Browse
Submit Data
Databases
API
Help

Dataset Information

0 Views

0 Connections

0 Citations

0 Reanalyses

0 Downloads

Omics score: 0

Monohydroxylated fatty acid substrate specificity of human leukocyte 5-lipoxygenase and omega-hydroxylase.

ABSTRACT: Various monohydroxylated fatty acids were synthesized from eicosapolyenoic acids, namely arachidonic (20:4 omega-6), timnodonic (20:5 omega-3), dihomogammalinolenic (20:3 omega-6) and mead (20:3 omega-9) acids. 12-Hydroxy derivatives, as well as 12-hydroxy-5,8,10-heptadecatrienoic acid (HHT), were produced with platelets as the enzyme source, and 15-hydroxy derivatives were produced by soya bean lipoxygenase treatment. Each monohydroxylated fatty acid was incubated with human leukocytes in the presence or absence of the calcium ionophore A23187, and dihydroxylated products were analysed by h.p.l.c. 12-Hydroxy derivatives of 20:4 omega-6, 20:5 omega-3 and 20:3 omega-9 were similarly oxygenated by both the 5-lipoxygenase and the omega-hydroxylase. As expected, the 12-hydroxy derivative of 20:3 omega-6 was not a substrate for 5-lipoxygenase, but surprisingly, omega-6 oxygenated products, like 15-OH-20:4 or HHT, were not converted by the enzyme, although being potential substrates because of the presence of two double bonds at C-5 and C-8. omega-6 oxygenated derivatives were also poorly converted by leukotriene B4 omega-hydroxylase, a cytochrome P-450-dependent enzyme. It is concluded that both leukocyte 5-lipoxygenase and omega-hydroxylase exhibit a substrate specificity towards monohydroxylated fatty acids with respect to their double bonds and/or the carbon position of the alcohol function.

SUBMITTER: Guichardant M

PROVIDER: S-EPMC1135498 | biostudies-other | 1988 Dec

REPOSITORIES: biostudies-other

ACCESS DATA

Json Xml

Similar Datasets

Substrate specificity effects of lipoxygenase products and inhibitors on soybean lipoxygenase-1.

Project description:Recently, it has been shown that lipoxygenase (LO) products affect the substrate specificity of human 15-LO. In the current paper, we demonstrate that soybean LO-1 (sLO-1) is not affected by its own products, however, inhibitors which bind the allosteric site, oleyl sulfate (OS) and palmitoleyl sulfate (PS), not only lower catalytic activity, but also change the substrate specificity, by increasing the arachidonic acid (AA)/linoleic acid (LA) ratio to 4.8 and 4.0, respectively. The fact that LO inhibitors can lower activity and also change the LO product ratio is a new concept in lipoxygenase inhibition, where the goal is to not only reduce the catalytic activity but also alter substrate selectivity towards a physiologically beneficial product.

| S-EPMC2737062 | biostudies-literature

The Arabidopsis cytochrome P450 CYP86A1 encodes a fatty acid omega-hydroxylase involved in suberin monomer biosynthesis.

Project description:The lipophilic biopolyester suberin forms important boundaries to protect the plant from its surrounding environment or to separate different tissues within the plant. In roots, suberin can be found in the cell walls of the endodermis and the hypodermis or periderm. Apoplastic barriers composed of suberin accomplish the challenge to restrict water and nutrient loss and prevent the invasion of pathogens. Despite the physiological importance of suberin and the knowledge of the suberin composition of many plants, very little is known about its biosynthesis and the genes involved. Here, a detailed analysis of the Arabidopsis aliphatic suberin in roots at different developmental stages is presented. This study demonstrates some variability in suberin amount and composition along the root axis and indicates the importance of omega-hydroxylation for suberin biosynthesis. Using reverse genetics, the cytochrome P450 fatty acid omega-hydroxylase CYP86A1 (At5g58860) has been identified as a key enzyme for aliphatic root suberin biosynthesis in Arabidopsis. The corresponding horst mutants show a substantial reduction in omega-hydroxyacids with a chain length <C(20), demonstrating that CYP86A1 functions as a hydroxylase of root suberized tissue. Detailed expression studies revealed a strong root specificity and a localized expression in the root endodermis. Transgenic expression of CYP86A1 fused to GFP distributed CYP86A1 to the endoplasmic reticulum, indicating that suberin monomer biosynthesis takes place in this sub-cellular compartment before intermediates are exported in the apoplast.

| S-EPMC2423664 | biostudies-literature

Classification and substrate head-group specificity of membrane fatty acid desaturases.

