|
|
|
|
|
|
|
||
| ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
The Journal of General Physiology, Vol 92, 549-567, Copyright © 1988 by The Rockefeller University Press
ARTICLES |
J Neyton and C Miller
Graduate Department of Biochemistry, Brandeis University, Waltham, Massachusetts 02254.
Single high-conductance Ca2+-activated K+ channels from rat skeletal muscle were inserted into planar lipid bilayers, and discrete blocking by the Ba2+ ion was studied. Specifically, the ability of external K+ to reduce the Ba2+ dissociation rate was investigated. In the presence of 150 mM internal K+, 1-5 microM internal Ba2+, and 150 mM external Na+, Ba2+ dissociation is rapid (5 s-1) in external solutions that are kept rigorously K+ free. The addition of external K+ in the low millimolar range reduces the Ba2+ off-rate 20-fold. Other permeant ions, such as Tl+, Rb+, and NH4+ show a similar effect. The half- inhibition constants rise in the order: Tl+ (0.08 mM) less than Rb+ (0.1 mM) less than K+ (0.3 mM) less than Cs+ (0.5 mM) less than NH4+ (3 mM). When external Na+ is replaced by 150 mM N-methyl glucamine, the Ba2+ off-rate is even higher, 20 s-1. External K+ and other permeant ions reduce this rate by approximately 100-fold in the micromolar range of concentrations. Na+ also reduces the Ba2+ off-rate, but at much higher concentrations. The half-inhibition concentrations rise in the order: Rb+ (4 microM) less than K+ (19 microM) much less than Na+ (27 mM) less than Li+ (greater than 50 mM). The results require that the conduction pore of this channel contains at least three sites that may all be occupied simultaneously by conducting ions.
CiteULike 
Complore 
Connotea 
Del.icio.us 
Digg 
Facebook 
Reddit 
Technorati 
Twitter What's this?
This article has been cited by other articles:
|
|
 |
|
  A. Bruening-Wright, W.-S. Lee, J. P. Adelman, and J. Maylie Evidence for a Deep Pore Activation Gate in Small Conductance Ca2+-activated K+ Channels J. Gen. Physiol., November 26, 2007; 130(6): 601 - 610. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
G. Panyi and C. Deutsch Probing the Cavity of the Slow Inactivated Conformation of Shaker Potassium Channels J. Gen. Physiol., April 30, 2007; 129(5): 403 - 418. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 A. Qian and J. W. Johnson Permeant Ion Effects on External Mg2+ Block of NR1/2D NMDA Receptors. J. Neurosci., October 18, 2006; 26(42): 10899 - 10910. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
R. A. Piskorowski and R. W. Aldrich Relationship between Pore Occupancy and Gating in BK Potassium Channels J. Gen. Physiol., April 24, 2006; 127(5): 557 - 576. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
N. D'Avanzo, H. C. Cho, I. Tolokh, R. Pekhletski, I. Tolokh, C. Gray, S. Goldman, and P. H. Backx Conduction through the Inward Rectifier Potassium Channel, Kir2.1, Is Increased by Negatively Charged Extracellular Residues J. Gen. Physiol., April 25, 2005; 125(5): 493 - 503. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 S. Somodi, Z. Varga, P. Hajdu, J. G. Starkus, D. I. Levy, R. Gaspar, and G. Panyi pH-dependent modulation of Kv1.3 inactivation: role of His399 Am J Physiol Cell Physiol, October 1, 2004; 287(4): C1067 - C1076. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
T. Haug, D. Sigg, S. Ciani, L. Toro, E. Stefani, and R. Olcese Regulation of K+ Flow by a Ring of Negative Charges in the Outer Pore of BKCa Channels. Part I: Aspartate 292 modulates K+ Conduction by External Surface Charge Effect J. Gen. Physiol., July 26, 2004; 124(2): 173 - 184. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
G. Gibor, D. Yakubovich, A. Peretz, and B. Attali External Barium Affects the Gating of KCNQ1 Potassium Channels and Produces a Pore Block via Two Discrete Sites J. Gen. Physiol., June 28, 2004; 124(1): 83 - 102. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
