Skip to main content
PMC home page
Plant Physiology logoLink to Plant Physiology
. 1977 Apr;59(4):630–635. doi: 10.1104/pp.59.4.630

Pyruvate and Malate Transport and Oxidation in Corn Mitochondria 1

David A Day a,2, John B Hanson a
PMCID: PMC542463  PMID: 16659908

Abstract

Pyruvate oxidation and swelling in pyruvate solutions by corn (Zea mays) mitochondria were inhibited by α-cyano-4-hydroxy-cinnamic acid, an inhibitor of pyruvate transport in animal mitochondria; however, there was no inhibition of pyruvate dehydrogenase activity, and malate and NADH oxidation were not affected. These results suggest the presence of a pyruvate−-OH− exchange transporter which supplies the mitochondrion with oxidizable substrate. Lactate appears to be transported also, but not dicarboxylate anions or inorganic phosphate. The rate of pyruvate transport was much slower than that of malate, however, and valinomycin was required to elicit appreciable swelling in potassium pyruvate.

Malate oxidation contributed significantly to respiration supported by pyruvate plus malate, and malate did not act solely as a “sparker” for pyruvate oxidation. NAD+-malic enzyme activity was found in sonicated preparations, and comparison of O2 consumption with CO2 released from 1-14C-pyruvate indicated that transported malate was being converted to pyruvate, particularly as the malate to pyruvate ratio increased. The results suggest that pyruvate transport becomes limiting under conditions of high energy demand, but that rapid malate transport makes up the difference, supplying pyruvate via malic enzyme and replenishing losses of tricarboxylic acid cycle intermediates.

Full text

PDF
630

Selected References

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

  1. Brunton C. J., Palmer J. M. Pathways for the oxidation of malate and reduced pyridine nucleotide by wheat mitochondria. Eur J Biochem. 1973 Nov 1;39(1):283–291. doi: 10.1111/j.1432-1033.1973.tb03125.x. [DOI] [PubMed] [Google Scholar]
  2. Crompton M., Laties G. G. The regulatory function of potato pyruvate dehydrogenase. Arch Biochem Biophys. 1971 Mar;143(1):143–150. doi: 10.1016/0003-9861(71)90194-9. [DOI] [PubMed] [Google Scholar]
  3. Day D. A., Hanson J. B. Effect of phosphate and uncouplers on substrate transport and oxidation by isolated corn mitochondria. Plant Physiol. 1977 Feb;59(2):139–144. doi: 10.1104/pp.59.2.139. [DOI] [PMC free article] [PubMed] [Google Scholar]
  4. Halestrap A. P., Denton R. M. Specific inhibition of pyruvate transport in rat liver mitochondria and human erythrocytes by alpha-cyano-4-hydroxycinnamate. Biochem J. 1974 Feb;138(2):313–316. doi: 10.1042/bj1380313. [DOI] [PMC free article] [PubMed] [Google Scholar]
  5. Halestrap A. P. The mechanism of the inhibition of the mitochondrial pyruvate transportater by alpha-cyanocinnamate derivatives. Biochem J. 1976 Apr 15;156(1):181–183. doi: 10.1042/bj1560181. [DOI] [PMC free article] [PubMed] [Google Scholar]
  6. Halestrap A. P. The mitochondrial pyruvate carrier. Kinetics and specificity for substrates and inhibitors. Biochem J. 1975 Apr;148(1):85–96. doi: 10.1042/bj1480085. [DOI] [PMC free article] [PubMed] [Google Scholar]
  7. Hanson J. B. Ion transport induced by polycations and its relationship to loose coupling of corn mitochondria. Plant Physiol. 1972 May;49(5):707–715. doi: 10.1104/pp.49.5.707. [DOI] [PMC free article] [PubMed] [Google Scholar]
  8. Hatch M. D., Kagawa T. NAD malic enzyme in leaves with C-pathway photosynthesis and its role in C4 acid decarboxylation. Arch Biochem Biophys. 1974 Jan;160(1):346–349. doi: 10.1016/s0003-9861(74)80043-3. [DOI] [PubMed] [Google Scholar]
  9. LOWRY O. H., ROSEBROUGH N. J., FARR A. L., RANDALL R. J. Protein measurement with the Folin phenol reagent. J Biol Chem. 1951 Nov;193(1):265–275. [PubMed] [Google Scholar]
  10. Lips S. H., Beevers H. Compartmentation of Organic Acids in Corn Roots II. The Cytoplasmic Pool of Malic Acid. Plant Physiol. 1966 Apr;41(4):713–717. doi: 10.1104/pp.41.4.713. [DOI] [PMC free article] [PubMed] [Google Scholar]
  11. Macrae A. R., Moorhouse R. The oxidation of malate by mitochondria isolated from cauliflower buds. Eur J Biochem. 1970 Sep;16(1):96–102. doi: 10.1111/j.1432-1033.1970.tb01058.x. [DOI] [PubMed] [Google Scholar]
  12. Mowbray J. A mitochondrial monocarboxylate transporter in rat liver and heart and its possible function in cell control. Biochem J. 1975 Apr;148(1):41–47. doi: 10.1042/bj1480041. [DOI] [PMC free article] [PubMed] [Google Scholar]
  13. Papa S., Paradies G. On the mechanism of translocation of pyruvate and other monocarboxylic acids in rat-liver mitochondria. Eur J Biochem. 1974 Nov 1;49(1):265–274. doi: 10.1111/j.1432-1033.1974.tb03831.x. [DOI] [PubMed] [Google Scholar]
  14. Ting I. P., Dugger W. M. CO(2) Metabolism in Corn Roots. I. Kinetics of Carboxylation and Decarboxylation. Plant Physiol. 1967 May;42(5):712–718. doi: 10.1104/pp.42.5.712. [DOI] [PMC free article] [PubMed] [Google Scholar]
  15. Titheradge M. A., Coore H. G. The mitochondrial pyruvate carrier, its exchange properties and its regulation by glucagon. FEBS Lett. 1976 Mar 15;63(1):45–50. doi: 10.1016/0014-5793(76)80191-3. [DOI] [PubMed] [Google Scholar]
  16. WALKER D. A., BEEVERS H. Some requirements for pyruvate oxidation by plant mitochondrial preparations. Biochem J. 1956 Jan;62(1):120–127. doi: 10.1042/bj0620120. [DOI] [PMC free article] [PubMed] [Google Scholar]

Articles from Plant Physiology are provided here courtesy of Oxford University Press

RESOURCES