[Abstract]

Proteins play an important role in addressing global issues of sustainability and health. Proteins have well-defined structures with unique biological or chemical properties. The advances in recombinant protein techniques enable the production of a large amount of proteins including therapeutic proteins and biocatalysts. In order to design recombinant proteins with novel properties, our research group has been exploring biosynthesis of therapeutic proteins and enzymes using non-natural amino acid building blocks. Site-specific incorporation of a non-natural amino acid containing a reactive functional group into a target protein allows site-selective bioconjugation of a protein. Previously we demonstrated that the combination of the site-specific non-natural amino acid incorporation technique and chemoselective chemistries was successfully employed to improve the serum half-life of a recombinant protein in vivo. Recently, we extended this research to achieve the prolonged activity of a therapeutic protein in vivo via the site-selective albumination. Besides therapeutic proteins, enzymes catalyzing diverse reactions are another important group of proteins. In nature, multiple enzymes in on metabolic pathway are clustered to achieve efficient cascade reactions. Similarly, multiple enzymes of our choice can be combined to perform cascade reactions to produce value-added compounds. Our group exploited whether chemical conjugation of multiple enzymes can enhance an overall cascade reaction efficiency. Then, we developed a novel strategy to control the active site orientation in multiple enzymes and investigated the importance of the active site orientation on an overall cascade reaction efficiency.