Glutamate as an inhibitor of phosphoenolpyruvate carboxylase activity in Corynebacterium glutamicum.
The glutamate-producing bacterium, Corynebacterium glutamicum is known to possess two anaplerotic enzymes: pyruvate carboxylase (Pc) and phosphoenolpyruvate carboxylase (PEPc). In vitro, this latter enzyme appeared to be inhibited by different glutamic acid salts, whereas ammonium-glutamate had no influence on Pc activity. To investigate the in vivo relevance of PEPc activity inhibition, the intracellular concentration of glutamate was determined throughout the glutamate-producing process. The intracellular concentration was then shown to be sufficient to induce a dramatic inhibition of PEPc activity during the process. As a consequence, intracellular accumulation of glutamate could be at least partially responsible for the weak participation of PEPc within the anaplerosis activity in amino-acid-producing strains of C. glutamicum.
Delaunay
Stéphane
S
Laboratoire des Sciences du Génie Chimique, Institut National Polytechnique de Lorraine, 2 Avenue de la Forêt de Haye, BP 172, 54505, Vandoeuvre-lès-Nancy, France. Stephane.Delaunay@ensaia.inpl-nancy.fr
Daran-Lapujade
Pascale
P
Engasser
Jean-Marc
JM
Goergen
Jean-Louis
JL
D003352:Corynebacterium / Q000201:enzymology*; D005285:Fermentation; D018698:Glutamic Acid / Q000096:biosynthesis / Q000378:metabolism*; D007218:Industrial Microbiology; D010730:Phosphoenolpyruvate Carboxylase / Q000378:metabolism*; D011766:Pyruvate Carboxylase / Q000378:metabolism
D018698:Glutamic Acid; D010730:Phosphoenolpyruvate Carboxylase; D011766:Pyruvate Carboxylase