Journal of Lipid Research (Apr 1960)

Fat metabolism in higher plants: XIII. phosphatidic acid synthesis and diglyceride phosphokinase activity in mitochondria from peanut cotyledons*

  • Clive Bradbeer,
  • P.K. Stumpf

DOI
https://doi.org/10.1016/s0022-2275(20)39065-9
Journal volume & issue
Vol. 1, no. 3
pp. 214 – 220

Abstract

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A phosphatidic acid is the major lipid to become labeled when Pi32 (inorganic orthophosphate labeled with P32), under conditions of oxidative phosphorylation, or ATP32 is fed to mito-choline and phosphatidylethanolamine in the mitochondria obtained a much higher level of P32, the only cofactor required was Mg++. The stimulation of phosphatidic acid synthesis by an α,β-diglyceride provided support for the view that this synthesis is due to diglyceride phosphokinase activity in the mitochondria. Evidence is also presented that this enzyme preparation is capable of phosphorylating α-monoglycerides with the formation of monoacyl phosphatidic acids. When Pi32 was added to slices of peanut cotyledons, the phosphatidyl-choline and phosphatidylethanolamine in the mitochondria obtained a much higher level of radioactivity than that observed in experiments with the isolated mitochondria.