.What are the main types of bioorthogonal reactions that have been developed?

Can you guys briefly describe it?

Chen Peng’s research group at the School of Chemistry and Molecular Engineering at Peking University has long been committed to the development of exogenous chemical reactions in living cells, especially the proposal of bioorthogonal elimination reactions, which has enriched the content of bioorthogonal reactions.

Recently, they realized the "reverse electron demand Diels-Alder reaction" (referred to as the "Di-Alder" reaction) on proteins in living cells for the first time and applied it to the activation of protein enzymes.

Based on the analysis of the "(retro)Di-A" reaction, they found that for trans-cyclooctene in which the allyl position is substituted by an oxygen atom, it reacts with 3,6-dimethyl-1,2,4,5-

After the reaction of tetrazine, further rearrangement will occur, inducing the breakage of the C-O bond between the cyclooctene skeleton and the oxygen atom, resulting in a removal reaction.

This special "(reverse) Di-A" reaction type was first well verified on small organic molecules and model proteins.

Experiments have shown that this reaction is well compatible with biological systems and can efficiently convert trans-cyclooctene-protected lysine inserted into proteins in living cells into natural lysine within ten minutes.

On the basis of the above results, they applied the "(reverse) Di-A" reaction to small molecule-mediated protein activation.

Taking advantage of the quantitatively measurable nature of the enzyme activity, they correlated the reaction yield with the bioluminescence signal intensity to efficiently and quantitatively monitor this protein deprotection reaction in vivo.

Data show that this reaction can activate more than 90% of inhibited proteases within 15 minutes.

Bioorthogonal reactions refer to chemical reactions that can be carried out in living cells or tissues without interfering with the biochemical reactions of the organism itself.

Chemical biologists have devised various chemical strategies to meet the requirements of bioorthogonality.

The Diels-Alder reaction is a classic diene addition reaction. The "(reverse) Di-Alder" reaction also has important theoretical and application value. In recent years, it has been used in antibody modification, material synthesis and

In vivo labeling and other fields.