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Masuda M, Miyazaki-Anzai S, Keenan AL, Okamura K, Kendrick J, Chonchol M, Offermanns S, Ntambi JM, Kuro-O M, Miyazaki M. Saturated phosphatidic acids mediate saturated fatty acid-induced vascular calcification and lipotoxicity. J Clin Invest 2015; 125:4544-58. [PMID: 26517697 DOI: 10.1172/jci82871] [Citation(s) in RCA: 44] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2015] [Accepted: 09/10/2015] [Indexed: 01/06/2023] Open
Abstract
Recent evidence indicates that saturated fatty acid-induced (SFA-induced) lipotoxicity contributes to the pathogenesis of cardiovascular and metabolic diseases; however, the molecular mechanisms that underlie SFA-induced lipotoxicity remain unclear. Here, we have shown that repression of stearoyl-CoA desaturase (SCD) enzymes, which regulate the intracellular balance of SFAs and unsaturated FAs, and the subsequent accumulation of SFAs in vascular smooth muscle cells (VSMCs), are characteristic events in the development of vascular calcification. We evaluated whether SMC-specific inhibition of SCD and the resulting SFA accumulation plays a causative role in the pathogenesis of vascular calcification and generated mice with SMC-specific deletion of both Scd1 and Scd2. Mice lacking both SCD1 and SCD2 in SMCs displayed severe vascular calcification with increased ER stress. Moreover, we employed shRNA library screening and radiolabeling approaches, as well as in vitro and in vivo lipidomic analysis, and determined that fully saturated phosphatidic acids such as 1,2-distearoyl-PA (18:0/18:0-PA) mediate SFA-induced lipotoxicity and vascular calcification. Together, these results identify a key lipogenic pathway in SMCs that mediates vascular calcification.
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Yamazaki T, Kadokura M, Mutoh Y, Sakamoto T, Okazaki M, Mitsumoto A, Kawashima Y, Kudo N. Inducing effect of clofibric acid on stearoyl-CoA desaturase in intestinal mucosa of rats. Lipids 2014; 49:1203-14. [PMID: 25362535 DOI: 10.1007/s11745-014-3965-9] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2014] [Accepted: 10/16/2014] [Indexed: 10/24/2022]
Abstract
Fibrates have been reported to elevate the hepatic proportion of oleic acid (18:1n-9) through inducing stearoyl-CoA desaturase (SCD). Despite abundant studies on the regulation of SCD in the liver, little is known about this issue in the small intestine. The present study aimed to investigate the effect of clofibric acid on the fatty acid profile, particularly monounsaturated fatty acids (MUFA), and the SCD expression in intestinal mucosa. Treatment of rats with a diet containing 0.5% (w/w) clofibric acid for 7 days changed the MUFA profile of total lipids in intestinal mucosa; the proportion of 18:1n-9 was significantly increased, whereas those of palmitoleic (16:1n-7) and cis-vaccenic (18:1n-7) acids were not changed. Upon the treatment with clofibric acid, SCD was induced and the gene expression of SCD1, SCD2, and fatty acid elongase (Elovl) 6 was up-regulated, but that of Elovl5 was unaffected. Fat-free diet feeding for 28 days increased the proportions of 16:1n-7 and 18:1n-7, but did not effectively change that of 18:1n-9, in intestinal mucosa. Fat-free diet feeding up-regulated the gene expression of SCD1, but not that of SCD2, Elovl6, or Elovl5. These results indicate that intestinal mucosa significantly changes its MUFA profile in response to challenges by clofibric acid and a fat-free diet and suggest that up-regulation of the gene expression of SCD along with Elovl6 is indispensable to elevate the proportion of 18:1n-9 in intestinal mucosa.
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Affiliation(s)
- Tohru Yamazaki
- School of Pharmaceutical Sciences, Josai University, 1-1 Keyakidai, Sakado, Saitama, 350-0295, Japan
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Allen E, Johnson AR, Fogerty AC, Pearson JA, Shenstone FS. Inhibition by cyclopropene fatty acids of the desaturation of stearic acid in hen liver. Lipids 2012; 2:419-23. [PMID: 17805703 DOI: 10.1007/bf02531857] [Citation(s) in RCA: 58] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/1967] [Indexed: 10/23/2022]
Abstract
The mechanism of the hardening of body fats of animals by dietary lipids which contain cyclopropene fatty acids has been studied. Dietary methyl sterculate increased the stearic acid content of egg yolk lipid and decreased the activity of the stearic acid desaturase system of hen liver. The cyclopropene fatty acids were specific inhibitors of the stearic acid desaturase system of hen livers since other fatty acids, including two possible metabolites of sterculic acid, failed to inhibit the system at equivalent concentrations. Sterculic acid was a more effective inhibitor of the system than malvalic acid. Kinetic studies have shown that the inhibition is irreversible. Apparent kinetic constants were determined for the system.The results support the hypotheses that cyclopropene fatty acids inactivate an essential component of the desaturase system, probably by combination with-SH groups, and that this inhibition causes many of the effects of dietary cyclopropene fatty acids, including permeability disorders of eggs.
