Phosphorus-31 Nuclear Magnetic Resonance Studies of Wild-Type and Glycolytic Pathway Mutants of Saccharomyces cerevisiae

Gil Navon*, Robert G. Shulman, Tetsuo Yamane, T. Ross Eccleshall, Keng Bon Lam, Jerald J. Baronofsky, Julius Marmur, Keng Bon Lam

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

Abstract

High-resolution phosphorus-31 nuclear magnetic resonance (31P NMR) spectra of wild-type and mutant strains of Saccharomyces cerevisiae were observed at a frequency of 145.7 MHz. Levels of various phosphorus metabolites were investigated upon addition of glucose under both aerobic and anaerobic conditions. Three mutant strains were isolated and their biochemical defects characterized: pfk lacked phosphofructokinase activity; pgi lacked phosphoglucose isomerase activity; and cif had no glucose catabolite repression of the fructose bisphosphatase activity. Each mutant strain was found to accumulate characteristic sugar phosphates when glucose was added to the cell suspension. In the case of the phosphofructokinase deficient mutant, the appearance of a pentose shunt metabolite was observed. 31P NMR peak assignments were made by a pH titration of the acid extract of the cells. Separate signals for terminal, penultimate, and central phosphorus atoms in intracellular polyphosphates allowed the estimation of their average molecular weight. Signals for glycero(3)phosphocholine, glycero(3)phosphoserine, and glycero(3)phosphoethanolamine as well as three types of nucleotide diphosphate sugars could be observed. The intracellular pH in resting and anaerobic cells was in the range 6.5-6.8 and the level of adenosine 5'-triphosphate (ATP) low. Upon introduction of oxygen, the ATP level increased considerably and the intracellular pH reached a value of pH 7.2-7.3, irrespective of the external medium pH, indicating active proton transport in these cells. A new peak representing the inorganic phosphate of one of the cellular organelles, whose pH differed from the cytoplasmic pH, could be detected under appropriate conditions.

Original languageEnglish
Pages (from-to)4487-4499
Number of pages13
JournalBiochemistry
Volume18
Issue number21
DOIs
StatePublished - 1979
Externally publishedYes

Fingerprint

Dive into the research topics of 'Phosphorus-31 Nuclear Magnetic Resonance Studies of Wild-Type and Glycolytic Pathway Mutants of Saccharomyces cerevisiae'. Together they form a unique fingerprint.

Cite this