Project description:Membrane fatty acid desaturases are a diverse superfamily of enzymes that catalyze the introduction of double bonds into fatty acids. They are essential in a range of metabolic processes, such as the production of omega-3 fatty acids. However, our structure-function understanding of this superfamily is still developing and their range of activities and substrate specificities are broad, and often overlapping, which has made their systematic characterization challenging. A central issue with characterizing these proteins has been the lack of a structural model, which has been overcome with the recent publication of the crystal structures of two mammalian fatty acid desaturases. In this work, we have used sequence similarity networks to investigate the similarity among over 5000 related membrane fatty acid desaturase sequences, leading to a detailed classification of the superfamily, families and subfamilies with regard to their function and substrate head-group specificity. This work will facilitate rapid prediction of the function and specificity of new and existing sequences, as well as forming a basis for future efforts to manipulate the substrate specificity of these proteins for biotechnology applications.

| S-EPMC5037126 | biostudies-literature

Dietary omega-6 fatty acid lowering increases bioavailability of omega-3 polyunsaturated fatty acids in human plasma lipid pools.

Project description:BackgroundDietary linoleic acid (LA, 18:2n-6) lowering in rats reduces n-6 polyunsaturated fatty acid (PUFA) plasma concentrations and increases n-3 PUFA (eicosapentaenoic (EPA) and docosahexaenoic acid (DHA)) concentrations.ObjectiveTo evaluate the extent to which 12 weeks of dietary n-6 PUFA lowering, with or without increased dietary n-3 PUFAs, alters unesterified and esterified plasma n-6 and n-3 PUFA concentrations in subjects with chronic headache.DesignSecondary analysis of a randomized trial. Subjects with chronic headache were randomized for 12 weeks to (1) average n-3, low n-6 (L6) diet; or (2) high n-3, low n-6 LA (H3-L6) diet. Esterified and unesterified plasma fatty acids were quantified at baseline (0 weeks) and after 12 weeks on a diet.ResultsCompared to baseline, the L6 diet reduced esterified plasma LA and increased esterified n-3 PUFA concentrations (nmol/ml), but did not significantly change plasma arachidonic acid (AA, 20:4n-6) concentration. In addition, unesterified EPA concentration was increased significantly among unesterified fatty acids. The H3-L6 diet decreased esterified LA and AA concentrations, and produced more marked increases in esterified and unesterified n-3 PUFA concentrations.ConclusionDietary n-6 PUFA lowering for 12 weeks significantly reduces LA and increases n-3 PUFA concentrations in plasma, without altering plasma AA concentration. A concurrent increase in dietary n-3 PUFAs for 12 weeks further increases n-3 PUFA plasma concentrations and reduces AA.

| S-EPMC4035030 | biostudies-literature

Nutrigenomic response to Omega-3 fatty acid in human primary hepatocytes

Project description:Primary human hepatocytes were treated with 200µM DHA/EPA/OA or vehicle(ethanol) for 16 hours before cells were harvested for RNA extraction. Total RNA was isolated from primary human hepatocytes using KingFisher PURE RNA tissue Kit. The eluted RNA was subjected for strand specific sequencing libraries construction with illumina TruSeq RNA sample Prep Kit and subsequently sequenced by NHLBI DNA sequencing and Genomic Core using Illumina HiSeq 3000 paired-end sequencing platform.

