Low Binding of 2,3-Diphosphoglycerate to Haemoglobin F: A Contribution to the Knowledge of the Binding Site and an Explanation for the High Oxygen Affinity of Foetal Blood

Abstract

The binding of 2,3-diphosphoglycerate to human haemoglobin A and F was determined using an ultracentrifugation technique. The binding of the phosphocompound was much lower to haemoglobin F than to haemoglobin A, both in the oxygenated and deoxygenated states. It is concluded that this difference may explain, at least partly, the higher oxygen affinity of foetal blood. The result supports previously advanced arguments that binding of 2,3-diphosphoglycerate to haemoglobin A takes place at βH21 His.

Key Words:

• Foetal erythrocytes
• haemoglobulin F
• haemoglobulin F-2,3-diphosphoglycerate-binding
• oxygen affinity
• 2,3-diphosphoglycerate