WordNet

having an (over)abundance of flesh; "he hadnt remembered how fat she was"
a soft greasy substance occurring in organic tissue and consisting of a mixture of lipids (mostly triglycerides); "pizza has too much fat"
marked by great fruitfulness; "fertile farmland"; "a fat land"; "a productive vineyard"; "rich soil" (同)fertile, productive, rich
lucrative; "a juicy contract"; "a nice fat job" (同)juicy
having a relatively large diameter; "a fat rope"
street name for lysergic acid diethylamide (同)back breaker, battery-acid, dose, dot, Elvis, loony toons, Lucy in the sky with diamonds, pane, superman, window pane, Zen
any of various water-soluble compounds having a sour taste and capable of turning litmus red and reacting with a base to form a salt
having the characteristics of an acid; "an acid reaction"
containing or composed of fat; "fatty food"; "fat tissue" (同)fat

PrepTutorEJDIC

『脂肪』,脂肪分 / (動物の)あぶら身 / (料理用の)油,ヘット / 肥満,太り過ぎ / 『太った』,肥満した / 『脂肪の多い』 / たっぷりとはいった,分厚い / もうかる / (土地が)肥えた / …‘を'太らせる / ふとる,肥える
酸性の / 酸味のある,すっぱい(sour) / (言葉・態度などが)厳しい,しんらつな / 酸 / すっぱいもの / 《俗》=LSD
脂肪質の,脂肪の多い / でぶ,太っちょ

Wikipedia preview

出典(authority):フリー百科事典『ウィキペディア（Wikipedia）』「2017/07/21 01:47:05」(JST)

wiki en

A fatty acid desaturase is an enzyme that removes two hydrogen atoms from a fatty acid, creating a carbon/carbon double bond. These desaturases are classified as

delta - indicating that the double bond is created at a fixed position from the carboxyl group of a fatty acid (for example, Δ⁹desaturase creates a double bond at the 9th position from the carboxyl end).
omega (e.g. ω³desaturase) - indicating the double bond is created between the third and fourth carbon from the methyl end of the fatty acid.

In the biosynthesis of essential fatty acids, an elongase alternates with different desaturases (for example, Δ⁶desaturase) repeatedly inserting an ethyl group, then forming a double bond.

Function

Maintain structure and function of membranes within cells of the organisms above. This is important when temperatures changes and the membrane is under distress. The enzyme creates the double bond C-Cs which allow the membrane to become more fluid and the temperature is decreased.^[1] When temperatures change, a phase transition occurs. In the case of a temperature decrease, the membrane gels and becomes solid which can result in cracks and the imbedded proteins cannot partake in conformational changes, therefore it is important to maintain membrane fluidity.^[2]

Role in human metabolism

Fatty acid desaturase appear in all organisms: for example, bacteria fungus plants animals and humans.^[1] Four desaturases occur in humans: Δ⁹ desaturase, Δ⁶ desaturase, Δ⁵ desaturase, and Δ⁴ desaturase.

Δ⁹ desaturase, also known as stearoyl-CoA desaturase-1, is used to synthesize oleic acid, a monounsaturated, ubiquitous component of all cells in the human body. Δ⁹ desaturase produces oleic acid by desaturating stearic acid, a saturated fatty acid either synthesized in the body from palmitic acid or ingested directly.

Δ⁶ and Δ⁵ desaturases are required for the synthesis of highly unsaturated fatty acids such as eicosopentaenoic and docosahexaenoic acids (synthesized from α-linolenic acid), and arachidonic acid (synthesized from linoleic acid). This is a multi-stage process requiring successive actions by elongase and desaturase enzymes. The genes coding for Δ⁶ and Δ⁵ desaturase production have been located on human chromosome 11.

Human fatty acid desaturases:

DEGS1; DEGS2; FADS1; FADS2; FADS3; FADS6; SCD4; SCD5

Vertebrates are unable to synthesize polyunsaturated fatty acids because they do not have the necessary fatty acid desaturases to "convert oleic acid (18:1n-9) into linoleic acid (18:2n-6) and α-linolenic acid".^[3] These polyunsaturated fatty acids are important for ideal health within humans and are essential for development. By creating desaturations at the Δ6 and Δ5 positions in the carbon backbone with the addition of an elongation allows the process of linoleic acid to achidonic acid and from α-linolenic acid to eicosapentaenoic acid to partake.^[3]

Classification

Δ-desaturases are represented by two distinct families which do not seem to be evolutionarily related.

