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 Request Permissions Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Hesler, C. B. Articles by Haldar, D. Search for Related Content PubMed PubMed Citation Articles by Hesler, C. B. Articles by Haldar, D. Social Bookmarking                      What's this?

J. Biol. Chem., Vol. 265, Issue 12, 6600-6605, Apr, 1990

Transverse-plane topography of long-chain acyl-CoA synthetase in the mitochondrial outer membrane

CB Hesler, C Olymbios and D Haldar
Department of Biological Sciences, St. John's University, Jamaica, New York 11439.

Transverse-plane topography of mitochondrial outer-membrane long-chain acyl-CoA synthetase was investigated using proteases as probes for exposure of crucial domains, i.e. domains containing the active site or otherwise required for enzymatic activity. Incubation of intact mitochondria with the nonspecific proteases proteinase K and subtilisin resulted in a time-dependent loss of 90% or more of the long-chain acyl- CoA synthetase activity compared to control incubations. The integrity of the outer membrane before and during this treatment was shown by cytochrome c oxidase latency as well as the stability of adenylate kinase activity in the presence of protease. After a 15-min incubation in these conditions, site-specific proteases such as trypsin and chymotrypsin had only a limited inhibitory effect (29 and 58% loss of activity, respectively); however, treatment of hypotonically disrupted mitochondria with these proteases resulted in increased (71 and 77%, respectively) loss of activity. Exposure of trypsin-sensitive crucial domains on the inner surface of the membrane was directly demonstrated by incubation of trypsin-loaded outer-membrane vesicles. Together, these results suggest that mitochondrial long-chain acyl-CoA synthetase is a transmembrane enzyme, possessing crucial domains on both sides of the outer membrane. However, the cytosolic exposure of the enzyme does not appear to be affected by a change in the medium ionic strength as seen previously for other outer-membrane enzymes. In an experiment investigating the topography of the active site of the enzyme, an immobilized substrate analog, desulfo-CoA-agarose, was preincubated with intact mitochondria. This resulted in up to a 42% loss of the activity of long-chain acyl-CoA synthetase, consistent with a cytosolic exposure for at least the CoA-binding domain of the active site.
CiteULike    Complore    Connotea    Del.icio.us    Digg    Reddit    Technorati    What's this?

This article has been cited by other articles:

				H. A. Parkes, E. Preston, D. Wilks, M. Ballesteros, L. Carpenter, L. Wood, E. W. Kraegen, S. M. Furler, and G. J. Cooney Overexpression of acyl-CoA synthetase-1 increases lipid deposition in hepatic (HepG2) cells and rodent liver in vivo Am J Physiol Endocrinol Metab, October 1, 2006; 291(4): E737 - E744. [Abstract] [Full Text] [PDF]

				M. R. Gonzalez-Baro, D. A. Granger, and R. A. Coleman Mitochondrial Glycerol Phosphate Acyltransferase Contains Two Transmembrane Domains with the Active Site in the N-terminal Domain Facing the Cytosol J. Biol. Chem., November 9, 2001; 276(46): 43182 - 43188. [Abstract] [Full Text] [PDF]

				T. R. Chakraborty, A. Vancura, V. S. Balija, and D. Haldar Phosphatidic Acid Synthesis in Mitochondria. TOPOGRAPHY OF FORMATION AND TRANSMEMBRANE MIGRATION J. Biol. Chem., October 15, 1999; 274(42): 29786 - 29790. [Abstract] [Full Text] [PDF]

				C. E. Gargiulo, S. M. Stuhlsatz-Krouper, and J. E. Schaffer Localization of adipocyte long-chain fatty acyl-CoA synthetase at the plasma membrane J. Lipid Res., May 1, 1999; 40(5): 881 - 892. [Abstract] [Full Text]

				C. J. Glover and R. L. Felsted Identification and Characterization of Multiple Forms of Bovine Brain N-Myristoyltransferase J. Biol. Chem., September 29, 1995; 270(39): 23226 - 23233. [Abstract] [Full Text] [PDF]