OBJECTIVE: This study aimed to clone and characterize the oxiranedicarboxylate hydrolase (ORCH) from Labrys sp. WH-1. METHODS: Purification by column chromatography, characterization of enzymatic properties, gene cloning by protein terminal sequencing and polymerase chain reaction (PCR), and sequence analysis by secondary structure prediction and multiple sequence alignment were performed. RESULTS: The ORCH from Labrys sp. WH-1 was purified 26-fold with a yield of 12.7%. It is a monomer with an isoelectric point (pI) of 8.57 and molecular mass of 30.2 kDa. It was stable up to 55 °C with temperature at which the activity of the enzyme decreased by 50% in 15 min (T₅₀¹⁵) of 61 °C and the half-life at 50 °C (t_{1/2, 50 °C}) of 51 min and was also stable from pH 4 to 10, with maximum activity at 55 °C and pH 8.5. It is a metal-independent enzyme and strongly inhibited by Cu²⁺, Ag⁺, and anionic surfactants. Its kinetic parameters (K_m, k_cat, and k_cat/K_m) were 18.7 mmol/L, 222.3 s^-1, and 11.9 mmol/(L·s), respectively. The ORCH gene, which contained an open reading frame (ORF) of 825 bp encoding 274 amino acid residues, was overexpressed in Escherichia coli and the enzyme activity was 33 times higher than that of the wild strain. CONCLUSIONS The catalytic efficiency and thermal stability of the ORCH from Labrys sp. WH-1 were the best among the reported ORCHs, and it provides an alternative catalyst for preparation of L(+)-2,3-dihydrobutanedioic acid.
Alphaproteobacteria/enzymology* ; Cloning, Molecular ; Dicarboxylic Acids/metabolism* ; Enzyme Stability ; Epoxide Hydrolases/metabolism*

Soluble epoxide hydrolases (sEH) are enzymes present in all living organisms, metabolize epoxy fatty acids to 1,2-diols. sEH in the metabolism of polyunsaturated fatty acids plays a key role in inflammation. In addition, the endogenous lipid mediators in cardiovascular disease are also broken down to diols by the action of sEH that enhanced cardiovascular protection. In this study, sEH inhibitory guided fractionation led to the isolation of five phenolic compounds trans-resveratrol (1), trans-piceatannol (2), sulfuretin (3), (+)-balanophonin (4), and cassigarol E (5) from the ethanol extract of the seeds of Passiflora edulis Sims cultivated in Vietnam. The chemical structures of isolated compounds were determined by the interpretation of NMR spectral data, mass spectra, and comparison with data from the literature. The soluble epoxide hydrolase (sEH) inhibitory activity of isolated compounds was evaluated. Among them, trans-piceatannol (2) showed the most potent inhibitory activity on sEH with an IC₅₀ value of 3.4 µM. This study marks the first time that sulfuretin (3) was isolated from Passiflora edulis as well as (+)-balanophonin (4), and cassigarol E (5) were isolated from Passiflora genus.
Cardiovascular Diseases ; Epoxide Hydrolases ; Ethanol ; Fatty Acids ; Fatty Acids, Unsaturated ; Inflammation ; Metabolism ; Passiflora ; Passifloraceae ; Phenol ; Vietnam

Wild-type biocatalysts usually show high activity and selectivity towards their native substrates. Since non-native substrates are often used in synthetically useful biocatalytic transformations, it is necessary to engineer enzymes for improved activity, stability and selectivity (chemo-, regio- and stereoselectivity). Herein we give an overview of the recent advances in engineering the enantioselectivity of biocatalysts, with an aim to stimulate further development of this important field in China.
Animals ; Biocatalysis ; Epoxide Hydrolases ; genetics ; metabolism ; Esterases ; genetics ; metabolism ; Humans ; Lipase ; genetics ; metabolism ; Protein Engineering ; methods ; Stereoisomerism

OBJECTIVETo investigate antigen-induced changes of leukotriene B(4)(LTB(4))content and LTA(4)-hydrolase mRNA expression in lung tissue and cerebral cortex in sensitized rats.

