• coagulation factor concentrate;
  • hemostasis;
  • plasma derivatives;
  • proteomics;
  • recombinant proteins

Post-translational modifications (PTMs) located on the activation peptide (AP) of recombinant FIX (rFIX, BeneFIX®) and plasma-derived FIX (pdFIX, Betafact®) have been investigated by mass spectrometry to review the structural differences between these two products. Three major structural differences were pointed out. rFIX contains a low amount of phosphorylated and sulphated AP (4% for rFIX vs. 70% for pdFIX); rFIX N-glycans are only sialylated in the α2-3 linkage, whereas pdFIX N-glycans contain both type of α2-3 and α2-6 linkages, and rFIX does not contain any sialyl LewisX glycoantigens contrary to pdFIX. These variations might participate in the in vivo potential different behaviours of the two molecules.