Barium inhibition of the collapse of the Shaker K+ conductance in zero K+

5Citations
Citations of this article
5Readers
Mendeley users who have this article in their library.

Abstract

In the absence of K+ on both sides of the membrane, delivery of standard activating pulses collapses the Shaker B K+ conductance. Prolonged depolarizations restore the ability to conduct K+. It has been proposed that the collapse of the conductance results from the dwelling of the channels in a stable closed (noninactivated) state (Gomez-Lagunas, 1997, J. Physiol. (Lond.). 499:3-15). Here it is shown that 1) Ba2+ impedes the collapse of the K+ conductance, protecting it from both sides of the membrane; 2) external Ba2+ protection (K(d) = 63 μM at -80 mV) decreases slightly as the holding potential (HP) is made more negative; 3) external Ba2+ cannot restore the previously collapsed conductance; on the other hand, 4) internal Ba2+ (and K+) protection markedly decreases with hyperpolarized HPs (-80 to -120 mV), and it is not dependent on the pulse potential (0 to +60 mV). Ba2+ is an effective K+ substitute, inhibiting the passage of the channels into the stable nonconducting (noninactivated) mode of gating.

Cite

CITATION STYLE

APA

Gómez-Lagunas, F. (1999). Barium inhibition of the collapse of the Shaker K+ conductance in zero K+. Biophysical Journal, 77(6), 2988–2998. https://doi.org/10.1016/S0006-3495(99)77130-4

Register to see more suggestions

Mendeley helps you to discover research relevant for your work.

Already have an account?

Save time finding and organizing research with Mendeley

Sign up for free