Comparative study of Leishmania mexicana and Trypanosoma brucei NAD-dependent glycerol-3-phosphate dehydrogenase

• Published in: Molecular and biochemical parasitology Vol. 106; no. 1; pp. 83 - 91
• Main Authors: Marché, Sylvie, Michels, Paul A.M., Opperdoes, Fred R.
• Format: Journal Article
• Language: English
• Published: Netherlands Elsevier B.V 25.02.2000
• Subjects: Animals; Dihydroxyacetone Phosphate - metabolism; Enzyme Inhibitors - pharmacology; Enzyme Stability; Escherichia coli - enzymology; Glyceraldehyde-3-Phosphate Dehydrogenases - chemistry; Glyceraldehyde-3-Phosphate Dehydrogenases - genetics; Glyceraldehyde-3-Phosphate Dehydrogenases - metabolism; Glycerophosphates - metabolism; Glycosomal enzymes; Hydrogen-Ion Concentration; Kinetics; Leishmania mexicana; Leishmania mexicana - enzymology; Leishmania mexicana - genetics; NAD - metabolism; NAD-dependent glycerol-3-phosphate dehydrogenase; NADP - metabolism; Osmolar Concentration; Recombinant Proteins - metabolism; Sodium Chloride - pharmacology; Trypanocidal drugs; Trypanosoma brucei; Trypanosoma brucei brucei - enzymology; Glycosomal enzymes; Trypanosoma brucei; G3P, glycerol 3-phosphate; G3PDH, glycerol-3-phosphate dehydrogenase (EC 1.1.1.8); STE, sucrose–Tris–EDTA buffer; NAD-dependent glycerol-3-phosphate dehydrogenase; Trypanocidal drugs; Leishmania mexicana; DHAP, dihydroxyacetone phosphate; GAPDH, glyceraldehyde-3-phosphate dehydrogenase
• ISSN: 0166-6851; 1872-9428
• DOI: 10.1016/S0166-6851(99)00204-2

The NAD-dependent glycerol-3-phosphate dehydrogenases (G3PDH, EC 1.1.1.8) of Trypanosoma brucei and Leishmania mexicana are thought to have different roles in carbohydrate metabolism. Here the physicochemical and kinetic properties of natural G3PDH from T. brucei with the recombinant homologue of L. mexicana which share 63% positional identity are compared. Despite their supposed different functions in energy metabolism of the parasites the two G3PDHs have remarkably similar properties, including pH optima and K m value for dihydroxyacetone phosphate (DHAP) and NADH in the formation of glycerol 3-phosphate (G3P) and for NAD + and G3P in the reverse reaction. Both enzymes are subject to substrate inhibition by dihydroxyacetone phosphate at concentrations above 0.2 mM and are inhibited by the trypanocidal drugs suramin and melarsen oxide at sub-micromolar concentrations.