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Sample records for immobilized organophosphorus hydrolase

  1. AMPEROMETRIC THICK-FILM STRIP ELECTRODES FOR MONITORING ORGANOPHOSPHATE NERVE AGENTS BASED ON IMMOBILIZED ORGANOPHOSPHORUS HYDROLASE. (R823663)

    Science.gov (United States)

    An amperometric biosensor based on the immobilization of organophosphorus hydrolase(OPH) onto screen-printed carbon electrodes is shown useful for the rapid, sensitive, and low-costdetection of organophosphate (OP) nerve agents. The sensor relies upon the sensitive and ra...

  2. Fluorometric determination of paraoxon in human serum using a gold nanoparticle-immobilized organophosphorus hydrolase and coumarin 1 as a competitive inhibitor

    International Nuclear Information System (INIS)

    Kamelipour, Nahid; Mohsenifar, Afshin; Rahmani-Cherati, Tavoos; Tabatabaei, Meisam; Khoshnevisan, Kamyar; Allameh, Abdolamir; Milani, Majid M.; Etemadikia, Batool; Najavand, Saeid

    2014-01-01

    A dimeric organophosphorus hydrolase (OPH; EC 3.1.8.1; 72 kDa) was isolated from wild-type bacteria, analyzed for its 16s rRNA sequence, purified, and immobilized on gold nanoparticles (AuNPs) to form the transducer part of a biosensor. The isolated strain was identified as Pseudomonas aeruginosa. The AuNPs were characterized by transmission electron microscopy and localized surface plasmon resonance. Covalent binding of OPH to the AuNPs was confirmed by spectrophotometry, enzymatic activity assays, and FTIR spectroscopy. Coumarin 1, a competitive inhibitor of OPH, was used as a fluorogenic probe. The bioconjugates quench the emission of coumarin 1 upon binding, but the addition of paraoxon results in an enhancement of fluorescence that is directly proportional to the concentration of paraoxon. The gold-OPH conjugates were then used to determine paraoxon in serum samples spiked with varying levels of paraoxon. The method works in the 50 to 1,050 nM concentration range, has a low standard deviation (with a CV of 5.7–11 %), and a detection limit as low as 5 × 10 −11 M. (author)

  3. Optical Detection of Paraoxon Using Single-Walled Carbon Nanotube Films with Attached Organophosphorus Hydrolase-Expressed Escherichia coli

    Directory of Open Access Journals (Sweden)

    Intae Kim

    2015-05-01

    Full Text Available In whole-cell based biosensors, spectrophotometry is one of the most commonly used methods for detecting organophosphates due to its simplicity and reliability. The sensor performance is directly affected by the cell immobilization method because it determines the amount of cells, the mass transfer rate, and the stability. In this study, we demonstrated that our previously-reported microbe immobilization method, a microbe-attached single-walled carbon nanotube film, can be applied to whole-cell-based organophosphate sensors. This method has many advantages over other whole-cell organophosphate sensors, including high specific activity, quick cell immobilization, and excellent stability. A device with circular electrodes was fabricated for an enlarged cell-immobilization area. Escherichia coli expressing organophosphorus hydrolase in the periplasmic space and single-walled carbon nanotubes were attached to the device by our method. Paraoxon was hydrolyzed using this device, and detected by measuring the concentration of the enzymatic reaction product, p-nitrophenol. The specific activity of our device was calculated, and was shown to be over 2.5 times that reported previously for other whole-cell organophosphate sensors. Thus, this method for generation of whole-cell-based OP biosensors might be optimal, as it overcomes many of the caveats that prevent the widespread use of other such devices.

  4. Intensification of Organophosphorus Hydrolase Synthesis by Using Substances with Gas-Transport Function

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    Olga Senko

    2017-12-01

    Full Text Available We have performed studies and comparative analysis of the biosynthesis characteristics of intracellular recombinant enzyme, such as hexahistidine-containing organophosphorus hydrolase (His6-OPH in Escherichia coli SG13009[pREP4] cells when various perfluorocarbon compounds (PFC were introduced into the medium for cell cultivation. The PFC were found to facilitate the biosynthesis of His6-OPH: increased levels of the total OPH-activity (up to 37% were measured upon introduction of 1,1,1,2,2,3,3,4,4,5,5,6,6,6-tetradecafluorohexane (PFH and 4,7,10,13,16,19,22,25,28,31-decaoxaperfluoro-5,8,11,14,17,18,21,24,27,30-decamethyl tetratriacontane (Polyether II into culture medium. We have demonstrated the possibility of effective and multiple (at least five-fold use of PFH for biosynthesis of intracellular recombinant protein His6-OPH, which catalyzes the hydrolysis of organophosphorus pesticides (OP, is widely used in agriculture and can be applied as new antidote for OP-detoxification in vivo. The multiple use of PFH was achieved through recycling of this substance: sediment of Escherichia coli SG13009[pREP4] cell biomass was collected at the end of each culture growing step and disintegrated with ultrasound, and obtained residue containing almost all of the initially introduced PFC was then added to the medium at the start of the following culture growing step.

  5. Engineering and introduction of de novo disulphide bridges in organophosphorus hydrolase enzyme for thermostability improvement.

    Science.gov (United States)

    Farnoosh, Gholamreza; Khajeh, Khosro; Latifi, Ali Mohammad; Aghamollaei, Hossein

    2016-12-01

    The organophosphorus hydrolase (OPH) has been used to degrade organophosphorus chemicals, as one of the most frequently used decontamination methods. Under chemical and thermal denaturing conditions, the enzyme has been shown to unfold. To utilize this enzyme in various applications, the thermal stability is of importance. The engineering of de novo disulphide bridges has been explored as a means to increase the thermal stability of enzymes in the rational method of protein engineering. In this study, Disulphide by Design software, homology modelling and molecular dynamics simulations were used to select appropriate amino acid pairs for the introduction of disulphide bridge to improve protein thermostability. The thermostability of the wild-type and three selected mutant enzymes were evaluated by half-life, delta G inactivation (ΔGi) and structural studies (fluorescence and far-UV CD analysis). Data analysis showed that half-life of A204C/T234C and T128C/E153C mutants were increased up to 4 and 24 min, respectively; however, for the G74C/A78C mutant, the half-life was decreased up to 9 min. For the T128C/E124C mutant, both thermal stability and Catalytic efficiency (kcat) were also increased. The half-life and ΔGi results were correlated to the obtained information from structural studies by circular dichroism (CD) spectrometry and extrinsic fluorescence experiments; as rigidity increased in A204C/T2234C and T128C/E153C mutants, half-life and ΔGi also increased. For G74C/A78C mutant, these parameters decreased due to its higher flexibility. The results were submitted a strong evidence for the possibility to improve the thermostability of OPH enzyme by introducing a disulphide bridge after bioinformatics design, even though this design would not be always successful.

  6. Catalytic Characteristics of New Antibacterials Based on Hexahistidine-Containing Organophosphorus Hydrolase

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    Olga Maslova

    2017-09-01

    Full Text Available Catalytic characteristics of hexahistidine-containing organophosphorus hydrolase (His6-OPH and its enzyme-polyelectrolyte complexes with poly-l-glutamic acid or poly-l-aspartic acid (His6-OPH/PLD50, hydrolyzing organophosphorous compounds, and N-acyl homoserine lactones were studied in the presence of various antibiotics (ampicillin, gentamicin, kanamycin, and rifampicin. The antibiotics at concentrations below 1 g·L−1 had a negligible inhibiting effect on the His6-OPH activity. Mixed inhibition of His6-OPH was established for higher antibiotic concentrations, and rifampicin was the most potent inhibitor. Stabilization of the His6-OPH activity was observed in the presence of antibiotics at a concentration of 0.2 g·L−1 during exposure at 25–41 °C. Molecular docking of antibiotics to the surface of His6-OPH dimer revealed the antibiotics binding both to the area near active centers of the enzyme subunits and to the region of contact between subunits of the dimer. Such interactions between antibiotics and His6-OPH were verified with Fourier-transform infrared (FTIR spectroscopy. Considering all the results of the study, the combination of His6-OPH/PLD50 with β-lactam antibiotic ampicillin was established as the optimal one in terms of exhibition and persistence of maximal lactonase activity of the enzyme.

