The Oxidation of Fatty-Acyl Derivatives by Mitochondria from Bovine Fetal and Calf Hearts

1971 ◽  
Vol 49 (12) ◽  
pp. 1296-1300 ◽  
Author(s):  
J. T. Brosnan ◽  
I. B. Fritz
Keyword(s):  
Ionic Strength ◽  
Fatty Acyl ◽  
Carnitine Palmitoyltransferase ◽  
Basal Rate ◽  
Rate Of Oxygen Consumption ◽  
Carnitine Acyltransferases ◽  
Substrate Respiration ◽  
Fetal Bovine ◽  
Carnitine Palmitoyltransferase Activity ◽  
Acyl Derivatives

Functional activity of the "external" carnitine palmitoyltransferase in intact mitochondria, prepared from hearts from various sources, was estimated by measuring respiration by mitochondria in the presence of palmitoyl-CoA plus or minus l-carnitine. When palmitoyl-CoA alone was substrate, respiration was not increased above the basal rate under all conditions examined. Addition of l-carnitine increased respiration, provided the ionic strength of the incubation medium was sufficiently high. In the presence of palmitoyl-CoA plus l-carnitine, the rate of respiration increased as the ionic strength was increased to physiological levels. In contrast, the increase in rate of oxygen consumption by heart mitochondria which followed the addition of palmitoyl-l-carnitine was relatively independent of the ionic strength of the medium.Mitochondrial fractions prepared from fetal bovine hearts were shown to possess "external" carnitine palmitoyltransferase activity, as judged by the ability of l-carnitine to stimulate respiration by mitochondria incubated with palmitoyl-CoA under various conditions. These data were discussed in relation to information available concerning the functions of different carnitine acyltransferases in mitochondria.

scholarly journals Active sites residues of beef liver carnitine octanoyltransferase (COT) and carnitine palmitoyltransferase (CPT-II)

1998 ◽  
Vol 330 (2) ◽  
pp. 1029-1036 ◽  
Author(s):  
Nóirin NIC a'BHÁIRD ◽  
Victoria YANKOVSKAYA ◽  
R. Rona RAMSAY
Keyword(s):  
Active Sites ◽  
Chemical Reactivity ◽  
Fatty Acyl ◽  
Carnitine Palmitoyltransferase ◽  
Inactivation Kinetics ◽  
Beef Liver ◽  
First Order Kinetics ◽  
Carnitine Acyltransferases ◽  
Carnitine Palmitoyltransferase Ii ◽  
Selective Reagent

The carnitine acyltransferases which catalyse the reversible transfer of fatty acyl groups between carnitine and coenzyme A have been proposed to contain a catalytic histidine. Here, the chemical reactivity of active site groups has been used to demonstrate differences between the active sites of beef liver carnitine octanoyltransferase (COT) and carnitine palmitoyltransferase-II (CPT-II). Treatment of CPT-II with the histidine-selective reagent, diethyl pyrocarbonate (DEPC), resulted in simple linear pseudo-first-order kinetics. The reversal of the inhibition by hydroxylamine and the pKa (7.1) of the modified residue indicated that the residue was a histidine. The order of the inactivation kinetics showed that 1 mol of histidine was modified per mol of CPT-II.

scholarly journals Grafting ofchitosan with fatty acyl derivatives

2010 ◽  
Vol 21 (10) ◽  
pp. 1910-1916 ◽  
Author(s):  
Roberto S. Chiandotti ◽  
Paula C. Rodrigues ◽  
Leni Akcelrud
Keyword(s):  
Fatty Acyl ◽  
Acyl Derivatives

scholarly journals N-Lower-fatty-acyl Derivatives of Chitosan as Adsorbents for Lysozyme and Chitinase.

1991 ◽  
Vol 55 (6) ◽  
pp. 1683-1684 ◽  
Author(s):  
Shigehiro HIRANO ◽  
Hiroaki KANEKO ◽  
Motoko KITAGAWA
Keyword(s):  
Fatty Acyl ◽  
Derivatives Of ◽  
Acyl Derivatives

scholarly journals Chlorpromazine and carnitine-dependency of rat liver peroxisomal β-oxidation of long-chain fatty acids

1987 ◽  
Vol 241 (3) ◽  
pp. 783-791 ◽  
Author(s):  
J Vamecq
Keyword(s):  
Fatty Acids ◽  
Cytochrome C ◽  
Cytochrome C Oxidase ◽  
Rat Liver ◽  
Fatty Acyl ◽  
Carnitine Palmitoyltransferase ◽  
Acid Oxidation ◽  
Synthetase Activity ◽  
Mitochondrial Fatty Acid Oxidation ◽  
Mitochondrial Fatty Acid

The enzyme targets for chlorpromazine inhibition of rat liver peroxisomal and mitochondrial oxidations of fatty acids were studied. Effects of chlorpromazine on total fatty acyl-CoA synthetase activity, on both the first and the third steps of peroxisomal beta-oxidation, on the entry of fatty acyl-CoA esters into the peroxisome and on catalase activity, which allows breakdown of the H2O2 generated during the acyl-CoA oxidase step, were analysed. On all these metabolic processes, chlorpromazine was found to have no inhibitory action. Conversely, peroxisomal carnitine octanoyltransferase activity was depressed by 0.2-1 mM-chlorpromazine, which also inhibits mitochondrial carnitine palmitoyltransferase activity in all conditions in which these enzyme reactions are assayed. Different patterns of inhibition by the drug were, however, demonstrated for both these enzyme activities. Inhibitory effects of chlorpromazine on mitochondrial cytochrome c oxidase activity were also described. Inhibitions of both cytochrome c oxidase and carnitine palmitoyltransferase are proposed to explain the decreased mitochondrial fatty acid oxidation with 0.4-1.0 mM-chlorpromazine reported by Leighton, Persico & Necochea [(1984) Biochem. Biophys. Res. Commun. 120, 505-511], whereas depression by the drug of carnitine octanoyltransferase activity is presented as the factor responsible for the decreased peroxisomal beta-oxidizing activity described by the above workers.

