Bio-Protocol (May 2014)

Extraction and Measurement the Activities of Cytosolic Phosphoenolpyruvate Carboxykinase (PEPCK) and Plastidic NADP-dependent Malic Enzyme (ME) on Tomato (Solanum lycopersicum)

  • Sonia Osorio,
  • José Vallarino,
  • Marek Szecowka,
  • Shai Ufaz,
  • Vered Tzin,
  • Ruthie Angelovici,
  • Gad Galili,
  • Fayezeh Aarabi

DOI
https://doi.org/10.21769/BioProtoc.1122
Journal volume & issue
Vol. 4, no. 9

Abstract

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A recent study demonstrated that cytosolic phosphoenolpyruvate carboxykinase (PEPCK) and NADP-malic enzyme (NADP-ME) have an important role in malate metabolism during fruit ripening (Osorio et al., 2013). PEPCK catalyze the ATP-dependent decarboxylation of oxaloacetate (OAA) to phosphoenolpyruvate (PEP) and NADP-ME, the reversible conversion of malate and pyruvate. Here, we present the detailed protocols to measure PEPCK activity in carboxylation direction by following oxidation of NADH and to measure NADP-ME activity based upon the reduction of NADP+.