title: Effect of benzoate on the metabolism of fructose 2,6-bisphosphate in yeast.
abstract: When benzoate (2 mM, pH 3.5) was added together with glucose (0.1 M) to a suspension of Saccharomyces cerevisiae in the stationary phase, it caused a relative increase in the concentration of glucose 6-phosphate and fructose 6-phosphate and a decrease in the concentration of fructose 1,6-bisphosphate. These effects are in confirmation of similar observations made by Krebs et al. [Biochem. J. 214, 657-663 (1983)] and are indicative of an inhibition of 6-phosphofructo-1-kinase. Benzoate also caused an about fourfold relative decrease in the concentration of fructose 2,6-bisphosphate, an increase in that of cyclic AMP with no change in that of ATP. It also greatly decreased the activation of 6-phosphofructo-2-kinase, but not that of trehalase, both of which normally occur upon addition of glucose to a yeast suspension. When added 10 min after glucose, benzoate caused a rapid (within 2-3 min) decrease in fructose 2,6-bisphosphate concentration and in 6-phosphofructo-2-kinase activity. In the presence of benzoate, there was also a parallel decrease in the concentration of fructose 2,6-bisphosphate and in the rate of ethanol production when the external pH was dropped from 5.0 to 2.5, with minimal change in the concentration of ATP. Purified 6-phosphofructo-2-kinase was inhibited by benzoate and also by an acid pH. Experiments with cell-free extracts did not provide an explanation for the rapid disappearance of fructose-2,6-bisphosphate or the inactivation of 6-phosphofructo-2-kinase in yeast upon addition of benzoate.
mesh_terms: D000255:Adenosine Triphosphate / Q000378:metabolism; D001565:Benzoates / Q000494:pharmacology*; D002474:Cell-Free System; D003470:Culture Media / Q000032:analysis; D000242:Cyclic AMP / Q000378:metabolism; D004789:Enzyme Activation / Q000187:drug effects; D005635:Fructosediphosphates / Q000378:metabolism*; D005947:Glucose / Q000494:pharmacology; D006019:Glycolysis / Q000187:drug effects*; D006598:Hexosediphosphates / Q000378:metabolism*; D006600:Hexosephosphates / Q000378:metabolism; D006863:Hydrogen-Ion Concentration; D010732:Phosphofructokinase-1 / Q000378:metabolism; D012441:Saccharomyces cerevisiae / Q000187:drug effects / Q000378:metabolism*
chemical_list: D001565:Benzoates; D003470:Culture Media; D005635:Fructosediphosphates; D006598:Hexosediphosphates; D006600:Hexosephosphates; C027652:fructose 2,6-diphosphate; D000255:Adenosine Triphosphate; D000242:Cyclic AMP; D010732:Phosphofructokinase-1; D005947:Glucose