The Melolontha melolontha entomopoxvirus fusolin protein is a chitin-active lytic polysaccharide monooxygenase that displays extreme stability

Jennifer Sarah Maria Loose, Marion Boudes, Max Bergoin, Fasséli Coulibaly, Gustav Vaaje-Kolstad

Research output: Contribution to journalArticleResearchpeer-review

1 Citation (Scopus)


Spindles are intracellular crystals of the fusolin protein that enhances the oral virulence of insect poxviruses by disruption of the larval chitinous peritrophic matrix. The enigmatic fusolin protein is classified as a lytic polysaccharide monooxygenase (LPMO) by sequence and structure. Although circumstantial evidence points towards a role for fusolin in chitin degradation, no biochemical data exist to verify this claim. In the present study, we demonstrate that fusolin released from over 40-year-old spindles, stored for 10 years at 4 °C, are chitin-degrading LPMOs. Not only was fusolin active after long-term storage, but it also withstood high temperature and oxidative stress in its crystalline form, highlighting extreme stability that is beneficial to viral persistence and desirable for potential biotechnology applications.

Original languageEnglish
Pages (from-to)1375-1383
Number of pages9
JournalFEBS Letters
Issue number10
Publication statusPublished - May 2023


  • virulence factor
  • lytic polysaccharide monooxygenase
  • Poxvirus
  • Biomass recalcitrance
  • Biofuels

Cite this