Expanding the amino acid universe

A primary advantage of small molecules over proteins is the relatively infinite number of building blocks available to make them compared to the 20 amino acids that compose all proteins. But two articles in Science may lead to a more level playing field, as separate groups of researchers at the Scripps Research Institute published methods for incorporating modified synthetic amino acids into proteins in living cells. The approaches have multiple potential uses, including novel protein therapeutics with tailored properties, functional proteomics and industrial biomanufacturing.

In the first study, researchers introduced a mutated tyrosyl tRNA/aminoacyl-tRNA synthetase pair from Methanococcus jannaschii into E. coli, and showed that the pair led to the incorporation of a synthetic amino acid into a protein. The researchers suggested that the approach represents a method of altering living cells to include amino acids with novel structural, chemical and physical properties...