Potential glycation sites of the hemoglobin molecule
include the N-terminal amino acid valine of the four
polypeptide chains and all free ε-amino groups of lysine
residues within the chains. The predominant glycation
site is the N-terminal valine residue of the β-chain of the
hemoglobin molecule, which accounts for approximately
60% of all bound glucose. The term for this major
component is HbA1c. Other glucose molecules can bound
to one or more of the 44 glycation sites at the ε-amino
groups within the hemoglobin molecule (34% of all
bound glucose) or at the N-terminal valine of the α-chain
(about 6%).9,13,