Metabolism of D-glucose in a wall-less mutant of Neurospora crassa examined by /sup 13/C and /sup 31/P nuclear magnetic resonances: effects of insulin

Journal Article · Tue Nov 15 00:00:00 EST 1988 · Biochemistry; (United States)

OSTI ID:5981625

Greenfield, N J; McKenzie, M A; Adebodun, F; Jordan, F; Lenard, J

/sup 13/C NMR and /sup 31/P NMR have been used to investigate the metabolism of glucose by a wall-less strain of Neurospora crassa (slime), grown in a supplemented nutritionally defined medium and harvested in the early stationary stage of growth. With D-(1-/sup 13/C)- or D-(6-/sup 13/C)glucose as substrates, the major metabolic products identified from /sup 13/C NMR spectra were (2-/sup 13/C)ethanol, (3-/sup 13/C)alanine, and C/sub 1/- and C/sub 6/-labeled trehalose. Several observations suggested the existence of a substantial hexose monophosphate (HMP) shunt: (i) a 70% greater yield of ethanol from C/sub 6/- than from C/sub 1/-labeled glucose; (ii) C/sub 1/-labeled glucose yielded 19% C/sub 6/-labeled trehalose, while C/sub 6/-labeled glucose yielded only 4% C/sub 1/-labeled trehalose; (iii) a substantial transfer of /sup 13/C from C/sub 2/-labeled glucose to the C/sub 2/-position of ethanol. /sup 31/P NMR spectra showed millimolar levels of intracellular inorganic phosphate (P/sub i/), phosphodiesters, and diphosphates including sugar diphosphates and polyphosphate. Addition of glucose resulted in a decrease in cytoplasmic P/sub i/ and an increase in sugar monophosphates, which continued for at least 30 min. Phosphate resonances corresponding to metabolic intermediates of both the glycolytic and HMP pathways were identified in cell extracts. Addition of insulin (100 nM) with the glucose had the following effects relative to glucose alone: (i) a 24% increase in the rate of ethanol production; (ii) a 38% increase in the rate of alanine production; (iii) a 27% increase in the rate of glucose disappearance. Insulin thus increases the rates of production of ethanol and alanine in these cells, in addition to increasing production of CO/sub 2/ and glycogen, as previously shown.

• Research Organization: UMDNJ-Robert Wood Johnson Medical School, Piscataway, NJ (USA)
• OSTI ID: 5981625
• Journal Information: Biochemistry; (United States), Vol. 27:23
• Country of Publication: United States
• Language: English

Related Subjects

62 RADIOLOGY AND NUCLEAR MEDICINE
GLUCOSE
METABOLISM
INSULIN
BIOCHEMISTRY
NEUROSPORA
NUCLEAR MAGNETIC RESONANCE
CARBON 13
CHEMICAL SHIFT
ETHANOL
PHOSPHORUS 31
ALCOHOLS
ALDEHYDES
CARBOHYDRATES
CARBON ISOTOPES
CHEMISTRY
EUMYCOTA
EVEN-ODD NUCLEI
FUNGI
HEXOSES
HORMONES
HYDROXY COMPOUNDS
ISOTOPES
LIGHT NUCLEI
MAGNETIC RESONANCE
MONOSACCHARIDES
NUCLEI
ODD-EVEN NUCLEI
ORGANIC COMPOUNDS
PEPTIDE HORMONES
PHOSPHORUS ISOTOPES
PLANTS
RESONANCE
SACCHARIDES
STABLE ISOTOPES
550601* - Medicine- Unsealed Radionuclides in Diagnostics