Jove
Visualize
Contact Us
JoVE
x logofacebook logolinkedin logoyoutube logo
ABOUT JoVE
OverviewLeadershipBlogJoVE Help Center
AUTHORS
Publishing ProcessEditorial BoardScope & PoliciesPeer ReviewFAQSubmit
LIBRARIANS
TestimonialsSubscriptionsAccessResourcesLibrary Advisory BoardFAQ
RESEARCH
JoVE JournalMethods CollectionsJoVE Encyclopedia of ExperimentsArchive
EDUCATION
JoVE CoreJoVE BusinessJoVE Science EducationJoVE Lab ManualFaculty Resource CenterFaculty Site
Terms & Conditions of Use
Privacy Policy
Policies

Related Experiment Videos

Side-chain ionization states in a potassium channel.

K M Ranatunga1, I H Shrivastava, G R Smith

  • 1Biophysics Section, Blackett Laboratory, Imperial College of Science, Technology, and Medicine, London SW7 2BZ, United Kingdom.

Biophysical Journal
|February 27, 2001
PubMed
Summary

The KcsA potassium channel

Related Concept Videos

You might also read

Related Articles

Articles linked to this work by shared authors, journal, and citation graph.

Sort by
Same author

New Measurements of the Deuteron-to-Proton F_{2} Structure-Function Ratio.

Physical review letters·2025
Same author

Formation of protein adducts with Hydroperoxy-PE electrophilic cleavage products during ferroptosis.

Redox biology·2023
Same author

Measured proton electromagnetic structure deviates from theoretical predictions.

Nature·2022
Same author

Deeply Virtual Compton Scattering Cross Section at High Bjorken x_{B}.

Physical review letters·2022
Same author

Determination of the ^{27}Al Neutron Distribution Radius from a Parity-Violating Electron Scattering Measurement.

Physical review letters·2022
Same author

Form Factors and Two-Photon Exchange in High-Energy Elastic Electron-Proton Scattering.

Physical review letters·2022

Area of Science:

  • Biophysics
  • Structural Biology
  • Computational Biology

Background:

  • KcsA is a pH-gated bacterial potassium channel.
  • Its structure reveals key side chains near the selectivity filter.
  • Understanding ion permeation requires knowledge of channel gating mechanisms.

Purpose of the Study:

  • To investigate the interplay between pH-gating, ion occupancy, and side chain ionization states in the KcsA channel.
  • To elucidate how these factors influence the K+ ion permeation pathway.

Main Methods:

  • Continuum dielectric calculations were performed on the KcsA crystal structure.
  • The model included the channel protein embedded in a low dielectric slab.
  • Simulations analyzed the effects of K+ ion presence on side chain protonation states.

Main Results:

  • At pH 7, E71 and D80 form a proton-sharing pair, with E71 neutral and D80 negative.
  • K+ ion binding, particularly at site S3, alters this proton sharing.
  • Multiple K+ ions promote E71 ionization and D80 neutrality, affecting the ion's potential energy profile.

Conclusions:

  • The ionization states of E71-D80 modulate the K+ ion potential energy profile within the KcsA channel pore.
  • Reciprocal effects between ion occupancy and side chain ionization complicate simulations of ion permeation energetics.

Related Experiment Videos