Evidence map›Paper›PMID 39923128›Full record

ArticleBiophysical journal2025

Multiple structural states in an intrinsically disordered protein, SNAP-25, using circular dichroism.

Jarom S Sumsion, Samuel W Shumway, Tanner M Blocker, Thomas D Weed, Tasha M Chambers, Ryan J Poland, Dixon J Woodbury

Abstract read
In one paragraph

Article in Biophysical journal, 2025. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 3 papers.

0numbers the graph read from it
0cells of the map it votes in
3citing papers in PubMed
–field-weighted citation impact
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

3 citing papers in PubMed.

  1. Munc18 reprograms the intrinsic neuronal SNARE complex assembly pathway.bioRxiv : the preprint server for biology · 2026
    Article
  2. Article
  3. Membrane fusion and budding.Biophysical journal · 2025
    Article
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

7 authors.

Jarom S SumsionDepartment of Cell Biology & Physiology, Brigham Young University, Provo, Utah.
Samuel W ShumwayLake Erie College of Osteopathic Medicine, Greensburg, Pennsylvania.
Tanner M BlockerDepartment of Cell Biology & Physiology, Brigham Young University, Provo, Utah.
Thomas D WeedDepartment of Cell Biology & Physiology, Brigham Young University, Provo, Utah.
Tasha M ChambersNeuroscience Center, Brigham Young University, Provo, Utah.
Ryan J PolandNeuroscience Center, Brigham Young University, Provo, Utah.
Dixon J WoodburyDepartment of Cell Biology & Physiology, Brigham Young University, Provo, Utah; Neuroscience Center, Brigham Young University, Provo, Utah. Electronic address: dixon_woodbury@byu.edu.

Funding

No grant is acknowledged in the PubMed record.

6 · The paper itself

Abstract

SNAP-25, together with other SNARE proteins, drives fusion of synaptic vesicles with the nerve cell membrane, leading to neurotransmitter release. It is unique in contributing two α helices to the four-helix bundle known as the SNARE complex. Complex formation drives fusion as these proteins transform from a disordered to ordered (coiled-coil) state. SNAP-25 has two isoforms, -25A and -25B, but little is known of any structural differences, nor are there extensive reports of the structures of its two helical domains, SN1 and SN2. Thus, the benefit of having two distinct isoforms of SNAP-25, each with two distinct domains, is unknown. Here, we use circular dichroism spectroscopy and mass spectrometry to further characterize the secondary structure of SNAP-25A, SNAP-25B, SN1, SN2, and a cysteine-free version of SNAP-25A. We demonstrate that these proteins undergo structural transitions, with changing fractions of α helix, β sheet, and random coil. These different structures can be induced by varying the environmental conditions of ionic strength, pH, temperature, or redox state. We use triangle plots to directly display the change in ternary composition following changes in these four parameters. We report that SNAP-25A and SNAP-25B make distinctly different structural changes. We show that the secondary structure of SN1 is more variable than SN2. These data add to the ongoing literature characterizing SNAP-25 as an intrinsically disordered protein that is sensitive to environmental conditions in neuronal cells and may function as a redox sensor to modulate neurotransmitter release.

Indexed as

Circular DichroismIntrinsically Disordered ProteinsSynaptosomal-Associated Protein 25Hydrogen-Ion ConcentrationOsmolar ConcentrationProtein Structure, SecondaryTemperatureIntrinsically Disordered ProteinsSynaptosomal-Associated Protein 25

Identifiers

PMID39923128
PMCPMC12256890

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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.