Engineered proteins could thwart infections

Because the technology can be applied to a wide range of pathogens, the researchers believe that it could become a game-changer in anti-viral therapeutics with implications for human health and the farming industry. 

“Vaccines are important for prevention, but there is a great need for anti-viral medicines to treat people who have become infected,” said Wei Zhang from the University of Toronto in Canada. 

MERS is similar to SARS, the virus that killed almost 800 people in a 2002 global epidemic. 

Like many viruses, MERS works by hijacking the ubiquitin system in human cells composed of hundreds of proteins that rely on ubiquitin to keep the cells alive and well. 

Upon infection, viral enzymes alter ubiquitin pathways in a way that allows the virus to evade the immune defence while multiplying and destroying the host tissue as it spreads in the body. 

“Viruses have evolved proteins that allow them to hijack host proteins. We can now devise strategies to prevent this from happening,” Zhang said. 

Writing in the journal PLoS Pathogens, the team led by Professor Sachdev Sidhu of the University of Toronto described how they engineered the human ubiquitin protein into a new form that paralyses a key MERS enzyme, stopping the virus from replicating. 

These synthetic ubiquitin variants act quickly, completely eliminating MERS from cells in a dish within 24 hours. The researchers said they also created ubiquitin variant (UbVs) that blocks the Crimean-Congo virus, the cause of a haemorrhagic fever that kills about 40 per cent of those infected. And they are designed to only target only the virus - hopefully minimising side effects in any future drug. But before these engineered proteins can be developed into medicine, researchers first must find a way to deliver them into the right part of the body. 

“We are also working on an engineered ubiquitin that targets a corn virus responsible for destroying large swathes of corn fields in North America,” Zhang said.