scholarly journals Substrate specificity and preference of Δ6-desaturase ofMucor rouxii

FEBS Letters ◽  
2005 ◽  
Vol 579 (12) ◽  
pp. 2744-2748 ◽  
Author(s):  
Sutthicha Na-Ranong ◽  
Kobkul Laoteng ◽  
Prasat Kittakoop ◽  
Morakot Tantichareon ◽  
Supapon Cheevadhanarak
Keyword(s):  
Substrate Specificity ◽  
Δ6 Desaturase

scholarly journals Plastidic Δ6 fatty-acid desaturases with distinctive substrate specificity regulate the pool of c18-pufas in the ancestral picoalga ostreococcus tauri

2020 ◽  
Author(s):  
Charlotte Degraeve-Guilbault C. ◽  
Rodrigo E. Gomez ◽  
Cécile. Lemoigne ◽  
Nattiwong Pankansem ◽  
Soizic Morin ◽  
...  
Keyword(s):  
Substrate Specificity ◽  
Acyl Chain ◽  
Cytochrome B5 ◽  
Head Group ◽  
Fatty Acid Desaturases ◽  
Physiological Alterations ◽  
Lipid Head Group ◽  
Species Specific ◽  
Native Host ◽  
Δ6 Desaturase

ABSTRACTEukaryotic Δ6-desaturases are microsomal enzymes which balance the synthesis of ω-3 and ω-6 C18-polyunsaturated-fatty-acids (PUFA) accordingly to their specificity. In several microalgae, including O. tauri, plastidic C18-PUFA are specifically regulated by environmental cues suggesting an autonomous control of Δ6-desaturation of plastidic PUFA. Sequence retrieval from O. tauri desaturases, highlighted two putative Δ6/Δ8-desaturases sequences clustering, with other microalgal homologs, apart from other characterized Δ-6 desaturases. Their overexpression in heterologous hosts, including N. benthamiana and Synechocystis, unveiled their Δ6-desaturation activity and plastid localization. O. tauri lines overexpressing these Δ6-desaturases no longer adjusted their plastidic C18-PUFA amount under phosphate starvation but didn’t show any obvious physiological alterations. Detailed lipid analyses from the various overexpressing hosts, unravelled that the substrate features involved in the Δ6-desaturase specificity importantly involved the lipid head-group and likely the non-substrate acyl-chain, in addition to the overall preference for the ω-class of the substrate acyl-chain. The most active desaturase displayed a broad range substrate specificity for plastidic lipids and a preference for ω-3 substrates, while the other was selective for ω-6 substrates, phosphatidylglycerol and 16:4-galactolipid species specific to the native host. The distribution of plastidial Δ6-desaturase products in eukaryotic hosts suggested the occurrence of C18-PUFA export from the plastid.One sentence summaryOsteococcus tauri plastidic lipid C18-PUFA remodelling involves two plastid-located cytochrome-b5 fused Δ6-desaturases with distinct preferences for both head-group and acyl-chain.

Functional characterization and substrate specificity analysis of Δ6-desaturase from marine microalga Isochrysis sp.

2017 ◽  
Vol 40 (3) ◽  
pp. 577-584 ◽  
Author(s):  
S. Thiyagarajan ◽  
M. Arumugam ◽  
N. Senthil ◽  
S. Vellaikumar ◽  
S. Kathiresan
Keyword(s):  
Substrate Specificity ◽  
Functional Characterization ◽  
Marine Microalga ◽  
Δ6 Desaturase

scholarly journals Consensus Mutagenesis and Ancestral Reconstruction Provide Insight into the Substrate Specificity and Evolution of the Front-End Δ6-Desaturase Family

Biochemistry ◽  
2020 ◽  
Vol 59 (14) ◽  
pp. 1398-1409 ◽  
Author(s):  
Dongdi Li ◽  
Adam M. Damry ◽  
James R. Petrie ◽  
Thomas Vanhercke ◽  
Surinder P. Singh ◽  
...  
Keyword(s):  
Substrate Specificity ◽  
Ancestral Reconstruction ◽  
Front End ◽  
Insight Into ◽  
Δ6 Desaturase

scholarly journals Consensus mutagenesis and ancestral reconstruction provide insight into the substrate specificity and evolution of the front-end Δ6-desaturase family

2020 ◽  
Author(s):  
Dongdi Li ◽  
Adam M. Damry ◽  
James R. Petrie ◽  
Thomas Vanhercke ◽  
Surinder P. Singh ◽  
...  
Keyword(s):  
Fatty Acids ◽  
Substrate Specificity ◽  
Marine Algae ◽  
Cytochrome B5 ◽  
Structural Basis ◽  
Ancestral Reconstruction ◽  
Micromonas Pusilla ◽  
Ancestral Protein ◽  
Δ6 Desaturase

