Delta or Omega? Δ12 (ω6) fatty acid desaturases count 3C after the pre-existing double bond

Biochimie ◽  
2020 ◽  
Vol 179 ◽  
pp. 46-53
Author(s):  
Alexander Y. Starikov ◽  
Roman A. Sidorov ◽  
Kirill S. Mironov ◽  
Sergei V. Goriainov ◽  
Dmitry A. Los
Keyword(s):  
Fatty Acid ◽  
Double Bond ◽  
Fatty Acid Desaturases

scholarly journals Functional Characterization of Desaturases Involved in the Formation of the Terminal Double Bond of an Unusual 16:3Δ9, 12, 15 Fatty Acid Isolated from Sorghum bicolor Root Hairs

2006 ◽  
Vol 282 (7) ◽  
pp. 4326-4335 ◽  
Author(s):  
Zhiqiang Pan ◽  
Agnes M. Rimando ◽  
Scott R. Baerson ◽  
Mark Fishbein ◽  
Stephen O. Duke
Keyword(s):  
Fatty Acid ◽  
Double Bond ◽  
Sorghum Bicolor ◽  
Expressed Sequence Tag ◽  
Functional Characterization ◽  
Root Hairs ◽  
Fatty Acyl ◽  
Aliphatic Chain ◽  
Fatty Acid Desaturases ◽  
Terminal Double Bond

Sorgoleone, produced in root hair cells of sorghum (Sorghum bicolor), is likely responsible for much of the allelopathic properties of sorghum root exudates against broadleaf and grass weeds. Previous studies suggest that the biosynthetic pathway of this compound initiates with the synthesis of an unusual 16:3 fatty acid possessing a terminal double bond. The corresponding fatty acyl-CoA serves as a starter unit for polyketide synthases, resulting in the formation of 5-pentadecatrienyl resorcinol. This resorcinolic intermediate is then methylated by an S-adenosylmethionine-dependent O-methyltransferase and subsequently dihydroxylated, yielding the reduced (hydroquinone) form of sorgoleone. To characterize the corresponding enzymes responsible for the biosynthesis of the 16:3 fatty acyl-CoA precursor, we identified and cloned three putative fatty acid desaturases, designated SbDES1, SbDES2, and SbDES3, from an expressed sequence tag (EST) data base prepared from isolated root hairs. Quantitative real-time RT-PCR analyses revealed that these three genes were preferentially expressed in sorghum root hairs where the 16:2 and 16:3 fatty acids were exclusively localized. Heterologous expression of the cDNAs in Saccharomyces cerevisiae revealed that recombinant SbDES2 converted palmitoleic acid (16:1Δ9) to hexadecadienoic acid (16:2Δ9,12), and that recombinant SbDES3 was capable of converting hexadecadienoic acid into hexadecatrienoic acid (16:3Δ9,12,15). Unlike other desaturases reported to date, the double bond introduced by SbDES3 occurred between carbons 15 and 16 resulting in a terminal double bond aliphatic chain. Collectively, the present results strongly suggest that these fatty acid desaturases represent key enzymes involved in the biosynthesis of the allelochemical sorgoleone.

TRIGLYCERIDE COMPOSITION OF SIXTEEN STRAINS OF MARINE DIATOM

2013 ◽  
Vol 5 (1) ◽  
Author(s):  
Lily M.G. Panggabean ◽  
Abdullah Rasyid ◽  
Zarrah Duniani ◽  
Yana Meliana ◽  
Indah Kurniasih
Keyword(s):  
Mass Spectrometry ◽  
Fatty Acid ◽  
Double Bond ◽  
Unsaturated Fatty Acid ◽  
Ion Trap ◽  
Carbon Chain ◽  
Highly Unsaturated Fatty Acid ◽  
Marine Diatom ◽  
Ion Trap Mass Spectrometry ◽  
Spectra Analysis

