Tuberculosis (TB) remains one of the major health concerns worldwide. Mycobacterium tuberculosis (Mtb), the causative agent of TB, can flexibly change its metabolic processes during different life stages. Regulation of key metabolic enzyme activities by intracellular conditions, allosteric inhibition or feedback control can effectively contribute to Mtb survival under different conditions. Phosphofructokinase (Pfk) is one of the key enzymes regulating glycolysis. Mtb encodes two Pfk isoenzymes, Pfk A/Rv3010c and Pfk B/Rv2029c, which are differently expressed upon transition to the hypoxia-induced non-replicating state of the bacteria. While pfkB gene and protein expression are upregulated under hypoxic conditions, Pfk A levels decrease. Here, we present biochemical characterization of both Pfk isoenzymes, revealing that Pfk A and Pfk B display different kinetic properties. Although the glycolytic activity of Pfk A is higher than that of Pfk B, it is markedly inhibited by an excess of both substrates (fructose-6-phosphate and ATP), reaction products (fructose-1,6-bisphosphate and ADP) and common metabolic allosteric regulators. In contrast, synthesis of fructose-1,6-bisphosphatase catalyzed by Pfk B is not regulated by higher levels of substrates, and metabolites. Importantly, we found that only Pfk B can catalyze the reverse gluconeogenic reaction. Pfk B thus can support glycolysis under conditions inhibiting Pfk A function.
- Klíčová slova
- Mycobacterium tuberculosis, allosteric regulation, enzyme kinetics, glycolysis, phosphofructokinase A and B,
- MeSH
- adenosindifosfát metabolismus farmakologie MeSH
- adenosintrifosfát metabolismus farmakologie MeSH
- alosterická regulace MeSH
- bakteriální proteiny antagonisté a inhibitory metabolismus MeSH
- enzymová indukce MeSH
- fosfofruktokinasy antagonisté a inhibitory metabolismus MeSH
- fruktosadifosfáty biosyntéza farmakologie MeSH
- fruktosafosfáty metabolismus farmakologie MeSH
- glukoneogeneze MeSH
- glykolýza MeSH
- hexosafosfáty metabolismus MeSH
- izoenzymy antagonisté a inhibitory metabolismus MeSH
- katalýza MeSH
- kinetika MeSH
- kyslík farmakologie MeSH
- L-laktátdehydrogenasa metabolismus MeSH
- Mycobacterium tuberculosis účinky léků enzymologie MeSH
- pyruvátkinasa metabolismus MeSH
- rekombinantní proteiny metabolismus MeSH
- substrátová specifita MeSH
- zpětná vazba fyziologická MeSH
- Publikační typ
- časopisecké články MeSH
- srovnávací studie MeSH
- Názvy látek
- adenosindifosfát MeSH
- adenosintrifosfát MeSH
- bakteriální proteiny MeSH
- fosfofruktokinasy MeSH
- fructose-1,6-diphosphate MeSH Prohlížeč
- fructose-6-phosphate MeSH Prohlížeč
- fruktosadifosfáty MeSH
- fruktosafosfáty MeSH
- hexosafosfáty MeSH
- izoenzymy MeSH
- kyslík MeSH
- L-laktátdehydrogenasa MeSH
- phosphofructokinase A protein, Mycobacterium tuberculosis MeSH Prohlížeč
- pyruvátkinasa MeSH
- rekombinantní proteiny MeSH
- tagatose 6-phosphate MeSH Prohlížeč