  7. Evaluation of the organophosphorus hydrolase enzyme activity in creams and investigation of its stability

    Directory of Open Access Journals (Sweden)

    Mariye Rajaie

    2016-06-01

    Full Text Available The main purpose of this project is investigation of the organophosphorus hydrolase (OPH enzyme activity in water in oil (w/o and oil in water (o/w creams and investigation of the OPH enzyme stability in formulated creams. OPH enzyme was extracted and purified from strain flavobacterium. The w/o and o/w creams were prepared using different formulations. In order to achieve an emulsion with maximum stability, appropriate percentage of the cream components was selected by studying different formulations and the physical and chemical stability of the produced cream were considered. 5Uenzyme/90gcream enzyme was used for each formulation. To measure the enzyme activity in creams, extraction method was used and enzyme activity was determined based on parathion hydrolysis. The thermal stability of OPH in both types of w/o and o/w creams was studied at 4 and 30  °C for various time periods. The average enzyme activity was about 0.0065 U/gcream and 0.018 U/gcream for w/o and o/w creams respectivly. According to the results, the relative activity at 4 °C was reduced to 50% after 26 and 45 days in w/o and o/w creams, respectivly. The results showed that the OPH enzyme activity in o/w cream was 2.6 times more than that of w/o cream, because of the higher hydrophobicity of o/w cream compared to w/o. The OPH enzyme stability in o/w cream was greater in comparison to w/o cream. The OPH enzyme was active for nearly 2 months on o/w creams at 4 °C .

  8. Lysophosphatidylcholine hydrolases of human erythrocytes, lymphocytes, and brain: Sensitive targets of conserved specificity for organophosphorus delayed neurotoxicants

    International Nuclear Information System (INIS)

    Vose, Sarah C.; Holland, Nina T.; Eskenazi, Brenda; Casida, John E.

    2007-01-01

    Brain neuropathy target esterase (NTE), associated with organophosphorus (OP)-induced delayed neuropathy, has the same OP inhibitor sensitivity and specificity profiles assayed in the classical way (paraoxon-resistant, mipafox-sensitive hydrolysis of phenyl valerate) or with lysophosphatidylcholine (LysoPC) as the substrate. Extending our earlier observation with mice, we now examine human erythrocyte, lymphocyte, and brain LysoPC hydrolases as possible sensitive targets for OP delayed neurotoxicants and insecticides. Inhibitor profiling of human erythrocytes and lymphocytes gave the surprising result of essentially the same pattern as with brain. Human erythrocyte LysoPC hydrolases are highly sensitive to OP delayed neurotoxicants, with in vitro IC 50 values of 0.13-85 nM for longer alkyl analogs, and poorly sensitive to the current OP insecticides. In agricultural workers, erythrocyte LysoPC hydrolyzing activities are similar for newborn children and their mothers and do not vary with paraoxonase status but have high intersample variation that limits their use as a biomarker. Mouse erythrocyte LysoPC hydrolase activity is also of low sensitivity in vitro and in vivo to the OP insecticides whereas the delayed neurotoxicant ethyl n-octylphosphonyl fluoride inhibits activity in vivo at 1-3 mg/kg. Overall, inhibition of blood LysoPC hydrolases is as good as inhibition of brain NTE as a predictor of OP inducers of delayed neuropathy. NTE and lysophospholipases (LysoPLAs) both hydrolyze LysoPC, yet they are in distinct enzyme families with no sequence homology and very different catalytic sites. The relative contributions of NTE and LysoPLAs to LysoPC hydrolysis and clearance from erythrocytes, lymphocytes, and brain remain to be defined

  9. Improvement of enantioselectivity by immobilized imprinting of epoxide hydrolase from Rhodotorula glutinis

    NARCIS (Netherlands)

    Kronenburg, N.A.E.; Bont, de J.A.M.; Fischer, L.

    2001-01-01

    The yeast Rhodotorula glutinis contains an enantioselective, membrane-associated epoxide hydrolase (EH). Partially purified EH was immobilized in a two-step procedure. In the first step, the proteins were derivatized with itaconic anhydride. In the second step, the derivatized proteins were

  10. IMMOBILIZATION OF TANNIN ACYL HYDROLASE FROM ASPERGILLUS NIGER

    OpenAIRE

    B. Lenin Kumar*, N. Lokeswari and D. Sriramireddy

    2013-01-01

    ABSTRACT: Tannin acyl hydrolase, commonly referred to as tannase (E.C. 3.1.1.20), an inducible extra-cellular enzyme produced by a number of animals, plants and microbes. In this investigation, tannase production under solid-state fermentation by using Aspergillus niger and the waste residue of cashew husk was used as substrate for obtaining the desired fermented product. Microbial tannase is more stable than tannase from other sources like plants or animals. Tannase from fungal sources are r...

  11. Development of a Novel Optical Biosensor for Detection of Organophoshorus Pesticides Based on Methyl Parathion Hydrolase Immobilized by Metal-Chelate Affinity

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    Wensheng Lan

    2012-06-01

    Full Text Available We have developed a novel optical biosensor device using recombinant methyl parathion hydrolase (MPH enzyme immobilized on agarose by metal-chelate affinity to detect organophosphorus (OP compounds with a nitrophenyl group. The biosensor principle is based on the optical measurement of the product of OP catalysis by MPH (p-nitrophenol. Briefly, MPH containing six sequential histidines (6× His tag at its N-terminal was bound to nitrilotriacetic acid (NTA agarose with Ni ions, resulting in the flexible immobilization of the bio-reaction platform. The optical biosensing system consisted of two light-emitting diodes (LEDs and one photodiode. The LED that emitted light at the wavelength of the maximum absorption for p-nitrophenol served as the signal light, while the other LED that showed no absorbance served as the reference light. The optical sensing system detected absorbance that was linearly correlated to methyl parathion (MP concentration and the detection limit was estimated to be 4 μM. Sensor hysteresis was investigated and the results showed that at lower concentration range of MP the difference got from the opposite process curves was very small. With its easy immobilization of enzymes and simple design in structure, the system has the potential for development into a practical portable detector for field applications.

  12. Development of a Novel Optical Biosensor for Detection of Organophoshorus Pesticides Based on Methyl Parathion Hydrolase Immobilized by Metal-Chelate Affinity

    Science.gov (United States)

    Lan, Wensheng; Chen, Guoping; Cui, Feng; Tan, Feng; Liu, Ran; Yushupujiang, Maolidan

    2012-01-01

    We have developed a novel optical biosensor device using recombinant methyl parathion hydrolase (MPH) enzyme immobilized on agarose by metal-chelate affinity to detect organophosphorus (OP) compounds with a nitrophenyl group. The biosensor principle is based on the optical measurement of the product of OP catalysis by MPH (p-nitrophenol). Briefly, MPH containing six sequential histidines (6× His tag) at its N-terminal was bound to nitrilotriacetic acid (NTA) agarose with Ni ions, resulting in the flexible immobilization of the bio-reaction platform. The optical biosensing system consisted of two light-emitting diodes (LEDs) and one photodiode. The LED that emitted light at the wavelength of the maximum absorption for p-nitrophenol served as the signal light, while the other LED that showed no absorbance served as the reference light. The optical sensing system detected absorbance that was linearly correlated to methyl parathion (MP) concentration and the detection limit was estimated to be 4 μM. Sensor hysteresis was investigated and the results showed that at lower concentration range of MP the difference got from the opposite process curves was very small. With its easy immobilization of enzymes and simple design in structure, the system has the potential for development into a practical portable detector for field applications. PMID:23012501

  13. Isolation of the opdE gene that encodes for a new hydrolase of Enterobacter sp. capable of degrading organophosphorus pesticides.

