Incorporation of Amino Acids with Long-Chain Terminal Olefins into Proteins

Molecules. 2016 Feb 29;21(3):287. doi: 10.3390/molecules21030287.


The increasing need for site-specific protein decorations that mimic natural posttranslational modifications requires access to a variety of noncanonical amino acids with moieties enabling bioorthogonal conjugation chemistry. Here we present the incorporation of long-chain olefinic amino acids into model proteins with rational variants of pyrrolysyl-tRNA synthetase (PylRS). Nε-heptenoyl lysine was incorporated for the first time using the known promiscuous variant PylRS(Y306A/Y384F), and Nε-pentenoyl lysine was incorporated in significant yields with the novel variant PylRS(C348A/Y384F). This is the only example of rational modification at position C348 to enlarge the enzyme's binding pocket. Furthermore, we demonstrate the feasibility of our chosen amino acids in the thiol-ene conjugation reaction with a thiolated polysaccharide.

Keywords: metathesis; noncanonical amino acid; protein decoration; pyrrolysyl-tRNA synthetase; stop codon suppression; thiol-ene coupling.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Alkenes / chemistry*
  • Amino Acids / chemistry*
  • Amino Acyl-tRNA Synthetases / chemistry
  • Amino Acyl-tRNA Synthetases / metabolism
  • Binding Sites
  • Models, Molecular
  • Protein Processing, Post-Translational
  • Proteins / chemistry*
  • Substrate Specificity


  • Alkenes
  • Amino Acids
  • Proteins
  • Amino Acyl-tRNA Synthetases