Novel N-saturated-fatty-acyl derivatives of chitosan soluble in water and in aqueous acid and alkaline solutions

2002 ◽  
Vol 48 (2) ◽  
pp. 203-207 ◽  
Author(s):  
Shigehiro Hirano ◽  
Yasuhiro Yamaguchi ◽  
Mitsutomo Kamiya
Keyword(s):  
Fatty Acyl ◽  
Alkaline Solutions ◽  
Aqueous Acid ◽  
Derivatives Of ◽  
Acyl Derivatives

Cold acclimation increases carnitine palmitoyltransferase I activity in oxidative muscle of striped bass

1994 ◽  
Vol 266 (2) ◽  
pp. R405-R412 ◽  
Author(s):  
K. J. Rodnick ◽  
B. D. Sidell
Keyword(s):  
Cold Acclimation ◽  
Striped Bass ◽  
Fatty Acyl ◽  
Thermal Acclimation ◽  
Carnitine Palmitoyltransferase ◽  
Malonyl Coa ◽  
Red Muscle ◽  
Carnitine Palmitoyltransferase I ◽  
Cpt I ◽  
Long Chain

The effect of thermal acclimation on the activity of carnitine palmitoyltransferase I (CPT I), the rate-limiting enzyme for beta-oxidation of long-chain fatty acids, was determined in oxidative red muscle of striped bass (Morone saxatilis) acclimated at 5 or 25 degrees C. As observed in mammalian tissues, malonyl-CoA potently inhibited CPT I activity of mitochondria. Inhibition by malonyl-CoA required inclusions of both bovine serum albumin (BSA) and palmitoyl-CoA in the reaction media. Because BSA binds long-chain fatty acyl-CoAs, this observation suggests that free fatty acyl-CoAs may disrupt mitochondrial membranes and affect the CPT I protein. Cold acclimation increased citrate synthase activity 1.6-fold and total CPT activity 2-fold in homogenates of red muscle; free carnitine increased 62%, and specific activity of CPT I in mitochondria increased 2-fold. No differences were observed between cold- and warm-acclimated fish in substrate-binding properties of CPT I at an assay temperature of 15 degrees C, as judged by the Michaelis constant (Km) for carnitine (0.11 +/- 0.02 vs. 0.13 +/- 0.02 mM) or inhibition of CPT I, as determined by the half-maximal inhibition concentration (IC50) for malonyl-CoA (0.14 +/- 0.05 vs. 0.09 +/- 0.03 microM). Thermal sensitivity of CPT I (Q10 = 2.91 +/- 0.12 vs. 3.02 +/- 0.20) and preference of CPT I for different long-chain fatty acyl-CoA substrates (16:1-CoA = 16:0-CoA > 18:1-CoA) were not altered by thermal acclimation.(ABSTRACT TRUNCATED AT 250 WORDS)

scholarly journals Interacting effects of l-carnitine and malonyl-CoA on rat liver carnitine palmitoyltransferase

1985 ◽  
Vol 230 (1) ◽  
pp. 161-167 ◽  
Author(s):  
M I Bird ◽  
E D Saggerson
Keyword(s):  
Binding Sites ◽  
Concentration Ratio ◽  
Liver Mitochondria ◽  
Carnitine Palmitoyltransferase ◽  
Heart Mitochondria ◽  
Albumin Concentration ◽  
Latent Form ◽  
Malonyl Coa ◽  
Carnitine Palmitoyltransferase Activity ◽  
Overt Form

Malonyl-CoA significantly increased the Km for L-carnitine of overt carnitine palmitoyltransferase in liver mitochondria from fed rats. This effect was observed when the molar palmitoyl-CoA/albumin concentration ratio was low (0.125-1.0), but not when it was higher (2.0). In the absence of malonyl-CoA, the Km for L-carnitine increased with increasing palmitoyl-CoA/albumin ratios. Malonyl-CoA did not increase the Km for L-carnitine in liver mitochondria from 24h-starved rats or in heart mitochondria from fed animals. The Km for L-carnitine of the latent form of carnitine palmitoyltransferase was 3-4 times that for the overt form of the enzyme. At low ratios of palmitoyl-CoA/albumin (0.5), the concentration of malonyl-CoA causing a 50% inhibition of overt carnitine palmitoyltransferase activity was decreased by 30% when assays with liver mitochondria from fed rats were performed at 100 microM-instead of 400 microM-carnitine. Such a decrease was not observed with liver mitochondria from starved animals. L-Carnitine displaced [14C]malonyl-CoA from liver mitochondrial binding sites. D-Carnitine was without effect. L-Carnitine did not displace [14C]malonyl-CoA from heart mitochondria. It is concluded that, under appropriate conditions, malonyl-CoA may decrease the effectiveness of L-carnitine as a substrate for the enzyme and that L-carnitine may decrease the effectiveness of malonyl-CoA to regulate the enzyme.

Some novel N-fatty acyl derivatives of a microbial galactosaminan

1996 ◽  
Vol 18 (4) ◽  
pp. 307-309
Author(s):  
Min Zhang ◽  
Kimiko Yamashita ◽  
Kiyoshi Kadowaki ◽  
Shigehiro Hirano
Keyword(s):  
Fatty Acyl ◽  
Derivatives Of ◽  
Acyl Derivatives
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