|Research Fields||Synthetic Organic Chemistry, Chemical Biology|
|Academic Society Membership||The Chemical Society of Japan, The Pharmaceutical Society of Japan, The Japanese Peptide Society, International Chemical Biology Society|
Bioconjugation methods are techniques that have been extensively studied for covalent bond formation between a specific amino acid residue of a protein and a synthetic small compound. The methods are highly important in making protein-based biomaterials for therapeutic and biotechnology industries. In order to achieve reliable protein bioconjugation, the following requirements should be met: (1) stable covalent bond formation, (2) rapid reaction in aqueous solution, and (3) high conversion under physiological pH and mild temperature. We have developed tyrosine-specific bioconjugation methods with ruthenium photocatalysts, hemin, enzymes and electrochemistry.
The relative hydrophobicity of tyrosine combined with the π−π stacking tendency of the aromatic rings results in generally low accessibility. We have developed site-selective protein modification by targeting surface-exposed tyrosine residues and applied to antibody site-selective functionalization.
Furthermore, based on my unique methodology which controls the protein bioconjugation using single-electron transfer in proximity to the catalyst on the nanometer scale, we have developed a method for target-selective protein labeling in a protein mixture. This method enables us to identify target proteins of bioactive molecules.