Heme synthesizing enzymes of Plasmodium knowlesi: a simian malaria parasite.
Intraerythrocytic stages of cell-free Plasmodium knowlesi possess significant activities of heme biosynthetic enzymes, viz. delta-aminolevulinic acid synthase (delta-ALAS), delta-aminolevulinic acid dehydrase (delta-ALAD), ferrochelatase (FC), and tryptophan pyrrolase (enzyme representing free heme pool). delta-Aminolevulinic acid synthase and FC showed higher activities in schizont than in ring trophozoite stage. Uninfected monkey erythrocytes did not possess the above-mentioned enzyme activities; on the contrary, leucocytes showed detectable enzyme activities. delta-Aminolevulinic acid synthase was not appreciably inhibited by different antimalarials. Succinyl acetone and hemin exhibited a concentration-dependent inhibition of delta-ALAD and delta-ALAS, respectively.
Srivastava
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Division of Biochemistry, Central Drug Research Institute, Lucknow, India.
Pandey
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D000624:5-Aminolevulinate Synthetase / Q000187:drug effects / Q000378:metabolism; D000818:Animals; D000962:Antimalarials / Q000494:pharmacology; D004791:Enzyme Inhibitors / Q000494:pharmacology; D005294:Ferrochelatase / Q000378:metabolism; D005998:Glycine / Q000494:pharmacology; D006418:Heme / Q000096:biosynthesis*; D006427:Hemin / Q000494:pharmacology; D006537:Heptanoates / Q000494:pharmacology; D008253:Macaca mulatta; D016790:Plasmodium knowlesi / Q000187:drug effects / Q000201:enzymology*; D000623:Porphobilinogen Synthase / Q000037:antagonists & inhibitors / Q000187:drug effects / Q000378:metabolism; D014366:Tryptophan Oxygenase / Q000378:metabolism
D000962:Antimalarials; D004791:Enzyme Inhibitors; D006537:Heptanoates; D006418:Heme; C020804:succinylacetone; D006427:Hemin; D014366:Tryptophan Oxygenase; D000624:5-Aminolevulinate Synthetase; D000623:Porphobilinogen Synthase; D005294:Ferrochelatase; D005998:Glycine