Evidence map›Paper›PMID 41664997›Full record

ArticleJournal of neurochemistry2026

N-Truncated Superoxide Dismutase-1 in Cerebrospinal Fluid Is Folded and Active.

Laura Leykam, Karin M E Forsberg, Peter M Andersen, Thomas Brännström, Sophia Weiner, John Rönnholm, Kaj Blennow, Henrik Zetterberg, Stefan L Marklund, Johan Gobom and 1 more

Abstract read
In one paragraph

Article in Journal of neurochemistry, 2026. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 1 paper.

0numbers the graph read from it
0cells of the map it votes in
1citing 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

1 citing paper in PubMed.

  1. 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

11 authors.

Laura LeykamDepartment of Medical Biosciences, Clinical Chemistry, Umeå University, Umeå, Sweden.ORCID https://orcid.org/0009-0005-9020-3817
Karin M E ForsbergDepartment of Clinical Sciences, Neurosciences, Umeå University, Umeå, Sweden.ORCID https://orcid.org/0000-0003-2911-6026
Peter M AndersenDepartment of Clinical Sciences, Neurosciences, Umeå University, Umeå, Sweden.ORCID https://orcid.org/0000-0003-0094-5429
Thomas BrännströmDepartment of Medical Biosciences, Pathology, Umeå University, Umeå, Sweden.ORCID https://orcid.org/0000-0002-4201-8204
Sophia WeinerInstitute of Neuroscience and Physiology, Department of Psychiatry and Neurochemistry, University of Gothenburg, Mölndal, Sweden.ORCID https://orcid.org/0009-0000-2298-220X
John RönnholmInstitute of Neuroscience and Physiology, Department of Psychiatry and Neurochemistry, University of Gothenburg, Mölndal, Sweden.ORCID https://orcid.org/0009-0001-3945-6414
Kaj BlennowInstitute of Neuroscience and Physiology, Department of Psychiatry and Neurochemistry, University of Gothenburg, Mölndal, Sweden.ORCID https://orcid.org/0000-0002-1890-4193
Henrik ZetterbergInstitute of Neuroscience and Physiology, Department of Psychiatry and Neurochemistry, University of Gothenburg, Mölndal, Sweden.ORCID https://orcid.org/0000-0003-3930-4354
Stefan L MarklundDepartment of Medical Biosciences, Clinical Chemistry, Umeå University, Umeå, Sweden.ORCID https://orcid.org/0000-0002-3270-2854
Johan GobomInstitute of Neuroscience and Physiology, Department of Psychiatry and Neurochemistry, University of Gothenburg, Mölndal, Sweden.ORCID https://orcid.org/0000-0001-6193-6193
Per ZetterströmDepartment of Medical Biosciences, Clinical Chemistry, Umeå University, Umeå, Sweden.ORCID https://orcid.org/0000-0001-8718-3249

Funding

Cure Alzheimer's FundEuropean Partnership on MetrologyEuropean Union's Horizon Europe research and innovation programme 101053962Fort Knox Charity FoundationKing Gustaf V:s and Queen Victoria's Freemason's FoundationKnut och Alice Wallenbergs Stiftelse 2012.0091Knut och Alice Wallenbergs Stiftelse 2014.0305Knut och Alice Wallenbergs Stiftelse 2020.0232National Institute for Health and Care ResearchNeuroförbundet Association 2.1.12-1605-14Neuroförbundet Association 2.1.6-452-20Neuroförbundet Association 223-1881-13Neuroförbundet Association 223-2808-12Olsson och Olsson FoundationStiftelsen för Gamla TjänarinnorSwedish Brain Foundation 2012-0262Swedish Brain Foundation 2012-0305Swedish Brain Foundation 2013-0279Swedish Brain Foundation 2016-0303Swedish Brain Foundation 2020-0353Swedish Brain Foundation 2022-0270Swedish Brain Foundation 2024-0048Swedish Brain Foundation ALZ2022-0006UK Dementia Research InstituteUlla-Carin Lindquists stiftelse för ALS-forskningUniversity College LondonVästerbotten Läns LandstingVetenskapsrådet 2012-3167Vetenskapsrådet 2017-00915Vetenskapsrådet 2017-03100Vetenskapsrådet 2019-02397Vetenskapsrådet 2022-00732Vetenskapsrådet 2022-01018Vetenskapsrådet 2023-00356
6 · The paper itself

Abstract

Mutations in the antioxidant enzyme superoxide dismutase-1 (SOD1) are a well-established cause of amyotrophic lateral sclerosis (ALS). The mutations promote SOD1 misfolding, resulting in protein aggregation and motor neuron degeneration. SOD1 is normally a structurally stable enzyme, and the mechanisms underlying SOD1 misfolding remain poorly understood. Approximately one third of SOD1 in cerebrospinal fluid (CSF) exhibits an N-terminal truncation, the biological significance of which remains unclear. This is remarkable given the dramatic effects ALS-linked C-terminal truncations have on the enzyme. In this study, we identified the truncation site and investigated its impact on SOD1 stability and enzymatic activity. Edman degradation revealed the cleavage site between Asn-26 and Gly-27, generating a 26-residue peptide that was confirmed by mass spectrometry. We analyzed postmortem tissues from different parts of the central nervous system (CNS), including the choroid plexus, and found only trace amounts of N-terminally truncated SOD1. Biochemical characterization of the SOD1 in CSF was done by size exclusion chromatography, ion exchange chromatography, and mass spectrometry. Our findings demonstrate that SOD1 in CSF retains full enzymatic activity, that the N-terminally truncated variant is mainly present in heterodimers with native SOD1 subunits, and that the dimer remains folded and active, with both fragments of the truncated SOD1 fixed after proteolysis. Truncated SOD1 was absent in human plasma. In mice, only transgenically expressed human SOD1 underwent truncation in CSF, whereas endogenous murine SOD1 remained intact. Lastly, the N-terminal truncation does not induce misfolding, unlike the destabilizing effects observed with C-terminal truncations. The location where the truncation takes place and the underlying mechanism could not be identified. Whether the N-truncated SOD1 variant contributes to ALS pathogenesis remains to be determined.

Indexed as

Protein FoldingSuperoxide Dismutase-1Amyotrophic Lateral SclerosisAnimalsHumansMiceSOD1 protein, humanSuperoxide Dismutase-1amyotrophic lateral sclerosiscerebrospinal fluidposttranslational modificationsuperoxide dismutase‐1

Identifiers

PMID41664997
PMCPMC12887930

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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.