{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"institution":[{"name":"bioRxiv"}],"indexed":{"date-parts":[[2026,10,31]],"date-time":"2026-10-31T00:31:32Z","timestamp":1793406692375,"version":"4.5.0"},"posted":{"date-parts":[[2026,3,2]]},"group-title":"Microbiology","reference-count":55,"publisher":"openRxiv","license":[{"start":{"date-parts":[[2026,3,2]],"date-time":"2026-03-02T00:00:00Z","timestamp":1772409600000},"content-version":"vor","delay-in-days":0,"URL":"http:\/\/creativecommons.org\/licenses\/by-nc-nd\/4.0\/"}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":[],"accepted":{"date-parts":[[2026,3,2]]},"abstract":"<jats:title>Abstract<\/jats:title>\n                <jats:p>\n                  Although receptor-mediated mechanisms account for the therapeutic action of numerous FDA-approved drugs, emerging evidence suggests that many of these therapeutics have off-target antimicrobial activities. One example is fingolimod, an immunomodulator used to treat multiple sclerosis, that has been reported to have antimicrobial effects associated with membrane permeabilization. Yet the molecular mechanism by which fingolimod alters bacterial membranes remains unknown. As a cationic amphiphilic drug (CAD), fingolimod is comprised of both hydrophobic and positively charged regions that can enable membrane interactions. We show that fingolimod compromises membrane integrity in\n                  <jats:italic>E. coli<\/jats:italic>\n                  and\n                  <jats:italic>P. aeruginosa<\/jats:italic>\n                  , contributing to its antimicrobial activity. To determine how fingolimod disrupts membrane integrity, we used planar lipid bilayer electrophysiology with phospholipid compositions mimicking\n                  <jats:italic>E. coli<\/jats:italic>\n                  membranes. Using gramicidin A channels as molecular biosensors, we show that fingolimod alters both mechanical properties and surface charge of lipid bilayers at concentrations that have antimicrobial effects. At higher concentrations, fingolimod directly permeabilizes lipid bilayers, as revealed by conductance measurements and Bilayer Overtone Analysis. Molecular dynamics simulations correlate fingolimod\u2019s preference for pore-favoring curvature with its strong interactions with lipids and trans-leaflet translocation. These findings establish a molecular mechanism for fingolimod\u2019s off-target activity and provide a starting point for understanding how some CAD structures can drive membrane-specific effects that compromise bacterial physiology.\n                <\/jats:p>\n                <jats:sec>\n                  <jats:title>Importance<\/jats:title>\n                  <jats:p>Many commonly prescribed drugs, beyond their primary action via receptor targets, modify cell membranes. A mechanistic understanding of how these drugs interact with bacterial membranes will have a significant impact on drug design and on the evaluation of potential side effects. Furthermore, the emerging need for new antimicrobial drugs has led to increased interest in drug repurposing. Elucidating the molecular mechanisms of these compounds\u2019 interactions with bacterial membranes can ultimately provide critical insights into redesigning existing drugs as antimicrobials and into identifying unintended membrane-related effects that may contribute to their therapeutic or off-target effects.<\/jats:p>\n                <\/jats:sec>","DOI":"10.64898\/2026.03.02.709040","type":"posted-content","created":{"date-parts":[[2026,3,3]],"date-time":"2026-03-03T02:45:28Z","timestamp":1772505928000},"source":"Crossref","is-referenced-by-count":1,"title":["Multiple Sclerosis Drug Fingolimod Exhibits Antibacterial Activity through Bacterial Membrane Permeabilization"],"prefix":"10.64898","author":[{"given":"Antara","family":"Syam","sequence":"first","affiliation":[{"name":"Department of Biology, The Catholic University of America, Washington, DC, 20064, USA"},{"name":"Eunice Kennedy Shriver National Institute of Child Health and Human Development, NIH, Bethesda, MD, 20892, USA"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Benjamin","family":"Rees","sequence":"additional","affiliation":[{"name":"Department of Biology, The Catholic University of America, Washington, DC, 20064, USA"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Sebastian","family":"Cuervo","sequence":"additional","affiliation":[{"name":"Department of Biology, The Catholic University of America, Washington, DC, 20064, USA"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Fengtian","family":"Xue","sequence":"additional","affiliation":[{"name":"Department of Pharmaceutical Sciences, University of Maryland School of Pharmacy, Baltimore, MD, 21201, USA"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-5570-8212","authenticated-orcid":false,"given":"Alexander","family":"Sodt","sequence":"additional","affiliation":[{"name":"Eunice Kennedy Shriver National Institute of Child Health and Human Development, NIH, Bethesda, MD, 20892, USA"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Ekaterina M","family":"Nestorovich","sequence":"additional","affiliation":[{"name":"Department of Biology, The Catholic University of America, Washington, DC, 20064, USA"},{"name":"Eunice Kennedy Shriver National Institute of Child Health and Human Development, NIH, Bethesda, MD, 20892, USA"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Tatiana K","family":"Rostovtseva","sequence":"additional","affiliation":[{"name":"Eunice Kennedy Shriver National Institute of Child Health and Human Development, NIH, Bethesda, MD, 20892, USA"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Sergey M","family":"Bezrukov","sequence":"additional","affiliation":[{"name":"Eunice Kennedy Shriver National Institute of Child Health and Human Development, NIH, Bethesda, MD, 20892, USA"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-9196-3280","authenticated-orcid":false,"given":"John S","family":"Choy","sequence":"additional","affiliation":[{"name":"Department of Biology, The Catholic University of America, Washington, DC, 20064, USA"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"54368","reference":[{"issue":"7","key":"2026030504300853000_2026.03.02.709040v1.1","doi-asserted-by":"crossref","first-page":"373","DOI":"10.1038\/nrneurol.2010.76","article-title":"Fingolimod is a potential novel therapy for multiple sclerosis","volume":"6","year":"2010","journal-title":"Nature Reviews Neurology"},{"key":"2026030504300853000_2026.03.02.709040v1.2","doi-asserted-by":"publisher","DOI":"10.1016\/0006-2952(91)90340-B"},{"issue":"1","key":"2026030504300853000_2026.03.02.709040v1.3","doi-asserted-by":"crossref","first-page":"44277","DOI":"10.1038\/srep44277","article-title":"New insights into the intracellular distribution pattern of cationic amphiphilic drugs","volume":"7","year":"2017","journal-title":"Scientific Reports"},{"key":"2026030504300853000_2026.03.02.709040v1.4","doi-asserted-by":"publisher","DOI":"10.1177\/019262339702500111"},{"issue":"6","key":"2026030504300853000_2026.03.02.709040v1.5","first-page":"e02191","article-title":"TCA and SSRI antidepressants exert selection pressure for efflux-dependent antibiotic resistance mechanisms in Escherichia coli","volume":"13","year":"2022","journal-title":"MBio"},{"issue":"1","key":"2026030504300853000_2026.03.02.709040v1.6","doi-asserted-by":"crossref","first-page":"17878","DOI":"10.1038\/s41598-020-74934-9","article-title":"Unravelling the antimicrobial action of antidepressants on gut commensal microbes","volume":"10","year":"2020","journal-title":"Scientific reports"},{"key":"2026030504300853000_2026.03.02.709040v1.7","doi-asserted-by":"crossref","unstructured":"Shang Y , Huang Y , Meng Q , Yu Z , Wen Z , Yu F. 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