Hemoglobins from Erythrocytes of the Eel, Anguilla japonica*

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Abstract
1. Chromatographic separation of the two hemoglobins (HbE1 and HbE2) in the blood of the cel, Anguilla japonica, into their constituent subunits was studied. It was found that both hemoglobins were composed of four polypeptide chains, each having the valyl residue as the amino terminal amino acid. Analyses of the carboxyl terminal amino acid. and of the tryptic peptides, however, indicated that there was no polypeptide chain common to the two hemoglobins. The amino acid compositions of the subunits of the two hemoglobins were also studied. 2. Studies on the oxygen equilibria of the two hemoglobins revealed that they differed from each other with respect to their oxygen affinities, heme-heme interaction and the Bohr effect. HbE1 was half-saturated with oxygen at 2.1 mmHg, while HbE2 was half-saturated at 14 mmHg, at pH 7.0 and 20°C. The π value of Hill's equation was 2.4 for HbE1, and 1.0–1.8 for HbE2 varying with the pH. A Bohr effect was observed with HbE2, but not with HbE1. The oxygen equilibria of a hemolysate, a solution of HbE1 together with HbE2, and an erythrocyte suspension were also measured and compared with each other.