23bisfosfoglyserola

2,3-bisphosphoglycerate, often abbreviated as 2,3-BPG or BPG, is a molecule that plays a crucial role in regulating oxygen binding to hemoglobin within red blood cells. It is an organic bisphosphate found in erythrocytes and is a byproduct of glycolysis, the metabolic pathway that breaks down glucose for energy.

The primary function of 2,3-BPG is to allosterically modulate hemoglobin's affinity for oxygen. It binds to the deoxygenated form of hemoglobin, stabilizing it and reducing hemoglobin's ability to pick up oxygen in the lungs. However, this binding also decreases hemoglobin's affinity for oxygen in the tissues, promoting the release of oxygen where it is most needed, such as during strenuous exercise or in low-oxygen environments. This effect is known as the Bohr effect, although 2,3-BPG's action is distinct from the direct effect of protons and carbon dioxide.

The concentration of 2,3-BPG in red blood cells can increase in response to physiological changes. For instance, at high altitudes, where oxygen levels are lower, 2,3-BPG levels rise, facilitating greater oxygen delivery to tissues. Similarly, in certain conditions like chronic anemia or lung disease, increased 2,3-BPG helps compensate for reduced oxygen-carrying capacity or impaired oxygen uptake. Conversely, conditions that lead to increased oxygen affinity for hemoglobin, such as a transfusion of stored blood which has lower 2,3-BPG levels, can impair oxygen release to tissues.