Abstract
The insect stage of Trypanosoma brucei adapted the activities of 16 metabolic enzymes to growth rate and carbon source. Cells were grown in chemostats with glucose, rate limiting or in excess, or high concentrations of proline as carbon and energy sources. At each steady state, samples were collected for measurements of substrate and end product concentrations, cellular parameters, and enzyme activities. Correlation coefficients were calculated for all parameters and used to analyze the data set. Rates of substrate consumption and end product formation increased with increasing growth rate. Acetate and succinate were the major nonvolatile end products, but measurable quantities of alanine were also produced. More acetate than succinate was formed during growth on glucose, but growth on proline yielded an equimolar ratio. Growth rate barely affected the relative amounts of end products formed. The end products accounted for the glucose consumed during glucose-limited growth and growth at high rates on excess glucose. A discrepancy, indicating production of CO2, occurred during slow growth on excess glucose and, even more pronounced, in cells growing on proline. The activities of the metabolic enzymes varied by factors of 2 to 40. There was no single enzyme that correlated with consumption of substrate and/or end product formation in all cases. A group of enzymes whose activities rigorously covaried could also not be identified. These findings indicate that T. brucei adapted the activities of each of the metabolic enzymes studied separately. The results of this complex manner of adaptation were more or less constant ratios of the end products and a very efficient energy metabolism.
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- Bienen E. J., Hill G. C., Shin K. O. Elaboration of mitochondrial function during Trypanosoma brucei differentiation. Mol Biochem Parasitol. 1983 Jan;7(1):75–86. doi: 10.1016/0166-6851(83)90118-4. [DOI] [PubMed] [Google Scholar]
- Boiteux A., Hess B. Design of glycolysis. Philos Trans R Soc Lond B Biol Sci. 1981 Jun 26;293(1063):5–22. doi: 10.1098/rstb.1981.0056. [DOI] [PubMed] [Google Scholar]
- Brun R., Schönenberger Cultivation and in vitro cloning or procyclic culture forms of Trypanosoma brucei in a semi-defined medium. Short communication. Acta Trop. 1979 Sep;36(3):289–292. [PubMed] [Google Scholar]
- Cazzulo J. J., Franke de Cazzulo B. M., Engel J. C., Cannata J. J. End products and enzyme levels of aerobic glucose fermentation in trypanosomatids. Mol Biochem Parasitol. 1985 Sep;16(3):329–343. doi: 10.1016/0166-6851(85)90074-x. [DOI] [PubMed] [Google Scholar]
- Clayton C. E., Michels P. Metabolic compartmentation in African trypanosomes. Parasitol Today. 1996 Dec;12(12):465–471. doi: 10.1016/s0169-4758(96)10073-9. [DOI] [PubMed] [Google Scholar]
- Cross G. A., Klein R. A., Linstead D. J. Utilization of amino acids by Trypanosoma brucei in culture: L-threonine as a precursor for acetate. Parasitology. 1975 Oct;71(2):311–326. doi: 10.1017/s0031182000046758. [DOI] [PubMed] [Google Scholar]
- Hamm B., Schindler A., Mecke D., Duszenko M. Differentiation of Trypanosoma brucei bloodstream trypomastigotes from long slender to short stumpy-like forms in axenic culture. Mol Biochem Parasitol. 1990 Apr;40(1):13–22. doi: 10.1016/0166-6851(90)90075-w. [DOI] [PubMed] [Google Scholar]
- Hart D. T., Misset O., Edwards S. W., Opperdoes F. R. A comparison of the glycosomes (microbodies) isolated from Trypanosoma brucei bloodstream form and cultured procyclic trypomastigotes. Mol Biochem Parasitol. 1984 May;12(1):25–35. doi: 10.1016/0166-6851(84)90041-0. [DOI] [PubMed] [Google Scholar]
- Kacser H., Burns J. A. The control of flux. Biochem Soc Trans. 1995 May;23(2):341–366. doi: 10.1042/bst0230341. [DOI] [PubMed] [Google Scholar]
