Equilibria and ligand binding kinetics of hemoglobins from the sharks, Prionace glauca and Carcharhinus milberti

1. 1. The functional behavior of the hemoglobins from two sharks (Prionace glauca and Carcharhinus milberti) obtained off-shore from Kealakakua Bay, Hawaii, has been examined. 2. 2. Neither hemoglobin shows an apparent Root effect. The binding properties in general are very similar to those of mammalian hemoglobins. 3. 3. The oxygen equilibria of the maternal and fetal hemoglobins from C. milberti have been compared. The results show that fetal hemoglobin has a slightly higher oxygen affinity in the absence of endogenous phosphate, but the affinities of fetal and maternal hemoglobins appear identical in 0·8 mM. ATP.