Heterogeneity of Hemoglobin from Arca

Anadara satowi Molecular Weights and Oxygen Equilibria of Arca Hb I and II

Abstract

The heterogeneity of hemoglobin from Arca was demonstrated by the salting-out curve, the sedimentation pattern, gel filtration, electrophoresis, and ion-exchange chromatography. The two main components (Hb I and II) were purified by DEAEcellulose and CM-cellulose and appeared homogeneous on ultracentrifugation and electrophoresis. The oxygen equilibria of these hemoglobins showed that neither had a Bohr effect in the neutral region and that they had less heme-heme interaction than human adult hemoglobin. The molecular weights of Hb I and II, determined by the sedimentation equilibrium method, were 34, 000 and 69, 000, respectively, and heme conents per molecule were 2 for Hb I and 4 for Hb II.Hb I and II each dissociated to a monomer on treatment with sodium dodecyl sulfate. From the above experiments it was concluded that Hb I has a dimer structure and Hb II, a tetramer structure.