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Affiliation(s)
- E Allen
- CSIRO Division of Food Preservation, Ryde, N.S.W., Australia
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Effect of a linseed diet on lipogenesis, fatty acid composition and stearoyl-CoA-desaturase in rabbits. Animal 2011; 5:1993-2000. [DOI: 10.1017/s1751731111001145] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022] Open
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5
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Effect of a linseed diet or a sunflower diet on performances, fatty acid composition, lipogenic enzyme activities and stearoyl-CoA-desaturase activity in the pig. Livest Sci 2009. [DOI: 10.1016/j.livsci.2009.02.009] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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6
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Effect of a linseed diet on lipid oxidation, fatty acid composition of muscle, perirenal fat, and raw and cooked rabbit meat. Meat Sci 2008; 80:829-34. [DOI: 10.1016/j.meatsci.2008.03.029] [Citation(s) in RCA: 71] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2007] [Revised: 02/20/2008] [Accepted: 03/26/2008] [Indexed: 11/18/2022]
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7
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Kouba M, Enser M, Whittington FM, Nute GR, Wood JD. Effect of a high-linolenic acid diet on lipogenic enzyme activities, fatty acid composition, and meat quality in the growing pig. J Anim Sci 2003; 81:1967-79. [PMID: 12926779 DOI: 10.2527/2003.8181967x] [Citation(s) in RCA: 195] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Forty-eight Duroc-cross gilts (40 kg initial BW) were fed a control or a linseed diet containing 60 g of whole crushed linseed/kg. Both diets were supplemented with 150 mg of vitamin E/kg. Eight pigs from each dietary treatment were slaughtered at 20, 60, or 100 d after the start of the experiment. There was no effect (P > 0.05) of diet on growth, carcass characteristics, or foreloin tissue composition. Feeding the linseed diet increased (P < 0.05) the content of n-3 PUFA in plasma, muscle, and adipose tissue, but docosahexaenoic acid was not (P > 0.05) altered by diet. The proportions of n-3 PUFA were highest (P < 0.01) in pigs fed the linseed-diet for 60 d, regardless of tissue (plasma, muscle, or adipose tissue) or lipid (neutral lipids and phospholipids) class. The linseed diet produced a PUFA:saturated fatty acid ratio > or = 0.4 in all groups and tissues, which is close to the recommended value for the entire diet of humans, as well as a robust decrease in the n-6:n-3 ratio. The decrease (P < 0.01) in the percentage of oleic acid in adipose tissue of pigs fed the linseed diet for 60 d could be attributed to a 40% decrease (P < 0.001) in stearoyl-CoA-desaturase activity. Diet did not (P > 0.05) affect the activities of acetyl-CoA-carboxylase, malic enzyme, or glucose-6-phosphate-dehydrogenase in any tissues. Muscle vitamin E content was decreased (P < 0.001) 30% in pigs fed crushed linseed for 60 d, whereas lower (P < 0.001) concentrations of skatole in pork fat were observed in linseed-fed pigs at all slaughter times. Inclusion of linseed (flaxseed) in swine diets is a valid method of improving the nutritional value of pork without deleteriously affecting organoleptic characteristics, oxidation, or color stability.
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Affiliation(s)
- M Kouba
- Unité Mixte de Recherches Veau-Porc INRA-ENSAR, 35 590 Saint-Gilles, France.
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Imai K, Koyama M, Kudo N, Shirahata A, Kawashima Y. Increase in hepatic content of oleic acid induced by dehydroepiandrosterone in the rat. Biochem Pharmacol 1999; 58:925-33. [PMID: 10509745 DOI: 10.1016/s0006-2952(99)00159-8] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
The effects of dehydroepiandrosterone (DHEA) on the acyl composition of lipids in rat liver were studied. The content of oleic acid (18:1) in hepatic lipids was increased markedly by feeding rats a diet containing 0.5% (w/w) DHEA for 14 days. Treatment of rats with DHEA caused an increase in the activity of the terminal desaturase of the stearoyl-CoA desaturation system, without changing either the activity of NADH-cytochrome b5 reductase or the microsomal content of cytochrome b5. Among the changes observed in hepatic lipids, the increase in 18:1 content in phosphatidylcholine (PtdCho) was the most prominent; an approximately 2.5-fold increase in the proportion of 18:1 was induced at position 2, but not at position 1, by DHEA. This selective elevation of 18:1 at position 2 of PtdCho seems to be produced by the concerted actions of the induced 1-acylglycerophosphocholine (1-acyl-GPC) acyltransferase and the induced stearoyl-CoA desaturase. The content of 18:1 in serum lipids was unchanged by DHEA treatment, suggesting that secretion of lipids containing 18:1 into the circulation was not affected by DHEA. These results suggest that the elevation of hepatic content of 18:1 caused by DHEA treatment is mainly due to the induction of stearoyl-CoA desaturase.
