Hostname: page-component-8448b6f56d-xtgtn Total loading time: 0 Render date: 2024-04-18T15:37:29.540Z Has data issue: false hasContentIssue false

The mechanism of pyrimethamine resistance in Plasmodium falciparum

Published online by Cambridge University Press:  06 April 2009

A. Dieckmann
Affiliation:
Institute of Physiological Chemistry, University of Tübingen, Hoppe-Seyler-Str. 1, D-7400 Tübingen 1, DE
A. Jung
Affiliation:
Institute of Physiological Chemistry, University of Tübingen, Hoppe-Seyler-Str. 1, D-7400 Tübingen 1, DE

Summary

The uptake of radioactive pyrimethamine by a sensitive and a resistant strain of Plasmodium falciparum, the metabolic fate of pyrimethamine inside these parasites and the kinetic properties of dihydrofolate reductase (DHFR) from both strains have been studied. Uptake of the drug was identical in both strains and no metabolite of pyrimethamine was found in either strain. DHFR from the resistant strain was 300 times less sensitive to inhibition by pyrimethamine than the enzyme from the sensitive strain, while the Michaelis constant for dihydrofolate remained unchanged and inhibition was competitive in both cases. Altered properties of plasmodial DHFR are apparently the only mechanism responsible for pyrimethamine resistance in the strain of Plasmodium falciparum studied.

Type
Research Article
Copyright
Copyright © Cambridge University Press 1986

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

Beverley, S. M., Schimke, R. T., Coderre, J. A. & Santi, D. V. (1983). DNA amplification in methotrexate-resistant Leishmania. Journal of Cellular Biochemistry 7 (Suppl.), 12.Google Scholar
Dieckmann, A. & Jung, A. (1986). Mechanisms of sulfadoxine resistance in Plasmodium falciparum. Molecular and Biochemical Parasitology (in the Press).Google Scholar
Ferone, R. (1977). Folate metabolism in malaria. Bulletin of the World Health Organization 55, 291–8.Google ScholarPubMed
Ferone, R., Burchall, J. J. & Hitchings, G. H. (1969). Plasmodium berghei dihydrofolate reductase – isolation, properties and inhibition by antifolates. Molecular Pharmacology 5, 4959.Google Scholar
Kan, S. C. & Siddiqui, W. A. (1979). Comparative studies on dihydrofolate reductases from Plasmodium falciparum and Aotus trivirgatus. Journal of Protozoology 26, 660–4.Google Scholar
Lambros, C. & Vanderberg, J. P. (1979). Synchronization of Plasmodium falciparum erythrocytic stages in culture. Journal of Parasitology 65, 418–20.Google Scholar
McCutchan, T. F., Welsh, J. A., Dame, J. B., Quakyi, I. A., Graves, P. M., Drake, J. C. & Allegra, C. J. (1984). Mechanism of pyrimethamine resistance in recent isolates of Plasmodium falciparum. Antimicrobial Agents and Chemotherapy 26, 656–9.Google Scholar
Rüssmann, L., Jung, A. & Heidrich, G. (1982). The use of Percoll gradients, elutriator rotor elution and Mithramycin staining for the isolation and identification of intraerythrocytic stages of Plasmodium berghei. Zeitschrift für Parasitenkunde 66, 273–80.Google Scholar
Simmons, W. S. & DeAngelis, R. L. (1973). Quantitation of pyrimethamine and related diaminopyrimidines in situ by enhancement of fluorescence after thin layer chromatography. Analytical Chemistry 45, 1538–40.Google Scholar
Sirawaraporn, W. & Yongyuth, Y. (1984). Kinetic and molecular properties of dihydrofolate reductase from pyrimethamine-sensitive and pyrimethamine-resistant Plasmodium chabaudi. Molecular and Biochemical Parasitology 10, 355–67.CrossRefGoogle ScholarPubMed
Tan-Ariya, P. & Brockelman, C. R. (1983). Plasmodium falciparum: variations in p−aminobenzoic acid requirements as related to sulfadoxine sensitivity. Experimental Parasitology 55, 364–71.Google Scholar
Trager, W. & Jensen, B. (1976). Human malaria parasites in continuous culture. Science 193, 763–5.Google Scholar