The Chemistry of the Bohr Effect

Hemoglobin H is of particular interest since it consists only of j3 chains (1). This abnormal hemoglobin, therefore, presents a unique opportunity for investigating the imluence of a-j3 chain interactions on some of the structural and functional properties of hemoglobin. The hemoglobin H used for these studies was obtained from two patients. The first patient, L. G., was a 25-year-old woman of Negro and American Indian ancestry. The second patient, N. H., was a 51-year-old woman of Chinese ancestry. The evidence that the hemoglobin H of both of these patients is identical with hemoglobin H studied by others is summarized below. 1. Patient L. G. had a moderate microcytic hypochromic anemia; after incubation with brilliant cresyl blue, the erythrocytes showed characteristic inclusion bodies (2). Patient N. H. had been aware of anemia for many years and underwent a splenectomy at age 35; after incubation with brilliant cresyl blue, her erythrocytes showed the giant inclusion bodies noted in other patients with hemoglobin H who have undergone splenectomy (3). 2. A family study of patient L. G. showed an absence of hemoglobin H in both parents. This is usually the case in this disease. Examination of the cord blood of the baby of L. G., in April 1961, revealed Bart’s hemoglobin (four y chains). 3. Starch granule electrophoresis at pH 8.6 in barbital buffer revealed an abnormal rapid hemoglobin component in both L. G. and N. H. This component comprised 6 to 10% of the total pigment in L. G. and 35 to 40% in N. H. At pH 6.5 the abnormal hemoglobin from both patients migrated toward the anode only hemoglobin H exhibits this property (2). 4. The amino acid composition of globm prepared from hemoglobin H of each patient was compared with that reported by Hill and Craig (4) and by Braunitzer et al. (5) for isolated PA 1 chains as shown in Table I. As can be seen from these analyses, the correspondence between the composition of the hemoglobin H from the two patients and that of /3 ̂ chains is indeed very close. An exception is the occurrence of small amounts of isoleucine. It is unlikely that this is due to the presence of a small peptide which could be mistaken for isoleucine, since the amount of this material was not di-