Research Highlights

New “tags” could improve the study of proteins

Published online 31 August 2015

Scientists have designed new protein tags that can be easily detected and that overcome limits present in current ones. 

Nadia El-Awady

Researchers “tag” proteins to study their functions and structures. Tagging proteins makes them more easily distinguishable from other cellular components. Currently used protein tags, however, often interact with the protein, changing its structure, function, or location in the cell. 

A team of researchers in Spain, including a researcher from Egypt’s Zagazig University, undertook “a very aggressive bioinformatic approach”, according to computational biologist Modesto Orozco, analyzing a long list of polypeptides and imposing a series of filters to select a final, small set of potential tags. 

“This was a kind of exercise in ‘rational tag design’,” says Orozco. 

As a result of this, twelve potential innocuous tags, called ‘inntags’, were chosen for validation. They corresponded to different proteins with potentially good antigenic properties from plants, insects, bacteria and viruses, which the researchers believed would facilitate their further recognition by monoclonal antibodies. 

Further analysis helped the group reduce the list of potential inntags to three, two of which displayed excellent tagging properties during experiments, largely surpassing those of conventional tags in several critical applications.

Orozco believes these new inntags will become widely used, especially among cell biologists, he says.


Georgieva, M. V. et al. Inntags: small self-structured epitopes for innocuous protein tagging. Nat. Methods (2015).