Evidence for structural homology between human red cell phosphoglycerate mutase and 2,3-bisphosphoglycerate synthase.

Previous reports have suggested the possibility of extensive structural homology between human erythrocyte bisphosphoglycerate synthase (glycerate-1,3-P2 leads to glycerate-2,3-P2) and phosphoglycerate mutase (glycerate-3-P in equilibrium glycerate-2-P). This study lends credence to that conjecture through comparative physicochemical investigations involving peptide mapping, circular dichroism, and immunological techniques. The data indicate that despite differences in function, both enzymes apparently manifest a high degree of similarity in primary, secondary, and tertiary structure. Mapping data also indicate that each protein is comprised of two apparently identical subunits.