F. Gomez-Lagunas, C. V.F. Batista, T. Olamendi-Portugal, M. E. Ramirez-Dominguez, and L. D. Possani Inhibition of the Collapse of the Shaker K+ Conductance by Specific Scorpion Toxins J. Gen. Physiol., February 23, 2004; 123(3): 265 - 279. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
X. Gong and P. Linsdell Mutation-induced Blocker Permeability and Multiion Block of the CFTR Chloride Channel Pore J. Gen. Physiol., November 24, 2003; 122(6): 673 - 687. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 X. Gong and P. Linsdell Coupled movement of permeant and blocking ions in the CFTR chloride channel pore J. Physiol., June 1, 2003; 549(2): 375 - 385. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
J. Thompson and T. Begenisich Functional identification of ion binding sites at the internal end of the pore in Shaker K+ channels J. Physiol., May 15, 2003; 549(1): 107 - 120. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 T. E. Decoursey Voltage-Gated Proton Channels and Other Proton Transfer Pathways Physiol Rev, April 1, 2003; 83(2): 475 - 579. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
F. M. Mullins, S. Z. Stepanovic, R. R. Desai, A. L. George Jr., and J. R. Balser Extracellular Sodium Interacts with the HERG Channel at an Outer Pore Site J. Gen. Physiol., September 30, 2002; 120(4): 517 - 537. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
D. Guo and Z. Lu IRK1 Inward Rectifier K+ Channels Exhibit No Intrinsic Rectification J. Gen. Physiol., September 30, 2002; 120(4): 539 - 551. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
C. M. Nimigean and C. Miller Na+ Block and Permeation in a K+ Channel of Known Structure J. Gen. Physiol., August 26, 2002; 120(3): 323 - 335. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
Z. Varga, M. D. Rayner, and J. G. Starkus Cations Affect the Rate of Gating Charge Recovery in Wild-type and W434F Shaker Channels through a Variety of Mechanisms J. Gen. Physiol., May 1, 2002; 119(5): 467 - 486. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
P. Linsdell and X. Gong Multiple inhibitory effects of Au(CN)2- ions on cystic fibrosis transmembrane conductance regulator Cl- channel currents J. Physiol., April 1, 2002; 540(1): 29 - 38. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
A. Qian, S. M Antonov, and J. W Johnson Modulation by permeant ions of Mg2+ inhibition of NMDA-activated whole-cell currents in rat cortical neurons J. Physiol., January 1, 2002; 538(1): 65 - 77. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
F. Gomez-Lagunas Na+ Interaction with the Pore of Shaker B K+ Channels: Zero and Low K+ Conditions J. Gen. Physiol., December 1, 2001; 118(6): 639 - 648. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
T. Lu, L. Wu, J. Xiao, and J. Yang Permeant Ion-Dependent Changes in Gating of Kir2.1 Inward Rectifier Potassium Channels J. Gen. Physiol., November 1, 2001; 118(5): 509 - 522. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
M. LeMasurier, L. Heginbotham, and C. Miller Kcsa: It's a Potassium Channel J. Gen. Physiol., September 1, 2001; 118(3): 303 - 314. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
R-C Shieh and Y-L Lee Ammonium ions induce inactivation of Kir2.1 potassium channels expressed in Xenopus oocytes J. Physiol., September 1, 2001; 535(2): 359 - 370. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
N. Alagem, M. Dvir, and E. Reuveny Mechanism of Ba2+ block of a mouse inwardly rectifying K+ channel: differential contribution by two discrete residues J. Physiol., July 15, 2001; 534(2): 381 - 393. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
J. Thompson and T. Begenisich Affinity and Location of an Internal K+ Ion Binding Site in Shaker K Channels J. Gen. Physiol., May 1, 2001; 117(5): 373 - 384. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
N. Zilberberg, N. Ilan, R. Gonzalez-Colaso, and S. A.N. Goldstein Opening and Closing of KcnkO Potassium Leak Channels Is Tightly Regulated J. Gen. Physiol., November 1, 2000; 116(5): 721 - 734. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
