Click Amino Acid / trans-Cyclooct-2-en – L - Lysine (TCO*A)

trans-Cyclooct-2-en-L-Lysine (TCO-L-Lysine, CAS 1801936-26-4) is a synthetic amino acid containing a trans-cyclooctene (TCO*) moiety linked to the ε-amine of lysine (axial isomer). This modification enables bioorthogonal, copper-free click reactions via strain-promoted inverse electron-demand Diels–Alder cycloaddition (SPIEDAC) with tetrazine-functionalized probes.

Key Features:

• Highly reactive TCO* group for ultrafast, selective conjugation

• Copper-free chemistry – suitable for live-cell and in vivo labeling

• Axial isomer, offering enhanced reaction kinetics compared to standard TCO derivatives

• Stable, ready-to-use amino acid derivative

Applications:

• Protein and peptide labeling in vitro and in vivo

• Live-cell imaging with tetrazine-fluorophores

• Development of bioorthogonal probes and conjugates

• Preclinical bioconjugation studies without copper catalysts

 [T. Plass et al., Angew. Chem., Int. Ed. Engl. 2011, 50, 3878–3881 // T. Plass et al., Angew. Chem., Int. Ed. Engl. 2012, 51, 4166–4170 // I. Nikic, Angew. Chem., Int. Ed. Engl. 2014, 53, 1]