Isolation of Two Pyruvate Kinase Activities in the Parasitic Protozoan Leishmania mexicana amazonensis

Using phosphocellulose affinity chromatography we were able to separate two pyruvate kinase (EC 2.7.1.40) activities in the parasitic protozoan Leishmania mexicana amazonesis. One activity (PYKi) showed hyperbolic kinetics and was decreased by fructose 2,6-bisphosphate, whereas the second activity (PYK2) showed sigmoidal kinetics for the substrate phosphoenolpyruvate and was activated by fructose 2,6-bisphosphate. Molecular sieve chromatography (Sephacryl S-400) of PYKI produced a single peak of apparent molecular mass around 200,000, while PYK2 eluted at a position corresponding to Mr 55,000.