Family 1 includes Stearoyl-CoA desaturase-1 (SCD) (EC 1.14.19.1).^[4]

Family 2 is composed of:

- Bacterial fatty acid desaturases.
- Plant stearoyl-acyl-carrier-protein desaturase (EC 1.14.19.1),^[5] this enzyme catalyzes the introduction of a double bond at the delta(9) position of steraoyl-ACP to produce oleoyl-ACP. This enzyme is responsible for the conversion of saturated fatty acids to unsaturated fatty acids in the synthesis of vegetable oils.
- Cyanobacterial DesA,^[6] an enzyme that can introduce a second cis double bond at the delta(12) position of fatty acid bound to membranes glycerolipids. DesA is involved in chilling tolerance; the phase transition temperature of lipids of cellular membranes being dependent on the degree of unsaturation of fatty acids of the membrane lipids.

Related Research

Kodama et al. (1994) found that an increased amount of trienoic fatty acids allow plants to become more tolerant to cold temperatures.^[7] These trienoic fatty acids are associated with plant response to cold temperatures and allows the plant to adjust. They determined that transgenic tobacco plants that contained a fatty acid desaturase gene were able to tolerate low temperatures better than wild-type plants.^[7]

The yeast Saccharomyces cerevisiae has only a single Δ9 fatty acid desaturase encoded by the gene OLE1.^[8]

References

^ ^a ^b Los, Dmitry A.; Murata, Norio (1998-10-02). "Structure and expression of fatty acid desaturases". Biochimica et Biophysica Acta (BBA) - Lipids and Lipid Metabolism. 1394 (1): 3–15. PMID 9767077. doi:10.1016/S0005-2760(98)00091-5.
^ Alberts, Bruce (2015). Molecular Biology of the Cell. New York: Garland Science. p. 571. ISBN 978-0-8153-4453-7.
^ ^a ^b Hastings, Nicola; Agaba, Morris; Tocher, Douglas R.; Leaver, Michael J.; Dick, James R.; Sargent, John R.; Teale, Alan J. (2001-12-04). "A vertebrate fatty acid desaturase with Δ5 and Δ6 activities". Proceedings of the National Academy of Sciences. 98 (25): 14304–14309. ISSN 0027-8424. PMC 64677 . PMID 11724940. doi:10.1073/pnas.251516598.
^ Lane MD, Ntambi JM, Kaestner KH, Kelly Jr TJ (1989). "Differentiation-induced gene expression in 3T3-L1 preadipocytes. A second differentially expressed gene encoding stearoyl-CoA desaturase". J. Biol. Chem. 264 (25): 14755–14761. PMID 2570068.
^ Shanklin J, Somerville C (1991). "Stearoyl-acyl-carrier-protein desaturase from higher plants is structurally unrelated to the animal and fungal homologs". Proc. Natl. Acad. Sci. U.S.A. 88 (6): 2510–2514. PMC 51262 . PMID 2006187. doi:10.1073/pnas.88.6.2510.
^ Wada H, Gombos Z, Murata N (1990). "Enhancement of chilling tolerance of a cyanobacterium by genetic manipulation of fatty acid desaturation". Nature. 347 (6289): 200–203. PMID 2118597. doi:10.1038/347200a0.
^ ^a ^b Kodama, H.; Hamada, T.; Horiguchi, G.; Nishimura, M.; Iba, K. (1994-06-01). "Genetic Enhancement of Cold Tolerance by Expression of a Gene for Chloroplast [omega]-3 Fatty Acid Desaturase in Transgenic Tobacco". Plant Physiology. 105 (2): 601–605. ISSN 1532-2548. PMC 159399 . PMID 12232227. doi:10.1104/pp.105.2.601.
^ Stukey, Joseph; McDonough, Virginia; Martin, Charles (1989). "Isolation and characterization of OLE1, a gene affecting fatty acid desaturation from Saccharomyces cerevisiae.". J. Biol. Chem. 264 (28): 16537–44. PMID 2674136.

