ArticleProceedings of the National Academy of Sciences of the United States of America2012
Protonation state of E71 in KcsA and its role for channel collapse and inactivation.
Article in Proceedings of the National Academy of Sciences of the United States of America, 2012. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 48 papers.
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48 citing papers in PubMed, 75 citations in OpenAlex.
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- High-Resolution Magic Angle Spinning NMR of KcsA in Liposomes: The Highly Mobile C-Terminus.Biomolecules · 2022Article
- Direct Detection of Bound Ammonium Ions in the Selectivity Filter of Ion Channels by Solid-State NMR.Journal of the American Chemical Society · 2022Article
- Informing NMR experiments with molecular dynamics simulations to characterize the dominant activated state of the KcsA ion channel.The Journal of chemical physics · 2021Article
- NMR studies of lipid regulation of the KBiochimica et biophysica acta. Biomembranes · 2021Article
- Mechanism of C-type inactivation in the hERG potassium channel.Science advances · 2021Article
- Membrane Protein Structure Determination and Characterisation by Solution and Solid-State NMR.Biology · 2020Review
- Open and Closed Structures of a Barium-Blocked Potassium Channel.Journal of molecular biology · 2020Article
- Probing allosteric coupling in a constitutively open mutant of the ion channel KcsA using solid-state NMR.Proceedings of the National Academy of Sciences of the United States of America · 2020Article
- Conformational changes upon gating of KirBac1.1 into an open-activated state revealed by solid-state NMR and functional assays.Proceedings of the National Academy of Sciences of the United States of America · 2020Article
- The influence of membrane bilayer thickness on KcsA channel activity.Channels (Austin, Tex.) · 2019Article
- High-speed AFM reveals accelerated binding of agitoxin-2 to a KScience advances · 2019Article
- pH-Dependent Conformational Changes of KcsA Tetramer and Monomer Probed by Raman Spectroscopy.International journal of molecular sciences · 2019Article
- Identifying coupled clusters of allostery participants through chemical shift perturbations.Proceedings of the National Academy of Sciences of the United States of America · 2019Article
- Shifts in the selectivity filter dynamics cause modal gating in KNature communications · 2019Article
- Rapid constriction of the selectivity filter underlies C-type inactivation in the KcsA potassium channel.The Journal of general physiology · 2018Article
- Structure and Dynamics of Membrane Proteins from Solid-State NMR.Annual review of biophysics · 2018Review
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2 authors at 1 institution in 1 country.
Funding
Abstract
The prototypical prokaryotic potassium channel KcsA alters its pore depending on the ambient potassium; at high potassium, it exists in a conductive form, and at low potassium, it collapses into a nonconductive structure with reduced ion occupancy. We present solid-state NMR studies of KcsA in which we test the hypothesis that an important channel-inactivation process, known as C-type inactivation, proceeds via a state similar to this collapsed state. We test this using an inactivation-resistant mutant E71A, and show that E71A is unable to collapse its pore at both low potassium and low pH, suggesting that the collapsed state is structurally similar to the inactivated state. We also show that E71A has a disordered selectivity filter. Using site-specific K(+) titrations, we detect a local change at E71 that is coupled to channel collapse at low K(+). To gain more insight into this change, we site specifically measure the chemical shift tensors of the side-chain carboxyls of E71 and its hydrogen bond partner D80, and use the tensors to assign protonation states to E71 and D80 at high K(+) and neutral pH. Our measurements show that E71 is protonated at pH 7.5 and must have an unusually perturbed pK(a) (> 7.5) suggesting that the change at E71 is a structural rearrangement rather than a protonation event. The results offer new mechanistic insights into why the widely used mutant KcsA-E71A does not inactivate and establish the ambient K(+) level as a means to populate the inactivated state of KcsA in a controlled way.
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Read under generation 80e0d062 · epoch 390. Bibliography from PubMed, PubMed Central and OpenAlex; grants from NIH RePORTER; trial links from ClinicalTrials.gov; estimates, votes and beliefs from the OpenQuestion graph.