Solution to PS 3 #8

a) Fetal Hb binds O2 more strongly that adult Hb.
b) Fetal Hb has a a2g2 structure with less Lys residues to bind BPG compared to the normal adult a2b2 structure.
c) Fetal Hb binds BPG less strongly than adult Hb.  Since BPG stablizes the deoxy form of Hb this leads to an increased affinity for O2 in fetal Hb.
d) Fetal Hb must be able to get O2 from the mothers blood, it therefore needs to always have a higher affinity for O2 than adult Hb in order to do this at all partial pressures of O2.



Return to Problem Set #3