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Affiliation(s)
- K Imai
- Department of Pharmacy, Saitama Cardiovascular and Respiratory Center, Japan
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9
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Kouba M, Hermier D, Le Dividich J. Influence of a high ambient temperature on stearoyl-CoA-desaturase activity in the growing pig. Comp Biochem Physiol B Biochem Mol Biol 1999; 124:7-13. [PMID: 10582316 DOI: 10.1016/s0305-0491(99)00090-5] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
An experiment was conducted to determine the influence of a high ambient temperature on the stearoyl-CoA-desaturase activity and fatty acid composition of backfat, leaf fat, Longissimus dorsi muscle and liver, in the growing pig. Eighteen Large White X Landrace castrated pigs (20 kg body weight) were divided into three groups: I (31 degrees C, ad libitum), II (20 degrees C, pair-fed on the 31 degrees C group) and III (20 degrees C, ad libitum) until 35 kg body weight. At 20 degrees C, the level of feed intake had no effect on stearoyl-CoA-desaturase activity, whatever the tissue (groups II and III). At similar levels of feeding, (groups I and II), the stearoyl-CoA-desaturase activity was lower at 31 degrees C (P < 0.001) than at 20 degrees C, regardless of the tissue, with the exception of the hepatic stearoyl-CoA-desaturase activity, which was similar in all three groups. This reduction of the stearoyl-CoA-desaturase activity at 31 degrees C could be related to a decrease in the monounsaturated fatty acid percentage in all the tissues, in hot conditions. The present results show that changes in fatty acid composition caused by environmental temperature, in the pig, may be attributed at least in part to an alteration in the stearoyl-CoA-desaturase activity.
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Abstract
Desaturation of a fatty acid first involves the enzymatic removal of a hydrogen from a methylene group in an acyl chain, a highly energy-demanding step that requires an activated oxygen intermediate. Two types of desaturases have been identified, one soluble and the other membrane-bound, that have different consensus motifs. Database searching for these motifs reveals that these enzymes belong to two distinct multifunctional classes, each of which includes desaturases, hydroxylases, and epoxidases that act on fatty acids or other substrates. The soluble class has a consensus motif consisting of carboxylates and histidines that coordinate an active site diiron cluster. The integral membrane class contains a different consensus motif composed of histidines. Biochemical and structural similarities between the integral membrane enzymes suggest that this class also uses a diiron cluster for catalysis. Soluble and membrane enzymes have been successfully re-engineered for substrate specificity and reaction outcome. It is anticipated that rational design of these enzymes will result in new and desired activities that may form the basis for improved oil crops.
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Affiliation(s)
- John Shanklin
- Department of Biology, Brookhaven National Laboratory, Upton, New York 11973; e-mail:
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11
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Bouvier F, Keller Y, d'Harlingue A, Camara B. Xanthophyll biosynthesis: molecular and functional characterization of carotenoid hydroxylases from pepper fruits (Capsicum annuum L.). BIOCHIMICA ET BIOPHYSICA ACTA 1998; 1391:320-8. [PMID: 9555077 DOI: 10.1016/s0005-2760(98)00029-0] [Citation(s) in RCA: 75] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
To dissect the mechanism by which carotenoid hydroxylases catalyze xanthophyll formation, we have cloned two pepper cDNAs encoding beta-cryptoxanthin and zeaxanthin biosynthetic enzymes. Using an in vitro system, we find that both enzymes are ferredoxin dependent and that their activity is strongly inhibited by iron chelators such as o-phenanthroline or 8-hydroxyquinoline. This suggests the transfer of a reducing equivalent from NADPH to the hydroxylase via ferredoxin and the involvement of an iron activated oxygen insertion process. Based on sequence analysis, the putative histidine clusters involved in the iron coordination were identified and their roles evaluated. Following site-directed mutagenesis of the identified histidine residues hydroxylase activity was totally inactivated. Collectively, our data indicate that carotenoid hydroxylases belong to a new class of diiron proteins structurally related to membrane fatty acid desaturases. Mechanistically, both types of enzymes exploit iron activated oxygen to break the C-H bond with concomitant formation of double bond or oxygen insertion. We propose that the same mechanism operates for beta-carotene ketolase and probably for other carotenoid oxygenases as well.
