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

This Article Full Text (PDF) 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 Declercq, P. E. Articles by McGarry, J. D. Search for Related Content PubMed PubMed Citation Articles by Declercq, P. E. Articles by McGarry, J. D. Social Bookmarking                      What's this?

J. Biol. Chem., Vol. 262, Issue 20, 9812-9821, 07, 1987

Characterization of the mitochondrial carnitine palmitoyltransferase enzyme system. I. Use of inhibitors

PE Declercq, JR Falck, M Kuwajima, H Tyminski, DW Foster and JD McGarry

The effects of various inhibitors of carnitine palmitoyltransferase I were examined in mitochondria from rat liver and skeletal muscle. Three types of inhibitors were used: malonyl-CoA (reversible), tetradecylglycidyl-CoA and three of its analogues (irreversible), and 2- bromopalmitoyl-CoA (essentially irreversible when added with carnitine). Competitive binding studies between labeled and unlabeled ligands together with electrophoretic analysis of sodium dodecyl sulfate-solubilized membranes revealed that in mitochondria from both tissues all of the inhibitors interacted with a single protein. While the binding capacity for inhibitors was similar in liver and muscle (6- 8 pmol/mg of mitochondrial protein) the proteins involved were of different monomeric size (Mr 94,000 and 86,000, respectively). Treatment of mitochondria with the detergent, octyl glucoside, yielded a soluble form of carnitine palmitoyltransferase and residual membranes that were devoid of enzyme activity. The solubilized enzyme displayed the same activity regardless of whether carnitine palmitoyltransferase I of the original mitochondria had first been exposed to an irreversible inhibitor or destroyed by chymotrypsin. It eluted as a single activity peak through four purification steps. The final product from both liver and muscle migrated as single band on sodium dodecyl sulfate-polyacrylamide electrophoresis with Mr of approximately 80,000. The data are consistent with the following model. The inhibitor binding protein is carnitine palmitoyltransferase I itself (as opposed to a regulatory subunit). The hepatic monomer is larger than the muscle enzyme. Each inhibitor interacts via its thioester group at the palmitoyl-CoA binding site of the enzyme but also at a second locus that is probably different for each agent and dictated by the chemical substituent on carbon 2. Disruption of the mitochondrial inner membrane by octyl glucoside causes inactivation of carnitine palmitoyltransferase I while releasing carnitine palmitoyltransferase II in active form. The latter is readily purified, is a smaller protein than carnitine palmitoyltransferase I, and has the same molecular weight in liver and muscle. It is insensitive to inhibitors where on or off the mitochondrial membrane.
CiteULike    Complore    Connotea    Del.icio.us    Digg    Reddit    Technorati    What's this?

This article has been cited by other articles:

				W. Guo, T. Pirtskhalava, T. Tchkonia, W. Xie, T. Thomou, J. Han, T. Wang, S. Wong, A. Cartwright, F. G. Hegardt, et al. Aging results in paradoxical susceptibility of fat cell progenitors to lipotoxicity Am J Physiol Endocrinol Metab, April 1, 2007; 292(4): E1041 - E1051. [Abstract] [Full Text] [PDF]

				M. Cnop, J. C. Hannaert, A. Hoorens, D. L. Eizirik, and D. G. Pipeleers Inverse Relationship Between Cytotoxicity of Free Fatty Acids in Pancreatic Islet Cells and Cellular Triglyceride Accumulation Diabetes, August 1, 2001; 50(8): 1771 - 1777. [Abstract] [Full Text] [PDF]

				F. Caserta, T. Tchkonia, V. N. Civelek, M. Prentki, N. F. Brown, J. D. McGarry, R. A. Forse, B. E. Corkey, J. A. Hamilton, and J. L. Kirkland Fat depot origin affects fatty acid handling in cultured rat and human preadipocytes Am J Physiol Endocrinol Metab, February 1, 2001; 280(2): E238 - E247. [Abstract] [Full Text] [PDF]

				R. L. Dobbins, L. S. Szczepaniak, B. Bentley, V. Esser, J. Myhill, and J. D. McGarry Prolonged Inhibition of Muscle Carnitine Palmitoyltransferase-1 Promotes Intramyocellular Lipid Accumulation and Insulin Resistance in Rats Diabetes, January 1, 2001; 50(1): 123 - 130. [Abstract] [Full Text]

				D. M. Mott, C. Hoyt, R. Caspari, K. Stone, R. Pratley, and C. Bogardus Palmitate oxidation rate and action on glycogen synthase in myoblasts from insulin-resistant subjects Am J Physiol Endocrinol Metab, September 1, 2000; 279(3): E561 - E569. [Abstract] [Full Text] [PDF]

				N. D. Oakes, A. Kjellstedt, G.-B. Forsberg, T. Clementz, G. Camejo, S. M. Furler, E. W. Kraegen, M. Ölwegård-Halvarsson, A. B. Jenkins, and B. Ljung Development and initial evaluation of a novel method for assessing tissue-specific plasma free fatty acid utilization in vivo using (R)-2-bromopalmitate tracer J. Lipid Res., June 1, 1999; 40(6): 1155 - 1169. [Abstract] [Full Text]

				C. L. Hoppel, J. Kerner, P. Turkaly, J. Turkaly, and B. Tandler The Malonyl-CoA-sensitive Form of Carnitine Palmitoyltransferase Is Not Localized Exclusively in the Outer Membrane of Rat Liver Mitochondria J. Biol. Chem., September 4, 1998; 273(36): 23495 - 23503. [Abstract] [Full Text] [PDF]

				Y. Xia, L. M. Buja, and J. B. McMillin Change in Expression of Heart Carnitine Palmitoyltransferase I Isoforms with Electrical Stimulation of Cultured Rat Neonatal Cardiac Myocytes J. Biol. Chem., May 17, 1996; 271(20): 12082 - 12087. [Abstract] [Full Text] [PDF]

				D. C. Henly, J. W. Phillips, and M. N. Berry Suppression of Glycolysis Is Associated with an Increase in Glucose Cycling in Hepatocytes from Diabetic Rats J. Biol. Chem., May 10, 1996; 271(19): 11268 - 11271. [Abstract] [Full Text] [PDF]

				N. F. Brown, B. C. Weis, J. E. Husti, D. W. Foster, and J. D. McGarry Mitochondrial Carnitine Palmitoyltransferase I Isoform Switching in the Developing Rat Heart J. Biol. Chem., April 14, 1995; 270(15): 8952 - 8957. [Abstract] [Full Text] [PDF]

				V. N. Jackson, V. A. Zammit, and N. T. Price Identification of Positive and Negative Determinants of Malonyl-CoA Sensitivity and Carnitine Affinity within the Amino Termini of Rat Liver- and Muscle-type Carnitine Palmitoyltransferase I J. Biol. Chem., December 1, 2000; 275(49): 38410 - 38416. [Abstract] [Full Text] [PDF]