Evidence map›Paper›PMID 41136717›Full record

ArticleScientific reports2025

Elucidating the activation mechanism of botulinum neurotoxin a: role of α-clostripain and NTNH.

Shani Pitel, Ada Barnea, Eran Diamant, Amram Torgeman, Tal Noy-Porat, Reut Falach, Ran Zichel, Zvi Hayouka, Alon Ben David

Abstract read
In one paragraph

Article in Scientific reports, 2025. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 2 papers.

0numbers the graph read from it
0cells of the map it votes in
2citing 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

2 citing papers in PubMed.

  1. Review
  2. The unsung hero:Frontiers in cellular and infection microbiology · 2026
    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

9 authors.

Shani PitelDepartment of Biotechnology, Israel Institute for Biological Research, 74100, Ness-Ziona, Israel.
Ada BarneaDepartment of Biotechnology, Israel Institute for Biological Research, 74100, Ness-Ziona, Israel.
Eran DiamantDepartment of Biotechnology, Israel Institute for Biological Research, 74100, Ness-Ziona, Israel.
Amram TorgemanDepartment of Biotechnology, Israel Institute for Biological Research, 74100, Ness-Ziona, Israel.
Tal Noy-PoratDepartment of Biochemistry and Molecular Genetics, Israel Institute for Biological Research, 74100, Ness-Ziona, Israel.
Reut FalachDepartment of Biochemistry and Molecular Genetics, Israel Institute for Biological Research, 74100, Ness-Ziona, Israel.
Ran ZichelDepartment of Biotechnology, Israel Institute for Biological Research, 74100, Ness-Ziona, Israel.
Zvi HayoukaThe Robert H. Smith Faculty of Agricultural, Institute of Biochemistry, Food Science and Nutrition, Food and Environment, The Hebrew University of Jerusalem, 76100, Rehovot, Israel. Zvi.hayouka@mail.huji.ac.il.
Alon Ben DavidDepartment of Biotechnology, Israel Institute for Biological Research, 74100, Ness-Ziona, Israel. alonb@iibr.gov.il.

Funding

No grant is acknowledged in the PubMed record.

6 · The paper itself

Abstract

Botulinum neurotoxin A (BoNT/A) is one of the most toxic substances known. The bacterium Clostridium botulinum produces it as a 150-kDa polypeptide with relatively low potency. Surprisingly, the endogenous protease that transforms this polypeptide into an activated, full-potency toxin, consisting of a 100-kDa heavy chain connected to a 50-kDa light chain (LC) by a disulfide bond, is still unknown. This study aimed to identify the BoNT/A-activating protease. We screened cation-exchange chromatography fractions of C. botulinum A culture supernatant for activity using a toxin-simulating substrate comprising the LC and the translocation domain (HN). Proteomic analysis of the active fraction identified α-clostripain as a candidate BoNT/A-activating protease. Recombinant α-clostripain cleaved the simulating substrate between the toxin LC and HN. However, incubation of recombinant α-clostripain with recombinant inactivated BoNT/A (rBoNT/Ai) resulted in non-specific digestion of the toxin. Since similar non-specific digestion was observed also by C. botulinum A culture supernatant, we hypothesized that the toxin should be protected by an accessory protein to prevent non-specific cleavage. Indeed, incubation of rBoNT/Ai with α-clostripain or culture supernatant in the presence of recombinant NTNH (non-toxic non-hemagglutinin) resulted in specific cleavage of the toxin into 100- and 50-kDa fragments. Subsequently, we evaluated the activation of rBoNT/A by α-clostripain in a mouse model. Cleavage of rBoNT/A by α-clostripain in the presence of NTNH resulted in a 77-fold increase in toxicity, corresponding to toxin activation. To the best of our knowledge, these results elucidate the mechanism of BoNT/A activation for the first time.

Indexed as

Botulinum Toxins, Type AClostridium botulinumCysteine EndopeptidasesAnimalsMiceRecombinant ProteinsBotulinum Toxins, Type ACysteine EndopeptidasesRecombinant Proteins

Identifiers

PMID41136717
PMCPMC12552653

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