Nakamura MT, Nara TY (2004). "Structure, function and dietary regulation of Δ6, Δ5 and Δ9 desaturases". Annual Review of Nutrition. 24 (1): 345–76. PMID 15189125. doi:10.1146/annurev.nutr.24.121803.063211.

This article incorporates text from the public domain Pfam and InterPro IPR005067

UpToDate Contents

全文を閲覧するには購読必要です。 To read the full text you will need to subscribe.

1. 早産児および正期産児のn-3長鎖不飽和脂肪酸（LCPUFA） n 3 long chain polyunsaturated fatty acids lcpufa for preterm and term infants
2. 乳児および小児における低血糖に対するアプローチ approach to hypoglycemia in infants and children
3. 魚油と海洋由来オメガ3脂肪酸 fish oil and marine omega 3 fatty acids
4. 食事中の脂肪 dietary fat
5. 成人における非アルコール性脂肪肝疾患の自然経過およびマネージメント natural history and management of nonalcoholic fatty liver disease in adults

English Journal

Candidate gene marker associations with fatty acid profiles in heavy pigs.

Renaville B, Prandi A, Fan B, Sepulcri A, Rothschild MF, Piasentier E.SourceVeterinary Physiology and Nutrition Lab, Department of Food Science, University of Udine, Italy. Electronic address: benedicte.renaville@uniud.it.
Meat science.Meat Sci.2013 Mar;93(3):495-500. doi: 10.1016/j.meatsci.2012.11.019. Epub 2012 Nov 15.
Heavy pigs are used in Italy to produce fresh meat, dry-cured ham, salami and lard. Fatty acid profile determines both the dietary and organoleptic qualities of these products. The objective was to study the polymorphisms of two genes that code for enzymes of the fatty acid metabolism, namely, Stear
PMID 23273456

Association analyses of DNA polymorphisms in bovine SREBP-1, LXRα, FADS1 genes with fatty acid composition in Canadian commercial crossbred beef steers.

Han C, Vinsky M, Aldai N, Dugan ME, McAllister TA, Li C.SourceCollege of Animal science, Tarim University, Alar, Xinjiang, 843300, China; Agriculture and Agri-Food Canada, Lacombe Research Centre, 6000 C&E Trail, Lacombe, Alberta, Canada T4L 1W1.
Meat science.Meat Sci.2013 Mar;93(3):429-36. doi: 10.1016/j.meatsci.2012.10.006. Epub 2012 Nov 9.
Two previously reported DNA polymorphisms of sterol regulatory element binding transcription factor 1 (SREBP-1) and liver X receptor alpha (LXRα) and two DNA polymorphisms of fatty acid desaturase 1 (FADS1) were evaluated for associations with fatty acids in brisket adipose tissue of Canadian cross
PMID 23273446

Japanese Journal

Jacaric Acid, a Linolenic Acid Isomer with a Conjugated Triene System, Reduces Stearoyl-CoA Desaturase Expression in Liver of Mice

Shinohara Nahoko,Ito Junya,Tsuduki Tsuyoshi [他]
Journal of Oleo Science 61(8), 433-441, 2012-08
NAID 40019348697

Increased Stearoyl-CoA Desaturase Index and Triglyceride Content in the Liver of Rats after a Single Bout of Swimming Exercise

OCHIAI Masaru,MATSUO Tatsuhiro
Bioscience, biotechnology, and biochemistry 76(7), 1350-1355, 2012-07-23
NAID 10030982101

Related Pictures

★リンクテーブル★

リンク元	「脂肪酸不飽和化酵素」「脂肪酸デサチュラーゼ」
関連記事	「fatty」「desaturase」「fat」

「脂肪酸不飽和化酵素」

Fatty acid desaturase, type 2
Identifiers
Symbol	Fatty_acid_desaturase-2
Pfam	PF03405
InterPro	IPR005067
Available protein structures:
Pfam	structures
PDB	RCSB PDB; PDBe; PDBj
PDBsum	structure summary

Available protein structures:
Pfam	structures
PDB	RCSB PDB; PDBe; PDBj
PDBsum	structure summary

Fatty acid desaturase, type 1
Identifiers
Symbol	Fatty_acid_desaturase-1
Pfam	PF00487
InterPro	IPR005804
Available protein structures:
Pfam	structures
PDB	RCSB PDB; PDBe; PDBj
PDBsum	structure summary