Comparison of the phosphofructokinase and pyruvate kinase activities of Cryptosporidium parvum, Eimeria tenella and Toxoplasma gondii

H Denton, S M Brown, C W Roberts, J Alexander, V McDonald, K W Thong, G H Coombs

Research output: Contribution to journalArticlepeer-review

53 Citations (Scopus)

Abstract

Oocysts of Cryptosporidium parvum were shown to contain a pyrophosphate-dependent phosphofructokinase (PPi-PFK) similar to those previously described for Eimeria tenella and Toxoplasma gondii. PPi-PFK of C. parvum displayed simple hyperbolic kinetics with respect to its substrate fructose 6-phosphate and was not affected by fructose 2,6-bisphosphate, the major allosteric activator of most ATP-PFKs. Inorganic pyrophosphatase was not detectable in any of the three parasites. T. gondii tachyzoites and C. parvum cysts both contained a pyruvate kinase (PK) specific for ADP rather than PPi/AMP. The PK of T. gondii was similar to that of E. tenella in that it displayed strong positive cooperativity with respect to its substrate phosphoenolpyruvate and was heterotropically activated by glucose 6-phosphate, fructose 6-phosphate and fructose 1,6-bisphosphate. PK of C. parvum showed no evidence of allosteric properties. The results suggest that the three coccidia are similar in depending heavily on anaerobic energy production via glycolysis but that the mechanisms for regulating glycolysis are not common to all species.
Original languageEnglish
Pages (from-to)23-29
Number of pages7
JournalMolecular and Biochemical Parasitology
Volume76
Issue number1-2
DOIs
Publication statusPublished - Feb 1996

Keywords

  • anaerobiosis
  • animals
  • cryptosporidium parvum
  • eimeria tenella
  • glycolysis
  • phosphofructokinase-1
  • pyrophosphatases
  • pyruvate kinase
  • toxoplasma

Cite this