Enzymes of the Human Erythrocyte

The enzymatic interconversion involves a net transfer of hydrogen which migrates as a proton (1). In spite of an early reference (2) to the role and existence of this glycolytic enzyme within a variety of animal tissues, it apparently has not been prepared previously in a significantly purified state from any source. Fractions rich in this enzyme have been separated from rabbit muscle (3), and a purification of a phosphomannose isomertie has also been achieved from this tissue (4). The possibility of obtaining phosphoglucose isomerase in purified form from human erythrocytes was considered after a report (5) which described appreciable activity as associated with these cells. Previous papers of this series (6-8) have been concerned with the isolation and characterization of various enzymes obtained from the human erythrocyte. The present report will summarize information pertinent to obtaining phosphoglucose isomerase in a highly purified form and will also describe certain characteristic properties of the enzyme.