Unnatural amino acid incorporation into virus-like particles

Bioconjug Chem. 2008 Apr;19(4):866-75. doi: 10.1021/bc700390r. Epub 2008 Mar 5.


Virus-like particles composed of hepatitis B virus (HBV) or bacteriophage Qbeta capsid proteins have been labeled with azide- or alkyne-containing unnatural amino acids by expression in a methionine auxotrophic strain of E. coli. The substitution does not affect the ability of the particles to self-assemble into icosahedral structures indistinguishable from native forms. The azide and alkyne groups were addressed by Cu(I)-catalyzed [3 + 2] cycloaddition: HBV particles were decomposed by the formation of more than 120 triazole linkages per capsid in a location-dependent manner, whereas Qbeta suffered no such instability. The marriage of these well-known techniques of sense-codon reassignment and bioorthogonal chemical coupling provides the capability to construct polyvalent particles displaying a wide variety of functional groups with near-perfect control of spacing.

Publication types

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

MeSH terms

  • Allolevivirus / metabolism*
  • Amino Acid Sequence
  • Amino Acids / metabolism*
  • Capsid Proteins / chemistry
  • Capsid Proteins / metabolism*
  • Dimerization
  • Hepatitis B virus / metabolism*
  • Humans
  • Models, Molecular
  • Molecular Sequence Data
  • Protein Structure, Quaternary
  • Trypsin / metabolism


  • Amino Acids
  • Capsid Proteins
  • Trypsin