Human Embryonic Hemoglobins

Abstract

The recent studies on the changes in conformation of hemoglobin during the oxygenation/reduction cycle by Muirhead and Perutz (1963) show how beautifully the structure of hemoglobin is adapted to its function. It is therefore not surprising that hemoglobins of the same species which function under different physiological conditions have different structures. For example, tadpole hemoglobin differs from that found in the frog (Riggs, 1951; Dessauer, Fox, and Ramirez, 1957) and the hemoglobin found in chicken embryos differs from that of the adult hen (Manwell, Baker, Roslansky, and Foght, 1963). In the same way, the hemoglobin found in the human adult, when oxygenation is via the lungs, differs from that found in the human fetus, when oxygenation is via the placenta (Körber, 1866). These hemoglobins are called adult hemoglobin or Hb-A and fetal hemoglobin or Hb-F. During intra-uterine development, red cells containing hemoglobin are definitely present by the 18th day of...