EFFECT OF ERYTHROCYTE PYRIDOXAL KINASE-ACTIVITY ON THE IN-VITRO GROWTH-RATES OF PLASMODIUM-FALCIPARUM

Pyridoxal kinase is an essential enzyme for intracellular protein synt hesis. It phosphorylates vitamin B6 to its active coenzyme, pyridoxal- 5'-phosphate, which then plays a central role in transamination and ot her critical biochemical reactions. Since Afro-Americans have a high f requency of the low erythrocyte pyridoxal kinase activity, it has been postulated that this enzyme defect may afford protection against fata l malaria infections. The in vitro growth rates of P.falciparum parasi tes were measured in erythrocytes with high, low and intermediate PLK enzyme activity and no significant difference in parasite growth rates was observed. Erythrocytes with low PLK activity were capable of supp orting normal in vitro growth and development of P.falciparum parasite s. Even though, P. falciparum parasites lack PLK activity, their compl ete dependence on red cell enzyme activity has yet to be established.