Publication: Guanosine triphosphate cyclohydrolase in Plasmodium falciparum and other Plasmodium species
Issued Date
1985-01-01
Resource Type
ISSN
01666851
Other identifier(s)
2-s2.0-0022357858
Rights
Mahidol University
Rights Holder(s)
SCOPUS
Bibliographic Citation
Molecular and Biochemical Parasitology. Vol.17, No.3 (1985), 265-276
Suggested Citation
Jerapan Krungkrai, Yongyuth Yuthavong, H. Kyle Webster Guanosine triphosphate cyclohydrolase in Plasmodium falciparum and other Plasmodium species. Molecular and Biochemical Parasitology. Vol.17, No.3 (1985), 265-276. doi:10.1016/0166-6851(85)90001-5 Retrieved from: https://repository.li.mahidol.ac.th/handle/20.500.14594/30758
Research Projects
Organizational Units
Authors
Journal Issue
Thesis
Title
Guanosine triphosphate cyclohydrolase in Plasmodium falciparum and other Plasmodium species
Other Contributor(s)
Abstract
GTP cyclohydrolase (EC 3.5.4.16), the first enzyme in the pteridine pathway leading to the de novo formation of folic acid, has been identified and isolated from the human malaria parasite, Plasmodium falciparum. The enzyme was purified 200-fold by high performance size-exclusion chromatography on a TSK-G-3000 SW protein column. The molecular weight was estimated at 300 000. Optimal enzyme activity was observed at pH 8.0 and 42°C. The Kmfor GTP was 54.6 μM. Products of the enzyme reaction were identified as the carbon-8 of GTP and d-erythro-dihydroneopterin triphosphate. ATP was a competitive inhibitor (Ki= 600 μM) of the enzyme. Activity of the enzyme was Mg2+-independent, whereas Mn2+, Cu2+and Hg2+(5 mM) were inhibitory. GTP cyclohydrolase activity was also identified in a murine parasite, Plasmodium berghei, and a simian parasite, Plasmodium knowlesi. Activity of the enzyme in P. knowlesi, an intrinsically synchronous quotidian parasite, was found to be dependent on the stage of parasite development. © 1985.