The effect of 2,3-diphosphoglycerate on the oxygen dissociation curve of human haemoglobin.
1. Oxygen dissociation curves for concentrated human haemoglobin solutions (1.6 mmol dm-3 in haem) have been measured by mixing known quantities of oxy- and deoxyhaemoglobin solutions and measuring the resulting partial pressure of oxygen with an oxygen electrode. 2. Observations in the presence of 2,3-diphosphoglycerate support previous conclusions derived from experiments at low haemoglobin concentrations, the validity of which has been questioned. 3. The two affinity state model of Monod, Wyman & Changeux (1965) does not fully describe the actions of 2,3-diphosphoglycerate and a model in which this allosteric effector not only binds preferentially to the T state but also lowers the oxygen affinity of this state gives an improved fit to the data.
D000495:Allosteric Site; D004163:Diphosphoglyceric Acids / Q000494:pharmacology*; D006454:Hemoglobins / Q000378:metabolism*; D006801:Humans; D008954:Models, Biological; D010100:Oxygen / Q000097:blood*; D010313:Partial Pressure
D004163:Diphosphoglyceric Acids; D006454:Hemoglobins; D010100:Oxygen