This Article Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Services Email this article to a friend Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via HighWire Citing Articles via CrossRef Citing Articles via Google Scholar Google Scholar Articles by Stahl, R. J. Articles by Sparace, S. A. Search for Related Content PubMed PubMed Citation Articles by Stahl, R. J. Articles by Sparace, S. A. Agricola Articles by Stahl, R. J. Articles by Sparace, S. A.

Metabolism and Enzymology

Characterization of Fatty Acid Biosynthesis in Isolated Pea Root Plastids ¹

Plant Science Department, Macdonald College of McGill University, 21111 Lakeshore Road, Ste. Anne de Bellevue, Quebec, H9X 1CO, Canada

Fatty acid biosynthesis from Na[1-¹⁴C]acetate was characterized in plastids isolated from primary roots of 7-day-old germinating pea (Pisum sativum L.) seeds. Fatty acid synthesis was maximum at 82 nanomoles per hour per milligram protein in the presence of 200 micromolar acetate, 0.5 millimolar each of NADH, NADPH, and coenzyme A, 6 millimolar each of ATP and MgCl₂, 1 millimolar each of MnCl₂ and glycerol-3-phosphate, 15 millimolar KHCO₃, 0.31 molar sucrose, and 0.1 molar Bis-Tris-propane, pH 8.0, incubated at 35°C. At the standard incubation temperature of 25°C, fatty acid synthesis was essentially linear for up to 6 hours with 80 to 120 micrograms per milliliter plastid protein. ATP and coenzyme A were absolute requirements, whereas divalent cations, potassium bicarbonate, and reduced nucleotides all variously improved activity two- to 10-fold. Mg²⁺ and NADH were the preferred cation and nucleotide, respectively. Glycerol-3-phosphate had little effect, whereas dithiothreitol and detergents generally inhibited the incorporation of [¹⁴C]acetate into fatty acids. On the average, the principal radioactive products of fatty acid biosynthesis were approximately 39% palmitic, 9% stearic, and 52% oleic acid. The proportions of these fatty acids synthesized depended on the experimental conditions.

This article has been cited by other articles:

				C. V. Hoang and K. D. Chapman Biochemical and Molecular Inhibition of Plastidial Carbonic Anhydrase Reduces the Incorporation of Acetate into Lipids in Cotton Embryos and Tobacco Cell Suspensions and Leaves Plant Physiology, April 1, 2002; 128(4): 1417 - 1427. [Abstract] [Full Text] [PDF]