Protein Engineering Using Unnatural Amino Acids

Proteins are composed of 20 proteinogenic amino acids and are central in many biological processes. While traditional mutagenesis is restricted to the 20 proteinogenic amino acids, unnatural amino acid s (UAA s) can be incorporated into protein through chemical synthesis, chemical mutagenesis, using auxotrophic strains, genetic codon expansion, and other methods, which greatly expands the toolbox for protein engineering. UAAs have been used to increase protein stability, study mechanism of action, tune enzyme activity or selectivity, design novel protein functions, and even engineer synthetic life. Together with other protein engineering methods, UAA incorporation will play an important role in protein engineering, greatly expand what the already very powerful molecules are capable of.