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Affiliation(s)
- F Bouvier
- Institut de Biologie Moléculaire des Plantes du Centre, National de la Recherche Scientifique, Université Louis Pasteur, 12 rue du Général Zimmer, 67084 Strasbourg, France
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13
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ERWIN J, HULANICKA D, BLOCH K. COMPARATIVE ASPECTS OF UNSATURATED FATTY ACID SYNTHESIS. ACTA ACUST UNITED AC 1996; 12:191-207. [PMID: 14200721 DOI: 10.1016/0010-406x(64)90174-4] [Citation(s) in RCA: 39] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
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Production of a new compound, 7,10-dihydroxy-8-(E)-octadecenoic acid from oleic acid byPseudomonas sp. PR3. ACTA ACUST UNITED AC 1991. [DOI: 10.1007/bf01576074] [Citation(s) in RCA: 55] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
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17
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Hou CT, Bagby MO, Plattner RD, Koritala S. A novel compound, 7,10-dihydroxy-8(E)-octadecenoic acid from oleic acid by bioconversion. J AM OIL CHEM SOC 1991. [DOI: 10.1007/bf02662326] [Citation(s) in RCA: 56] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
Affiliation(s)
- C. T. Hou
- ; U.S. Department of Agriculture; Northern Regional Research Center, Agricultural Research Service; Peoria IL 61604
| | - M. O. Bagby
- ; U.S. Department of Agriculture; Northern Regional Research Center, Agricultural Research Service; Peoria IL 61604
| | - R. D. Plattner
- ; U.S. Department of Agriculture; Northern Regional Research Center, Agricultural Research Service; Peoria IL 61604
| | - S. Koritala
- ; U.S. Department of Agriculture; Northern Regional Research Center, Agricultural Research Service; Peoria IL 61604
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Abstract
Using yeast microsomes, 23-hydroxysterols were tested as intermediates in the formation of the sterol side delta 22-double bond. No evidence could be found supporting a two-stage mechanism of desaturation via hydroxylation and dehydration. Sterols with various side chains were tested as substrates. Those with alkyl substituents in the 24-alpha position were poor substrates. A series of sterols, including cyclopropyl sterols, were tested as mechanism-based inhibitors without success. Inhibition was observed with an isocyano-sterol.
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Affiliation(s)
- J L Giner
- Department of Chemistry, Stanford University, CA 94305
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19
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Kawashima Y, Uy-Yu N, Kozuka H. Sex-related differences in the enhancing effects of perfluoro-octanoic acid on stearoyl-CoA desaturase and its influence on the acyl composition of phospholipid in rat liver. Comparison with clofibric acid and tiadenol. Biochem J 1989; 263:897-904. [PMID: 2574572 PMCID: PMC1133515 DOI: 10.1042/bj2630897] [Citation(s) in RCA: 40] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
The effects of the peroxisome proliferators clofibric acid (p-chlorophenoxyisobutyric acid), tiadenol [2,2'-(decamethylenedithio)diethanol] and perfluoro-octanoic acid (PFOA) on hepatic stearoyl-CoA desaturation in male and female rats were compared. Treatment of male rats with the three peroxisome proliferators increased markedly the activity of stearoyl-CoA desaturase. Administration of clofibric acid or tiadenol to female rats increased greatly the hepatic activity of stearoyl-CoA desaturase, the extent of the increases being slightly less pronounced than those of male rats. In contrast with the other two peroxisome proliferators, however, PFOA did not change the activity of stearoyl-CoA desaturase in female rats. Hormonal manipulations revealed that this sex-related difference in the effect of PFOA on stearoyl-CoA desaturase activity is strongly dependent on testosterone. The increase in stearoyl-CoA desaturase activity by peroxisome proliferators was not accompanied by any notable increases in the microsomal content of cytochrome b5 or the activity of NADH: cytochrome b5 reductase. The administration of the peroxisome proliferators greatly altered the acyl composition of hepatic phosphatidylcholine and phosphatidylethanolamine (namely the proportions of C18:1 and C20:3,n-9 fatty acids increased in both phospholipids), and the alterations were partially associated with the increase in stearoyl-CoA desaturase activity.
