Studies of anaerobic and aerobic glycolysis in Saccharomyces cerevisiae
Glucose metabolism was followed in suspensions of Saccharomyces cerevisiae by using 13C NMR and 14C radioactive labeling techniques and by Warburg manometer experiments. These experiments were performed for cells grown with various carbon sources in the growth medium, so as to evaluate the effect of catabolite repression. The rate of glucose utilization was most conveniently determined by the 13C NMR experiments, which measured the concentration of (1-13C)glucose, whereas the distribution of end products was determined from the 13C and the 14C experiments. By combining these measurements the flows into the various pathways that contribute to glucose catabolism were estimated, and the effect of oxygen upon glucose catabolism was evaluated. From these measurements, the Pasteur quotient (PQ) for glucose catabolism was calculated to be 2.95 for acetate-grown cells and 1.89 for cells grown on glucose into saturation. The Warburg experiments provided an independent estimate of glucose catabolism. The PQ estimated from Warburg experiments was 2.9 for acetate-grown cells in excellent agreement with the labeled carbon experiments and 4.6 for cells grown into saturation, which did not agree. Possible explanations of these differences are discussed. From these data an estimate is obtained of the net flow through the Embden-Meyerhof-Parnas pathway. The backward flow through fructose-1,6-bisphosphatase (Fru-1,6-P2-ase) was calculated from the scrambling of the 13C label of (1-13C)glucose into the C1 and C6 positions of trehalose. Combining these data allowed us to calculate the net flux through phosphofructokinase (PFK). For acetate-grown cells we found that the relative flow through PFK is a factor of 1.7 faster anaerobically than aerobically.
- Research Organization:
- Yale Univ., New Haven, CT
- OSTI ID:
- 5742864
- Journal Information:
- Biochemistry; (United States), Vol. 1
- Country of Publication:
- United States
- Language:
- English
Similar Records
Examining Escherichia coli glycolytic pathways, catabolite repression, and metabolite channeling using Δpfk mutants
Carbohydrate Metabolism and Carbon Fixation in Roseobacter denitrificans OCh114
Related Subjects
GLUCOSE
METABOLISM
CARBON 13
CARBON 14 COMPOUNDS
CATABOLISM
GLYCOLYSIS
NUCLEAR MAGNETIC RESONANCE
SACCHAROMYCES CEREVISIAE
ALDEHYDES
CARBOHYDRATES
CARBON ISOTOPES
EVEN-ODD NUCLEI
FUNGI
HEXOSES
ISOTOPES
LABELLED COMPOUNDS
LIGHT NUCLEI
MAGNETIC RESONANCE
MICROORGANISMS
MONOSACCHARIDES
NUCLEI
ORGANIC COMPOUNDS
PLANTS
RESONANCE
SACCHARIDES
SACCHAROMYCES
STABLE ISOTOPES
YEASTS
550201* - Biochemistry- Tracer Techniques