Ligand kinetics in hemoglobin Hiroshima.

Hemoglobin Hiroshima is an electrophoretically fast-moving variant with a fourfold increase in oxygen affinity and a decreased Bohr effect. Based on a decreased rate of dissociation of O(2) in the presence of dithionite and an increased rate of binding of CO by the deoxy form, we have concluded that the kinetic basis of the high affinity exhibited by Hb Hiroshima is the concurrence of a faster combination rate and a slower dissociation rate for ligands.