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Affiliation(s)
- Y Kawashima
- Faculty of Pharmaceutical Sciences, Toyama Medical and Pharmaceutical University, Japan
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Croft JE, Harrelson WG, Parandoosh Z, Philpot RM. Unique properties of NADPH- and NADH-dependent metabolism of p-nitroanisole catalyzed by cytochrome P-450 isozyme 2 in pulmonary and hepatic microsomal preparations from rabbits. Chem Biol Interact 1986; 57:143-60. [PMID: 3955788 DOI: 10.1016/0009-2797(86)90034-7] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
Approximately 90% of the NADPH- and NADH-dependent O-demethylation of p-nitroanisole (PNA) in the hepatic microsomal fraction from phenobarbital (PB)-treated rabbits and in the pulmonary microsomal fraction from untreated rabbits is catalyzed by the same isozyme of cytochrome P-450. This isozyme of cytochrome P-450 catalyzes less than 60% of this reaction in the hepatic microsomal fraction from untreated rabbits. Antibodies to NADPH-cytochrome P-450 reductase inhibit NADPH-dependent metabolism of p-nitroanisole by about 90% but have no effect on NADH-dependent metabolism. Hepatic NADPH-dependent metabolism of pNA and reduction of cytochrome c are inhibited to the same extent with varying amounts of antibodies to NADPH cytochrome P-450 reductase. The same relationship between inhibition of monooxygenase and reductase activities is observed for the hepatic and pulmonary metabolism of benzphetamine and 7-ethoxycoumarin. In contrast, the relationship between inhibition of the pulmonary NADPH-dependent metabolism of pNA and reductase activity is biphasic; at 75% inhibition of reductase activity, metabolism of pNA is inhibited by less than 25%. For NADH-dependent metabolism of pNA, our results indicate that both electrons are transferred to cytochrome P-450 from cytochrome b5.
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Effects of transient anaerobic stress on fatty acid desaturation and electron-transport system in Tetrahymena microsomes. ACTA ACUST UNITED AC 1984. [DOI: 10.1016/0005-2760(84)90278-9] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
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22
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Ghesquier D, Carreau JP, Robert JC, Abastado M, Cheret AM, Lewin MJ. Cytochrome b5-dependent delta 9 desaturation of fatty acids in gastric microsomes. BIOCHIMICA ET BIOPHYSICA ACTA 1983; 751:349-54. [PMID: 6849948 DOI: 10.1016/0005-2760(83)90293-x] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Abstract
Stearyl-CoA was shown to stimulate the reoxidation rate of cytochrome b5 of gastric microsomes and to decrease the reduction rate of trypsin-purified hog liver cytochrome b5 by the NADH-cytochrome b5 reductase of these microsomes. This latter effect was (1) proportional to microsome concentration and to stearyl-CoA concentration with an apparent Km of 3.3 . 10(-6) M and a Vmax of 71 nmol per min and per mg microsomal protein, (2) insensitive to ATP and inhibited by 1.4 mM KCN, (3) mimicked by palmityl-CoA but not by stearic nor palmitic acid. Direct assays carried out using [14C]stearyl- and [14C]palmityl-CoA as substrates showed a production of 0.12 nmol of oleic and palmitoleic acid, respectively, per min per mg of microsomal protein. In the presence of Tb5 antibodies the reaction was inhibited by 40%. These results support the occurrence of cytochrome b5-dependent fatty acid delta 9 desaturation in gastric microsomes.
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Fujiwara Y, Okayasu T, Ishibashi T, Imai Y. Immunochemical evidence for the enzymatic difference of delta 6-desaturase from delta 9- and delta 5-desaturase in rat liver microsomes. Biochem Biophys Res Commun 1983; 110:36-41. [PMID: 6404254 DOI: 10.1016/0006-291x(83)91256-1] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
Abstract
The enzymatic properties of the three types of microsomal acyl-CoA desaturases, delta 6-, delta 9- and delta 5-desaturases, were immunologically compared using a monospecific antibody raised against the purified linoleoyl-CoA desaturase (delta 6-desaturase). By the double immunodiffusion technique, the anti-delta 6-desaturase antibody showed a single precipitin line to the purified delta 6-desaturase and microsomes treated with Triton X-100, but no line was observed with the partially purified delta 9-desaturase. The antibody even inhibited definitely delta 6-desaturase activity in microsomes, but neither stearoyl-CoA (delta 9-) nor eicosatrienoic acid (delta 5-) desaturations were inhibited. By these immunological investigations it was confirmed that terminal delta 6-desaturase is different enzyme from desaturases delta 9- and delta 5.
