Embryonic and Fetal Human Hemoglobins: Structures, Oxygen Binding, and Physiological Roles.

Embryonic and Fetal Human Hemoglobins: Structures, Oxygen Binding, and Physiological Roles. Subcell Biochem. 2020;94:275-296 Authors: Manning JM, Manning LR, Dumoulin A, Padovan JC, Chait B Abstract During the past two decades, significant advances have been made in our understanding of the human fetal and embryonic hemoglobins made possible by the availability of pure, highly characterized materials and novel methods, e.g., nano gel filtration, to study their properties and to correct some misconceptions. For example, whereas the structures of the human adult, fetal, and embryonic hemoglobins are very similar, it has generally been assumed that functional differences between them are due to primary sequence effects. However, more recent studies indicate that the strengths of the interactions between their subunits are very different leading to changes in their oxygen binding properties compared to adult hemoglobin. Fetal hemoglobin in the oxy conformation is a much stronger tetramer than adult hemoglobin and dissociates to dimers 70-times less than adult hemoglobin. This property may form the basis for its protective effect against malaria. A major source of the increased strength of fetal hemoglobin resides within the A-helix of its gamma subunit as demonstrated in studies with the hybrid hemoglobin Felix and related hybrids. Re-activating fetal hemoglobin synthesis in vivo is currently a major focus of clinical efforts designed to...
Source: Sub-Cellular Biochemistry - Category: Biochemistry Authors: Tags: Subcell Biochem Source Type: research