Mitochondrial flux is currently accessible at low resolution. Here we introduce a genetically-encoded FRET sensor for pyruvate, and methods for quantitative measurement of pyruvate transport, pyruvate production and mitochondrial pyruvate consumption in intact individual cells at high temporal resolution. In HEK293 cells, neurons and astrocytes, mitochondrial pyruvate uptake was saturated at ph...

Pyruvate is the substrate for diacetyl and acetoin synthesis by lactobacilli. Exogenous pyruvate stimulates acetoin production when glucose is present as an energy source. In Lactobacillus plantarum ATCC 8014, the energy derived from glucose via glycolysis generated a constant proton motive force of about -120 mV. At a low external pH, energized cells rapidly transported and accumulated pyruvat...

1. Kinetic data concerning the substrate and product inhibition by pyruvate and L-lactate have been obtained with the Md and Hd fractions separated from crystalline rabbit muscle lactic dehydrogenase. 2. The studies indicate that the product inhibition by L-lactate or by pyruvate is predominantly noncompetitive for both the Mq and Hq isozymes. Ki values for product inhibition by L-lactate were ...

A comparative study of the transport of pyruvate in mitochondria isolated from normal rat liver and from three tumors has been carried out. The Km for net pyruvate uptake in mitochondria isolated from Ehrlich ascites tumor cells is practically equal to that measured in normal rat liver mitochondria while, on the other hand, it is higher in Morris hepatomas 44 and 3924A. The Vmax of pyruvate upt...

Agitation of broth cultures of Lactobacillus casei retarded cellular dry weight accumulation but enhanced production of both diacetyl and acetoin. Addition of pyruvate overcame this retardation, but addition of sulfhydryl-protecting reagents did not. Both pyruvate and citrate enhanced accumulated dry weight of L. casei incubated without agitation, but only pyruvate increased diacetyl accumulati...

1. Kinetic data concerning the substrate and product inhibition by pyruvate and L-lactate have been obtained with the Md and Hd fractions separated from crystalline rabbit muscle lactic dehydrogenase. 2. The studies indicate that the product inhibition by L-lactate or by pyruvate is predominantly noncompetitive for both the Mq and Hq isozymes. Ki values for product inhibition by L-lactate were ...

Pyruvate kinase is an enzyme that catalyzes the conversion of phosphoenolpyruvate and ADP to pyruvate and ATP in glycolysis and plays a role in regulating cell metabolism. There are four mammalian pyruvate kinase isoforms with unique tissue expression patterns and regulatory properties. The M2 isoform of pyruvate kinase (PKM2) supports anabolic metabolism and is expressed both in cancer and nor...

A comparative study of the transport of pyruvate in mitochon dria isolated from normal rat liver and from three tumors has been carried out. The Kmfor net pyruvate uptake in mitochondria isolated from Ehrlich ascites tumor cells is practically equal to that measured in normal rat liver mitochondria while, on the other hand, it is higher in Morris hepatomas 44 and 3924A. The Vm» of pyruvate upt...

Pyruvic acid (pyruvate) is a cellular metabolite found at the biochemical junction of glycolysis and the tricarboxylic acid cycle. Pyruvate is used in food, cosmetics, pharmaceutical and agricultural applications. Microbial production of pyruvate from either yeast or bacteria relies on restricting the natural catabolism of pyruvate, while also limiting the accumulation of the numerous potential...