HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS		QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

J. Biol. Chem., Vol. 278, Issue 36, 34084-34089, September 5, 2003

This Article Full Text Full Text (PDF) All Versions of this Article: 278/36/34084    most recent M305826200v1 Alert me when this article is cited Alert me if a correction is posted Citation Map 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 Google Scholar Google Scholar Articles by Napal, L. Articles by Woldegiorgis, G. Search for Related Content PubMed PubMed Citation Articles by Napal, L. Articles by Woldegiorgis, G. Social Bookmarking                      What's this?

A Single Amino Acid Change (Substitution of the Conserved Glu-590 with Alanine) in the C-terminal Domain of Rat Liver Carnitine Palmitoyltransferase I Increases its Malonyl-CoA Sensitivity Close to That Observed with the Muscle Isoform of the Enzyme^*

Laura Napal  , Jia Dai  , Michelle Treber , Diego Haro ¶, Pedro F. Marrero ¶ and Gebre Woldegiorgis  ||

From the Department of Environmental and Biomolecular Systems, OGI School of Science & Engineering, Oregon Health & Science University, Beaverton, Oregon 97006-8921 and the ^¶Department of Biochemistry and Molecular Biology, University of Barcelona, School of Pharmacy, 08028 Barcelona, Spain

Carnitine palmitoyltransferase I (CPTI) catalyzes the conversion of long-chain fatty acyl-CoAs to acylcarnitines in the presence of L-carnitine. To determine the role of the highly conserved C-terminal glutamate residue, Glu-590, on catalysis and malonyl-CoA sensitivity, we separately changed the residue to alanine, lysine, glutamine, and aspartate. Substitution of Glu-590 with aspartate, a negatively charged amino acid with only one methyl group less than the glutamate residue in the wild-type enzyme, resulted in complete loss in the activity of the liver isoform of CPTI (L-CPTI). A change of Glu-590 to alanine, glutamine, and lysine caused a significant 9- to 16-fold increase in malonyl-CoA sensitivity but only a partial decrease in catalytic activity. Substitution of Glu-590 with neutral uncharged residues (alanine and glutamine) and/or a basic positively charged residue (lysine) significantly increased L-CPTI malonyl-CoA sensitivity to the level observed with the muscle isoform of the enzyme, suggesting the importance of neutral and/or positive charges in the switch of the kinetic properties of L-CPTI to the muscle isoform of CPTI. Since a conservative substitution of Glu-590 to aspartate but not glutamine resulted in complete loss in activity, we suggest that the longer side chain of glutamate is essential for catalysis and malonyl-CoA sensitivity. This is the first demonstration whereby a single residue mutation in the C-terminal region of the liver isoform of CPTI resulted in a change of its kinetic properties close to that observed with the muscle isoform of the enzyme and provides the rationale for the high malonyl-CoA sensitivity of muscle CPTI compared with the liver isoform of the enzyme.

Received for publication, June 3, 2003 , and in revised form, June 18, 2003.

^* This research was supported by National Institutes of Health Grant HL52571 (to G. W.) and a fellowship from the Ministry of Science and Technology of Spain (to L. N.). The costs of publication of this article were defrayed in part by the payment of page charges. This article must therefore be hereby marked "advertisement" in accordance with 18 U.S.C. Section 1734 solely to indicate this fact.

Both authors contributed equally to this work.

^|| To whom correspondence should be addressed: Dept. of Environmental and Biomolecular Systems, OGI School of Science & Engineering, 20000 N. W. Walker Rd., Beaverton, OR 97006-8921. Tel.: 503-748-1676; Fax: 503-748-1464; E-mail: gwoldeg{at}ebs.ogi.edu.

CiteULike    Complore    Connotea    Del.icio.us    Digg    Reddit    Technorati    What's this?

This article has been cited by other articles:

				G. P. Holloway, V. Bezaire, G. J. F. Heigenhauser, N. N. Tandon, J. F. C. Glatz, J. J. F. P. Luiken, A. Bonen, and L. L. Spriet Mitochondrial long chain fatty acid oxidation, fatty acid translocase/CD36 content and carnitine palmitoyltransferase I activity in human skeletal muscle during aerobic exercise J. Physiol., February 15, 2006; 571(1): 201 - 210. [Abstract] [Full Text] [PDF]

				N. Yang, J. S. Kays, T. R. Skillman, L. Burris, T. W. Seng, and C. Hammond C75 [4-Methylene-2-octyl-5-oxo-tetrahydro-furan-3-carboxylic Acid] Activates Carnitine Palmitoyltransferase-1 in Isolated Mitochondria and Intact Cells without Displacement of Bound Malonyl CoA J. Pharmacol. Exp. Ther., January 1, 2005; 312(1): 127 - 133. [Abstract] [Full Text] [PDF]

				J. Kerner, A. M. Distler, P. Minkler, W. Parland, S. M. Peterman, and C. L. Hoppel Phosphorylation of Rat Liver Mitochondrial Carnitine Palmitoyltransferase-I: EFFECT ON THE KINETIC PROPERTIES OF THE ENZYME J. Biol. Chem., September 24, 2004; 279(39): 41104 - 41113. [Abstract] [Full Text] [PDF]