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Shand JH, Noble RC. The characterization of the linoleic acid desaturation and elongation system in ovine placental tissue. THE INTERNATIONAL JOURNAL OF BIOCHEMISTRY 1983; 15:1367-71. [PMID: 6642054 DOI: 10.1016/0020-711x(83)90028-9] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Abstract
The desaturation and elongation of linoleic acid has been studied in homogenates and in subfractions of ovine placental tissue. The reaction was characterized in terms of pH and temperature optima, time course and protein concentration. Activity was found to be confined to the 11,000 g supernatant fraction of the tissue and the results suggest that the enzymes are membrane bound. The cytosolic fraction and ATP were required for full activity and the reaction was inhibited by cyanide. The properties of the reaction are compared with those of other desaturation systems and their implications with regard to possible reaction mechanisms are discussed.
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Yoichi K, Hiroshi K. Increased activity of stearoyl-CoA desaturation in liver from rat fed clofibric acid. ACTA ACUST UNITED AC 1982. [DOI: 10.1016/0005-2760(82)90322-8] [Citation(s) in RCA: 33] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
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Enser M, Roberts JL. The regulation of hepatic stearoyl-coenzyme A desaturase in obese-hyperglycaemic (ob/ob) mice by food intake and the fatty acid composition of the diet. Biochem J 1982; 206:561-70. [PMID: 6128973 PMCID: PMC1158624 DOI: 10.1042/bj2060561] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
Abstract
1. The effects of food intake and the fatty acid composition of the diet on the hepatic stearoyl-CoA desaturase activity of obese-hyperglycaemic (ob/ob) mice were investigated. 2. Obese mice fed on a commercial mouse diet, ad libitum, had 6.5-fold more activity per liver cell than had lean mice. 3. On a diet containing 14% corn oil the activity was 65% less in obese mice and 62% less in lean mice compared with animals fed on the commercial diet. 4. Feeding with 14% saturated fat in the diet doubled the activity in lean mice compared with those on the commercial diet, but had no effect on the activity in obese mice. 5. Obese mice fed on the corn-oil diet contained a higher proportion of linoleic acid in the liver lipids than did lean mice fed on the commercial diet, but the acyl-CoA desaturase activity was 125% higher than in the lean mice. 6. Limiting the food intake of obese mice by pair-feeding with lean mice decreased their acyl-CoA desaturase activity when the animals were fed on the saturated-fat diet, but the activity remained 75% higher than in lean mice, whereas in obese mice pair-fed on the corn-oil diet the activity was the same as in lean mice. 7. During starvation the acyl-CoA desaturase activity in livers from obese mice decreased more slowly and proportionately less than in livers from lean mice. 8. It is concluded that increased substrate supply as a result of hyperphagia and not low concentration of linoleic acid is the main factor causing high acyl-CoA desaturase activity in obese mice.
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Adachi S, Suyama K, Tsuchida J, Danbara H. Effect of breeding bull on the fatty acid composition of the carcass lipid in steers of a beef breed cattle. Meat Sci 1982; 7:139-45. [DOI: 10.1016/0309-1740(82)90079-1] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/1981] [Indexed: 10/27/2022]
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Wang DL, Dillwith JW, Ryan RO, Blomquist GJ, Reitz RC. Characterization of the acyl-CoA desaturase in the housefly, Musca domestica L. ACTA ACUST UNITED AC 1982. [DOI: 10.1016/0020-1790(82)90024-5] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
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Okayasu T, Nagao M, Ishibashi T, Imai Y. Purification and partial characterization of linoleoyl-CoA desaturase from rat liver microsomes. Arch Biochem Biophys 1981; 206:21-8. [PMID: 7212717 DOI: 10.1016/0003-9861(81)90061-8] [Citation(s) in RCA: 111] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
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Kshirsagar SS, Nair PM. Isolation and properties of a particulate fraction for the desaturation of palmitic acid from Alcaligenes faecalis. BIOCHIMICA ET BIOPHYSICA ACTA 1979; 574:369-78. [PMID: 39619 DOI: 10.1016/0005-2760(79)90233-9] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
A particulate fraction obtained from Alcaligenes faecalis could desaturate palmitic acid to palmitoleic acid. NADPH, ATP, CoA, Fe2+ and Mg2+ were essential cofactors for the reaction. The desaturation showed an absolute requirement for O2. Metal ions like Mn2+, Mo6+ and Cu2+ did not affect the desaturation, while Zn2+ was inhibitory. Sulfhydryl agents such as cysteine, glutathione and beta-mercaptoethanol had no effect, but SH-blocking agents like HgCl2 and p-hydroxymercuribenzoate inhibited the reaction. Azide and cyanide strongly inhibited the reaction while CO had no effect. The presence of a b-type cytochrome in the enzyme preparation was confirmed by the spectral studies on the reaction of enzyme with NADPH. Involvement of b-type cytochrome in the desaturation reaction was demonstrated by the reoxidation of b-type cytochrome initially reduced with NADPH, by the addition of palmitic acid and other cofactors. The pH optimum for the enzyme activity was 7.4. The optimum temperature for enzyme activity was 25 degrees C and maximum activity was obtained at the end of 45 min.
