Researchers at the University of Toronto have discovered that the TMPRSS11D protein serves as a “gateway” that helps flu, cold, and COVID-19 viruses effectively enter human respiratory cells. The findings of their study were published in the journal Nature Communications.

Using optical microscopy techniques, the researchers have for the first time identified the crystal structures of the human TMPRSS11D protein, which viruses use as an “entrance” into the body.

Understanding the molecular structure of this “gateway” protein is important for finding effective drugs against coronavirus and flu viruses because it is very similar to other important proteins in the human body, said Brian Fraser, lead author of the study.

Many important proteins involved in the blood clotting process are similar to TMPRSS, Fraser explained.

The researchers noted that the influence of the TMPRSS protein may also be an important factor between stopping infections and disrupting the wound healing process.

A major challenge in this field is finding truly effective compounds or drug candidates that are selective for the target of interest and do not block other important functions, Fraser noted.

The researchers added that the new data will help find effective ways to target coronaviruses that pose a pandemic threat.