Skip to main content
PMC home page
Plant Physiology logoLink to Plant Physiology
. 1982 Sep;70(3):723–727. doi: 10.1104/pp.70.3.723

Metabolism of trans-Aconitic Acid in Maize 1

II. Regulatory Properties of Two Compartmented Forms of Citrate Dehydrase

David Brauer 1,2, Merle R Teel 1
PMCID: PMC1065759  PMID: 16662564

Abstract

Kinetics of two molecular forms of K-dependent citrate dehydrase in maize (Zea mays L.) are reported. The isozymes, designated CD I and CD II, were found to be compartmented in mitochondria and cytosol, respectively.

CD I exhibited hyperbolic kinetics with respect to both citrate and potassium with Km 2.3 and 12 millimolar, respectively. Maximum velocity was 0.38 micromole of trans-aconitic acid per minute per milligram protein. The pH optimum was 7.2. trans-aconitic synthesis by CD I is regulated by both citrate concentration and pH.

CD II exhibited hyperbolic kinetics with respect to citrate (Km 0.6 millimolar) but sigmoidal kinetics with respect to potassium. trans-aconitic acid synthesis by CD II is regulated by potassium. This may account for the positive correlation between leaf potassium and trans-aconitic acid in certain grasses (Clark 1968 Crop Sci 8: 165).

Full text

PDF
724

Selected References

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

  1. Brauer D., Teel M. R. Metabolism of trans-Aconitic Acid in Maize : I. PURIFICATION OF TWO MOLECULAR FORMS OF CITRATE DEHYDRASE. Plant Physiol. 1981 Dec;68(6):1406–1408. doi: 10.1104/pp.68.6.1406. [DOI] [PMC free article] [PubMed] [Google Scholar]
  2. Douce R., Mannella C. A., Bonner W. D., Jr The external NADH dehydrogenases of intact plant mitochondria. Biochim Biophys Acta. 1973 Jan 18;292(1):105–116. doi: 10.1016/0005-2728(73)90255-7. [DOI] [PubMed] [Google Scholar]
  3. EISENMAN G. Cation selective glass electrodes and their mode of operation. Biophys J. 1962 Mar;2(2 Pt 2):259–323. doi: 10.1016/s0006-3495(62)86959-8. [DOI] [PMC free article] [PubMed] [Google Scholar]
  4. Frieden C. Slow transitions and hysteretic behavior in enzymes. Annu Rev Biochem. 1979;48:471–489. doi: 10.1146/annurev.bi.48.070179.002351. [DOI] [PubMed] [Google Scholar]
  5. HOGEBOOM G. H., SCHNEIDER W. C., STRIEBICH M. J. Cytochemical studies. VII. Localization of endogenous citrate in rat liver fractions. J Biol Chem. 1956 Oct;222(2):969–977. [PubMed] [Google Scholar]
  6. Kenefick D. G., Hanson J. B. Contracted state as an energy source for ca binding and ca + inorganic phosphate accumulation by corn mitochondria. Plant Physiol. 1966 Dec;41(10):1601–1609. doi: 10.1104/pp.41.10.1601. [DOI] [PMC free article] [PubMed] [Google Scholar]
  7. Klinman J. P., Rose I. A. Purification and kinetic properties of aconitate isomerase from Pseudomonas putida. Biochemistry. 1971 Jun 8;10(12):2253–2259. doi: 10.1021/bi00788a011. [DOI] [PubMed] [Google Scholar]
  8. Mitchell P. Keilin's respiratory chain concept and its chemiosmotic consequences. Science. 1979 Dec 7;206(4423):1148–1159. doi: 10.1126/science.388618. [DOI] [PubMed] [Google Scholar]
  9. RACKER E. Spectrophotometric measurements of the enzymatic formation of fumaric and cis-aconitic acids. Biochim Biophys Acta. 1950 Jan;4(1-3):211–214. doi: 10.1016/0006-3002(50)90026-6. [DOI] [PubMed] [Google Scholar]

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

RESOURCES