Enzyme could hold the key to changing blood type

6 May 2015

Every sixty seconds, someone in Canada needs blood.

But the delivery of life-saving transfusions is complicated by the fact that those in need must receive either their own blood type or a universal type – O-negative – carried by only 7 percent of Canadians.

The ability to give any blood type to any recipient represents a dream scenario that would dramatically reduce blood shortages. Thanks to new research by a team from the University of British Columbia – including five current or former MSFHR award holders – that dream is one step closer.

In a new study published recently in the Journal of the American Chemical Society, the UBC researchers outline their creation of a new enzyme with the potential to turn Type A or B blood into the universal Type O. The enzyme works to cut off sugars that are bound to the surface of red blood cells. These sugars – called antigens – determine an individual’s blood type, and their presence can trigger a potentially fatal immune response in mismatched recipients.

The idea of using an enzyme to remove antigens is not new, but the method adopted by the UBC team has proven much more effective than previous attempts.

Using a process called directed evolution, the researchers created a mutated form of the enzyme that cut the antigens from Type A and B blood much more efficiently. In only five generations of evolution, the mutated enzyme became 170 times more effective.

“This enzyme has been discovered before, it’s been characterized. But we’ve used our methodology to improve its activity towards these antigens,” the study’s lead author Dr. David Kwan, a 2011 MSFHR Trainee, told Global News.

Using the new enzyme, 2011 MSFHR Scholar Dr. Jayachandran Kizhakkedathu and colleagues at the Centre for Blood Research were able to remove a majority of the antigens from Type A and B blood. The process will need to remove all antigens before it can be approved for clinical use, as even small amounts can trigger a dangerous reaction. However, the researchers are confident the enzyme can be made more effective and will eventually produce usable universal blood.

In addition to Kwan and Kizhakkedathu, three other MSFHR-supported researchers contributed to this discovery: Dr. Rafi Chapanian (2011 Trainee), Dr. Melanie Higgins (2008 Trainee), and Dr. Alisdair Boraston (2007 Scholar).

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