2021-03-10 | GSE165354 | GEO

Substrate structure and computation guided engineering of a lipase for omega-3 fatty acid selectivity.

Project description:Enrichment of omega-3 fatty acids (ɷ-3 FAs) in natural oils is important to realize their health benefits. Lipases are promising catalysts to perform this enrichment, however, fatty acid specificity of lipases is poor. We attempted to improve the fatty acid selectivity of a lipase from Geobacillus thermoleovorans (GTL) by two approaches. In a semi-rational approach, amino acid positions critical for binding were identified by docking the substrate to the GTL and best substitutes at these positions were identified by site saturation mutagenesis followed by screening to obtain a variant of GTL (CM-GTL). In the second approach based on rational design, a variant of GTL was designed (DM-GTL) wherein the active site was narrowed by incorporating two heavier amino acids in the lining of acyl-binding pocket to hinder access to bulky ɷ-3 FAs. The affinities DM-GTL with designed substrates were evaluated in silico. Both, CM-GTL and DM-GTL have shown excellent ability to discriminate against the ɷ-3 FAs during hydrolysis of oils. Engineering the binding pocket of an enzyme of a complex substrate, such as a triglyceride, by incorporating the information on substrate structure and computationally derived binding modes, has resulted in designing two efficient lipase variants with improved substrate selectivity.

| S-EPMC7145112 | biostudies-literature

Comparative modeling and molecular docking of orphan human CYP4V2 protein with fatty acid substrates: Insights into substrate specificity.

Project description:Cytochromes P450 (CYPs) are a super family of heme-containing enzymes well-known for their monooxgenase reaction. There are 57 CYP isoenzymes found in human which exhibit specific physiological functions. Thirteen members of this super family are classified as "orphan" CYP because of their unknown enzymatic functions. CYP4V2 is found to be a potential drug target for Bietti crystalline corneoretinal dystrophy (BCD). However, three-dimensional structure, the active site topology and substrate binding modes of CYP4V2 remain unclear. In this study, the three-dimensional model of CYP4V2 was constructed using the homology modeling method. Four possible fatty acid substrates namely, caprylic, lauric, myrisitc and palmitic acids were optimized and evaluated for drug likeness using Lipinski's rule of five. Further, these substrates were docked into active sites of CYP4V2 and several key residues responsible for substrate binding were identified. These findings will be helpful for the structure-based drug design and detailed characterization of the biological roles of CYP4V2.

| S-EPMC3280491 | biostudies-literature

The Effect of Omega-3 and Omega-6 Polyunsaturated Fatty Acids on the Production of Cyclooxygenase and Lipoxygenase Metabolites by Human Umbilical Vein Endothelial Cells.

Project description:Although the correlation between polyunsaturated fatty acids (PUFA) and the production of pro- and anti-inflammatory metabolites is well documented, little is known about the simultaneous effect of different PUFA on the production of cyclooxygenase and lipoxygenase metabolites. The present research examines the association between different omega-3 (?-3) and omega-6 (?-6) PUFA and the release of four cyclooxygenase and six lipoxygenase metabolites in cell medium by human umbilical vein endothelial cells (HUVEC). The different combinations of ?-3 and ?-6 PUFA were prepared according to a full 24 factorial design that enables studying not only the main effects but also the different interactions between fatty acids. In addition, interactions diagrams and principal component analysis were useful tools for interpreting higher order interactions. To the best of our knowledge, this is the first report addressing the combined effect of ?-3 and ?-6 PUFA on the signaling of prostaglandins, prostacyclins, leukotrienes and resolvins by HUVEC.

| S-EPMC6567278 | biostudies-literature

5 S,15 S-Dihydroperoxyeicosatetraenoic Acid (5,15-diHpETE) as a Lipoxin Intermediate: Reactivity and Kinetics with Human Leukocyte 5-Lipoxygenase, Platelet 12-Lipoxygenase, and Reticulocyte 15-Lipoxygenase-1.

