title: Human malaria parasite adenosine deaminase. Characterization in host enzyme-deficient erythrocyte culture.
abstract: Human malaria infected erythrocytes show a dramatic increase in adenosine deaminase activity in vitro. Using recently developed culture techniques, adenosine deaminase-deficient human erythrocytes were infected in vitro with the major human pathogen Plasmodium falciparum. Adenosine deaminase activity was undetectable in the uninfected host red cells, but increased by 2-fold over normal levels in these cells with an 8% parasitemia. The enzyme in these cells appeared unique in that its activity was markedly elevated over that of other parasite purine enzymes, was not cross-reactive with antibody against human erythrocyte adenosine deaminase, and though inhibited competitively by deoxycoformycin was relatively insensitive to erythro-9-(2-hydroxy-3-nonyl) adenine. The use of adenosine deaminase-deficient erythrocytes for the in vitro cultivation of Plasmodium provides a unique system for the study of parasite enzyme and allows further insight into the purine metabolism of the intraerythrocytic malaria parasite.
mesh_terms: D000243:Adenosine Deaminase / Q000172:deficiency / Q000302:isolation & purification / Q000378:metabolism*; D000818:Animals; D003070:Coformycin / Q000031:analogs & derivatives / Q000494:pharmacology; D004912:Erythrocytes / Q000502:physiology*; D006801:Humans; D007166:Immunosuppressive Agents / Q000494:pharmacology; D007700:Kinetics; D009700:Nucleoside Deaminases / Q000378:metabolism*; D015649:Pentostatin; D010963:Plasmodium falciparum / Q000201:enzymology*
chemical_list: D007166:Immunosuppressive Agents; D003070:Coformycin; D015649:Pentostatin; D009700:Nucleoside Deaminases; D000243:Adenosine Deaminase