| 2,3-diphosphoglycerate | A highly anionic organic phosphate which is present in human red blood cells at about the same molar ratio as haemoglobin. It binds to deoxyhemoglobin but not the oxygenated form, therefore diminishing the oxygen affinity of haemoglobin. This is essential in enabling haemoglobin to unload oxygen in tissue capillaries. It is also an intermediate in the conversion of 3-phosphoglycerate to 2-phosphoglycerate by phosphoglycerate mutase (EC 5.4.2.1). (12 Dec 1998) |
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