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Photo by Elise Amendola
Chemists have generated an enzyme that shows the potential for converting type A or B blood into a universal blood type.
The enzyme works by snipping off the antigens found in blood types A and B, making these blood types more like O, which can be given to patients of all blood types.
The enzyme was able to remove most of the antigens in type A and B blood. Before it can be used in clinical settings, however, all of the antigens would need to be removed.
David Kwan, PhD, of the University of British Columbia in Vancouver, Canada, and his colleagues described their work with this enzyme in the Journal of the American Chemical Society.
“We produced a mutant enzyme that is very efficient at cutting off the sugars in A and B blood and is much more proficient at removing the subtypes of the A antigen that the parent enzyme struggles with,” Dr Kwan said.
To create the enzyme, Dr Kwan and his colleagues used a technology called directed evolution. It involves inserting mutations into the gene that codes for the enzyme and selecting mutants that are more effective at cutting the antigens.
The team started with the family 98 glycoside hydrolase from Streptococcus pneumoniae SP3-BS71 (Sp3GH98), which cleaves the entire terminal trisaccharide antigenic determinants of both A and B antigens from some of the linkages on red blood cell surface glycans.
Through directed evolution, the researchers developed variants of Sp3GH98 that showed improved activity toward some of the linkages that are resistant to cleavage by the wild-type enzyme.
In 5 generations, the enzyme became 170 times more effective. This Sp3GH98 variant could remove the majority of the antigens in type A and B blood.
The researchers said the enzyme must be able to remove all of the antigens before it can be used in the clinic. The immune system is highly sensitive to blood groups, and even small amounts of residual antigens could trigger an immune response.
The concept of using an enzyme to change blood types is not new, said study author Steve Withers, PhD, also from the University of British Columbia.
“But, until now, we needed so much of the enzyme to make it work that it was impractical,” he said. “Now, I’m confident that we can take this a whole lot further.” 
Photo by Elise Amendola
Chemists have generated an enzyme that shows the potential for converting type A or B blood into a universal blood type.
The enzyme works by snipping off the antigens found in blood types A and B, making these blood types more like O, which can be given to patients of all blood types.
The enzyme was able to remove most of the antigens in type A and B blood. Before it can be used in clinical settings, however, all of the antigens would need to be removed.
David Kwan, PhD, of the University of British Columbia in Vancouver, Canada, and his colleagues described their work with this enzyme in the Journal of the American Chemical Society.
“We produced a mutant enzyme that is very efficient at cutting off the sugars in A and B blood and is much more proficient at removing the subtypes of the A antigen that the parent enzyme struggles with,” Dr Kwan said.
To create the enzyme, Dr Kwan and his colleagues used a technology called directed evolution. It involves inserting mutations into the gene that codes for the enzyme and selecting mutants that are more effective at cutting the antigens.
The team started with the family 98 glycoside hydrolase from Streptococcus pneumoniae SP3-BS71 (Sp3GH98), which cleaves the entire terminal trisaccharide antigenic determinants of both A and B antigens from some of the linkages on red blood cell surface glycans.
Through directed evolution, the researchers developed variants of Sp3GH98 that showed improved activity toward some of the linkages that are resistant to cleavage by the wild-type enzyme.
In 5 generations, the enzyme became 170 times more effective. This Sp3GH98 variant could remove the majority of the antigens in type A and B blood.
The researchers said the enzyme must be able to remove all of the antigens before it can be used in the clinic. The immune system is highly sensitive to blood groups, and even small amounts of residual antigens could trigger an immune response.
The concept of using an enzyme to change blood types is not new, said study author Steve Withers, PhD, also from the University of British Columbia.
“But, until now, we needed so much of the enzyme to make it work that it was impractical,” he said. “Now, I’m confident that we can take this a whole lot further.”
Photo by Elise Amendola
Chemists have generated an enzyme that shows the potential for converting type A or B blood into a universal blood type.
The enzyme works by snipping off the antigens found in blood types A and B, making these blood types more like O, which can be given to patients of all blood types.
The enzyme was able to remove most of the antigens in type A and B blood. Before it can be used in clinical settings, however, all of the antigens would need to be removed.
David Kwan, PhD, of the University of British Columbia in Vancouver, Canada, and his colleagues described their work with this enzyme in the Journal of the American Chemical Society.
“We produced a mutant enzyme that is very efficient at cutting off the sugars in A and B blood and is much more proficient at removing the subtypes of the A antigen that the parent enzyme struggles with,” Dr Kwan said.
To create the enzyme, Dr Kwan and his colleagues used a technology called directed evolution. It involves inserting mutations into the gene that codes for the enzyme and selecting mutants that are more effective at cutting the antigens.
The team started with the family 98 glycoside hydrolase from Streptococcus pneumoniae SP3-BS71 (Sp3GH98), which cleaves the entire terminal trisaccharide antigenic determinants of both A and B antigens from some of the linkages on red blood cell surface glycans.
Through directed evolution, the researchers developed variants of Sp3GH98 that showed improved activity toward some of the linkages that are resistant to cleavage by the wild-type enzyme.
In 5 generations, the enzyme became 170 times more effective. This Sp3GH98 variant could remove the majority of the antigens in type A and B blood.
The researchers said the enzyme must be able to remove all of the antigens before it can be used in the clinic. The immune system is highly sensitive to blood groups, and even small amounts of residual antigens could trigger an immune response.
The concept of using an enzyme to change blood types is not new, said study author Steve Withers, PhD, also from the University of British Columbia.
“But, until now, we needed so much of the enzyme to make it work that it was impractical,” he said. “Now, I’m confident that we can take this a whole lot further.”