METHODSThe contents of LTB(4) in lung tissue and cerebral cortex homogenates and LTA(4)-hydrolase mRNA expression after antigen challenge by aerosol were respectively detected by reverse-phase high performance liquid chromatography(RP-HPLC) and semi-quantitative RT-PCR.

RESULTThe LTB(4) levels in lung tissue and cerebral cortex homogenates in asthmatic rats were significantly higher than those in control (P%0.05), and LTA4-hydrolase mRNA expression was also increased in asthmatic group. Dexamethason(DXM, 0.5 mg/kg, i.p.) decreased the LTB(4) content and inhibited the LTA(4)-hydrolase mRNA expression significantly in asthmatic rats(P%0.05).

CONCLUSIONLTB(4) content and LTA(4)-hydrolase mRNA expression in cerebral cortex and lung tissue are increased in asthmatic rats, and there may exist neuroimmunological cross-talking between central nervous system and lung tissue in asthma.

Animals ; Asthma ; metabolism ; Cerebral Cortex ; chemistry ; metabolism ; Epoxide Hydrolases ; genetics ; Female ; Leukotriene B4 ; analysis ; Lung ; chemistry ; metabolism ; Male ; RNA, Messenger ; analysis ; Rats ; Rats, Sprague-Dawley

AIM: To investigate the relationship between cerebroprotection of pinocembrin and epoxyeicosatrienoic acids (EETs) and their regulating enzyme soluble epoxide hydrolase (sEH). METHODS: Rats underwent middle cerebral artery occlusion (MCAO) to mimic permanent focal ischemia, and pinocembrin was administrated via tail vein injection at 10 min, 4 h, 8 h and 23 h after MCAO. After 24 MCAO, rats were re-anesthetized, and the blood and brain were harvested and analyzed. RESULTS: Pinocembrin displayed significant protective effects on MCAO rats indicated by reduced neurological deficits and infarct volume. Importantly, co-administration of 0.2 mg·kg(-1) 14, 15-EEZE, a putative selective EET antagonist, weakened the beneficial effects of pinocembrin. 14, 15-EET levels in the blood and brain of rats after 24 h MCAO were elevated in the presence of pinocembrin. In an assay for hydrolase activity, pinocembrin significantly lowered brain sEH activity of MCAO rats and inhibited recombinant human sEH activity in a concentration-dependent manner (IC50, 2.58 μmol·L(-1)). In addition, Western blot and immunohistochemistry analysis showed that pinocembrin at doses of 10 mg·kg(-1) and 30 mg·kg(-1) significantly down-regulated sEH protein in rat brain, especially the hippocampus CA1 region of MCAO rats. CONCLUSION Inhibiting sEH and then increasing the potency of EETs may be one of the mechanisms through which pinocembrin provides cerebral protection.
Animals ; Arachidonic Acids ; metabolism ; Brain ; drug effects ; enzymology ; metabolism ; Brain Ischemia ; drug therapy ; enzymology ; genetics ; metabolism ; prevention & control ; Disease Models, Animal ; Epoxide Hydrolases ; genetics ; metabolism ; Flavanones ; administration & dosage ; Humans ; Male ; Protective Agents ; administration & dosage ; Rats ; Rats, Sprague-Dawley

To screen potential human soluble epoxide hydrolase (hsEH) inhibitors, a high-throughput screening model in 384-well microplate with total volume of 50 microL was established. Recombinant hsEH was cloned and expressed in E. coli. and its specific substrate PHOME was synthesized. The HTS model was based on fluorescence analysis with enhanced sensitivity and specificity (Z' = 0.65). A total of 47 360 samples (including 25 040 compounds and 22 320 natural products) were screened, of which 950 samples with inhibition greater than 80% were selected for further rescreening. Finally, two compounds with high inhibitory activity were identified, whose IC50 value were 8.56 and 4.31 micromol x L(-1), separately. The results indicated that the method was stable, sensitive, reproducible and also suitable for high-throughput screening.
Drug Evaluation, Preclinical ; methods ; Enzyme Inhibitors ; analysis ; chemistry ; Epoxide Hydrolases ; antagonists & inhibitors ; chemistry ; metabolism ; Escherichia coli ; metabolism ; High-Throughput Screening Assays ; methods ; Inhibitory Concentration 50 ; Recombinant Proteins ; metabolism ; Reproducibility of Results ; Sensitivity and Specificity ; Spectrometry, Fluorescence ; methods ; Substrate Specificity

