Kinetic studies of differences between α- and β-chains of human hemoglobin: an approach for determination of the chain affinity to oxygen

A new approach is proposed to provide ultimate answers to such problem as the affinity difference between individual α- and β-subunits in different conformational forms of tetrameric hemoglobin. The approach is based on determination of the bimolecular association rate constant for O2 rebinding and the apparent quantum yield of photodissociation from single flash photolysis experiment. The potential of the approach is demonstrated with α- and β-subunits within human hemoglobin in the R-state.