A Modified Method for the Determination of 2,3-Diphosphoglycerate in Erythrocytes

Abstract

A modified assay for 2,3-diphosphoglycerate in erythrocytes is described. 3-phosphoglycerate, specifically formed by the action of glycerate phosphomutase modified by 2-phosphoglycolate, is determined by using a sequence of enzymes starting with phosphoglycerate kinase and ending with glycerol 1-phosphate dehydrogenase. This procedure gives a high sensitivity (2 moles NADH per mole DPG) and a favourable overall equilibrium for the assay. The effect of other metabolites and of changing the volume of the protein-precipitating solution (0.6 mol/1 PCA) was investigated. The accuracy of the method was tested by comparison with a chromatographic method and by determination of the mean value from 29 healthy non-anaemic men.