OBJECTIVETo investigate the associations of polymorphisms of metabolic enzyme genes with urinary 1-hydroxypyrene levels in coke oven workers.

METHODSOne hundred and forty-eight workers from a coke oven plant and 69 controls without occupational PAHs exposure were selected in this study. Urinary 1-hydroxypyrene was detected by high performance liquid chromatography with florescence detector. The genotypes at I462V site in exon 7 of CYP1A1 gene, GSTM1, GSTT1, I105V site in GSTP1gene, Pst1 and Dra1 sites in CYP2E1 gene, P187S site in NQO1 gene, Kpn1, BamH1 and Taq1 sites in NAT2 gene, and H113Y, R139H sites in mEH gene were determined by PCR-based methods. Personal information including occupational exposure history, age, sex, smoking and drinking status was collected by the questionnaire.

RESULTSThe level of urinary 1-hydroxypyrene in coke oven workers [(5.61 +/- 1.04) mol/mol Cr] was higher than that in control [(0.74 +/- 0.32) micro mol/mol Cr]. After adjusting external occupational exposure category and smoking, coke oven workers with variant homozygotes at H113Y site of mEH gene had significantly higher urinary 1-hydroxypyrene concentrations than those with heterozygotes, and wild homozygotes (6.41 +/- 1.09 vs. 6.24 +/- 1.08, and 4.62 +/- 0.95 micro mol/mol Cr, P < 0.05), and gene-gene interaction was found between CYP1A1 and mEH.

CONCLUSIONGenetic polymorphism of mEH gene could be a susceptible biomarker in coke oven workers which was involved in the individual susceptibility on metabolism of PAHs.

Coke ; adverse effects ; Cytochrome P-450 CYP1A1 ; genetics ; DNA Damage ; genetics ; Epoxide Hydrolases ; genetics ; Genetic Predisposition to Disease ; genetics ; Glutathione Transferase ; genetics ; Humans ; Male ; Occupational Exposure ; Polycyclic Aromatic Hydrocarbons ; poisoning ; Polymorphism, Genetic ; Pyrenes ; analysis ; metabolism

OBJECTIVETo explore the relationship between genetic polymorphisms of microsomal epoxide hydrolase (mEH) and susceptibility of chronic benzene poisoning (BP).

METHODA case-control study was conducted. 152 BP patients and 152 workers occupationally exposed to benzene without poisoning manifestations were investigated. Polymerase chain reaction-restrained fragment length polymorphism technique (PCR-RFLP) was applied to detect the single nucleotide polymorphisms (SNPs) on c.113 and c.139 of mEH gene.

RESULTSThe risk of BP for individuals carrying mEHc.113 C/C genotype was 0.60 (OR = 0.60, 95% CI: 0.37 - 0.97, P = 0.04) of those carrying T/T and T/C genotypes. In non-smoking population, the risk of BP for subjects carrying mEHc.113 C/C genotype was 0.56 (OR = 0.56, 95% CI: 0.33 - 0.96, P = 0.03) of those carrying T/T and T/C genotypes, and in non-drinking population, the individuals carrying mEHc.113 C/C genotype was 0.51 (OR = 0.51, 95% CI: 0.30 - 0.86, P = 0.01) of those carrying T/T and T/C genotypes.

CONCLUSIONThe subjects carrying mEHc.113 C/C genotype and together with non-smoking or non-drinking habit may have lower risk of chronic benaene poisoning.