    Science.gov (United States)

    Chino-Flores, Concepción; Dantán-González, Edgar; Vázquez-Ramos, Alejandra; Tinoco-Valencia, Raunel; Díaz-Méndez, Rafael; Sánchez-Salinas, Enrique; Castrejón-Godínez, Maria Luisa; Ramos-Quintana, Fernando; Ortiz-Hernández, Maria Laura

    2012-06-01

    Microbial enzymes that can hydrolyze organophosphorus compounds have been isolated, identified and characterized from different microbial species in order to use them in biodegradation of organophosphorus compounds. We isolated a bacterial strain Cons002 from an agricultural soil bacterial consortium, which can hydrolyze methyl-parathion (MP) and other organophosphate pesticides. HPLC analysis showed that strain Cons002 is capable of degrading pesticides MP, parathion and phorate. Pulsed-field gel electrophoresis and 16S rRNA amplification were performed for strain characterization and identification, respectively, showing that the strain Cons002 is related to the genus Enterobacter sp. which has a single chromosome of 4.6 Mb and has no plasmids. Genomic library was constructed from DNA of Enterobacter sp. Cons002. A gene called opdE (Organophosphate Degradation from Enterobacter) consists of 753 bp and encodes a protein of 25 kDa, which was isolated using activity methods. This gene opdE had no similarity to any genes reported to degrade organophosphates. When kanamycin-resistance cassette was placed in the gene opdE, hydrolase activity was suppressed and Enterobacter sp. Cons002 had no growth with MP as a nutrients source.

  14. Immobilization of Organophosphorus Acid Anhydrolase Mutant Y212F on Silica Nanospheres

    Science.gov (United States)

    2016-09-01

    wild type organophosphorus acid anhydrolase (OPAA) for activity on G-type chemical nerve agents and observed increased activity on the most- toxic ...eventual use in determining particle-binding efficiency and enzymatic activity ..................................................4 5. Fluoride assay...7 TABLES 1. Results of Fluoride Release Assay from DFP Testing of Y212F Enzyme, before and after Conjugation to

  15. Efficient Degradation of Malathion in the Presence of Detergents Using an Engineered Organophosphorus Hydrolase Highly Expressed by Pichia pastoris without Methanol Induction.

    Science.gov (United States)

    Bai, Yun-Peng; Luo, Xiao-Jing; Zhao, Yu-Lian; Li, Chun-Xiu; Xu, Dian-Sheng; Xu, Jian-He

    2017-10-18

    The biodegradation of pesticides by organophosphorus hydrolases (OPHs) requires an efficient enzyme production technology in industry. Herein, a Pichia pastoris strain was constructed for the extracellular expression of PoOPH M9 , an engineered malathion-degrading enzyme. After optimization, the maximum titer and yield of fermentation reached 50.8 kU/L and 4.1 g protein /L after 3 days, with the highest space-time yield (STY) reported so far, 640 U L -1 h -1 . PoOPH M9 displayed its high activity and stability in the presence of 0.1% (w/w) plant-derived detergent. Only 0.04 mg/mL enzyme could completely remove 0.15 mM malathion in aqueous solution within 20 min. Furthermore, 12 μmol malathion on apples and cucumbers surfaces was completely removed by 0.05 mg/mL PoOPH M9 in tap water after 35 min washing. The efficient production of the highly active PoOPH M9 has cleared a major barrier to biodegradation of pesticide residues in food industry.

  16. Immobilization of Glycoside Hydrolase Families GH1, GH13, and GH70: State of the Art and Perspectives

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    Natália G. Graebin

    2016-08-01

    Full Text Available Glycoside hydrolases (GH are enzymes capable to hydrolyze the glycosidic bond between two carbohydrates or even between a carbohydrate and a non-carbohydrate moiety. Because of the increasing interest for industrial applications of these enzymes, the immobilization of GH has become an important development in order to improve its activity, stability, as well as the possibility of its reuse in batch reactions and in continuous processes. In this review, we focus on the broad aspects of immobilization of enzymes from the specific GH families. A brief introduction on methods of enzyme immobilization is presented, discussing some advantages and drawbacks of this technology. We then review the state of the art of enzyme immobilization of families GH1, GH13, and GH70, with special attention on the enzymes β-glucosidase, α-amylase, cyclodextrin glycosyltransferase, and dextransucrase. In each case, the immobilization protocols are evaluated considering their positive and negative aspects. Finally, the perspectives on new immobilization methods are briefly presented.

  17. Improvement of Aspergillus flavus saponin hydrolase thermal stability and productivity via immobilization on a novel carrier based on sugarcane bagasse

    Directory of Open Access Journals (Sweden)

    Hala A. Amin

    2018-03-01

    Full Text Available Soyasapogenol B (SB is known to have many biological activities such as hepatoprotective, anti-inflammatory, anti-mutagenic, antiviral and anticancer activities. Enzymatic conversion of soyasaponins to SB was carried out using saponin hydrolase (SH extracted from Aspergillus flavus. The partially purified enzyme was immobilized on different carriers by physical adsorption, covalent binding or entrapment. Among the investigated carriers, Eupergit C and sugarcane bagasse (SCB activated by DIC and NHS were the most suitable two carriers for immobilization (the immobilized forms recovered 46.5 and 37.1% of the loaded enzyme activity, respectively. Under optimized immobilization conditions, immobilized SH on Eupergit C and on activated SBC recovered 87.7 and 83.3% of its original activity, respectively. Compared to free SH, immobilized SH on Eupergit C and on activated SCB showed higher optimum pH, activation energy, half-lives and lower deactivation constant rate. Also, their SB productivities were improved by 2.3- and 2.2-folds compared to free SH (87.7 and 83.3 vs. 37.5%, respectively. Hence, being SCB more sustainable and an inexpensive material, it can be considered a good alternative to Eupergit C as a support for SH immobilization. SH immobilization on industrially applicable and inexpensive carrier is necessary to improve SB yield and reduce its production cost. The chemical structure of SCB and the resulting cellulose derivatives were studied by ATR-IR spectroscopy. The thermal analysis technique was used to study the chemical treatment of SCB and coupling with the enzyme. This technique confirmed the removal of lignin and hemicellulose by chemical treatment of SCB.

  18. Covalent Coupling of Organophosphorus Hydrolase Loaded Quantum Dots to Carbon Nanotube/Au Nanocomposite for Enhanced Detection of Methyl Parathion

    Energy Technology Data Exchange (ETDEWEB)

    Du, Dan; Chen, Wenjuan; Zhang, Weiying; Liu, Deli; Li, Haibing; Lin, Yuehe

    2010-02-15

    An amperometric biosensor for highly selective and sensitive determination of methyl parathion (MP) was developed based on dual signal amplification: (1) a large amount of introduced enzyme on the electrode surface and (2) synergistic effects of nanoparticles towards enzymatic catalysis. The fabrication process includes (1) electrochemical deposition of gold nanoparticles by a multi-potential step technique at multiwalled carbon nanotube (MWCNT) film pre-cast on a glassy carbon electrode and (2) immobilization of methyl parathion degrading enzyme (MPDE) onto a modified electrode through CdTe quantum dots (CdTe QDs) covalent attachment. The introduced MWCNT and gold nanoparticles significantly increased the surface area and exhibited synergistic effects towards enzymatic catalysis. CdTe QDs are further used as carriers to load a large amount of enzyme. As a result of these two important enhancement factors, the proposed biosensor exhibited extremely sensitive, perfectly selective, and rapid response to methyl parathion in the absence of a mediator.

