Sulfonyl azide-mediated norbornene aziridination for orthogonal peptide and protein labeling

We describe a new bioconjugation reaction based on the aziridination of norbornenes using electron-deficient sulfonyl azides. The reaction enables to attach various useful tags to peptides and proteins under mild conditions

Synthesis of epsilon-N-propionyl-, epsilon-N-butyryl-, and epsilon-N-crotonyl-lysine containing histone H3 using the pyrrolysine system

Recently new lysine modifications were detected in histones and other proteins. Using the pyrrolysine amber suppression system we genetically inserted three of the newamino acids epsilon-N-propionyl-, epsilon-N-butyryl-, and epsilon-N-crotonyl-lysine site specifically into histone H3. The lysine at position 9 (H3 K9), which is known to be highly modified in chromatin, was replaced by these unnatural amino acids

Orchestrating the biosynthesis of an unnatural pyrrolysine amino acid for its direct incorporation into proteins inside living cells

We here report the construction of an E. coli expression system able to manufacture an unnatural amino acid by an artificial biosynthesis. This can be orchestrated with incorporation into protein by amber stop codon suppression inside a living cell. In our case an alkyne bearing pyrrolysine amino acid was biosynthesized and incorporated site-specifically allowing orthogonal double protein labeling