{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,6,30]],"date-time":"2026-06-30T00:53:28Z","timestamp":1782780808224,"version":"3.54.5"},"reference-count":41,"publisher":"MDPI AG","issue":"9","license":[{"start":{"date-parts":[[2025,9,4]],"date-time":"2025-09-04T00:00:00Z","timestamp":1756944000000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"name":"Japan Society for the Promotion of Science (JSPS) KAKENHI","award":["19K21257"],"award-info":[{"award-number":["19K21257"]}]},{"name":"Japan Society for the Promotion of Science (JSPS) KAKENHI","award":["20K16240"],"award-info":[{"award-number":["20K16240"]}]},{"name":"Japan Society for the Promotion of Science (JSPS) KAKENHI","award":["23K14517"],"award-info":[{"award-number":["23K14517"]}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Toxins"],"abstract":"<jats:p>Botulinum toxin (BoNT) causes flaccid paralysis by blocking the release of neurotransmitters. BoNTs associate with neurotoxin-associated proteins to form medium and large progenitor toxin complexes. The large progenitor toxin complex serotype A-62A (L-PTC\/A-62A) specifically targets intestinal M cells for invasion, whereas large progenitor toxin complex serotype B-Okra (L-PTC\/B-Okra) is mainly taken up by enterocytes and exhibits higher toxicity via the oral route. Hemagglutinin (HA) is a neurotoxin-associated protein that promotes BoNT absorption from the intestine and has carbohydrate-binding and barrier-disrupting activities. In this study, we established an in vitro reconstitution and purification system for recombinant L-PTC\/B-Okra and created a recombinant L-PTC\/B-Okra mutant rL-PTC\/B-KA with carbohydrate-binding activity but not barrier-disrupting activity. rL-PTC\/B-KA showed significantly reduced oral toxicity. Our results demonstrate that the B-Okra toxin disrupts the epithelial barrier of enterocytes and exerts oral toxicity.<\/jats:p>","DOI":"10.3390\/toxins17090443","type":"journal-article","created":{"date-parts":[[2025,9,4]],"date-time":"2025-09-04T08:08:46Z","timestamp":1756973326000},"page":"443","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":4,"title":["Botulinum Toxin Complex Serotype B-Okra Exerts Systemic Toxicity via the Oral Route by Disrupting the Intestinal Epithelial Barrier"],"prefix":"10.3390","volume":"17","author":[{"given":"Chiyono","family":"Morimoto","sequence":"first","affiliation":[{"name":"Department of Bacteriology, Graduate School of Medical Sciences, Kanazawa University, Kanazawa 920-8640, Japan"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-0692-264X","authenticated-orcid":false,"given":"Sho","family":"Amatsu","sequence":"additional","affiliation":[{"name":"Department of Bacteriology, Graduate School of Medical Sciences, Kanazawa University, Kanazawa 920-8640, Japan"},{"name":"Department of Forensic Medicine and Pathology, Graduate School of Medical Sciences, Kanazawa University, Kanazawa 920-8640, Japan"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-3747-829X","authenticated-orcid":false,"given":"Takuhiro","family":"Matsumura","sequence":"additional","affiliation":[{"name":"Department of Bacteriology, Graduate School of Medical Sciences, Kanazawa University, Kanazawa 920-8640, Japan"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Masahiko","family":"Zuka","sequence":"additional","affiliation":[{"name":"Department of Forensic Medicine and Pathology, Graduate School of Medical Sciences, Kanazawa University, Kanazawa 920-8640, Japan"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Yukako","family":"Fujinaga","sequence":"additional","affiliation":[{"name":"Department of Bacteriology, Graduate School of Medical Sciences, Kanazawa University, Kanazawa 920-8640, Japan"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1968","published-online":{"date-parts":[[2025,9,4]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"717","DOI":"10.1152\/physrev.2000.80.2.717","article-title":"Neurotoxins Affecting Neuroexocytosis","volume":"80","author":"Schiavo","year":"2000","journal-title":"Physiol. 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