Glucose-6-phosphate dehydrogenase from Plasmodium berghei: kinetic and electrophoretic characterization

Evidence is given for the existence of a parasite-specific glucose-6-phosphate dehydrogenase in Plasmodium berghei by characterization of its kinetic and electrophoretic properties. After separating the parasites from infected RBC the G6PD was purified by affinity chromatography with 2'5'-ADP-Sepharose 4B. In cellulose acetate electrophoresis malarial G6PD significantly differs from the red cell enzyme. The subunits of the parasite-specific G6PD have a molecular weight of 55 kD in contrast to 59 kD of the RBC enzyme. G6PD from P. berghei shows no cross-reactivity with antibodies against G6PD from rat erythrocytes. The Km-value for G6P of malarial G6PD is increased by one order of magnitude compared with the host cell enzyme.