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Seleno-detergent MAD phasing of leukotriene C4 synthase in complex with dodecyl-?-D-selenomaltoside.

ABSTRACT: Dodecyl-?-D-selenomaltoside (SeDDM) is a seleno-detergent with a ?-glycosidic seleno-ether in place of the ether moiety in dodecyl-?-D-maltoside. Seleno-detergents are candidates for heavy-atom agents in experimental phasing of membrane proteins in protein crystallography. Crystals of a nuclear membrane-embedded enzyme, leukotriene C(4) synthase (LTC(4)S), in complex with SeDDM were prepared and a multiwavelength anomalous diffraction (MAD) experiment was performed. The SeDDM in the LTC(4)S crystal exhibited sufficient anomalous diffraction for determination of the structure using MAD phasing.

SUBMITTER: Saino H

PROVIDER: S-EPMC3232166 | biostudies-literature | 2011 Dec

REPOSITORIES: biostudies-literature

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Seleno-detergent MAD phasing of leukotriene C4 synthase in complex with dodecyl-β-D-selenomaltoside.

Saino Hiromichi H Ago Hideo H Ukita Yoko Y Miyano Masashi M

Acta crystallographica. Section F, Structural biology and crystallization communications 20111129 Pt 12

Dodecyl-β-D-selenomaltoside (SeDDM) is a seleno-detergent with a β-glycosidic seleno-ether in place of the ether moiety in dodecyl-β-D-maltoside. Seleno-detergents are candidates for heavy-atom agents in experimental phasing of membrane proteins in protein crystallography. Crystals of a nuclear membrane-embedded enzyme, leukotriene C(4) synthase (LTC(4)S), in complex with SeDDM were prepared and a multiwavelength anomalous diffraction (MAD) experiment was performed. The SeDDM in the LTC(4)S crys ...[more]

PMID: 22139193

Similar Datasets

Structure and inhibition of mouse leukotriene C4 synthase.

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| S-EPMC4014545 | biostudies-literature

Crystal structures of leukotriene C4 synthase in complex with product analogs: implications for the enzyme mechanism.

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Arginine 104 is a key catalytic residue in leukotriene C4 synthase.

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| S-EPMC5000086 | biostudies-literature

Novel complex MAD phasing and RNase H structural insights using selenium oligonucleotides.

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Molecular cloning and expression of human leukotriene-C4 synthase.

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| S-EPMC44893 | biostudies-other

14,15-Dehydroleukotriene A4: a specific substrate for leukotriene C4 synthase.

Project description:We studied the metabolism of 14,15-dehydro-leukotriene A4 (14, 15-dehydro-LTA4) by human platelet leukotriene C4 (LTC4) synthase and polymorphonuclear leucocyte (PMNL) leukotriene A4 (LTA4) hydrolase. Metabolites were separated and identified using reversed-phase HPLC coupled to diode-array UV detection. Human platelets metabolize 14,15-dehydro-LTA4 to 14,15-dehydro-LTC4 with apparent kinetics identical with authentic LTA4. Metabolism to 14, 15-dehydro-LTC4 is inhibited by MK-886, a reported LTC4 synthase inhibitor in human platelets, with a potency comparable with that shown by LTA4. In contrast, neither human red-blood-cell lysates nor human PMNL enzymically convert 14,15-dehydro-LTA4 into 14, 15-dehydro-leukotriene B4. Minor amounts of 14,15-dehydro-LTC4, observed in some PMNL preparations, result from variable eosinophil contamination, as confirmed using highly purified neutrophil and eosinophil-enriched preparations. In addition, 14,15-dehydro-LTA4 irreversibly inhibits PMNL LTA4 hydrolase with an IC50 of 0.73 microM. The geometry of the methyl terminus of LTA4 does not influence the metabolism by human platelet LTC4 synthase. The double bond at C-14,15 is essential for the catalytic activity of LTA4 hydrolase but not for binding to this enzyme.

| S-EPMC1218910 | biostudies-other

Elevated levels of leukotriene C4 synthase mRNA distinguish a subpopulation of eosinophilic oesophagitis patients.

Project description:Cysteinyl leukotrienes contribute to Th2-type inflammatory immune responses. Their levels in oesophageal tissue, however, do not distinguish patients with eosinophilic oesophagitis (EoE) from controls.We asked whether mRNA levels of leukotriene C4 synthase (LTC4 S), a key regulator of leukotriene production, could serve as a marker for EoE.Digital mRNA expression profiling (nCounter(®) Technology) was performed on proximal and distal oesophageal biopsies of 30 paediatric EoE patients and 40 non-EoE controls. Expression data were confirmed with RT-qPCR. LTC4 S mRNA levels were quantified in whole blood samples. Leukotriene E4 was measured in urine.LTC4 S mRNA levels were elevated in proximal (2.6-fold, P < 0.001) and distal (2.9-fold, P < 0.001) oesophageal biopsies from EoE patients. Importantly, increased LTC4 S mRNA transcripts identified a subpopulation of EoE patients (28%). This patient subgroup had higher serum IgE levels (669 U/mL vs. 106 U/mL, P = 0.01), higher mRNA transcript numbers of thymic stromal lymphopoietin (TSLP) (1.6-fold, P = 0.009) and CD4 (1.4-fold, P = 0.04) but lower IL-23 mRNA levels (0.5-fold, P = 0.04). In contrast, elevated levels of IL-23 mRNA were found in oesophageal biopsies of patients with reflux oesophagitis. LTC4 S mRNA transcripts in whole blood and urinary excretion of leukotriene E4 were similar in EoE patient subgroups and non-EoE patients.Elevated oesophageal expression of LTC4 S mRNA is found in a subgroup of EoE patients, concomitant with higher serum IgE levels and an oesophageal transcriptome indicative of a more-pronounced allergic phenotype. Together with TSLP and IL-23 mRNA levels, oesophageal LTC4 S mRNA may facilitate diagnosis of an EoE subpopulation for personalized therapy.

| S-EPMC3728707 | biostudies-literature

Association of Leukotriene C4 Synthase A-444C Polymorphism with Asthma and Asthma Phenotypes in Romanian Population.

Project description:IntroductionLeukotriene C4 synthase (LTC4S) gene -444A/C polymorphism has been implicated in susceptibility to asthma, but a large number of studies have reported inconclusive results. The aim of this study was to investigate the association between the -444A/C polymorphism of LTC4S gene and asthma, asthma phenotypes (aspirin intolerant/tolerant asthma) and different characteristics of the patients.Material and methodsWe included 106 patients with asthma (60 with aspirin tolerant asthma - ATA, 46 with aspirin intolerant asthma - AIA) and 103 controls. All the subjects were genotyped for LTC4S-444 A/C by Real-Time PCR. We assessed the association of LTC4S promoter polymorphism with asthma and its phenotypes and with clinical and biological characteristics of asthmatic patients.ResultsWe did not find a significant association between the studied polymorphism and asthma, but the minor allele tended to be more frequent in AIA patients. We found a significant association between the minor allele C and lower levels of serum total immunoglobulin E and eosinophils, suggesting a possible role of -444A/C LTC4S polymorphism as modulating factor of allergic inflammation in asthma.ConclusionThe results show that LTC4S -444A/C SNP is not associated with susceptibility to asthma in Romanian patients, but could influence asthma phenotype, namely aspirin intolerant asthma.

| S-EPMC5327799 | biostudies-literature

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