{
  "abstract": "Cholesterol is a key biomolecule that regulates lipid bilayer fluidity, and cholesterol-rich domains in host cells and virions are critical for virion entry and egress. Here, using Alphavirus Sindbis virus (SINV) as a model, we combine new experimental methods and single-particle biological characterization to revisit how envelope cholesterol affects particle stability and the biological consequences for infectivity. To this end, we generated two SINV populations with a 3-fold difference in envelope cholesterol levels (SINV LC and SINV HC ) to assess how cholesterol affects SINV stability and infectivity. Transmission electron microscopy and dynamic light scattering showed minimal differences in morphology and size, indicating that cholesterol minimally alters virion structure. Electrochemical measurements between SINV LC and SINV HC particles revealed similar Zeta Potentials (ζ-potential ~ -31 mV), which implies that the surface distribution of the E1-E2 glycoprotein heterotrimers within the envelope is cholesterol-independent. Titer measurements showed that SINV HC retains nearly an order of magnitude more infectious particles than SINV LC when pre-exposed to 30 minutes of thermal stress, corresponding to a 1.25-fold faster decay rate for the low-cholesterol virions, with SINV LC and SINV HC showing values of 0.34/min and 0.27/min, respectively. Single-particle fluorescence lifetime imaging microscopy analysis using the fluidity-sensitive dye DI-8-ANEPPS revealed a statistically significant increase (≥ 0.2 ns; p < 0.0001) in photon arrival times in the SINV HC population, indicating that elevated cholesterol enhances membrane rigidity. Because virion size and ζ-potential remained unchanged while fluorescence lifetimes increased with cholesterol level, these findings indicate that membrane fluidity is the primary parameter governing viral stability and subsequent infectivity.",
  "abstract_shown": true,
  "affiliations": [
    "Department of Biology",
    "Indiana University",
    "Department of Chemistry"
  ],
  "article_type": null,
  "arxiv": null,
  "author_total": 6,
  "authors": [
    {
      "affs": [
        0,
        1
      ],
      "name": "Ciara N. Richardson"
    },
    {
      "affs": [
        2,
        1
      ],
      "name": "Sarah J. Cox-Vázquez"
    },
    {
      "affs": [
        2,
        1
      ],
      "name": "Celeste Carlos"
    },
    {
      "affs": [
        0,
        1
      ],
      "name": "Barry Stein"
    },
    {
      "affs": [
        0,
        1
      ],
      "name": "Suchetana Mukhopadhyay"
    },
    {
      "affs": [
        2,
        1
      ],
      "name": "Ricardo Javier Vázquez",
      "orcid": "0000-0003-3245-8123"
    }
  ],
  "bibtex": "https://research.draconitic.com/paper/8dy971vykxrf9.bib",
  "cited_by": 0,
  "doi": "10.26434/chemrxiv.15006138/v2",
  "fulltext_url": null,
  "id": "8dy971vykxrf9",
  "issns": [],
  "landing_url": "https://chemrxiv.org/doi/full/10.26434/chemrxiv.15006138/v2",
  "language": null,
  "licence": "CC-BY",
  "licence_label": "CC BY",
  "licence_source": "journal",
  "licence_url": "https://creativecommons.org/licenses/by/4.0/",
  "metadata_licence": null,
  "native_subjects": [
    [
      "openalex",
      "1312|Lipid Membrane Structure and Behavior"
    ]
  ],
  "openalex": "W7223097012",
  "pdf_url": "https://chemrxiv.org/doi/pdf/10.26434/chemrxiv.15006138/v2",
  "pmcid": null,
  "pmid": null,
  "published": "2026-10-21",
  "publisher": "American Chemical Society (ACS)",
  "ris": "https://research.draconitic.com/paper/8dy971vykxrf9.ris",
  "sources": [
    {
      "first_seen": "2026-10-30T12:17:24Z",
      "native_id": "10.26434/chemrxiv.15006138",
      "source": "chemrxiv",
      "url": "https://chemrxiv.org/doi/full/10.26434/chemrxiv.15006138/v2"
    }
  ],
  "subjects": [
    {
      "field": "biochemistry",
      "origin": "openalex:1312|Lipid Membrane Structure and Behavior",
      "subfield": "molecular-biology"
    }
  ],
  "title": "Cholesterol-Dependent Membrane Fluidity in Sindbis Virus Governs Viral Particle Stability and Infectivity",
  "title_text": "Cholesterol-Dependent Membrane Fluidity in Sindbis Virus Governs Viral Particle Stability and Infectivity",
  "type": "preprint",
  "updated_at": "2026-10-30T12:17:24Z",
  "url": "https://research.draconitic.com/paper/8dy971vykxrf9",
  "venue": "ChemRxiv",
  "versions": []
}