These tools will no longer be maintained as of December 31, 2024. Archived website can be found here. PubMed4Hh GitHub repository can be found here. Contact NLM Customer Service if you have questions.


Pubmed for Handhelds

PUBMED FOR HANDHELDS

Search MEDLINE/PubMed

  • Title: The role of malic enzyme as the provider of NADPH in oleaginous microorganisms: a reappraisal and unsolved problems.
    Author: Ratledge C.
    Journal: Biotechnol Lett; 2014 Aug; 36(8):1557-68. PubMed ID: 24752812.
    Abstract:
    Malic enzyme (ME; NADP(+)-dependent; EC 1.1.40) provides NADPH for lipid biosynthesis in oleaginous microorganisms. Its role in vivo depends on there being an adequate supply of NADH to drive malate dehydrogenase to convert oxaloacetate to malate as a component of a cycle of three reactions: pyruvate → oxaloacetate → malate and, by the action of ME, back to pyruvate. However, the availability of cytosolic NADH is limited and, consequently, ancillary means of producing NADPH are necessary. Stoichiometries are given for the conversion of glucose to triacylglycerols involving ME with and without the reactions of the pentose phosphate pathway (PPP) as an additional source of NADPH. Some oleaginous microorganisms (such as Yarrowia lipolytica), however, lack a cytosolic ME and, if the PPP is the sole provider of NADPH, the theoretical yield of triacylglycerol from glucose falls to 27.6 % (w/w) from 31.6 % when ME is present. An alternative route for NADPH generation via a cytosolic isocitrate dehydrogenase (NADP(+)-dependent) is then discussed.
    [Abstract] [Full Text] [Related] [New Search]