Skip to main content
Advertisement

Main menu

  • Home
  • Articles
    • Current Issue
    • Fast Forward
    • Latest Articles
    • Special Sections
    • Archive
  • Information
    • Instructions to Authors
    • Submit a Manuscript
    • FAQs
    • For Subscribers
    • Terms & Conditions of Use
    • Permissions
  • Editorial Board
  • Alerts
    • Alerts
    • RSS Feeds
  • Virtual Issues
  • Feedback
  • Submit
  • Other Publications
    • Drug Metabolism and Disposition
    • Journal of Pharmacology and Experimental Therapeutics
    • Molecular Pharmacology
    • Pharmacological Reviews
    • Pharmacology Research & Perspectives
    • ASPET

User menu

  • My alerts
  • Log in
  • My Cart

Search

  • Advanced search
Molecular Pharmacology
  • Other Publications
    • Drug Metabolism and Disposition
    • Journal of Pharmacology and Experimental Therapeutics
    • Molecular Pharmacology
    • Pharmacological Reviews
    • Pharmacology Research & Perspectives
    • ASPET
  • My alerts
  • Log in
  • My Cart
Molecular Pharmacology

Advanced Search

  • Home
  • Articles
    • Current Issue
    • Fast Forward
    • Latest Articles
    • Special Sections
    • Archive
  • Information
    • Instructions to Authors
    • Submit a Manuscript
    • FAQs
    • For Subscribers
    • Terms & Conditions of Use
    • Permissions
  • Editorial Board
  • Alerts
    • Alerts
    • RSS Feeds
  • Virtual Issues
  • Feedback
  • Submit
  • Visit molpharm on Facebook
  • Follow molpharm on Twitter
  • Follow molpharm on LinkedIn
Abstract

Barium blockade of a clonal potassium channel and its regulation by a critical pore residue.

M Taglialatela, J A Drewe and A M Brown
Molecular Pharmacology July 1993, 44 (1) 180-190;
M Taglialatela
  • Find this author on Google Scholar
  • Find this author on PubMed
  • Search for this author on this site
J A Drewe
  • Find this author on Google Scholar
  • Find this author on PubMed
  • Search for this author on this site
A M Brown
  • Find this author on Google Scholar
  • Find this author on PubMed
  • Search for this author on this site
  • Article
  • Info & Metrics
  • eLetters
  • PDF
Loading

Abstract

Barium ion (Ba2+) has the same crystal radius as potassium ion but blocks rather than permeates the ion-conducting pore of K+ channels. Ba2+ ion may therefore be used as a probe of residues lining the pore of K+ channels, and we applied it to test the position and function of a residue crucial for K+/Rb+ selectivity and blockade by internal tetraethylammonium. We examined blockade by internal and external Ba2+ of the delayed rectifier K+ channel DRK1 (Kv2.1) and tested the effects of point mutations at pore residue 374. Internal Ba2+ blocked the wild-type open channel with high affinity (Kd = 13 microM). Blockade involved more than one site, was voltage dependent, and increased at more positive potentials. Mutation of V374 to threonine or serine produced a significant decrease in the rate of dissociation of internal Ba2+ from the pore, whereas mutation of V374 to isoleucine produced no change. For wild-type channels, external Ba2+ decreased the rate of activation of the K+ current, suggesting that Ba2+ can interact with closed DRK1 channels. This result was unaffected by the V374T substitution. Furthermore, external Ba2+ also caused a very low affinity (Kd approximately 30 mM) and voltage-independent block of the open DRK1 channel. Thus, Ba2+ blocked the pore at internal and external sites, which were clearly distinguishable. The effects of substitution at position 374 with residues having polar hydroxyls are consistent with position 374 being at a surface position critical for ion permeation, near the inner mouth of the pore.

MolPharm articles become freely available 12 months after publication, and remain freely available for 5 years. 

Non-open access articles that fall outside this five year window are available only to institutional subscribers and current ASPET members, or through the article purchase feature at the bottom of the page. 

 

  • Click here for information on institutional subscriptions.
  • Click here for information on individual ASPET membership.

 

Log in using your username and password

Forgot your user name or password?

Purchase access

You may purchase access to this article. This will require you to create an account if you don't already have one.
PreviousNext
Back to top

In this issue

Molecular Pharmacology
Vol. 44, Issue 1
1 Jul 1993
  • Table of Contents
  • Table of Contents (PDF)
  • Index by author
  • Back Matter (PDF)
  • Editorial Board (PDF)
  • Front Matter (PDF)
Download PDF
Article Alerts
Sign In to Email Alerts with your Email Address
Email Article

Thank you for sharing this Molecular Pharmacology article.

NOTE: We request your email address only to inform the recipient that it was you who recommended this article, and that it is not junk mail. We do not retain these email addresses.

Enter multiple addresses on separate lines or separate them with commas.
Barium blockade of a clonal potassium channel and its regulation by a critical pore residue.
(Your Name) has forwarded a page to you from Molecular Pharmacology
(Your Name) thought you would be interested in this article in Molecular Pharmacology.
CAPTCHA
This question is for testing whether or not you are a human visitor and to prevent automated spam submissions.
Citation Tools
Abstract

Barium blockade of a clonal potassium channel and its regulation by a critical pore residue.

M Taglialatela, J A Drewe and A M Brown
Molecular Pharmacology July 1, 1993, 44 (1) 180-190;

Citation Manager Formats

  • BibTeX
  • Bookends
  • EasyBib
  • EndNote (tagged)
  • EndNote 8 (xml)
  • Medlars
  • Mendeley
  • Papers
  • RefWorks Tagged
  • Ref Manager
  • RIS
  • Zotero

Share
Abstract

Barium blockade of a clonal potassium channel and its regulation by a critical pore residue.

M Taglialatela, J A Drewe and A M Brown
Molecular Pharmacology July 1, 1993, 44 (1) 180-190;
Reddit logo Twitter logo Facebook logo Mendeley logo
  • Tweet Widget
  • Facebook Like
  • Google Plus One

Jump to section

  • Article
  • Info & Metrics
  • eLetters
  • PDF

Related Articles

Cited By...

Similar Articles

Advertisement
  • Home
  • Alerts
Facebook   Twitter   LinkedIn   RSS

Navigate

  • Current Issue
  • Fast Forward by date
  • Fast Forward by section
  • Latest Articles
  • Archive
  • Search for Articles
  • Feedback
  • ASPET

More Information

  • About Molecular Pharmacology
  • Editorial Board
  • Instructions to Authors
  • Submit a Manuscript
  • Customized Alerts
  • RSS Feeds
  • Subscriptions
  • Permissions
  • Terms & Conditions of Use

ASPET's Other Journals

  • Drug Metabolism and Disposition
  • Journal of Pharmacology and Experimental Therapeutics
  • Pharmacological Reviews
  • Pharmacology Research & Perspectives
ISSN 1521-0111 (Online)

Copyright © 2023 by the American Society for Pharmacology and Experimental Therapeutics