When 2,3-bisphosphoglycerate (2,3-BPG) levels increase, hemoglobin release oxygen.
2,3-bisphosphoglycerate is present in human red blood cells (erythrocyte).
2,3-BPG nteracts with deoxygenated hemoglobin and decrease his affinity for oxygen, so it allosterically promotes the release of the remaining oxygen molecules.
