A HUMAN HEMOGLOBIN WITH LOWERED OXYGEN AFFINITY AND IMPAIRED HEME-HEME INTERACTIONS*

Abstract

A familial human hemoglobin variant is described which caused markedly diminished oxygen saturation of the blood in the presence of normal arterial oxygen tensions. The shift of the entire oxyhemoglobin dissociation curve was due to an abnormally low oxygen affinity of the hemoglobin. The oxygen equilibria of the pigment in buffer solutions revealed a Bohr effect of normal magnitude but probably no heme-heme interactions. The absorption spectra of its oxy and reduced form in the visible and ultraviolet spectral region were those of normal hemoglobin. The alkaline and acid methemoglobin showed spectral abnormalities. On starch block electrophoresis, the methemoglobin form of the pigment migrated more slowly than methemoglobin A. The lowered oxygen affinity is attributed to molecular aberrations in the globin which interfere with normal heme-globin interactions.