  19. Organophosphorus poisoning (acute).

    Science.gov (United States)

    Blain, Peter G

    2011-05-17

    Acetylcholinesterase inhibition by organophosphorus pesticides or organophosphate nerve agents can cause acute parasympathetic system dysfunction, muscle weakness, seizures, coma, and respiratory failure. Prognosis depends on the dose and relative toxicity of the specific compound, as well as pharmacokinetic factors. We conducted a systematic review and aimed to answer the following clinical question: What are the effects of treatments for acute organophosphorus poisoning? We searched: Medline, Embase, The Cochrane Library, and other important databases up to April 2010 (Clinical Evidence reviews are updated periodically; please check our website for the most up-to-date version of this review). We included harms alerts from relevant organisations such as the US Food and Drug Administration (FDA) and the UK Medicines and Healthcare products Regulatory Agency (MHRA). We found 62 systematic reviews, RCTs, or observational studies that met our inclusion criteria. We performed a GRADE evaluation of the quality of evidence for interventions. In this systematic review we present information relating to the effectiveness and safety of the following interventions: activated charcoal (single or multiple doses), alpha(2) adrenergic receptor agonists, atropine, benzodiazepines, butyrylcholinesterase replacement therapy, cathartics, extracorporeal clearance, gastric lavage, glycopyrronium bromide (glycopyrrolate), ipecacuanha (ipecac), magnesium sulphate, milk or other home remedy immediately after ingestion, N-methyl-D-aspartate receptor antagonists, organophosphorus hydrolases, oximes, removing contaminated clothes and washing the poisoned person, and sodium bicarbonate.

  20. An amperometric biosensor based on acetylcholinesterase immobilized onto iron oxide nanoparticles/multi-walled carbon nanotubes modified gold electrode for measurement of organophosphorus insecticides

    Energy Technology Data Exchange (ETDEWEB)

    Chauhan, Nidhi [Department of Biochemistry, M.D. University, Rohtak 124001, Haryana (India); Pundir, Chandra Shekhar, E-mail: pundircs@rediffmail.com [Department of Biochemistry, M.D. University, Rohtak 124001, Haryana (India)

    2011-09-02

    Graphical abstract: The stepwise amperometric biosensor fabrication process and immobilized acetylcholinesterase inhibition in pesticide solution. Highlights: {center_dot} Constructed a novel composite material using Fe{sub 3}O{sub 4}NP and c-MWCNT at Au electrode for electrocatalysis. {center_dot} The properties of nanoparticles modified electrodes were studied by SEM, FTIR, CVs and EIS. {center_dot} The biosensor exhibited good sensitivity (0.475 mA {mu}M{sup -1}) {center_dot} The half life of electrode was 2 months. {center_dot} The sensor was suitable for trace detection of OP pesticide residues in milk and water. - Abstract: An acetylcholinesterase (AChE) purified from maize seedlings was immobilized covalently onto iron oxide nanoparticles (Fe{sub 3}O{sub 4}NP) and carboxylated multi walled carbon nanotubes (c-MWCNT) modified Au electrode. An organophosphorus (OP) biosensor was fabricated using this AChE/Fe{sub 3}O{sub 4}/c-MWCNT/Au electrode as a working electrode, Ag/AgCl as standard and Pt wire as an auxiliary electrode connected through a potentiostat. The biosensor was based on inhibition of AChE by OP compounds/insecticides. The properties of nanoparticles modified electrodes were studied by scanning electron microscopy (SEM), Fourier transform infrared (FTIR), cyclic voltammograms (CVs) and electrochemical impedance spectroscopy (EIS). The synergistic action of Fe{sub 3}O{sub 4}NP and c-MWCNT showed excellent electrocatalytic activity at low potential (+0.4 V). The optimum working conditions for the sensor were pH 7.5, 35 deg. C, 600 {mu}M substrate concentration and 10 min for inhibition by pesticide. Under optimum conditions, the inhibition rates of OP pesticides were proportional to their concentrations in the range of 0.1-40 nM, 0.1-50 nM, 1-50 nM and 10-100 nM for malathion, chlorpyrifos, monocrotophos and endosulfan respectively. The detection limits were 0.1 nM for malathion and chlorpyrifos, 1 nM for monocrotophos and 10 nM for endosulfan. The

  1. Photocatalytic degradation of an organophosphorus pesticide from agricultural waste by immobilized TiO2 under solar radiation

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    Marcia Regina Assalin

    2016-11-01

    Full Text Available This paper describes solar heterogeneous photocatalysis using immobilized TiO2 applied in the treatment of agricultural waste resulting from the application of commercial formulations of methyl parathion. The disappearance of the insecticide, as well as the formation of its metabolite, was monitored by high-performance liquid chromatography-tandem mass spectrometry (LC-MS/MS, while mineralization efficiency was monitored by measurements of total organic carbon (TOC. Toxicity studies were performed using the microcrustacean Artemia salina. The TOC removal efficiency by photocatalytic process was 48.5%. After 45 minutes of treatment, the removal efficiency of methyl parathion was 90%, being completely mineralized at the end of treatment. The formation and removal of the metabolite methyl paraoxon was observed during the photocatalytic process. The photocatalytic treatment resulted in increased microcrustacean mobility, indicating a reduction of acute toxicity.

  2. Surface Chemistry of Enzymes for Detection and Decontamination of Organophosphorus Compounds

    National Research Council Canada - National Science Library

    Leblanc, Roger

    2003-01-01

    ...), organophosphorus acid hydrolase (OPH), and covalent bonding of the enzyme onto the substrate. Results are encouraging and the studied enzymes form stable monolayers at the interface and can be transferred on to the solid substrate...

  3. Preparation of Electrochemical Biosensor for Detection of Organophosphorus Pesticides

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    Ashish Gothwal

    2014-01-01

    Full Text Available Polyvinyl chloride (PVC can be used to develop reaction beaker which acts as electrochemical cell for the measurement of OP pesticides. Being chemically inert, corrosion resistant, and easy in molding to various shapes and size, PVC can be used for the immobilization of enzyme. Organophosphorus hydrolase was immobilized covalently onto the chemically activated inner surface of PVC beaker by using glutaraldehyde as a coupling agent. The carbon nanotubes paste working electrode was constructed for amperometric measurement at a potential of +0.8 V. The biosensor showed optimum response at pH 8.0 with incubation temperature of 40°C. Km and Imax for substrate (methyl parathion were 322.58 µM and 1.1 µA, respectively. Evaluation study showed a correlation of 0.985, which was in agreement with the standard method. The OPH biosensor lost 50% of its initial activity after its regular use for 25 times over a period of 50 days when stored in 0.1 M sodium phosphate buffer, pH 8.0 at 4°C. No interference was observed by interfering species.

  4. Actinide immobilization in the subsurface environment by in-situ treatment with a hydrolytically unstable organophosphorus complexant: Uranyl uptake by calcium phytate

    International Nuclear Information System (INIS)

    Nash, K.L.; Jensen, M.P.; Schmidt, M.A.

