Fetal hemoglobin (HbF) contains serine instead of histidine…
Fetal hemoglobin (HbF) contains serine instead of histidine at position 143 of the gamma chain, which is the equivalent of the adult hemoglobin (HbA) beta chain. Position 143 faces the central cavity between the gamma chains. Blank #1: Why does 2,3-biphosphoglycerate (2,3-BPG) bind more tightly to deoxy HbA than to deoxy HbF? Blank #2: What is the effect of 2,3-BPG binding less tightly to deoxy HbF than to HbA have on the affinity of HbF for O2? (increase affinity/decrease affinity)