R. K. Cloues, S. M. Cibulsky, and W. A. Sather Ion Interactions in the High-Affinity Binding Locus of a Voltage-Gated Ca2+ Channel J. Gen. Physiol., October 1, 2000; 116(4): 569 - 586. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
S. M. Cibulsky and W. A. Sather The Eeee Locus Is the Sole High-Affinity Ca2+ Binding Structure in the Pore of a Voltage-Gated Ca2+ Channel: Block by Ca2+ Entering from the Intracellular Pore Entrance J. Gen. Physiol., September 1, 2000; 116(3): 349 - 362. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
J. Thompson and T. Begenisich Interaction between Quaternary Ammonium Ions in the Pore of Potassium Channels: Evidence against an Electrostatic Repulsion Mechanism J. Gen. Physiol., June 1, 2000; 115(6): 769 - 782. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
Y. Jiang and R. MacKinnon The Barium Site in a Potassium Channel by X-Ray Crystallography J. Gen. Physiol., March 1, 2000; 115(3): 269 - 272. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 S. M. Antonov and J. W. Johnson Permeant ion regulation of N-methyl-D-aspartate receptor channel block by Mg2+ PNAS, December 7, 1999; 96(25): 14571 - 14576. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
C. Vergara, O. Alvarez, and R. Latorre Localization of the K+ Lock-in and the Ba2+ Binding Sites in a Voltage-Gated Calcium-Modulated Channel: Implications for Survival of K+ Permeability J. Gen. Physiol., September 1, 1999; 114(3): 365 - 376. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
M. Spassova and Z. Lu Tuning the Voltage Dependence of Tetraethylammonium Block with Permeant Ions in an Inward-Rectifier K+ Channel J. Gen. Physiol., September 1, 1999; 114(3): 415 - 426. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 M. Grunnet, H.-G. Knaus, C. Solander, and D. A. Klaerke Quantification and distribution of Ca2+-activated maxi K+ channels in rabbit distal colon Am J Physiol Gastrointest Liver Physiol, July 1, 1999; 277(1): G22 - G30. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
E. Garcia, M. Scanlon, and D. Naranjo A Marine Snail Neurotoxin Shares with Scorpion Toxins a Convergent Mechanism of Blockade on the Pore of Voltage-Gated K Channels J. Gen. Physiol., July 1, 1999; 114(1): 141 - 158. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
E. M. Ogielska and R. W. Aldrich Functional Consequences of a Decreased Potassium Affinity in a Potassium Channel Pore: Ion Interactions and C-Type Inactivation J. Gen. Physiol., February 1, 1999; 113(2): 347 - 358. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
H. Choe, H. Sackin, and L. G. Palmer Permeation and Gating of an Inwardly Rectifying Potassium Channel: Evidence for a Variable Energy Well J. Gen. Physiol., October 1, 1998; 112(4): 433 - 446. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
M. Spassova and Z. Lu Coupled Ion Movement Underlies Rectification in an Inward-Rectifier K+ Channel J. Gen. Physiol., August 1, 1998; 112(2): 211 - 221. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
E. M. Ogielska and R. W. Aldrich A Mutation in S6 of Shaker Potassium Channels Decreases the K+ Affinity of an Ion Binding Site Revealing Ion-Ion Interactions in the Pore J. Gen. Physiol., August 1, 1998; 112(2): 243 - 257. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
G. A Hicks and N. V Marrion Ca2+-dependent inactivation of large conductance Ca2+-activated K+ (BK) channels in rat hippocampal neurones produced by pore block from an associated particle J. Physiol., May 1, 1998; 508(3): 721 - 734. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
R. A. Bello and K. L. Magleby Time-irreversible Subconductance Gating Associated with Ba2+ Block of Large Conductance Ca2+-activated K+ Channels J. Gen. Physiol., February 1, 1998; 111(2): 343 - 362. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
Z. Varga, M. D. Rayner, and J. G. Starkus Cations Affect the Rate of Gating Charge Recovery in Wild-type and W434F Shaker Channels through a Variety of Mechanisms J. Gen. Physiol., May 1, 2002; 119(5): 467 - 486. [Abstract] [Full Text] [PDF]
|
|
|
|