    1997-01-01

    In addition to naturally occurring uranium and thorium, actinide ions exist in the subsurface environment as a result of accidental releases and intentional disposal practices associated with nuclear weapons production. These species present a significant challenge to cost-effective remediation of contaminated environments. An attractive approach to decreasing the probability of actinide migration in the subsurface is to transform the ions into a less mobile form by remote treatment. We have under development a process which relies on a polyfunctional organophosphorus complexant to sequester the mobile metal ions by complexation/cation exchange in the near term, and to subsequently decompose, transforming the actinides into insoluble phosphate mineral forms in the long term. Studies to date include identification of a suitable organophosphorus reagent, profiling of its decomposition kinetics, verification of the formation of phosphate mineral phases upon decomposition of the reagent, and extensive comparison of the actinide uptake ability of the calcium salt of the reagent as compared with hydroxyapatite. In this report, we briefly describe the process with focus on the cation exchange behavior of the calcium salt of the organophosphorus sequestrant

  5. Ethanol production with a flocculating mutant of Zymomonas mobilis and immobilized glycoside hydrolases. Ethanolgewinnung mit einer flockenden Mutante von Zymomonas mobilis und immobilisierten Glycosidhydrolasen

    Energy Technology Data Exchange (ETDEWEB)

    Tramm-Werner, S.

    1987-05-25

    A method to extend the substrate spectrum of Z. mobilis was developed. Higher ethanol yields were achieved by simultaneous use of hydrolases cross-linked with glutar aldehyde together with the flocculating Zymomonas cells (TW 602). Apart from the high product yields, the method is characterized by low susceptibility to infections.

  6. Electron paramagnetic resonance spin label titration: a novel method to investigate random and site-specific immobilization of enzymes onto polymeric membranes with different properties

    International Nuclear Information System (INIS)

    Butterfield, D. Allan; Colvin, Joshua; Liu Jiangling; Wang Jianquan; Bachas, Leonidas; Bhattacharrya, Dibakar

    2002-01-01

    The immobilization of biological molecules onto polymeric membranes to produce biofunctional membranes is used for selective catalysis, separation, analysis, and artificial organs. Normally, random immobilization of enzymes onto polymeric membranes leads to dramatic reduction in activity due to chemical reactions involved in enzyme immobilization, multiple-point binding, etc., and the extent of activity reduction is a function of membrane hydrophilicity (e.g. activity in cellulosic membrane >> polysulfone membrane). We have used molecular biology to effect site-specific immobilization of enzymes in a manner that orients the active site away from the polymeric membrane surface, thus resulting in higher enzyme activity that approaches that in solution and in increased stability of the enzyme relative to the enzyme in solution. A prediction of this site-specific method of enzyme immobilization, which in this study with subtilisin and organophosphorus hydrolase consists of a fusion tag genetically added to these enzymes and subsequent immobilization via the anti-tag antibody and membrane-bound protein A, is that the active site conformation will more closely resemble that of the enzyme in solution than is the case for random immobilization. This hypothesis was confirmed using a new electron paramagnetic resonance (EPR) spin label active site titration method that determines the amount of spin label bound to the active site of the immobilized enzyme. This value nearly perfectly matched the enzyme activity, and the results suggested: (a) a spectroscopic method for measuring activity and thus the extent of active enzyme immobilization in membrane, which may have advantages in cases where optical methods can not be used due to light scattering interference; (b) higher spin label incorporation (and hence activity) in enzymes that had been site-specifically immobilized versus random immobilization; (c) higher spin label incorporation in enzymes immobilized onto hydrophilic

  7. Rapid biodegradation of organophosphorus pesticides by Stenotrophomonas sp. G1

    International Nuclear Information System (INIS)

    Deng, Shuyan; Chen, Yao; Wang, Daosheng; Shi, Taozhong; Wu, Xiangwei; Ma, Xin; Li, Xiangqiong; Hua, Rimao; Tang, Xinyun; Li, Qing X.

    2015-01-01

    Highlights: • Stenotrophomonas sp. G1 was isolated from chlorpyrifos contaminated sludge. • Strain G1 is closest to Stenotrophomonas acidaminiphila. • Strain G1 can efficiently degrade 8 organophosphorus pesticides (OPs). • Intracellular methyl parathion hydrolase is responsible for the OP degradation. • Three factors were orthogonally optimized for degradation of methyl parathion. - Abstract: Organophosphorus insecticides have been widely used, which are highly poisonous and cause serious concerns over food safety and environmental pollution. A bacterial strain being capable of degrading O,O-dialkyl phosphorothioate and O,O-dialkyl phosphate insecticides, designated as G1, was isolated from sludge collected at the drain outlet of a chlorpyrifos manufacture plant. Physiological and biochemical characteristics and 16S rDNA gene sequence analysis suggested that strain G1 belongs to the genus Stenotrophomonas. At an initial concentration of 50 mg/L, strain G1 degraded 100% of methyl parathion, methyl paraoxon, diazinon, and phoxim, 95% of parathion, 63% of chlorpyrifos, 38% of profenofos, and 34% of triazophos in 24 h. Orthogonal experiments showed that the optimum conditions were an inoculum volume of 20% (v/v), a substrate concentration of 50 mg/L, and an incubation temperature in 40 °C. p-Nitrophenol was detected as the metabolite of methyl parathion, for which intracellular methyl parathion hydrolase was responsible. Strain G1 can efficiently degrade eight organophosphorus pesticides (OPs) and is a very excellent candidate for applications in OP pollution remediation

  8. Rapid biodegradation of organophosphorus pesticides by Stenotrophomonas sp. G1

    Energy Technology Data Exchange (ETDEWEB)

    Deng, Shuyan; Chen, Yao [Key Laboratory of Agri-food Safety of Anhui Province, Lab of Quality & Safety and Risk Assessment for Agro-products on Storage and Preservation (Hefei), Ministry of Agriculture, School of Resource and Environment, Anhui Agricultural University, Hefei 230036 (China); Wang, Daosheng [School of Life Science, Anhui Agricultural University, Hefei 230036 (China); Shi, Taozhong; Wu, Xiangwei; Ma, Xin; Li, Xiangqiong [Key Laboratory of Agri-food Safety of Anhui Province, Lab of Quality & Safety and Risk Assessment for Agro-products on Storage and Preservation (Hefei), Ministry of Agriculture, School of Resource and Environment, Anhui Agricultural University, Hefei 230036 (China); Hua, Rimao, E-mail: rimaohua@ahau.edu.cn [Key Laboratory of Agri-food Safety of Anhui Province, Lab of Quality & Safety and Risk Assessment for Agro-products on Storage and Preservation (Hefei), Ministry of Agriculture, School of Resource and Environment, Anhui Agricultural University, Hefei 230036 (China); Tang, Xinyun [School of Life Science, Anhui Agricultural University, Hefei 230036 (China); Li, Qing X. [Department of Molecular Biosciences and Bioengineering, University of Hawaii at Manoa, 1955 East–West Road, Honolulu, HI 957822 (United States)

    2015-10-30

    Highlights: • Stenotrophomonas sp. G1 was isolated from chlorpyrifos contaminated sludge. • Strain G1 is closest to Stenotrophomonas acidaminiphila. • Strain G1 can efficiently degrade 8 organophosphorus pesticides (OPs). • Intracellular methyl parathion hydrolase is responsible for the OP degradation. • Three factors were orthogonally optimized for degradation of methyl parathion. - Abstract: Organophosphorus insecticides have been widely used, which are highly poisonous and cause serious concerns over food safety and environmental pollution. A bacterial strain being capable of degrading O,O-dialkyl phosphorothioate and O,O-dialkyl phosphate insecticides, designated as G1, was isolated from sludge collected at the drain outlet of a chlorpyrifos manufacture plant. Physiological and biochemical characteristics and 16S rDNA gene sequence analysis suggested that strain G1 belongs to the genus Stenotrophomonas. At an initial concentration of 50 mg/L, strain G1 degraded 100% of methyl parathion, methyl paraoxon, diazinon, and phoxim, 95% of parathion, 63% of chlorpyrifos, 38% of profenofos, and 34% of triazophos in 24 h. Orthogonal experiments showed that the optimum conditions were an inoculum volume of 20% (v/v), a substrate concentration of 50 mg/L, and an incubation temperature in 40 °C. p-Nitrophenol was detected as the metabolite of methyl parathion, for which intracellular methyl parathion hydrolase was responsible. Strain G1 can efficiently degrade eight organophosphorus pesticides (OPs) and is a very excellent candidate for applications in OP pollution remediation.

