{
  "abstract": "Multivalent cations are abundant in cells and play essential roles in DNA duplex stability, genome packaging, and DNA–protein interactions. They can also condense DNA, making it challenging to determine their influence on DNA duplex stability. To overcome this challenge, we studied DNA unpeeling at equilibrium under high tension using magnetic tweezers, thereby preventing condensation. Experiments show that DNA duplex stability first increases and then decreases as cation concentration increases and the maximum DNA duplex stability increases with cation valence. The maximum free energy change of DNA was 3.33 kBT/bp for Na+ and increased to 3.98 kBT/bp for protamine, which is a small arginine-rich protein with a highly positive charge (≈21 for salmon sperm), corresponding to a relative increase of 19.5%. Consistently, all-atom molecular dynamics simulations show that higher-valent cations preferentially embed in the minor groove of DNA and clamp the minor groove, in contrast to the major-groove clamping reported for RNA, thereby stabilizing the helix more efficiently. These findings establish a single-molecule framework for quantifying DNA thermodynamics in complex ionic environments, which contributes to understanding ionic control of genome stability and to designing ion-tunable DNA-based nanostructures and delivery systems.",
  "abstract_shown": true,
  "affiliations": [
    "Hubei Key Laboratory of Cell Homeostasis, College of Life Sciences, School of Physics and Technology, Women and Children's Hospital, Renmin Hospital of Wuhan University, Wuhan University Wuhan 430072 China",
    "School of Physics and Optical Engineering, Zhejiang University of Technology Hangzhou 310023 China",
    "Department of Clinical Laboratory, Renmin Hospital of Wuhan University Wuhan China"
  ],
  "article_type": "research article",
  "arxiv": null,
  "author_total": 5,
  "authors": [
    {
      "affs": [
        0
      ],
      "name": "Yun-Long Chen"
    },
    {
      "affs": [
        0,
        1
      ],
      "name": "Chen-Chen Zheng"
    },
    {
      "affs": [
        2
      ],
      "name": "Yan Zhang"
    },
    {
      "affs": [
        0
      ],
      "name": "Zhi-Jie Tan"
    },
    {
      "affs": [
        0
      ],
      "name": "Xing-Hua Zhang",
      "orcid": "0000-0002-9487-191X"
    }
  ],
  "bibtex": "https://research.draconitic.com/paper/043f1qqnrf35p.bib",
  "cited_by": 0,
  "doi": "10.1039/d6sc03808e",
  "fulltext_url": "https://pmc.ncbi.nlm.nih.gov/articles/PMC13552422/",
  "id": "043f1qqnrf35p",
  "issns": [
    "2041-6520",
    "2041-6539"
  ],
  "landing_url": "https://doi.org/10.1039/d6sc03808e",
  "language": "en",
  "licence": "CC-BY-3.0",
  "licence_label": "CC BY 3.0",
  "licence_source": "article",
  "licence_url": "https://creativecommons.org/licenses/by/3.0/",
  "metadata_licence": null,
  "native_subjects": [
    [
      "heading",
      "Chemistry"
    ],
    [
      "openalex",
      "1312|DNA and Nucleic Acid Chemistry"
    ]
  ],
  "openalex": "W7204942077",
  "pdf_url": "https://pubs.rsc.org/sc/article-pdf/doi/10.1039/D6SC03808E/13730720/d6sc03808e.pdf",
  "pmcid": "PMC13552422",
  "pmid": "42713224",
  "published": "2026-09-01",
  "publisher": "Royal Society of Chemistry",
  "ris": "https://research.draconitic.com/paper/043f1qqnrf35p.ris",
  "sources": [
    {
      "first_seen": "2026-10-31T12:23:45Z",
      "native_id": "PMC13552422",
      "source": "pmc",
      "url": "https://doi.org/10.1039/d6sc03808e"
    }
  ],
  "subjects": [
    {
      "field": "biochemistry",
      "origin": "openalex:1312|DNA and Nucleic Acid Chemistry",
      "subfield": "molecular-biology"
    }
  ],
  "title": "Multivalent cations stabilize DNA duplexes beyond charge neutralization",
  "title_text": "Multivalent cations stabilize DNA duplexes beyond charge neutralization",
  "type": "peer-reviewed",
  "updated_at": "2026-11-01T12:20:53Z",
  "url": "https://research.draconitic.com/paper/043f1qqnrf35p",
  "venue": "Chemical Science",
  "versions": []
}