ABSTRACTMarine algae are a major source of omega (ω)-3 long-chain polyunsaturated fatty acids (ω3-LCPUFAs), which are conditionally essential nutrients in humans and a target for industrial production. The biosynthesis of these molecules in marine algae begins with the desaturation of fatty acids by Δ6-desaturases and enzymes from different species display a range of specificities towards ω3 and ω6 LCPUFAs. In the absence of a molecular structure, the structural basis for the variable substrate specificity of Δ6-desaturases is poorly understood. Here we have conducted a consensus mutagenesis and ancestral protein reconstruction-based analysis of the Δ6-desaturase family, focusing on the ω3-specific Δ6-desaturase from Micromonas pusilla (MpΔ6des) and the bispecific (ω3/ω6) Δ6-desaturase from Ostreococcus tauri (OtΔ6des). Our characterization of consensus amino acid substitutions in MpΔ6des revealed that residues in diverse regions of the protein, such as the N-terminal cytochrome b5 domain, can make important contributions to determining substrate specificity. Ancestral protein reconstruction also suggests that some extant Δ6-desaturases, such as OtΔ6des, could have adapted to different environmental conditions by losing specificity for ω3-LCPUFAs. This dataset provides a map of regions within Δ6-desaturases that contribute to substrate specificity and could facilitate future attempts to engineer these proteins for use in biotechnology.

Substrate specificity and inducibility of TACE (tumour necrosis factor α-converting enzyme) revisited: the Ala-Val preference, and induced intrinsic activity

2003 ◽  
Vol 70 ◽  
pp. 39-52 ◽  
Author(s):  
Roy A. Black ◽  
John R. Doedens ◽  
Rajeev Mahimkar ◽  
Richard Johnson ◽  
Lin Guo ◽  
...  
Keyword(s):  
Substrate Specificity ◽  
Recent Work ◽  
Tumour Necrosis Factor ◽  
Tumour Necrosis ◽  
Transforming Growth Factor ◽  
Intrinsic Activity ◽  
Converting Enzyme ◽  
Tumour Necrosis Factor Α ◽  
Factor Α ◽  
Necrosis Factor

Tumour necrosis factor α (TNFα)-converting enzyme (TACE/ADAM-17, where ADAM stands for a disintegrin and metalloproteinase) releases from the cell surface the extracellular domains of TNF and several other proteins. Previous studies have found that, while purified TACE preferentially cleaves peptides representing the processing sites in TNF and transforming growth factor α, the cellular enzyme nonetheless also sheds proteins with divergent cleavage sites very efficiently. More recent work, identifying the cleavage site in the p75 TNF receptor, quantifying the susceptibility of additional peptides to cleavage by TACE and identifying additional protein substrates, underlines the complexity of TACE-substrate interactions. In addition to substrate specificity, the mechanism underlying the increased rate of shedding caused by agents that activate cells remains poorly understood. Recent work in this area, utilizing a peptide substrate as a probe for cellular TACE activity, indicates that the intrinsic activity of the enzyme is somehow increased.

Substrate Specificity of Leukocyte and Platelet Elastases

1978 ◽  
Vol 39 (03) ◽  
pp. 785-786 ◽  
Author(s):  
Y Legrand ◽  
J Caen ◽  
L Robert
Keyword(s):  
Substrate Specificity

PRKACA mutations in adrenal Cushing can alter substrate specificity

2017 ◽  
Author(s):  
Kerstin Bathon ◽  
Isabel Weigand ◽  
Jens T Vanselow ◽  
Cristina L Ronchi ◽  
Dalmazi Guido Di ◽  
...  
Keyword(s):  
Substrate Specificity

Human Neuraminidases Have Reduced Activity Towards Modified Sialic Acids on Glycoproteins

2020 ◽  
Author(s):  
Carmanah D. Hunter ◽  
Elizabeth Porter ◽  
Christopher Cairo
Keyword(s):  
Substrate Specificity ◽  
General Trend ◽  
Sialic Acids ◽  
Enzyme Specificity ◽  
Naturally Occurring ◽  
Bovine Submaxillary Mucin ◽  
Reduced Activity

This work investigated the substrate specificity of hNEU enzymes for a glycoprotein substrate (bovine submaxillary mucin) containing 9-<i>O</i>-acetylated and Neu5Gc residues. Using this model substrate, we observe a general trend for hNEU tolerance of Neu5Ac>Neu5Gc>>>Neu5,9Ac<sub>2</sub>, consistent with our previous results with glycolipid substrates. These results expand our understanding of hNEU enzyme specificity and suggest that naturally occurring modifications of sialic acids can play a role in regulating hNEU activity.

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