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Enzymic Synthesis of Mevalonic Acid in Plants

  • J. Bach
  • T. Weber

Abstract

The biosynthesis of mevalonic acid (“MVA”), starting from acetyl-CoA (“Ac-CoA”), requires the action of three enzymes: a) acetoacetyl-CoA thiolase (“AACT”, EC 2.3.1.9), b) 3-hydroxy-3-methylglutaryl-CoA synthase (“HMGS”, EC 4.1.3.5), and c) HMG-CoA reductase (“HMGR”, EC 1.1.1.34). Our recent research has mainly centered around the purification and characterization of membrane-bound HMGR from radish seedlings (1–3). HMGR activity is commonly regarded as playing an important role in the regulation of substrate flux from acetate to the various isoprenoid endproducts, mainly of sterols (cf. 2,6). It is well documented that regulation of mammalian HMGR is mediated by rapid processes both at the translational and post-translational level (cf. 10). Regulation of mammalian HMGS appears to parallel that of HMGR (cf. 5). Similar processes can be expected to occur in plant cells. A thorough study in this direction requires a profound knowledge of the properties of the enzymes involved in the formation of HMG-CoA. This substrate, besides being reduced by HMGR to yield MVA, can also be utilized by HMG-CoA lyase (“HMGL”, EC 4.1.3.4) to form acetoacetate, Ac-CoA and HS-CoA, an important reaction which in mammalian cells (mitochondria) contributes to the HMG-CoA cycle and hence to the formation of ketone bodies.

Keywords

Ammonium Sulfate Ketone Body Apparent Molecular Mass Mevalonic Acid Isoprenoid Pathway 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.

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Literature

  1. 1).
    Bach, T.J.- Hydroxymethylglutaryl-CoA reductase, a key enzyme in phytosterol synthesis? Lipids 21: 82–88 (1986).PubMedCrossRefGoogle Scholar
  2. 2).
    Bach, T.J.- Synthesis and metabolism of mevalonic acid in plants. Plant Physiol. Biochem. 23: 163–178 (1987).Google Scholar
  3. 3).
    Bach, T.J., D.H. Rogers, and H. Rudney.- Detergent-solubilization, purification and characterization of 3-hydroxy-3-methylglutaryl-CoA reductase from radish seedlings. Eur. J. Biochem. 154: 103–111 (1986).PubMedCrossRefGoogle Scholar
  4. 4).
    Clinkenbeard, K.D., D.W. Reed, R.A. Mooney, and M.D. Lane.- Intracellular localization of the 3-hydroxy-3-methylglutaryl coenzyme A cycle enzymes in liver: Separate cytoplasmic and mitochondrial 3- hydroxy-3-methylglutaryl coenzyme A generating systems for cholestero- genesis and ketogenesis. J. Biol. Chem. 250: 3108–3116 (1975).PubMedGoogle Scholar
  5. 5).
    Gil, G., J.L. Goldstein, C.A. Slaughter, and M.S. Brown.- Cytoplasmic 3- hydroxy-3-methylglutaryl coenzyme A synthase from hamster: I. Isolation and sequencing of a full-length cDNA. J. Biol. Chem. 261: 3710–3716 (1986).PubMedGoogle Scholar
  6. 6).
    Gray, J.C.- Control of isoprenoid biosynthesis in higher plants. Adv. Bot. Res. 14: 25–91 (1987).CrossRefGoogle Scholar
  7. 7).
    Kaprelyant, A.S.- Dynamic spatial distribution of proteins in the cell. Trends Biochem Sci. 13: 43–46 (1988).CrossRefGoogle Scholar
  8. 8).
    Kirtley, M.E., and H Rudney.- Some properties and mechanisms of action of the B-hydroxy-B-methylglutaryl coenzyme A reductase of yeast. Biochemistry 6: 230–238 (1967).PubMedCrossRefGoogle Scholar
  9. 9).
    Nes, W.D., and T.J. Bach.- Evidence for a mevalonate shunt in a tracheophyte. Proc. R. Soc. Lond. B 225: 425–444 (1985).CrossRefGoogle Scholar
  10. 10).
    Sabine, J.R.- Monographs on enzyme biology: HMG-CoA reductase, J.R. Sabine ed., CRC Press, Boca Raton 1983.Google Scholar

Copyright information

© Akadémiai Kiadó, Budapest 1989

Authors and Affiliations

  • J. Bach
    • 1
  • T. Weber
    • 1
  1. 1.Botanisches Institut IIUniversität KarlsruheKalsruhe 1Germany

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