Role of 2,3-biphosphoglycerate in hemoglobin function

Role of 2,3-biphosphoglycerate in hemoglobin function

1. BPG binds to the deoxygenated form of hemoglobin but not the oxygenated form.

   • presence = equilibrium tipped towards the deoxygenated form.

2. oxygenated hemoglobin = BPG can no longer fit into the cavity

3. importance = in embryos. there must be a transfer of oxygen from the mother's hemoglobin to the empbyo

   • fetal hemoglobin = beta chain is replaced by a gamma chain.
   • fetal chain has one less posiitive charge in BPG binding cavity than adult hemoglobin and binds BPG less tightly
   • fetal hemoglobin has a higher oxygen affinity than the adult form