  9. Glycoside hydrolases having multiple hydrolase activities

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Zhiwei; Friedland, Gregory D.; Chhabra, Swapnil R.; Chivian, Dylan C.; Simmons, Blake A

    2017-08-08

    Glycoside hydrolases having at least two different hydrolytic activities are provided. In one embodiment, an isolated recombinant hydrolase having at least two activities selected from a group including asparagine derivatives, glutamine derivatives, and histidine derivatives is provided. Further, a method of generating free sugars from a mixture comprising asparagine derivatives, glutamine derivatives, and histidine derivatives is provided.

  10. The organophosphorus extractants

    International Nuclear Information System (INIS)

    Zaoul, B.; Attou, M.; Azzouz, A.

    1989-07-01

    This work consists in a bibliographic review dealing with phosphorus and organophosphorus compounds chemistry and especially with the main extracting agents used in uranium ore treatment. In this context, a special interest is devoted to TBP, D 2 EHPA and TOPO. The content of this work is based on a large bibliography including cca. One hundred references related to many aspects concerning as well the nomenclature, the classification and the chemical structures of the organophosphorus compounds as synthesis methods, purification and analysis of the main extracting agents used in uranium extraction

  11. Construction of genetically engineered bacteria that degrades organophosphorus pesticide residues and can be easily detected by the fluorescence.

    Science.gov (United States)

    Li, Qin; Wang, Pan; Chen, Rui; Li, Wei; Wu, Yi-Jun

    2014-01-01

    Organophosphorus compounds (OPs) are widely used in agriculture and industry and there is increased concern about their toxicological effects in the environment. Bioremediation can offer an efficient and cost-effective option for the removal of OPs. Herein, we describe the construction of a genetically engineered microorganism (GEM) that can degrade OPs and be directly detected and monitored in the environment using an enhanced green fluorescent protein (EGFP) fusion strategy. The coding regions of EGFP, a reporter protein that can fluoresce by itself, and organophosphorus hydrolase (OPH), which has a broad substrate specificity and is able to hydrolyse a number of organophosphorus pesticides, were cloned into the expression vector pET-28b. The fusion protein of EGFP-OPH was expressed in E. coli BL21 (DE3) and the protein expression reached the highest level at 11 h after isopropyl beta-D-thiogalactopyranoside induction. The fluorescence of the GEM was detected by fluorescence spectrophotometry and microscopy, and its ability to degrade OPs was determined by OPH activity assay. Those GEM that express the fusion protein (EGFP and OPH) exhibited strong fluorescence intensity and also potent hydrolase activity, which could be used to degrade organophosphorus pesticide residues in the environment and can also be directly monitored by fluorescence.

  12. Variants of glycoside hydrolases

    Science.gov (United States)

    Teter, Sarah [Davis, CA; Ward, Connie [Hamilton, MT; Cherry, Joel [Davis, CA; Jones, Aubrey [Davis, CA; Harris, Paul [Carnation, WA; Yi, Jung [Sacramento, CA

    2011-04-26

    The present invention relates to variants of a parent glycoside hydrolase, comprising a substitution at one or more positions corresponding to positions 21, 94, 157, 205, 206, 247, 337, 350, 373, 383, 438, 455, 467, and 486 of amino acids 1 to 513 of SEQ ID NO: 2, and optionally further comprising a substitution at one or more positions corresponding to positions 8, 22, 41, 49, 57, 113, 193, 196, 226, 227, 246, 251, 255, 259, 301, 356, 371, 411, and 462 of amino acids 1 to 513 of SEQ ID NO: 2 a substitution at one or more positions corresponding to positions 8, 22, 41, 49, 57, 113, 193, 196, 226, 227, 246, 251, 255, 259, 301, 356, 371, 411, and 462 of amino acids 1 to 513 of SEQ ID NO: 2, wherein the variants have glycoside hydrolase activity. The present invention also relates to nucleotide sequences encoding the variant glycoside hydrolases and to nucleic acid constructs, vectors, and host cells comprising the nucleotide sequences.

  13. Peptidoglycan Hydrolases of Escherichia coli

    Science.gov (United States)

    van Heijenoort, Jean

    2011-01-01

    Summary: The review summarizes the abundant information on the 35 identified peptidoglycan (PG) hydrolases of Escherichia coli classified into 12 distinct families, including mainly glycosidases, peptidases, and amidases. An attempt is also made to critically assess their functions in PG maturation, turnover, elongation, septation, and recycling as well as in cell autolysis. There is at least one hydrolytic activity for each bond linking PG components, and most hydrolase genes were identified. Few hydrolases appear to be individually essential. The crystal structures and reaction mechanisms of certain hydrolases having defined functions were investigated. However, our knowledge of the biochemical properties of most hydrolases still remains fragmentary, and that of their cellular functions remains elusive. Owing to redundancy, PG hydrolases far outnumber the enzymes of PG biosynthesis. The presence of the two sets of enzymes acting on the PG bonds raises the question of their functional correlations. It is difficult to understand why E. coli keeps such a large set of PG hydrolases. The subtle differences in substrate specificities between the isoenzymes of each family certainly reflect a variety of as-yet-unidentified physiological functions. Their study will be a far more difficult challenge than that of the steps of the PG biosynthesis pathway. PMID:22126997

  14. Organophosphorus pesticide poisoning : cases and developments

    NARCIS (Netherlands)

    Aardema, H.; Ligtenberg, J. J. M.; Peters-Polman, O. M.; Tulleken, J. E.; Zijlstra, J. G.; Meertens, John H. J. M.

    Self-poisoning with organophosphate pesticides is a major health problem world-wide. Through the inhibition of acetylcholinesterase, organophosphorus poisoning is characterised by the clinical picture of acute cholinergic crisis. Other manifestations are the intermediate neurotoxic syndrome and

  15. Method for purifying bidentate organophosphorus compounds

    International Nuclear Information System (INIS)

    Schulz, W.W.

    1977-01-01

    Bidentate organophosphorus compounds useful for extracting actinide elements from acidic nuclear waste solutions are purified of undesirable acidic impurities by contacting the compounds with ethylene glycol which preferentially extracts the impurities found in technical grade bidentate compounds

  16. Management of acute organophosphorus pesticide poisoning

    OpenAIRE

    Eddleston, Michael; Buckley, Nick A; Eyer, Peter; Dawson, Andrew H

    2008-01-01

    Summary Organophosphorus pesticide self-poisoning is an important clinical problem in rural regions of the developing world, and kills an estimated 200?000 people every year. Unintentional poisoning kills far fewer people but is a problem in places where highly toxic organophosphorus pesticides are available. Medical management is difficult, with case fatality generally more than 15%. We describe the limited evidence that can guide therapy and the factors that should be considered when design...

