Red Blood Cell Cheat Sheet
ABO Blood Group
Discovered in 1901 by Karl Landsteiner
Routinely tested for alongside Rh
The ABO blood groups are an indirect product of the A and B alleles of the ABO gene
A and B Antigens
The antigens are oligosaccharides that are synthesised by glycosyltransferases
These glycotransferases transfer the monosaccharides to H antigen
o For A antigen, A transferase adds GalNac to H antigen
o For B antigen, B transferase adds Gal to H antigen
The ABH antigens are found at the tip of the glycan chain
Blood Group Antigens
Expressed on membrane proteins or glycoconjugates that are attached to membrane
proteins or lipids
These antigens cause blood group incompatibility
Conventional blood grouping is carried out by mixing washed RBCs with specific group
antibodies
Red Cell Membrane
The red cell membrane consists of a lipid bilayer of phospholipids
The major component of the lipid bilayer is cholesterol
The four main types of phospholipids are
o Choline
o Phosphatidylcholine
o Phosphatidylserine
o Phosphatidylethanolamine
, The membrane has a spectrin network underneath with transmembrane protein scattered
throughout
The key components of the erythrocyte membrane are
o Ankyrin-Rh complex
o Spectrin-lipid interaction
o Spectrin-ankyrin-band 3 interaction
o Spectrin dimer-dimer
Vertical and Horizontal Interactions
The vertical interactions of the cytoskeleton include
o Band 3- ankyrin
o GPC- protein 4.1R-p55 - actin
o Rh core complex-ankyrin
The horizontal interactions of the cytoskeleton include
o Spectrin dimers
o Protein 4.1R-phophatidylserine
Red Cell Membrane Components
Band 3 exchange protein is an anion exchanger which carriers the Diego blood group
o It is important for chlorine and carbonate exchange which enables rapid expulsion
o It also acts as a nucleation site for glycolytic enzymes
Protein 4.2 is needed in terms of flexibility and stability
o A reduction in band 3 also reduced protein 4.2
o This protein also binds to spectrin
Ankyrin is a major membrane anchoring protein
o It interacts with beta spectrin and band 3
o It has 3 domains
Band 3 binding domain 89kDa N-terminal
Central 62kDa regulatory binding domain
Acidic 55kDa regulatory domain C-terminal
Protein 4.1 is a protein of the skeletal network
ABO Blood Group
Discovered in 1901 by Karl Landsteiner
Routinely tested for alongside Rh
The ABO blood groups are an indirect product of the A and B alleles of the ABO gene
A and B Antigens
The antigens are oligosaccharides that are synthesised by glycosyltransferases
These glycotransferases transfer the monosaccharides to H antigen
o For A antigen, A transferase adds GalNac to H antigen
o For B antigen, B transferase adds Gal to H antigen
The ABH antigens are found at the tip of the glycan chain
Blood Group Antigens
Expressed on membrane proteins or glycoconjugates that are attached to membrane
proteins or lipids
These antigens cause blood group incompatibility
Conventional blood grouping is carried out by mixing washed RBCs with specific group
antibodies
Red Cell Membrane
The red cell membrane consists of a lipid bilayer of phospholipids
The major component of the lipid bilayer is cholesterol
The four main types of phospholipids are
o Choline
o Phosphatidylcholine
o Phosphatidylserine
o Phosphatidylethanolamine
, The membrane has a spectrin network underneath with transmembrane protein scattered
throughout
The key components of the erythrocyte membrane are
o Ankyrin-Rh complex
o Spectrin-lipid interaction
o Spectrin-ankyrin-band 3 interaction
o Spectrin dimer-dimer
Vertical and Horizontal Interactions
The vertical interactions of the cytoskeleton include
o Band 3- ankyrin
o GPC- protein 4.1R-p55 - actin
o Rh core complex-ankyrin
The horizontal interactions of the cytoskeleton include
o Spectrin dimers
o Protein 4.1R-phophatidylserine
Red Cell Membrane Components
Band 3 exchange protein is an anion exchanger which carriers the Diego blood group
o It is important for chlorine and carbonate exchange which enables rapid expulsion
o It also acts as a nucleation site for glycolytic enzymes
Protein 4.2 is needed in terms of flexibility and stability
o A reduction in band 3 also reduced protein 4.2
o This protein also binds to spectrin
Ankyrin is a major membrane anchoring protein
o It interacts with beta spectrin and band 3
o It has 3 domains
Band 3 binding domain 89kDa N-terminal
Central 62kDa regulatory binding domain
Acidic 55kDa regulatory domain C-terminal
Protein 4.1 is a protein of the skeletal network
