Skip to main content
NCBI home page
Biochemical Journal logoLink to Biochemical Journal
. 1974 Jun;140(3):369–375. doi: 10.1042/bj1400369

The concentration and control of cytoplasmic free inorganic pyrophosphate in rat liver in vivo

Robert W Guynn 1,*, Dulce Veloso 1, J W Randolph Lawson 1, Richard L Veech 1
PMCID: PMC1168013  PMID: 4374936

Abstract

The concentration of cytoplasmic free pyrophosphate was calculated in freeze-clamped livers of rats from the measured concentration of reactants and Keq. of the UDP-glucose pyrophosphorylase reaction (UDP–α-d-glucose 1-phosphate uridylyltransferase, EC 2.7.7.9). The Keq. of the UDP-glucose pyrophosphorylase reaction was redetermined at 38°C, pH7.0, I=0.25mol/l and free [Mg2+]=1mm, and was 4.55 in the direction of glucose 1-phosphate formation. The activity of UDP-glucose pyrophosphorylase in rat liver was between 46 and 58μmol of glucose 1-phosphate formed/min per g fresh wt. in the four dietary conditions studied. A fluorimetric assay with enzymic cycling was developed for the measurement of glucose 1-phosphate in HClO4 extracts of rat liver. The calculated free cytoplasmic PPi concentration in nmol/g fresh wt. of liver was 2.3±0.3 in starved, 3.8±0.4 in fed, 4.9±0.6 in meal-fed and 5.2±0.4 in sucrose-re-fed animals. These values agree well with recently determined direct measurements of total PPi in rat liver and suggest that there is not a large amount of bound or metabolically inert PPi in rat liver. The cytoplasmic [ATP]/[AMP][PPi] ratio is 103 times the cytoplasmic [ATP]/[ADP][Pi] ratio and varies differently with dietary state. The reaction PPi+H2O→2Pi catalysed by inorganic pyrophosphatase (EC 3.6.1.1) does not attain near-equilibrium in vivo. PPi should be considered as one of the group of small inorganic ions which is metabolically active and capable of exerting a controlling function in a number of important metabolic reactions.

Full text

PDF
369

Selected References

These references are in PubMed. This may not be the complete list of references from this article.

