Location of the bacteriophage P22 coat protein C-terminus provides opportunities for the design of capsid-based materials

Biomacromolecules. 2013 Sep 9;14(9):2989-95. doi: 10.1021/bm400796c. Epub 2013 Aug 27.


Rational design of modifications to the interior and exterior surfaces of virus-like particles (VLPs) for future therapeutic and materials applications is based on structural information about the capsid. Existing cryo-electron microscopy-based models suggest that the C-terminus of the bacteriophage P22 coat protein (CP) extends toward the capsid exterior. Our biochemical analysis through genetic manipulations of the C-terminus supports the model where the CP C-terminus is exposed on the exterior of the P22 capsid. Capsids displaying a 6xHis tag appended to the CP C-terminus bind to a Ni affinity column, and the addition of positively or negatively charged coiled coil peptides to the capsid results in association of these capsids upon mixing. Additionally, a single cysteine appended to the CP C-terminus results in the formation of intercapsid disulfide bonds and can serve as a site for chemical modifications. Thus, the C-terminus is a powerful location for multivalent display of peptides that facilitate nanoscale assembly and capsid modification.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, U.S. Gov't, Non-P.H.S.

MeSH terms

  • Amino Acid Sequence
  • Bacteriophage P22 / chemistry*
  • Bacteriophage P22 / genetics
  • Bacteriophage P22 / isolation & purification
  • Capsid Proteins / chemistry*
  • Capsid Proteins / genetics
  • Capsid Proteins / isolation & purification
  • Chromatography, Affinity
  • Cystine / chemistry
  • Dithiothreitol / chemistry
  • Molecular Sequence Data
  • Nanostructures / chemistry
  • Protein Engineering
  • Protein Stability
  • Protein Structure, Secondary
  • Protein Structure, Tertiary
  • Reducing Agents / chemistry


  • Capsid Proteins
  • Reducing Agents
  • Cystine
  • Dithiothreitol