Evidence map›Paper›PMID 19211559›Full record

ArticleThe Journal of biological chemistry2009

The mechanism of photo-energy storage in the Halorhodopsin chloride pump.

Christoph Pfisterer, Andreea Gruia, Stefan Fischer

Open access · hybridAbstract read
In one paragraph

Article in The Journal of biological chemistry, 2009. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 7 papers.

0numbers the graph read from it
0cells of the map it votes in
7citing papers in PubMed
0.6field-weighted citation impact, top 39% 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

7 citing papers in PubMed, 17 citations in OpenAlex.

  1. Article
  2. Article
  3. Energy utilization in fluctuating biological energy converters.Structural dynamics (Melville, N.Y.) · 2016
    Article
  4. Article
  5. Catalytic strategy used by the myosin motor to hydrolyze ATP.Proceedings of the National Academy of Sciences of the United States of America · 2014
    Article
  6. The photochemical determinants of color vision: revealing how opsins tune their chromophore's absorption wavelength.BioEssays : news and reviews in molecular, cellular and developmental biology · 2014
    Review
  7. Optical control of neuronal activity.Annual review of biophysics · 2010
    Review
4 · The record

Corrections and comments

PubMed lists nothing against this paper. Absence here is not a guarantee, only a check that was made.

5 · Who and what money

Authors and funding

3 authors at 1 institution in 1 country.

Christoph PfistererComputational Biochemistry Group, IWR, University of Heidelberg, 69120 Heidelberg, Germany.
Andreea GruiaComputational Biochemistry Group, IWR, University of Heidelberg, 69120 Heidelberg, Germany.
Stefan FischerComputational Biochemistry Group, IWR, University of Heidelberg, 69120 Heidelberg, Germany. Electronic address: Stefan.Fischer@iwr.uni-heidelberg.de.
Heidelberg University · DE

Funding

No grant is acknowledged in the PubMed record.

6 · The paper itself

Abstract

The light-driven pump Halorhodopsin (hR) uses the energy stored in an initial meta-stable state (K), in which the bound retinal chromophore has been photoisomerized from all-trans to 13-cis, to drive the translocation of one chloride anion across the membrane. Thus far it was unclear whether retinal twisting or charge separation between the positive Schiff base of the retinal and the chloride anion is the primary mechanism of energy storage. Here, combined quantum mechanical/molecular mechanical (QM/MM) simulations show that the energy is predominantly stored by charge separation. However, a large variability in retinal twisting is observed, thus reconciling the contradictory hypotheses for storage. Surprisingly, the energy stored in the K-state amounts to only one-fifth of the photon energy. We explain why the protein cannot store more: even though this would accelerate chloride pumping, raising the K-state also reduces the relative energy barriers against unproductive decay, in particular via the premature cis to trans back-isomerization. Indeed, the protein has maximized its storage so that the back-isomerization barriers are just high enough (> or =18 kcal/mol) to keep the decay rate (1/100 ms) slower than the remaining photocycle (1/20 ms). This need to stabilize the captured photon-energy until it can be used in subsequent steps is inherent to light-driven proteins.

Indexed as

Models, ChemicalHalobacterium salinarumHalorhodopsinsIon TransportPhotosynthesisHalorhodopsins

Identifiers

PMID19211559
PMCPMC2679457
OpenAlexW2012122513

What OpenQuestion holds

Textmetadata
Read underepoch 390

Registered trials

None linked

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.