Scaffold expulsion and genome packaging trigger stabilization of herpes simplex virus capsids

Wouter H. Roos, Kerstin Radtke, Edward Kniesmeijer, Hylkje Geertsema, Beate Sodeik, Gijs J. L. Wuite

Research output: Contribution to journalArticleAcademicpeer-review

114 Citations (Scopus)


Herpes simplex virus type 1 (HSV1) capsids undergo extensive structural changes during maturation and DNA packaging. As a result, they become more stable and competent for nuclear egress. To further elucidate this stabilization process, we used biochemical and nanoindentation approaches to analyze the structural and mechanical properties of scaffold-containing (B), empty (A), and DNA-containing (C) nuclear capsids. Atomic force microscopy experiments revealed that A and C capsids were mechanically indistinguishable, indicating that the presence of DNA does not account for changes in mechanical properties during capsid maturation. Despite having the same rigidity, the scaffold-containing B capsids broke at significantly lower forces than A and C capsids. An extraction of pentons with guanidine hydrochloride (GuHCl) increased the flexibility of all capsids. Surprisingly, the breaking forces of the modified A and C capsids dropped to similar values as those of the GuHCl-treated B capsids, indicating that mechanical reinforcement occurs at the vertices. Nonetheless, it also showed that HSV1 capsids possess a remarkable structural integrity that was preserved after removal of pentons. We suggest that HSV1 capsids are stabilized after removal of the scaffold proteins, and that this stabilization is triggered by the packaging of DNA, but independent of the actual presence of DNA.
Original languageEnglish
Pages (from-to)9673-9678
Number of pages6
JournalProceedings of the National Academy of Sciences of the United States of America
Issue number24
Publication statusPublished - 16-Jun-2009
Externally publishedYes


  • Atomic force microscopy
  • Nanoindentation
  • Penton
  • Viral structure
  • Virus mechanics
  • DNA
  • guanidine
  • scaffold protein
  • article
  • atomic force microscopy
  • controlled study
  • Herpes simplex virus 1
  • nanoanalysis
  • nonhuman
  • priority journal
  • structure analysis
  • virus capsid
  • virus genome

Cite this