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 Web of Science 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 Web of Science (12) Citing Articles via Google Scholar Google Scholar Articles by Hills, M. J. Articles by Beevers, H. Search for Related Content PubMed PubMed Citation Articles by Hills, M. J. Articles by Beevers, H. Agricola Articles by Hills, M. J. Articles by Beevers, H.

Metabolism and Enzymology

Inhibition of Neutral Lipase from Castor Bean Lipid Bodies by Coenzyme A (CoA) and Oleoyl-CoA ¹

Biology Department, University of Santa Cruz, Santa Cruz, California 95064

The neutral lipase (EC 3.1.1.3) in lipid body membranes isolated from the endosperm of 4 day old castor (Ricinus communis L.) seedlings catalyzes the hydrolysis of [¹⁴C]trioleoylglycerol, releasing [¹⁴C]oleic acid for up to 4 hours. However, the addition of Mg-ATP and coenzyme A (CoA), which are present in the cytoplasm of plant cells, caused a progressive inhibition of the neutral lipase such that after 15 minutes, release of [¹⁴C]oleic acid was almost undetectable. A fatty acyl CoA synthetase was found in the lipid body membrane which converts [¹⁴C]oleic acid produced from the lipase reaction to [¹⁴C]oleoyl-CoA under these conditions. The concentration of free oleoyl-CoA in the reaction mixture when the lipase was inhibited by 50% was calculated to be about 21 micromolar. It was found that a mixture of exogenously added oleoyl-CoA and CoA was most effective in causing lipase inhibition. Little inhibition of lipase was detected in the presence of CoA alone. It is possible that this effect is important In vivo in coordinating lipase activity with fatty acid oxidation.

³ Present address: Botany Department, University of Durham, South Road, Durham, DH1 3LE, UK.

¹ Supported by grant PCM 84-03542 from the U.S. National Science Foundation.

This article has been cited by other articles:

				N. Linka, F. L. Theodoulou, R. P. Haslam, M. Linka, J. A. Napier, H. E. Neuhaus, and A. P.M. Weber Peroxisomal ATP Import Is Essential for Seedling Development in Arabidopsis thaliana PLANT CELL, December 1, 2008; 20(12): 3241 - 3257. [Abstract] [Full Text] [PDF]

				P. J. Eastmond SUGAR-DEPENDENT1 Encodes a Patatin Domain Triacylglycerol Lipase That Initiates Storage Oil Breakdown in Germinating Arabidopsis Seeds PLANT CELL, March 1, 2006; 18(3): 665 - 675. [Abstract] [Full Text] [PDF]

				P. J. Eastmond Cloning and Characterization of the Acid Lipase from Castor Beans J. Biol. Chem., October 29, 2004; 279(44): 45540 - 45545. [Abstract] [Full Text] [PDF]