  17. of Several Organophosphorus Insecticide Metabolites

    Directory of Open Access Journals (Sweden)

    Russell L. Carr

    2015-01-01

    Full Text Available Paraoxonase (PON1 is a calcium dependent enzyme that is capable of hydrolyzing organophosphate anticholinesterases. PON1 activity is present in most mammals and previous research established that PON1 activity differs depending on the species. These studies mainly used the organophosphate substrate paraoxon, the active metabolite of the insecticide parathion. Using serum PON1 from different mammalian species, we compared the hydrolysis of paraoxon with the hydrolysis of the active metabolites (oxons of two additional organophosphorus insecticides, methyl parathion and chlorpyrifos. Paraoxon hydrolysis was greater than that of methyl paraoxon, but the level of activity between species displayed a similar pattern. Regardless of the species tested, the hydrolysis of chlorpyrifos-oxon was significantly greater than that of paraoxon or methyl paraoxon. These data indicate that chlorpyrifos-oxon is a better substrate for PON1 regardless of the species. The pattern of species differences in PON1 activity varied with the change in substrate to chlorpyrifos-oxon from paraoxon or methyl paraoxon. For example, the sex difference observed here and reported elsewhere in the literature for rat PON1 hydrolysis of paraoxon was not present when chlorpyrifos-oxon was the substrate.

  18. Immobilization of oxidases and their analytical applications

    International Nuclear Information System (INIS)

    Yasinzai, M.

    2007-01-01

    Immobilized enzymes are replacing their soluble counter-parts in nearly every field of application. These enzyme modifications have evolved from a research curiosity into an entire branch of Biotechnology. An immobilization method for flavin containing oxidases and their use in flow injection system is described. An electrochemical detector for H/sub 2/O/sub 2/ is assembled which is used effectively for the determination of glucose using more common glucose oxidase and the simultaneous determination of sugars. The combination of oxidases with hydrolases have been used for the determination of maltose and starch. (author)

  19. Lysophospholipase inhibition by organophosphorus toxicants

    International Nuclear Information System (INIS)

    Quistad, Gary B.; Casida, John E.

    2004-01-01

    Lysophospholipases (LysoPLAs) are a large family of enzymes for removing lysophospholipids from cell membranes. Potent inhibitors are needed to define the importance of LysoPLAs as targets for toxicants and potential therapeutics. This study considers organophosphorus (OP) inhibitors with emphasis on mouse brain total LysoPLA activity relative to the mipafox-sensitive neuropathy target esterase (NTE)-LysoPLA recently established as 17% of the total activity and important in the action of OP delayed toxicants. The most potent inhibitors of total LysoPLA in mouse brain are isopropyl dodecylphosphonofluoridate (also for LysoPLA of Vibrio bacteria), ethyl octylphosphonofluoridate (EOPF), and two alkyl-benzodioxaphosphorin 2-oxides (BDPOs)[(S)-octyl and dodecyl] (IC50 2-8 nM). OP inhibitors acting in vitro and in vivo differentiate a more sensitive portion but not a distinct NTE-LysoPLA compared with total LysoPLA activity. For 10 active inhibitors, NTE-LysoPLA is 17-fold more sensitive than total LysoPLA, but structure-activity comparisons give a good correlation (r 2 = 0.94) of IC50 values, suggesting active site structural similarity or identity. In mice 4 h after intraperitoneal treatment with discriminating doses, EOPF, tribufos (a plant defoliant), and dodecanesulfonyl fluoride inhibit 41-57% of the total brain LysoPLA and 85-99% of the NTE-LysoPLA activity. Total LysoPLA as well as NTE-LysoPLA is decreased in activity in Nte +/- -haploinsufficient mice compared to their Nte +/+ littermates. The lysolecithin level of spinal cord but not brain is elevated significantly following EOPF treatment (3 mg/kg), thereby focusing attention on localized rather than general alterations in lysophospholipid metabolism in OP-induced hyperactivity and toxicity

  20. CELL SURFACE DISPLAY OF ORGANOPHOSPHORUS HYDROLASE USING ICE NUCLEATION PROTEIN. (R827227)

    Science.gov (United States)

    The perspectives, information and conclusions conveyed in research project abstracts, progress reports, final reports, journal abstracts and journal publications convey the viewpoints of the principal investigator and may not represent the views and policies of ORD and EPA. Concl...

  1. Efficacious Oxime for Organophosphorus Poisoning: A Minireview

    African Journals Online (AJOL)

    Erah

    Abstract. Oximes are well known as acetylcholinesterase reactivators and are used in ... activity against structurally different kinds of organophosphorus ... serious threat with regard to occupational .... choose an oxime for unknown OPC exposure. Secondly, there is a lack of .... oximes, and hence cannot pass the blood.

  2. A retrospective analysis of acute organophosphorus poisoning ...

    African Journals Online (AJOL)

    A retrospective analysis of acute organophosphorus poisoning cases admitted to the tertiary care teaching hospital in South India. ... Young adult males were more commonly involved than females (M:F 2.5:1). The mean age of the patients was 28 years (range 2-72 years, SD ± 14.3 years). Mean time to receive treatment ...

  3. A retrospective analysis of acute organophosphorus poisoning ...

    African Journals Online (AJOL)

    organophosphorus (OP) poisoning cases in a tertiary care hospital. Materials and ... In a pre-structured proforma, data regarding age, sex, time elapsed after intake, circumstances of poisoning, duration of hospitalization ... responsible for majority of self-attempted deaths ... cleansed with water at the time of admission.

  4. Determination of selected organophosphorus pesticides using GC ...

    African Journals Online (AJOL)

    A reproducible analytical method utilising GC-MS is presented for the analysis of thirteen organophosphorus insecticides (OPs) often found in environmental aqueous samples. Extraction of filtered river and canal water (100 mL), fortified with the OPs, was conducted using solid-phase extraction and eluted with a variety of ...

  5. Efficacious Oxime for Organophosphorus Poisoning: A Minireview ...

    African Journals Online (AJOL)

    Oximes are well known as acetylcholinesterase reactivators and are used in organophosphorus poisoning to reactivate inhibited acetylcholinesterase. Therapeutically available oximes, namely, pralidoxime (2-PAM), obidoxime, trimedoxime and Hagedorn oxime (HI-6), have no broad-spectrum activity against structurally ...

  6. Microorganism immobilization

    Science.gov (United States)

    Compere, Alicia L.; Griffith, William L.

    1981-01-01

    Live metabolically active microorganisms are immobilized on a solid support by contacting particles of aggregate material with a water dispersible polyelectrolyte such as gelatin, crosslinking the polyelectrolyte by reacting it with a crosslinking agent such as glutaraldehyde to provide a crosslinked coating on the particles of aggregate material, contacting the coated particles with live microorganisms and incubating the microorganisms in contact with the crosslinked coating to provide a coating of metabolically active microorganisms. The immobilized microorganisms have continued growth and reproduction functions.

  7. Biochemical Markers for Exposure to Low Doses of Organophosphorus Insecticides

    National Research Council Canada - National Science Library

    Lockridge, Oksana

    2003-01-01

    Though acetylcholinesterase is the primary target of organophosphorus toxicants, our finding that acetylcholinesterase knockout mice are supersensitive to the lethal effects of VX, DFP, chlorpyrifos...

  8. Biochemical Markers for Exposure to Low Doses of Organophosphorus Insecticides

    National Research Council Canada - National Science Library

    Lockridge, Oksana

    2004-01-01

    Though acetylcholinesterase is the primary target of organophosphorus toxicants, our finding that acetylcholinesterase knockout mice are supersensitive to the lethal effects of VX, DFP, chlorpyrifos...

  9. Biochemical Markers for Exposure to Low Doses of Organophosphorus Insecticides

    National Research Council Canada - National Science Library

    Lockridge, Oksana

    2002-01-01

    Though acetyicholinesterase is the primary target of organophosphorus toxicants, our finding that acetyicholinesterase knockout mice are supersensitive to the lethal effects of VX, DFP, chlorpyrifos...

