Influence of 2,3-diphosphoglycerate on phosphofructokinase of human erythrocytes?

Phosphofructokinase catalyzes the conversion of fructose-6-phosphate to fructose-1,6-diphosphate. Control of glycolysis is usually explained in terms of the properties of three enzymes: hexokinase, phosphofructokinase and pyruvate kinase. Recently Beutler reported that phosphofructokinase (PFK) of human erythrocytes is inhibited by 2,3-DPG. It is known that the concentration of 2,3-DPG in erythrocytes is very high. In view of control of glycolysis the finding by Beutler is very important. However, our results are in disagreement with those of Beutler

A new variant of red blood cell pyruvate kinase deficiency

A new mutant pyruvate kinase (ATP: pyruvate phosphotransferase, EC 2.7.1.40) from human erythrocytes is described. The mutant enzyme shows an increased thermolability, a decreased Km value for the substrate phosphoenolpyruvate and a loss of allosteric properties during the lifespan of the erythrocytes. By comparing the previous obtained data from other patients it seems that there can be distinguished at least three types of pyruvate kinase deficiencies

A new variant of red blood cell pyruvate kinase deficiency

A new mutant pyruvate kinase (ATP: pyruvate phosphotransferase, EC 2.7.1.40) from human erythrocytes is described. The mutant enzyme shows an increased thermolability, a decreased Km value for the substrate phosphoenolpyruvate and a loss of allosteric properties during the lifespan of the erythrocytes. By comparing the previous obtained data from other patients it seems that there can be distinguished at least three types of pyruvate kinase deficiencies

The influence of glucose 1,6-diphosphate on the enzymatic activity of pyruvate kinase

1. 1. The influence of Glc-1,6-P2 on hepatic and red blood cell pyruvate kinase (ATP: pyruvate phosphotransferase, EC 2.7.1.40) is quite similar to that of Fru-1,6-P2. The hexose diphosphates can replace each other in stimulating pyruvate kinase; after maximal stimulation by one of the compounds, the other is not capable of further stimulation. 2. 2. The regulatory role of Fru-1,6-P2 on the activity of pyruvate kinase is discussed in view of the results obtained