Evidence map›Paper›PMID 24940785›Full record

ArticleBiophysical journal2014

Molecular dynamics simulations elucidate the mechanism of proton transport in the glutamate transporter EAAT3.

Germano Heinzelmann, Serdar Kuyucak

Open access · bronzeAbstract read
In one paragraph

Article in Biophysical journal, 2014. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 9 papers.

0numbers the graph read from it
0cells of the map it votes in
9citing papers in PubMed
1.0field-weighted citation impact, top 29% of its field
1 · What the graph read from it

What it found

Each row is one number read from the abstract, on the scale the paper reported it, with its interval. Left of the dashed line favours the treatment, right favours the comparator. Under each row is the sentence it came from. New to these charts? A ten-minute tutorial.

The abstract states no effect estimate the extractor could read, or names no intervention and outcome on the map, so this paper lights no cell and moves no belief. It is still indexed, cited and linked below.

2 · The registry

The trial behind it

Trials whose registry record cites this paper, or whose number appears in the abstract. A trial that started after this paper was published is citing it as background, not reporting it.

Neither the registry nor the abstract names a trial number. If this is a trial report, that itself is worth knowing.

3 · Its place in the literature

Who cites it

9 citing papers in PubMed, 13 citations in OpenAlex.

  1. Review
  2. Article
  3. Article
  4. A KThe Journal of biological chemistry · 2019
    Article
  5. Shared dynamics of LeuT superfamily members and allosteric differentiation by structural irregularities and multimerization.Philosophical transactions of the Royal Society of London. Series B, Biological sciences · 2018
    Article
  6. Article
  7. Review
  8. Review
  9. Article
4 · The record

Corrections and comments

5 · Who and what money

Authors and funding

2 authors at 1 institution in 1 country.

Germano HeinzelmannSchool of Physics, University of Sydney, NSW 2006, Australia.
Serdar KuyucakSchool of Physics, University of Sydney, NSW 2006, Australia. Electronic address: serdar@physics.usyd.edu.au.
University of Sydney · AU

Funding

No grant is acknowledged in the PubMed record.

6 · The paper itself

Abstract

The uptake of glutamate in nerve synapses is carried out by the excitatory amino acid transporters (EAATs), involving the cotransport of a proton and three Na(+) ions and the countertransport of a K(+) ion. In this study, we use an EAAT3 homology model to calculate the pKa of several titratable residues around the glutamate binding site to locate the proton carrier site involved in the translocation of the substrate. After identifying E374 as the main candidate for carrying the proton, we calculate the protonation state of this residue in different conformations of EAAT3 and with different ligands bound. We find that E374 is protonated in the fully bound state, but removing the Na2 ion and the substrate reduces the pKa of this residue and favors the release of the proton to solution. Removing the remaining Na(+) ions again favors the protonation of E374 in both the outward- and inward-facing states, hence the proton is not released in the empty transporter. By calculating the pKa of E374 with a K(+) ion bound in three possible sites, we show that binding of the K(+) ion is necessary for the release of the proton in the inward-facing state. This suggests a mechanism in which a K(+) ion replaces one of the ligands bound to the transporter, which may explain the faster transport rates of the EAATs compared to its archaeal homologs.

Indexed as

Molecular Dynamics SimulationProtonsAmino Acid Transport System X-AGBinding SitesCrystallography, X-RayGlutamic AcidIon TransportModels, MolecularProtein ConformationStructural Homology, ProteinThermodynamicsAmino Acid Transport System X-AGGlutamic AcidProtons

Identifiers

PMID24940785
PMCPMC4070078
OpenAlexW2118621293

What OpenQuestion holds

Textmetadata
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Registered trials

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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.