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Masayuki O, Ryo S, Yuzo Y, Christian B, Helmut R. Mutant and immunochemical studies on the involvement of cytochrome b5 in fatty acid desaturation by yeast microsomes. ACTA ACUST UNITED AC 1979. [DOI: 10.1016/0005-2760(79)90051-1] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
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Mamer OA, Montgomery JA, Tjoa SS, Crawhall JC, Feldkamp CS. Profiles in altered metabolism I--the organic acids accumulating in acute non-diabetic ketoacidosis associated with alcoholism. BIOMEDICAL MASS SPECTROMETRY 1978; 5:287-90. [PMID: 638235 DOI: 10.1002/bms.1200050403] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
Several organic acids, among them the acidic catabolites of the branched chain amino acids and tyrosine, have been found to be elevated in the sera of non-diabetic patients presenting acute ketoacidosis associated with alcohol abuse. These findings are interpreted in terms of insufficiency of dietary co-factors required for their further catabolism. Butane-2,3-diol is also found frequently elevated in the urine of these patients and suggests interception of hydroxyethyl thiamine pyrophosphate by circulating high levels of acetaldehyde.
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Abstract
The activity of delta9 desaturase was determined in the microsomal fraction of normal mouse liver and hepatoma SS1K in the presence of the 105,000 x g supernatant. Neither hepatic nor hepatoma soluble fractions were able to modify the low desaturating capacity. Two enzymes from the microsomal electron transport chain associated with delta9 desaturase, namely NADH-cytochrom b5 reductase and NADH-cytochrom C reductase were also measured. The results indicate that the low delta9 desaturase activity in hepatoma SS1K could be related to the reduced amount of desaturase.
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Shipiro H, Prescott D, Rabinowitz JL. Preliminary characterization of the delta-9 desaturase of Tetrahymena pyriformis W. COMPARATIVE BIOCHEMISTRY AND PHYSIOLOGY. B, COMPARATIVE BIOCHEMISTRY 1978; 61:513-20. [PMID: 45543 DOI: 10.1016/0305-0491(78)90044-5] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
1. In vitro assay conditions have been defined for measurement of delta 9 desaturase activity in Tetrahymena pyriformis W. 2. The reaction depends on the presence of oxygen and a reduced pyridine nucleotide cofactor. FAD supports a low level of enzymatic activity. 3. Both stearyl-CoA and palmityl-CoA are acceptable substrates. Oleate formation is maximal at 30 degrees C. 4. Delta-9 desaturase activity appears to be localized in the microsomal fraction. Delta-6 and/or delta 12 desaturase activities have also been observed. 5. When the specificity of the delta 9 desaturase towards stearyl-CoA and palmityl-CoA was observed at 30 and 16 degrees C it was found that lowering the assay temperature did not affect specificity. Stearyl-CoA was more readily desaturated at both temperatures. 6. Exogenous oleyl-CoA and diisopropylfluorophosphate had little effect on delta 9 desaturase activity. However, cyanide strongly inhibited desaturation and a sensitivity to sulfhydryl-binding reagents has also been demonstrated.
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Lee TC, Baker RC, Stephens N, Snyder F. Evidence for participation of cytochrome b5 in microsomal delta-6 desaturation of fatty acids. BIOCHIMICA ET BIOPHYSICA ACTA 1977; 489:25-31. [PMID: 410449 DOI: 10.1016/0005-2760(77)90228-4] [Citation(s) in RCA: 33] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
The delta-6 desaturation of linoleic acid to gamma-linolenic acid and oleic acid to 6,9-octadecadienoic acid by rat liver microsomes was investigated. Using a specific antibody prepared against purified rat liver cytochrome b5, we demonstrated that cytochrome b5 participated in delta-6 desaturation of both fatty acids. The reaction products were identified as their methyl ester derivatives by argentation thin-layer chromatography, gas-liquid chromatography, and reductive ozonolysis followed by gas-liquid chromatography.
