tion as measured by the hydroxamate reaction did not change appreciably, and furthermore, the amount of oxaloacetate synthesized was almost twice the amount of acetyl-CoA added. In other experiments enzymatic measurements of acetyl-CoA concentration gave similar results. The indirect role of acetyl-CoA is further confirmed by experiments shown in Table III. Oxaloacetate was formed from various ...

Phosphoenolpyruvate carboxykinase (PCK) catalyzes the decarboxylation and phosphorylation of oxaloacetate to phosphoenolpyruvate in the gluconeogenic pathway in most organisms. A pckA gene encoding PCK was cloned and sequenced from strain Rhizobium pusense NRCPB100, a spontaneous rifampicin resistant mutant of R. pusense NRCPB10 (JCM16209) of a recently described new species of a non-nodulating...

Activated T cells engage aerobic glycolysis and anabolic metabolism for growth, proliferation, and effector functions. We propose that a glucose-poor tumor microenvironment limits aerobic glycolysis in tumor-infiltrating T cells, which suppresses tumoricidal effector functions. We discovered a new role for the glycolytic metabolite phosphoenolpyruvate (PEP) in sustaining T cell receptor-mediate...

Using analytical data and the results of degradation of glucose, lactate, and glutamate produced from [Z-14C]pyruvate or lactate, we have estimated the pathways of carbon flow during active gluconeogenesis in the kidney cortex. This approach involves a steady state model and solution with the aid of a digital computer. By the isotopic method one can estimate the rates of pyruvate carboxylase, p...

Enzymatic activities involved in glucose fermentation of Actinomyces naeslundii were studied with glucose-grown cells from batch cultures. Glucose could be phosphorylated to glucose 6-phosphate by a glucokinase that utilized polyphosphate and GTP instead of ATP as a phosphoryl donor. Glucose 6-phosphate was further metabolized to the end products lactate, formate, acetate, and succinate through...

Published, JBC Papers in Press, July 27, 2009, DOI 10.1074/jbc.R109.040543 Jianqi Yang, Satish C. Kalhan, and Richard W. Hanson From the Department of Biochemistry, Case Western Reserve University School of Medicine, Cleveland, Ohio 44106-4936 and the Departments of Pathobiology and Medicine, Cleveland Clinic Lerner College of Medicine of Case Western Reserve University, Cleveland Clinic, Cleve...

Tuberculosis, the second leading infectious disease killer after HIV, remains a top public health priority. The causative agent of tuberculosis, Mycobacterium tuberculosis (Mtb), which can cause both acute and clinically latent infections, reprograms metabolism in response to the host niche. Phosphoenolpyruvate carboxykinase (Pck) is the enzyme at the center of the phosphoenolpyruvate-pyruvate-...

The gene encoding cytosolic phosphoenolpyruvate carboxykinase (PEPCK) is expressed in multiple cell types in diverse tissues including liver, kidney, intestine, and white and brown adipose tissues. It can thus be considered a model system for examining the regulation of cell-specific transcription. The PEPCK gene is transcribed from a single start site, but studies of transgenic mice have revea...

Phosphoenolpyruvate carboxykinase (PEPCK) is present in parasites as well as in their mammalian hosts it serves different functions. In the host PEPCK catalyses the reaction from oxaloacetate to make phosphoenol pyruvate and carbon dioxide, part of the gluconeogenesis pathway. Parasite PEPCK catalyses the reverse reaction to form oxaloacetate, the precursor of malate, which is metabolized anaer...

Chicken liver mitochondrial phosphoenolpyruvate carboxykinase is inactivated by o-phthalaldehyde. The inactivation followed pseudo first-order kinetics, and the second-order rate constant for the inactivation process was 29 M-1 s-1 at pH 7.5 and 25 degrees C. The modified enzyme showed maximal fluorescence at 427 nm upon excitation at 337 nm, consistent with the formation of isoindole derivativ...