The amphibian antimicrobial peptide uperin 3.5 is a cross-α/cross-β chameleon functional amyloid

Nir Salinas, Einav Tayeb-Fligelman, Massimo D. Sammito, Daniel Bloch, Raz Jelinek, Dror Noy, Isabel Usón, Meytal Landau

Research output: Contribution to journalArticlepeer-review

36 Scopus citations


Antimicrobial activity is being increasingly linked to amyloid fibril formation, suggesting physiological roles for some human amyloids, which have historically been viewed as strictly pathological agents. This work reports on formation of functional cross-α amyloid fibrils of the amphibian antimicrobial peptide uperin 3.5 at atomic resolution, an architecture initially discovered in the bacterial PSMα3 cytotoxin. The fibrils of uperin 3.5 and PSMα3 comprised antiparallel and parallel helical sheets, respectively, recapitulating properties of β-sheets. Uperin 3.5 demonstrated chameleon properties of a secondary structure switch, forming mostly cross-β fibrils in the absence of lipids. Uperin 3.5 helical fibril formation was largely induced by, and formed on, bacterial cells or membrane mimetics, and led to membrane damage and cell death. These findings suggest a regulation mechanism, which includes storage of inactive peptides as well as environmentally induced activation of uperin 3.5, via chameleon cross-α/β amyloid fibrils.

Original languageEnglish
Article numbere2014442118
JournalProceedings of the National Academy of Sciences of the United States of America
Issue number3
StatePublished - 19 Jan 2021


  • Amyloid
  • Antimicrobial peptides
  • Cross-alpha
  • Functional fibril

ASJC Scopus subject areas

  • General


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