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Assay for the terminal enzyme of the stearoyl coenzyme A desaturase system using chick embryo liver microsomes. J Lipid Res 1977. [DOI: 10.1016/s0022-2275(20)41711-0] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
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Tamura Y, Yoshida Y, Sato R, Kumaoka H. Fatty acid desaturase system of yeast microsomes. Involvement of cytochrome b5-containing electron-transport chain. Arch Biochem Biophys 1976; 175:284-94. [PMID: 8011 DOI: 10.1016/0003-9861(76)90510-5] [Citation(s) in RCA: 40] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
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Klein HP, Volkmann CM. Factors affecting the palmitoyl-coenzyme A desaturase of Saccharomyces cerevisiae. J Bacteriol 1975; 124:718-23. [PMID: 1102529 PMCID: PMC235959 DOI: 10.1128/jb.124.2.718-723.1975] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022] Open
Abstract
The activity and stability of the palmitoyl-coenzyme A (CoA) desaturase complex of Saccharomyces cerevisiae was influenced by several factors. Cells, grown nonaerobically and then incubated with glucose, either in air or under N2, showed a marked increase in desaturase activity. Cycloheximide, added during such incubations, prevented the increase in activity, suggesting de novo synthesis. The stability of the desaturase from cells grown nonaerobically was affected by subsequent treatment of the cells; enzyme from freshly harvested cells, or from cells that were then shaken under nitrogen, readily lost activity upon washing or during density gradient analysis, whereas aerated cells, in the presence or absence of glucose, yielded stable enzyme preparations. The loss of activity in nonaerobic preparations could be reversed by adding soluble supernatant from these homogenates and could be prevented by growing the cells in the presence of palmitoleic acid and ergosterol, but not with several other lipids tested.
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Role of Cytochrome b5 in Hydroxylation by a Reconstituted Cytochrome P-450-containing System. J Biol Chem 1974. [DOI: 10.1016/s0021-9258(19)42117-0] [Citation(s) in RCA: 97] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
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Wells P, Aftergood L, Alfin-Slater RB, Straus R. Effect of sterculic acid upon aflatoxicosis in rats fed diets containing saturated and unsaturated fat. J AM OIL CHEM SOC 1974; 51:456-60. [PMID: 4413094 DOI: 10.1007/bf02635154] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
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Jaworski JG, Stumpf PK. Fat metabolism in higher plants. Properties of a soluble stearyl-acyl carrier protein desaturase from maturing Carthamus tinctorius. Arch Biochem Biophys 1974; 162:158-65. [PMID: 4831331 DOI: 10.1016/0003-9861(74)90114-3] [Citation(s) in RCA: 96] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
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de Tomas ME, Peluffo RO, Mercuri O. Effect of dietary glycerol on the (I- 14 C)stearic acid and (I- 14 (I- 14 C)linoleic acid desaturation of normal and diabetic rats. BIOCHIMICA ET BIOPHYSICA ACTA 1973; 306:149-55. [PMID: 4268280 DOI: 10.1016/0005-2760(73)90220-8] [Citation(s) in RCA: 21] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
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Ghaneker AS, Nair PM. Evidence for the existence of an aerobic pathway for synthesis of monounsaturated fatty acids by Alcaligenes faecalis. J Bacteriol 1973; 114:618-24. [PMID: 4706190 PMCID: PMC251817 DOI: 10.1128/jb.114.2.618-624.1973] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023] Open
Abstract
Studies on the composition of total fatty acids of Alcaligenes faecalis harvested at different growth phases have been carried out. Ability of the organism to desaturate palmitic and stearic acid has also been tested. The organism contained palmitic (16:0), stearic (18:0), palmitoleic (16:1), cis-vaccenic (18:1), cyclopropane (17: big dn tri, open and 19: big dn tri, open), and three hydroxy acids. Increase in cyclopropane acids and corresponding decrease in monounsaturated acids in direct proportion to the age of the culture were observed, whereas other fatty acids remained relatively unaltered. A growing culture of the organism was found to desaturate [1-(14)C]palmitic acid supplied in the medium to hexadecanoic acid. Resting cells desaturated [1-(14)C]palmitic and [1-(14)C]stearic acid giving rise to about 50% of (14)C in the COOH group of corresponding monounsaturated fatty acids.
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Cook HW, Spence MW. Formation of Monoenoic Fatty Acids by Desaturation in Rat Brain Homogenate. J Biol Chem 1973. [DOI: 10.1016/s0021-9258(19)44259-2] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022] Open
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GILLIS AT, ESKIN NAM, CLIPLEF RL. FATTY ACID COMPOSITION OF BOVINE INTRAMUSCULAR AND SUBCUTANEOUS FAT AS RELATED TO BREED AND SEX. J Food Sci 1973. [DOI: 10.1111/j.1365-2621.1973.tb01441.x] [Citation(s) in RCA: 23] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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