MYOCARDIAL CARNITINE PALMITOYLTRANSFERASE OF THE MITOCHONDRIAL OUTER-MEMBRANE IS NOT ALTERED BY FASTING

被引:28
|
作者
MYNATT, RL [1 ]
LAPPI, MD [1 ]
COOK, GA [1 ]
机构
[1] UNIV TENNESSEE,CTR HLTH SCI,COLL MED,DEPT PHARMACOL,874 UNION AVE,MEMPHIS,TN 38163
关键词
CARNITINE PALMITOYLTRANSFERASE; FATTY ACID OXIDATION; MITOCHONDRION; ENZYME REGULATION; FASTING; (HEART);
D O I
10.1016/0005-2760(92)90263-U
中图分类号
Q5 [生物化学]; Q7 [分子生物学];
学科分类号
071010 ; 081704 ;
摘要
The regulation of heart carnitine palmitoyltransferase was studied during the transition to the fasting state. Using decanoyl-CoA or palmitoyl-CoA as substrates, we found no differences in carnitine palmitoyltransferase activity or in its sensitivity to inhibition by malonyl-CoA between fed and fasted states. No cooperativity was seen with either substrate, and the malonyl-CoA-induced shift to sigmoid kinetics normally observed with liver mitochondria was not obvious with heart mitochondria. Analysis of malonyl-CoA inhibition data revealed that mitochondria from rat heart exhibited incomplete maximum inhibition of carnitine palmitoyltransferase (partial inhibition). Homogenization of intact liver mitochondria resulted in a similar pattern of incomplete inhibition and suggested that the malonyl-CoA-insensitive carnitine palmitoyltransferase of the inner membrane was also being assayed. Carnitine palmitoyltransferase in mitochondrial outer membranes, isolated from the heart, proved to be extremely sensitive to malonyl-CoA inhibition and had maximum inhibition values of 90-100% with either decanoyl-CoA or palmitoyl-CoA as substrates, but fasting had no effect. Fasting produced no change in the K(i) for malonyl-CoA (0.10 +/- 0.04 and 0.14 +/- 0.02 mu m for the fed and fasted groups, respectively). Acyl-CoA chain length specificity was C1O > C16 > C14 > C12 > C18 = C8 for carnitine palmitoyltransferase in heart mitochondrial outer membranes. It is concluded that the regulation of carnitine palmitoyltransferase of heart mitochondrial outer membranes differs from regulation of the liver enzyme in three characteristics - the heart enzyme (a) has greater sensitivity to malonyl-CoA inhibition, (b) is resistant to the effects of fasting and (c) has somewhat different acyl-CoA substrate specificity.
引用
收藏
页码:105 / 111
页数:7
相关论文
共 50 条
  • [31] STRUCTURE OF THE MITOCHONDRIAL OUTER-MEMBRANE CHANNEL, VDAC
    GUO, XW
    BRYANT, S
    BITTER, M
    COGNON, B
    MANNELLA, CA
    FASEB JOURNAL, 1992, 6 (01): : A14 - A14
  • [32] IMPORT AND INSERTION OF PROTEINS INTO THE MITOCHONDRIAL OUTER-MEMBRANE
    SHORE, GC
    MCBRIDE, HM
    MILLAR, DG
    STEENAART, NAE
    NGUYEN, M
    EUROPEAN JOURNAL OF BIOCHEMISTRY, 1995, 227 (1-2): : 9 - 18
  • [33] Carnitine/acylcarnitine translocase and carnitine palmitoyltransferase 2 form a complex in the inner mitochondrial membrane
    Console, Lara
    Giangregorio, Nicola
    Indiveri, Cesare
    Tonazzi, Annamaria
    MOLECULAR AND CELLULAR BIOCHEMISTRY, 2014, 394 (1-2) : 307 - 314
  • [34] CARNITINE PALMITOYLTRANSFERASE (CPT2) FROM LIVER MITOCHONDRIAL INNER MEMBRANE BECOMES INHIBITABLE BY MALONYL-COA IF RECONSTITUTED WITH OUTER-MEMBRANE MALONYL-COA BINDING-PROTEIN
    GHADIMINEJAD, I
    SAGGERSON, ED
    FEBS LETTERS, 1990, 269 (02) : 406 - 408
  • [35] EFFECT OF INSULIN ON CARNITINE PALMITOYLTRANSFERASE IN THE FASTING RAT
    COOK, GA
    WEAKLEY, LJ
    FEDERATION PROCEEDINGS, 1987, 46 (06) : 2177 - 2177
  • [36] Mitochondrial Carnitine Palmitoyltransferase 1a (CPT1a) Is Part of an Outer Membrane Fatty Acid Transfer Complex
    Lee, Kwangwon
    Kerner, Janos
    Hoppel, Charles L.
    JOURNAL OF BIOLOGICAL CHEMISTRY, 2011, 286 (29) : 25655 - 25662
  • [37] Erratum to: Carnitine/acylcarnitine translocase and carnitine palmitoyltransferase 2 form a complex in the inner mitochondrial membrane
    Lara Console
    Nicola Giangregorio
    Cesare Indiveri
    Annamaria Tonazzi
    Molecular and Cellular Biochemistry, 2014, 394 : 315 - 315
  • [38] RUPTURE OF THE MITOCHONDRIAL OUTER-MEMBRANE IMPAIRS PORIN ASSEMBLY
    SMITH, M
    HICKS, S
    BAKER, K
    MCCAULEY, R
    JOURNAL OF BIOLOGICAL CHEMISTRY, 1994, 269 (45) : 28460 - 28464
  • [39] REVERSAL OF THE ORIENTATION OF AN INTEGRAL PROTEIN OF THE MITOCHONDRIAL OUTER-MEMBRANE
    LI, JM
    SHORE, GC
    SCIENCE, 1992, 256 (5065) : 1815 - 1817
  • [40] INTERACTION OF SOME CYTOSOLIC PROTEINS WITH MITOCHONDRIAL OUTER-MEMBRANE
    MARINO, W
    HALDAR, D
    FASEB JOURNAL, 1992, 6 (01): : A229 - A229