Adult ; Benzene ; metabolism ; poisoning ; Case-Control Studies ; Epoxide Hydrolases ; genetics ; Female ; Genetic Predisposition to Disease ; Humans ; Life Style ; Male ; Middle Aged ; Occupational Diseases ; genetics ; Point Mutation ; Polymerase Chain Reaction ; Polymorphism, Restriction Fragment Length

Inflammatory diseases are common medical conditions seen in disorders of human immune system. There is a great demand for anti-inflammatory drugs. There are major inflammatory mediators in arachidonic acid metabolic network. Several enzymes in this network have been used as key targets for the development of anti-inflammatory drugs. However, specific single-target inhibitors can not sufficiently control the network balance and may cause side effects at the same time. Most inflammation induced diseases come from the complicated coupling of inflammatory cascades involving multiple targets. In order to treat these complicated diseases, drugs that can intervene multi-targets at the same time attracted much attention. The goal of this review is mainly focused on the key enzymes in arachidonic acid metabolic network, such as phospholipase A2, cyclooxygenase, 5-lipoxygenase and eukotriene A4 hydrolase. Advance in single target and multi-targe inhibitors is summarized.
Animals ; Anti-Inflammatory Agents ; therapeutic use ; Arachidonate 5-Lipoxygenase ; metabolism ; therapeutic use ; Arachidonic Acid ; metabolism ; Cyclooxygenase Inhibitors ; therapeutic use ; Drug Delivery Systems ; methods ; Epoxide Hydrolases ; antagonists & inhibitors ; metabolism ; therapeutic use ; Humans ; Inflammation ; drug therapy ; Lipoxygenase Inhibitors ; Metabolic Networks and Pathways ; drug effects ; Phospholipase A2 Inhibitors ; Phospholipases A2 ; metabolism ; therapeutic use ; Prostaglandin-Endoperoxide Synthases ; metabolism

OBJECTIVETo observe the effects of soluble epoxide hydrolase inhibitor t-AUCB on foam cell formation and cholesterol efflux in macrophage.

METHODSMouse macrophages RAW264.7 were cultured and stimulated with ox-LDL (80 µmol/L) in the absence (group A) or presence of t-AUCB (1, 10, 50, 100 µmol/L, group B) or t-AUCB (100 µmol/L) pretreated with PPARγ antagonist GW9662 (5 µmol/L, group C). The foam cell was identified by oil red O staining. The cholesterol efflux rates of (3)H-cholesterol in cells were measured by liquid scintillation counter. mRNA and protein expressions of ABCA1 were detected by real-time PCR or Western blot, respectively.

RESULTSOil red O staining showed that t-AUCB (100 µmol/L) significantly inhibited foam cell formation which could be significantly reversed by GW9662 (all P < 0.05). t-AUCB dose-dependently increased cholesterol efflux rates in mouse macrophage [(5.91 ± 0.18)% in group A, (7.03 ± 0.33)%, (8.05 ± 0.32)%, (9.04 ± 0.14)%, (10.06 ± 0.85)% in 1, 10, 50, 100 µmol/L t-AUCB groups, all P < 0.05 vs. group A], which could be reversed by pretreatment with GW9662 [(6.33 ± 0.15)% in 100 µmol/L t-AUCB + GW9662 group].t-AUCB also upregulated ABCA1 mRNA and protein expressions in a dose-dependent manner which could be significantly attenuated by pretreatment with GW9662.

CONCLUSIONt-AUCB could inhibit foam cell formation by improving cholesterol efflux through activating PPARγ-ABCA1 pathway in macrophage.

ATP Binding Cassette Transporter 1 ; ATP-Binding Cassette Transporters ; metabolism ; Animals ; Benzoates ; pharmacology ; Cell Differentiation ; drug effects ; Cell Line ; Cholesterol ; metabolism ; Enzyme Inhibitors ; pharmacology ; Epoxide Hydrolases ; antagonists & inhibitors ; Foam Cells ; drug effects ; Macrophages ; cytology ; drug effects ; metabolism ; Mice ; PPAR gamma ; metabolism ; Urea ; analogs & derivatives ; pharmacology