- Klein R. A., Linstead D. J., Wheeler M. V. Carbon dioxide fixation in trypanosomatids. Parasitology. 1975 Aug;71(1):93–107. doi: 10.1017/s003118200005318x. [DOI] [PubMed] [Google Scholar]
- Misset O., Opperdoes F. R. Simultaneous purification of hexokinase, class-I fructose-bisphosphate aldolase, triosephosphate isomerase and phosphoglycerate kinase from Trypanosoma brucei. Eur J Biochem. 1984 Nov 2;144(3):475–483. doi: 10.1111/j.1432-1033.1984.tb08490.x. [DOI] [PubMed] [Google Scholar]
- Müller S., Boles E., May M., Zimmermann F. K. Different internal metabolites trigger the induction of glycolytic gene expression in Saccharomyces cerevisiae. J Bacteriol. 1995 Aug;177(15):4517–4519. doi: 10.1128/jb.177.15.4517-4519.1995. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Njogu R. M., Whittaker C. J., Hill G. C. Evidence for a branched electron transport chain in Trypanosoma brucei. Mol Biochem Parasitol. 1980 Mar;1(1):13–29. doi: 10.1016/0166-6851(80)90038-9. [DOI] [PubMed] [Google Scholar]
- Opperdoes F. R., Borst P. Localization of nine glycolytic enzymes in a microbody-like organelle in Trypanosoma brucei: the glycosome. FEBS Lett. 1977 Aug 15;80(2):360–364. doi: 10.1016/0014-5793(77)80476-6. [DOI] [PubMed] [Google Scholar]
- Opperdoes F. R., Borst P., Spits H. Particle-bound enzymes in the bloodstream form of Trypanosoma brucei. Eur J Biochem. 1977 Jun 1;76(1):21–28. doi: 10.1111/j.1432-1033.1977.tb11566.x. [DOI] [PubMed] [Google Scholar]
- Opperdoes F. R. Compartmentation of carbohydrate metabolism in trypanosomes. Annu Rev Microbiol. 1987;41:127–151. doi: 10.1146/annurev.mi.41.100187.001015. [DOI] [PubMed] [Google Scholar]
- Schaaff I., Heinisch J., Zimmermann F. K. Overproduction of glycolytic enzymes in yeast. Yeast. 1989 Jul-Aug;5(4):285–290. doi: 10.1002/yea.320050408. [DOI] [PubMed] [Google Scholar]
- Steiger R. F., Meshnick S. R. Amino-acid and glucose utilization of Leishmania donovani and L. braziliensis. Trans R Soc Trop Med Hyg. 1977;71(5):441–443. doi: 10.1016/0035-9203(77)90049-9. [DOI] [PubMed] [Google Scholar]
- Ter Kuile B. H., Opperdoes F. R. Chemostat cultures of Leishmania donovani promastigotes and Trypanosoma brucei procyclic trypomastigotes. Mol Biochem Parasitol. 1991 Mar;45(1):171–173. doi: 10.1016/0166-6851(91)90039-9. [DOI] [PubMed] [Google Scholar]
- Williams N., Choi S. Y., Ruyechan W. T., Frank P. H. The mitochondrial ATP synthase of Trypanosoma brucei: developmental regulation through the life cycle. Arch Biochem Biophys. 1991 Aug 1;288(2):509–515. doi: 10.1016/0003-9861(91)90228-b. [DOI] [PubMed] [Google Scholar]
- ter Kuile B. H. Carbohydrate metabolism and physiology of the parasitic protist Trichomonas vaginalis studied in chemostats. Microbiology. 1994 Sep;140(Pt 9):2495–2502. doi: 10.1099/13500872-140-9-2495. [DOI] [PubMed] [Google Scholar]
- ter Kuile B. H. Metabolic adaptation of Trichomonas vaginalis to growth rate and glucose availability. Microbiology. 1996 Dec;142(Pt 12):3337–3345. doi: 10.1099/13500872-142-12-3337. [DOI] [PubMed] [Google Scholar]
- ter Kuile B. H., Opperdoes F. R. Comparative physiology of two protozoan parasites, Leishmania donovani and Trypanosoma brucei, grown in chemostats. J Bacteriol. 1992 May;174(9):2929–2934. doi: 10.1128/jb.174.9.2929-2934.1992. [DOI] [PMC free article] [PubMed] [Google Scholar]
- ter Kuile B. H., Opperdoes F. R. Mutual adjustment of glucose uptake and metabolism in Trypanosoma brucei grown in a chemostat. J Bacteriol. 1992 Feb;174(4):1273–1279. doi: 10.1128/jb.174.4.1273-1279.1992. [DOI] [PMC free article] [PubMed] [Google Scholar]
- van Schaftingen E., Opperdoes F. R., Hers H. G. Stimulation of Trypanosoma brucei pyruvate kinase by fructose 2,6-bisphosphate. Eur J Biochem. 1985 Dec 2;153(2):403–406. doi: 10.1111/j.1432-1033.1985.tb09316.x. [DOI] [PubMed] [Google Scholar]