  1. ATKINSON M. R., JOHNSON E., MORTON R. K. Equilibrium constants of phosphoryl transfer from C-1 to C-6 of alpha-D-glucose 1-phosphate and from glucose 6-phosphate to water. Biochem J. 1961 Apr;79:12–15. doi: 10.1042/bj0790012. [DOI] [PMC free article] [PubMed] [Google Scholar]
  2. Albrecht G. J., Bass S. T., Seifert L. L., Hansen R. G. Crystallization and properties of uridine diphosphate glucose pyrophosphorylase from liver. J Biol Chem. 1966 Jun 25;241(12):2968–2975. [PubMed] [Google Scholar]
  3. Baltscheffsky H. Inorganic pyrophosphate and the evolution of biological energy transformation. Acta Chem Scand. 1967;21(7):1973–1974. doi: 10.3891/acta.chem.scand.21-1973. [DOI] [PubMed] [Google Scholar]
  4. Baltscheffsky H., Von Stedingk L. V., Heldt H. W., Klingenberg M. Inorganic pyrophosphate: formation in bacterial photophosphorylation. Science. 1966 Sep 2;153(3740):1120–1122. doi: 10.1126/science.153.3740.1120. [DOI] [PubMed] [Google Scholar]
  5. Burch H. B., Max P., Jr, Ghyu K., Lowry O. H. Metabolic intermediates in liver of rats given large amounts of fructose or dihydroxyacetone. Biochem Biophys Res Commun. 1969 Mar 10;34(5):619–626. doi: 10.1016/0006-291x(69)90783-9. [DOI] [PubMed] [Google Scholar]
  6. Gustafson G. L., Gander J. E. Uridine diphosphate glucose pyrophosphorylase from Sorghum vulgare. Purification and kinetic properties. J Biol Chem. 1972 Mar 10;247(5):1387–1397. [PubMed] [Google Scholar]
  7. Guynn R. W., Veech R. L. The equilibrium constants of the adenosine triphosphate hydrolysis and the adenosine triphosphate-citrate lyase reactions. J Biol Chem. 1973 Oct 25;248(20):6966–6972. [PubMed] [Google Scholar]
  8. Guynn R. W., Veloso D., Veech R. L. Enzymic determination of inorganic phosphate in the presence of creatine phosphate. Anal Biochem. 1972 Jan;45(1):277–285. doi: 10.1016/0003-2697(72)90028-0. [DOI] [PubMed] [Google Scholar]
  9. HOHORST H. J., KREUTZ F. H., BUECHER T. [On the metabolite content and the metabolite concentration in the liver of the rat]. Biochem Z. 1959;332:18–46. [PubMed] [Google Scholar]
  10. Henley K. S. Glycolytic substrates in cirrhosis and in quantitative undernutrition in the rat. J Lab Clin Med. 1968 Feb;71(2):183–191. [PubMed] [Google Scholar]
  11. Knop J. K., Hansen R. G. Uridine diphosphate glucose pyrophosphorylase. IV. Crystallization and properties of the enzyme from human liver. J Biol Chem. 1970 May 25;245(10):2499–2504. [PubMed] [Google Scholar]
  12. LOWRY O. H., PASSONNEAU J. V., ROCK M. K. The stability of pyridine nucleotides. J Biol Chem. 1961 Oct;236:2756–2759. [PubMed] [Google Scholar]
  13. LOWRY O. H., PASSONNEAU J. V., SCHULZ D. W., ROCK M. K. The measurement of pyridine nucleotides by enzymatic cycling. J Biol Chem. 1961 Oct;236:2746–2755. [PubMed] [Google Scholar]
  14. Lowry O. H., Passonneau J. V. Phosphoglucomutase kinetics with the phosphates of fructose, glucose, mannose, ribose, and galactose. J Biol Chem. 1969 Feb 10;244(3):910–916. [PubMed] [Google Scholar]
  15. NORDLIE R. C., ARION W. J. LIVER MICROSOMAL GLUCOSE 6-PHOSPHATASE, INORGANIC PYROPHOSPHATASE, AND PYROPHOSPHATE-GLUCOSE PHOSPHOTRANSFERASE. 3. ASSOCIATED NUCLEOSIDE TRIPHOSPHATE- AND NUCLEOSIDE DIPHOSPHATE-GLUCOSE PHOSPHOTRANSFERASE ACTIVITIES. J Biol Chem. 1965 May;240:2155–2164. [PubMed] [Google Scholar]
  16. NORDLIE R. C., LARDY H. A. Sub-cellular distribution of ratliver inorganic pyrophosphatase activity. Biochim Biophys Acta. 1961 Jun 10;50:189–191. doi: 10.1016/0006-3002(61)91083-6. [DOI] [PubMed] [Google Scholar]
  17. Reich J. G., Till U., Günther J., Zahn D., Tschisgale M., Frunder H. Enzymic flux rates in vivo through the Embden-Meyerhof pathway and the nucleotides of the mouse liver. Eur J Biochem. 1968 Nov;6(3):384–394. doi: 10.1111/j.1432-1033.1968.tb00459.x. [DOI] [PubMed] [Google Scholar]
  18. Russell R. G., Bisaz S., Donath A., Morgan D. B., Fleisch H. Inorganic pyrophosphate in plasma in normal persons and in patients with hypophosphatasia, osteogenesis imperfecta, and other disorders of bone. J Clin Invest. 1971 May;50(5):961–969. doi: 10.1172/JCI106589. [DOI] [PMC free article] [PubMed] [Google Scholar]
  19. SALAS M., VINUELA E., SOLS A. SPONTANEOUS AND ENZYMATICALLY CATALYZED ANOMERIZATION OF GLUCOSE 6-PHOSPHATE AND ANOMERIC SPECIFICITY OF RELATED ENZYMES. J Biol Chem. 1965 Feb;240:561–568. [PubMed] [Google Scholar]
  20. SCHIMKE R. T. Differential effects of fasting and protein-free diets on levels of urea cycle enzymes in rat liver. J Biol Chem. 1962 Jun;237:1921–1924. [PubMed] [Google Scholar]
  21. SIU P. M., WOOD H. G. Phosphoenolpyruvic carboxytransphosphorylase, a CO2 fixation enzyme from propionic acid bacteria. J Biol Chem. 1962 Oct;237:3044–3051. [PubMed] [Google Scholar]
  22. STETTEN M. R., TAFT H. L. METABOLISM OF INORGANIC PYROPHOSPHATE. II. THE PROBABLE IDENTITY OF MICROSOMAL INORGANIC PYROPHOSPHATASE, PYROPHOSPHATE PHOSPHOTRANSFERASE, AND GLUCOSE 6-PHOSPHATASE. J Biol Chem. 1964 Dec;239:4041–4046. [PubMed] [Google Scholar]
  23. TURNER D. H., TURNER J. F. Uridine diphosphoglucose pyrophosphorylase of pea seeds. Biochem J. 1958 Jul;69(3):448–452. doi: 10.1042/bj0690448. [DOI] [PMC free article] [PubMed] [Google Scholar]
  24. Veech R. L., Guynn R., Veloso D. The time-course of the effects of ethanol on the redox and phosphorylation states of rat liver. Biochem J. 1972 Apr;127(2):387–397. doi: 10.1042/bj1270387. [DOI] [PMC free article] [PubMed] [Google Scholar]
  25. Veech R. L., Raijman L., Krebs H. A. Equilibrium relations between the cytoplasmic adenine nucleotide system and nicotinamide-adenine nucleotide system in rat liver. Biochem J. 1970 Apr;117(3):499–503. doi: 10.1042/bj1170499. [DOI] [PMC free article] [PubMed] [Google Scholar]
  26. Veloso D., Guynn R. W., Oskarsson M., Veech R. L. The concentrations of free and bound magnesium in rat tissues. Relative constancy of free Mg 2+ concentrations. J Biol Chem. 1973 Jul 10;248(13):4811–4819. [PubMed] [Google Scholar]
  27. WILLIAMSON J. R. GLYCOLYTIC CONTROL MECHANISMS. I. INHIBITION OF GLYCOLYSIS BY ACETATE AND PYRUVATE IN THE ISOLATED, PERFUSED RAT HEART. J Biol Chem. 1965 Jun;240:2308–2321. [PubMed] [Google Scholar]
  28. Williamson D. H., Lund P., Krebs H. A. The redox state of free nicotinamide-adenine dinucleotide in the cytoplasm and mitochondria of rat liver. Biochem J. 1967 May;103(2):514–527. doi: 10.1042/bj1030514. [DOI] [PMC free article] [PubMed] [Google Scholar]

Articles from Biochemical Journal are provided here courtesy of The Biochemical Society

RESOURCES