Blood group antigens are sugars and they are attached to various
component in the red blood cell membrane, for example the antigen of the ABO
blood group are sugars, they are produced by a series of reactions in which
enzymes catalyze the transfer of sugar units. A persons DNA determines the type
of enzyme they have; and therefore, the type of antigen that ends up on their
red blood cell.
component in the red blood cell membrane, for example the antigen of the ABO
blood group are sugars, they are produced by a series of reactions in which
enzymes catalyze the transfer of sugar units. A persons DNA determines the type
of enzyme they have; and therefore, the type of antigen that ends up on their
red blood cell.
The different blood types in the ABO system arise from the existence of
similar molecules on the RBC membrane. In each type (A, B, O) the basic units
is the same- a protein with a lipid known as ‘ceramide’ associate with it; if
(four) sugars extend from the ceramide into the extracellular fluid, these
sugars (in other from the ceramide) are galactose
–u-acetylgalactoseamine-galactose. This base unit is referred to as the
H-antigen and is the unit present on type O blood.
similar molecules on the RBC membrane. In each type (A, B, O) the basic units
is the same- a protein with a lipid known as ‘ceramide’ associate with it; if
(four) sugars extend from the ceramide into the extracellular fluid, these
sugars (in other from the ceramide) are galactose
–u-acetylgalactoseamine-galactose. This base unit is referred to as the
H-antigen and is the unit present on type O blood.
Type A and Type B blood are distinguished by the addition of a fifth
sugar.
sugar.
Type a blood result when an enzyme that attached an additional sugar
(N-acetylgalactosamine) is produced in the red blood cell.
(N-acetylgalactosamine) is produced in the red blood cell.
Type B blood result when the enzyme produced attached a galactose to the
base-unit. The enzymes that lead to the production of type A and type B blood
are co-dominant therefore the presence of both gene will lead to type AB blood.
base-unit. The enzymes that lead to the production of type A and type B blood
are co-dominant therefore the presence of both gene will lead to type AB blood.
Type O blood is inherited when the person receives two copies of the
truncated genes. This lead to the presence of the H-antigen on red blood cell.
truncated genes. This lead to the presence of the H-antigen on red blood cell.
A and B antigen are not protein antigen but oligosaccharide antigen with
chemical structure of GaINAc (N-acetyl-D-galactosamine) and D-galactose for A
and B antigen respectively (Watkins and Morgan, 2012).
chemical structure of GaINAc (N-acetyl-D-galactosamine) and D-galactose for A
and B antigen respectively (Watkins and Morgan, 2012).