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 Zeiher, C. A. Articles by Randall, D. D. Search for Related Content PubMed PubMed Citation Articles by Zeiher, C. A. Articles by Randall, D. D. Agricola Articles by Zeiher, C. A. Articles by Randall, D. D.

Metabolism and Enzymology

Spinach Leaf Acetyl-Coenzyme A Synthetase: Purification and Characterization ¹

Department of Biochemistry, 117 Schweitzer Hall, University of Missouri, Columbia, Missouri 65211

Acetyl-coenzyme A (CoA) synthetase was purified 364-fold from leaves of spinach (Spinacia oleracea L.) using ammonium sulfate fractionation followed by ion exchange, dye-ligand, and gel permeation chromatography. The final specific activity was 2.77 units per milligram protein. The average M_r value of the native enzyme was about 73,000. The Michaelis constants determined for Mg-ATP, acetate, and coenzyme A were 150, 57, and 5 micromolar, respectively. The purified enzyme was sensitive to substrate inhibition by CoA with an apparent K_i for CoA of 700 micromolar. The enzyme was specific for acetate; other short and long chain fatty acids were ineffective as substrates. Several intermediates and end products of fatty acid synthesis were examined as potential inhibitors of acetyl-CoA synthetase activity, but none of the compounds tested significantly inhibited acetyl-CoA synthetase activity in vitro. The properties of the purified enzyme support the postulated role of acetyl-CoA synthetase as a primary source of chloroplast acetyl-CoA.

¹ This research was supported by the Missouri Agricultural Experiment Station and National Science Foundation grant DMB-8506473. This is journal report number 11,295 of the Missouri Agricultural Experiment Station.

This article has been cited by other articles:

				S. de Cima, J. Rua, P. del Valle, F. Busto, A. Baroja-Mazo, and D. de Arriaga Different Stabilities of Two AMP-forming Acetyl-CoA Synthetases from Phycomyces blakesleeanus Expressed under Different Environmental Conditions J. Biochem., August 1, 2007; 142(2): 247 - 255. [Abstract] [Full Text] [PDF]

				A. U. Igamberdiev and L. A. Kleczkowski Equilibration of adenylates in the mitochondrial intermembrane space maintains respiration and regulates cytosolic metabolism J. Exp. Bot., July 1, 2006; 57(10): 2133 - 2141. [Abstract] [Full Text] [PDF]