Project description:The reaction of 5 S,15 S-dihydroperoxyeicosatetraenoic acid (5,15-diHpETE) with human 5-lipoxygenase (LOX), human platelet 12-LOX, and human reticulocyte 15-LOX-1 was investigated to determine the reactivity and relative rates of producing lipoxins (LXs). 5-LOX does not react with 5,15-diHpETE, although it can produce LXA4 when 15-HpETE is the substrate. In contrast, both 12-LOX and 15-LOX-1 react with 5,15-diHpETE, forming specifically LXB4. For 12-LOX and 5,15-diHpETE, the kinetic parameters are kcat = 0.17 s-1 and kcat/ KM = 0.011 ?M-1 s-1 [106- and 1600-fold lower than those for 12-LOX oxygenation of arachidonic acid (AA), respectively]. On the other hand, for 15-LOX-1 the equivalent parameters are kcat = 4.6 s-1 and kcat/ KM = 0.21 ?M-1 s-1 (3-fold higher and similar to those for 12-HpETE formation by 15-LOX-1 from AA, respectively). This contrasts with the complete lack of reaction of 15-LOX-2 with 5,15-diHpETE [Green, A. R., et al. (2016) Biochemistry 55, 2832-2840]. Our data indicate that 12-LOX is markedly inferior to 15-LOX-1 in catalyzing the production of LXB4 from 5,15-diHpETE. Platelet aggregation was inhibited by the addition of 5,15-diHpETE, with an IC50 of 1.3 ?M; however, LXB4 did not significantly inhibit collagen-mediated platelet activation up to 10 ?M. In summary, LXB4 is the primary product of 12-LOX and 15-LOX-1 catalysis, if 5,15-diHpETE is the substrate, with 15-LOX-1 being 20-fold more efficient than 12-LOX. LXA4 is the primary product with 5-LOX but only if 15-HpETE is the substrate. Approximately equal proportions of LXA4 and LXB4 are produced by 12-LOX but only if LTA4 is the substrate, as described previously [Sheppard, K. A., et al. (1992) Biochim. Biophys. Acta 1133, 223-234].

| S-EPMC7270142 | biostudies-literature

Human Milk Omega-3 Fatty Acid Composition is Associated with Infant Temperament.

Project description:There is growing evidence that omega-3 (n-3) polyunsaturated fatty-acids (PUFAs) are important for the brain development in childhood and are necessary for an optimal health in adults. However, there have been no studies examining how the n-3 PUFA composition of human milk influences infant behavior or temperament. To fill this knowledge gap, 52 breastfeeding mothers provided milk samples at 3 months postpartum and completed the Infant Behavior Questionnaire (IBQ-R), a widely used parent-report measure of infant temperament. Milk was assessed for n-3 PUFAs and omega-6 (n-6) PUFAs using gas-liquid chromatography. The total fat and the ratio of n-6/n-3 fatty acids in milk were also examined. Linear regression models revealed that infants whose mothers' milk was richer in n-3 PUFAs had lower scores on the negative affectivity domain of the IBQ-R, a component of temperament associated with a risk for internalizing disorders later in life. These associations remained statistically significant after considering covariates, including maternal age, marital status, and infant birth weight. The n-6 PUFAs, n-6/n-3 ratio, and total fat of milk were not associated with infant temperament. These results suggest that mothers may have the ability to shape the behavior of their offspring by adjusting the n-3 PUFA composition of their milk.

| S-EPMC6949911 | biostudies-literature

OmicsDI is part of the ELIXIR infrastructure

OmicsDI is an Elixir interoperability service. Learn more ›

Tweets

OmicsDI Databases

PRIDE
PeptideAtlas
MassIVE
JPOST Repository
Physiome Model Repository

EGA
EVA
ENA
LINCS
PAXDB
Cell Collective

MetaboLights
Metabolomics Workbench
MetabolomeExpress
GNPS
BioModels
FAIRDOMHub

ArrayExpress
dbGaP
ExpressionAtlas
GEO
NODE

Information

Databases
Help
API
Contact us
Code on GitHub
Terms of use
Submit Data