Trigliceride or triacylglicerol (TAG) composition in crude oil of sixteen strain of marine diatom has been detected by spectra analyses on an Electrospray - Ion Trap – Mass Spectrometry (ESI-IT-MS) HCT Bruker-Daltonic GmbH instrument with AgNO3 used as coordination ionization agent. Biomass samples of each microalga strain were taken from early and late stationary cultures in f/2 enriched seawater and algal oils were extracted according to Bligh and Dyer. Results from spectra analysis showed that P-Pt-P (C16:0-C16:1-C16:0) were distinguished in TAG from diatom strains Chaetoceros sp.1, Chaetoceros sp.2, Thalasiossira sp.1, Thalasiossira sp.2, Thalasiossira sp.3, Navicula sp. 1, Navicula sp. 2, Navicula sp. 3, Navicula sp. 4, Nitzschia sp. 2 and Amphora sp. In contrast, TAGs in Melosira sp. included P-P-P (C16:0-C16:0-C16:0) and P-P-O (C16:0-C16:0-C18:1) were identified. TAGs from Chaetoceros sp. were the most varies among samples, i.e. P-Pt-P (C16:0-C16:1-C16:0), A-P-M (C20:4-C16:0-C14:0), P-Pt-Lt (C16:0-C16:1-C18:3), P-Pt-A (C16:0-C16:1-C20:4), D-P-P (C22:6-C16:0-C16:0), A-Ln-P (C20:4-C18:2-C16:0). Various TAGs were also detected in Nitzschia sp.2, i.e. P-Pt-M (C16:0-C16:1-C14:0), P-Pt-P (C16:0-C16:1-C16:0), P-Pt-S (C16:0-C16:1-C18:0), P-Pt-A (C16:0-C16:1-C20:4). TAGs composition in Skeletonema strains that similar to those in Nitzschia sp.1 has longer carbon, i.e. P-P-O (C16:0-C16:0-C18:1), P-O-O (C16:0-C18:1-C18:1) and O-O-O (C18:1-C18:1-C18:1). TAGs with longer carbon chain and more double bond including highly unsaturated fatty acid C20:4 were increased with culture age in diatoms Chaetoceros sp.1, Chaetoceros sp.2, Thalasiossira sp.2, Navicula sp.1 and Nitzschia sp. 2.Keywords: diatom, TAG, ESI-IT-MS, f/2, early and late stationary

Presence or absence? Primary structure, regioselectivity and evolution of Δ12/ω3 fatty acid desaturases in nematodes

2019 ◽  
Vol 1864 (9) ◽  
pp. 1194-1205 ◽  
Author(s):  
Ralph Menzel ◽  
Henrik von Chrzanowski ◽  
Tina Tonat ◽  
Kristina van Riswyck ◽  
Patrick Schliesser ◽  
...  
Keyword(s):  
Fatty Acid ◽  
Primary Structure ◽  
Fatty Acid Desaturases

ChemInform Abstract: Synthesis of Inhibitors of Fatty Acid Desaturases

ChemInform ◽  
2010 ◽  
Vol 28 (13) ◽  
pp. no-no
Author(s):  
J. R. AL DULAYYMI ◽  
M. S. BAIRD ◽  
C. M. DALE ◽  
B. GREHAN ◽  
M. F. SHORTT ◽  
...  
Keyword(s):  
Fatty Acid ◽  
Fatty Acid Desaturases

Saccharomyces kluyveri FAD3 encodes an ω3 fatty acid desaturase

Microbiology ◽  
2004 ◽  
Vol 150 (6) ◽  
pp. 1983-1990 ◽  
Author(s):  
Takahiro Oura ◽  
Susumu Kajiwara
Keyword(s):  
Fatty Acids ◽  
Fatty Acid ◽  
Linoleic Acid ◽  
Linolenic Acid ◽  
Functional Characterization ◽  
Fatty Acid Desaturase ◽  
Fatty Acid Desaturases ◽  
Desaturase Gene ◽  
Saccharomyces Kluyveri ◽  
Fatty Acid Desaturase Gene

Fungi, like plants, are capable of producing the 18-carbon polyunsaturated fatty acids linoleic acid and α-linolenic acid. These fatty acids are synthesized by catalytic reactions of Δ12 and ω3 fatty acid desaturases. This paper describes the first cloning and functional characterization of a yeast ω3 fatty acid desaturase gene. The deduced protein encoded by the Saccharomyces kluyveri FAD3 gene (Sk-FAD3) consists of 419 amino acids, and shows 30–60 % identity with Δ12 fatty acid desaturases of several eukaryotic organisms and 29–31 % identity with ω3 fatty acid desaturases of animals and plants. During Sk-FAD3 expression in Saccharomyces cerevisiae, α-linolenic acid accumulated only when linoleic acid was added to the culture medium. The disruption of Sk-FAD3 led to the disappearance of α-linolenic acid in S. kluyveri. These findings suggest that Sk-FAD3 is the only ω3 fatty acid desaturase gene in this yeast. Furthermore, transcriptional expression of Sk-FAD3 appears to be regulated by low-temperature stress in a manner different from the other fatty acid desaturase genes in S. kluyveri.

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