero at potentials more negative than -40 mV and increased sharply at this potential, then increased continuously until -20 mV, and finally slowly increased with voltages more positive than 0 mV. Deactivation tail currents decayed with two time constants and external potassium slowed down the faster component without affecting the slower component that is probably associated with the return between two of the closed states near the open state. In correlating gating currents and channel opening, Cole-Moore type experiments showed that charge moving in the negative region of voltage (-100 to -40 mV) is involved in the delay of the conductance activation but not in channel opening. The charge moving in the more positive voltage range (-40 to -10 mV) has a similar voltage dependence to the open probability of the channel, but it does not show the gradual increase with voltage seen in the Po(V).
This article has been cited by other articles:
 |
|
 |
|
  U. Laitko, P. F. Juranka, and C. E. Morris Membrane Stretch Slows the Concerted Step prior to Opening in a Kv Channel J. Gen. Physiol., May 30, 2006; 127(6): 687 - 701. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 J. P. A. Bannister, B. Chanda, F. Bezanilla, and D. M. Papazian Optical detection of rate-determining ion-modulated conformational changes of the ether-a-go-go K+ channel voltage sensor PNAS, December 20, 2005; 102(51): 18718 - 18723. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
K. J. Swartz Structure and Anticipatory Movements of the S6 Gate in K v Channels J. Gen. Physiol., October 31, 2005; 126(5): 413 - 417. [Full Text] [PDF]
|
|
|
|
 |
|
 M. Caprini, M. Fava, P. Valente, G. Fernandez-Ballester, C. Rapisarda, S. Ferroni, and A. Ferrer-Montiel Molecular Compatibility of the Channel Gate and the N Terminus of S5 Segment for Voltage-gated Channel Activity J. Biol. Chem., May 6, 2005; 280(18): 18253 - 18264. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
S. Chakrapani and A. Auerbach A speed limit for conformational change of an allosteric membrane protein PNAS, January 4, 2005; 102(1): 87 - 92. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
D. D.F. Loo, B. A. Hirayama, A. Cha, F. Bezanilla, and E. M. Wright Perturbation Analysis of the Voltage-sensitive Conformational Changes of the Na+/Glucose Cotransporter J. Gen. Physiol., December 28, 2004; 125(1): 13 - 36. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
M. Pathak, L. Kurtz, F. Tombola, and E. Isacoff The Cooperative Voltage Sensor Motion that Gates a Potassium Channel J. Gen. Physiol., December 28, 2004; 125(1): 57 - 69. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
A. Kuzmenkin, F. Bezanilla, and A. M. Correa Gating of the Bacterial Sodium Channel, NaChBac: Voltage-dependent Charge Movement and Gating Currents J. Gen. Physiol., September 27, 2004; 124(4): 349 - 356. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 D. L. Prole and N. V. Marrion Ionic Permeation and Conduction Properties of Neuronal KCNQ2/KCNQ3 Potassium Channels Biophys. J., March 1, 2004; 86(3): 1454 - 1469. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 L. Catacuzzeno, B. Fioretti, and F. Franciolini Voltage-Gated Outward K Currents in Frog Saccular Hair Cells J Neurophysiol, December 1, 2003; 90(6): 3688 - 3701. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
D. R. Piper, A. Varghese, M. C. Sanguinetti, and M. Tristani-Firouzi Gating currents associated with intramembrane charge displacement in HERG potassium channels PNAS, September 2, 2003; 100(18): 10534 - 10539. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
D. Sigg, F. Bezanilla, and E. Stefani Fast gating in the Shaker K+ channel and the energy landscape of activation PNAS, June 24, 2003; 100(13): 7611 - 7615. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
D. Sigg and F. Bezanilla A Physical Model of Potassium Channel Activation: From Energy Landscape to Gating Kinetics Biophys. J., June 1, 2003; 84(6): 3703 - 3716. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
F. Gomez-Lagunas, A. Melishchuk, and C. M. Armstrong Block of Shaker potassium channels by external calcium ions PNAS, January 7, 2003; 100(1): 347 - 351. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
M. Tristani-Firouzi, J. Chen, and M. C. Sanguinetti Interactions between S4-S5 Linker and S6 Transmembrane Domain Modulate Gating of HERG K+ Channels J. Biol. Chem., May 17, 2002; 277(21): 18994 - 19000. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 F. Bezanilla The Voltage Sensor in Voltage-Dependent Ion Channels Physiol Rev, April 1, 2000; 80(2): 555 - 592. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 J. C. Hesketh and D. Fedida Sequential gating in the human heart K+ channel Kv1.5 incorporates Q1 and Q2 charge components Am J Physiol Heart Circ Physiol, November 1, 1999; 277(5): H1956 - H1966. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 J. Li and H. A. Lester Single-Channel Kinetics of the Rat Olfactory Cyclic Nucleotide-Gated Channel Expressed in Xenopus Oocytes Mol. Pharmacol., May 1, 1999; 55(5): 883 - 893. [Abstract] [Full Text]
|
|
|
|
 |
|
 A. M. Correa Gating kinetics of Shaker K+ channels are differentially modified by general anesthetics Am J Physiol Cell Physiol, October 1, 1998; 275(4): C1009 - C1021. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
K. G. Klemic, D. M. Durand, and S. W. Jones Activation Kinetics of the Delayed Rectifier Potassium Current of Bullfrog Sympathetic Neurons J Neurophysiol, May 1, 1998; 79(5): 2345 - 2357. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 R. L. Rasmusson, M. J. Morales, S. Wang, S. Liu, D. L. Campbell, M. V. Brahmajothi, and H. C. Strauss Inactivation of Voltage-Gated Cardiac K+ Channels Circ. Res., April 20, 1998; 82(7): 739 - 750. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 X. Zhang, J. W. Anderson, and D. Fedida J. Pharmacol. Exp. Ther., June 1, 1997; 281(3): 1247 - 1256. [Abstract] [Full Text]
|
|
|
|
|
|
E. Stefani, M. Ottolia, F. Noceti, R. Olcese, M. Wallner, R. Latorre, and L. Toro Voltage-controlled gating in a large conductance Ca2+-sensitive K+channel (hslo) PNAS, May 13, 1997; 94(10): 5427 - 5431. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
M. Caprini, S. Ferroni, R. Planells-Cases, J. Rueda, C. Rapisarda, A. Ferrer-Montiel, and M. Montal Structural Compatibility between the Putative Voltage Sensor of Voltage-gated K+ Channels and the Prokaryotic KcsA Channel J. Biol. Chem., June 8, 2001; 276(24): 21070 - 21076. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
M. Song, G. Helguera, M. Eghbali, N. Zhu, M. M. Zarei, R. Olcese, L. Toro, and E. Stefani Remodeling of Kv4.3 Potassium Channel Gene Expression under the Control of Sex Hormones J. Biol. Chem., August 17, 2001; 276(34): 31883 - 31890. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 P. Castaldo, E. M. del Giudice, G. Coppola, A. Pascotto, L. Annunziato, and M. Taglialatela Benign Familial Neonatal Convulsions Caused by Altered Gating of KCNQ2/KCNQ3 Potassium Channels J. Neurosci., January 15, 2002; 22(2): RC199 - RC199. [Abstract] [Full Text] [PDF]
|
|
| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