  10. Different approaches to acute organophosphorus poison treatment.

    Science.gov (United States)

    Nurulain, Syed Muhammad

    2012-07-01

    Organophosphorus compounds (OPCs) have a wide variety of applications and are a serious threat for self-poisoning, unintentional misuse, terrorist attack, occupational hazard and warfare attack. The present standard treatment has been reported to be unsatisfactory. Many novel approaches are being used and tested for acute organophosphorus (OP) poison treatment. The bioscavenger concept captured high attention among the scientific community during the last few decades. Other approaches like alkalinisation of blood plasma/serum and use of weak inhibitors against strong inhibitors, though it showed promising results, did not get such wide attention. The introduction of a novel broad-spectrum oxime has also been in focus. In this mini-review, an update of the overview of four different approaches has been discussed. The standard therapy that is atropine+oxime+benzodiazepine along with supportive measures will continue to be the best option with only the replacement of a single oxime to improve its broad-spectrum efficacy.

  11. Management of acute organophosphorus pesticide poisoning.

    Science.gov (United States)

    Eddleston, Michael; Buckley, Nick A; Eyer, Peter; Dawson, Andrew H

    2008-02-16

    Organophosphorus pesticide self-poisoning is an important clinical problem in rural regions of the developing world, and kills an estimated 200,000 people every year. Unintentional poisoning kills far fewer people but is a problem in places where highly toxic organophosphorus pesticides are available. Medical management is difficult, with case fatality generally more than 15%. We describe the limited evidence that can guide therapy and the factors that should be considered when designing further clinical studies. 50 years after first use, we still do not know how the core treatments--atropine, oximes, and diazepam--should best be given. Important constraints in the collection of useful data have included the late recognition of great variability in activity and action of the individual pesticides, and the care needed cholinesterase assays for results to be comparable between studies. However, consensus suggests that early resuscitation with atropine, oxygen, respiratory support, and fluids is needed to improve oxygen delivery to tissues. The role of oximes is not completely clear; they might benefit only patients poisoned by specific pesticides or patients with moderate poisoning. Small studies suggest benefit from new treatments such as magnesium sulphate, but much larger trials are needed. Gastric lavage could have a role but should only be undertaken once the patient is stable. Randomised controlled trials are underway in rural Asia to assess the effectiveness of these therapies. However, some organophosphorus pesticides might prove very difficult to treat with current therapies, such that bans on particular pesticides could be the only method to substantially reduce the case fatality after poisoning. Improved medical management of organophosphorus poisoning should result in a reduction in worldwide deaths from suicide.

  12. Analysis of organophosphorus pesticides using FT-NMR

    International Nuclear Information System (INIS)

    Miyata, Yoshihiko; Takahashi, Yoshikazu; Ando, Hiroaki

    1988-01-01

    A rapid and highly selective method of the identification of 23 kinds of organophosphorus pesticides was develop by using 31 P FT-NMR with 1 H complete decoupling method. Chemical shifts referenced by 85 % H 3 PO 4 were within -4 to 100 ppm, and there was no overlapping among the organophosphorus pesticides used in this experiment. (author)

  13. Lysophosphatidic acids are new substrates for the phosphatase domain of soluble epoxide hydrolase[S

    OpenAIRE

    Oguro, Ami; Imaoka, Susumu

    2012-01-01

    Soluble epoxide hydrolase (sEH) is a bifunctional enzyme that has a C-terminus epoxide hydrolase domain and an N-terminus phosphatase domain. The endogenous substrates of epoxide hydrolase are known to be epoxyeicosatrienoic acids, but the endogenous substrates of the phosphatase activity are not well understood. In this study, to explore the substrates of sEH, we investigated the inhibition of the phosphatase activity of sEH toward 4-methylumbelliferyl phosphate by using lecithin and its hyd...

  14. Towards a Capacitive Enzyme Sensor for Direct Determination of Organophosphorus Pesticides: Fundamental Studies and Aspects of Development

    Directory of Open Access Journals (Sweden)

    Ashok Mulchandani

    2003-06-01

    Full Text Available The realisation of a miniaturised potentiometric enzyme biosensor is presented. The biosensor chip utilises the enzyme organophosphorus hydrolase (OPH for the direct determination of pesticides. The transducer structure of the sensors chip consists of a pH-sensitive capacitive electrolyte-insulator-semiconductor (EIS structure that reacts towards pH changes caused by the OPH-catalised hydrolysis of the organophosphate compounds. The biosensor is operated versus a conventional Ag/AgCl reference electrode. Measurements were performed in the capacitance/voltage (C/V and the constant capacitance (ConCap mode for the two different pesticides paraoxon and parathion. For the development of this new type of biosensor, different immobilisation strategies, influence of buffer composition and concentration, transducer material, detection limit, long-term stability and selectivity have been studied.

  15. Development of organophosphate hydrolase activity in a bacterial homolog of human cholinesterase

    Science.gov (United States)

    Legler, Patricia; Boisvert, Susanne; Compton, Jaimee; Millard, Charles

    2014-07-01

    We applied a combination of rational design and directed evolution (DE) to Bacillus subtilis p-nitrobenzyl esterase (pNBE) with the goal of enhancing organophosphorus acid anhydride hydrolase (OPAAH) activity. DE started with a designed variant, pNBE A107H, carrying a histidine homologous with human butyrylcholinesterase G117H to find complementary mutations that further enhance its OPAAH activity. Five sites were selected (G105, G106, A107, A190, and A400) within a 6.7 Å radius of the nucleophilic serine O?. All 95 variants were screened for esterase activity with a set of five substrates: pNP-acetate, pNP-butyrate, acetylthiocholine, butyrylthiocholine, or benzoylthiocholine. A microscale assay for OPAAH activity was developed for screening DE libraries. Reductions in esterase activity were generally concomitant with enhancements in OPAAH activity. One variant, A107K, showed an unexpected 7-fold increase in its kcat/Km for benzoylthiocholine, demonstrating that it is also possible to enhance the cholinesterase activity of pNBE. Moreover, DE resulted in at least three variants with modestly enhanced OPAAH activity compared to wild type pNBE. A107H/A190C showed a 50-fold increase in paraoxonase activity and underwent a slow time- and temperature-dependent change affecting the hydrolysis of OPAA and ester substrates. Structural analysis suggests that pNBE may represent a precursor leading to human cholinesterase and carboxylesterase 1 through extension of two vestigial specificity loops; a preliminary attempt to transfer the Ω-loop of BChE into pNBE is described. pNBE was tested as a surrogate scaffold for mammalian esterases. Unlike butyrylcholinesterase and pNBE, introducing a G143H mutation (equivalent to G117H) did not confer detectable OP hydrolase activity on human carboxylesterase 1. We discuss the importance of the oxyanion-hole residues for enhancing the OPAAH activity of selected serine hydrolases.

  16. Optimization of Cholinesterase-Based Catalytic Bioscavengers Against Organophosphorus Agents.

    Science.gov (United States)

    Lushchekina, Sofya V; Schopfer, Lawrence M; Grigorenko, Bella L; Nemukhin, Alexander V; Varfolomeev, Sergei D; Lockridge, Oksana; Masson, Patrick

    2018-01-01

    Organophosphorus agents (OPs) are irreversible inhibitors of acetylcholinesterase (AChE). OP poisoning causes major cholinergic syndrome. Current medical counter-measures mitigate the acute effects but have limited action against OP-induced brain damage. Bioscavengers are appealing alternative therapeutic approach because they neutralize OPs in bloodstream before they reach physiological targets. First generation bioscavengers are stoichiometric bioscavengers. However, stoichiometric neutralization requires administration of huge doses of enzyme. Second generation bioscavengers are catalytic bioscavengers capable of detoxifying OPs with a turnover. High bimolecular rate constants ( k cat / K m > 10 6 M -1 min -1 ) are required, so that low enzyme doses can be administered. Cholinesterases (ChE) are attractive candidates because OPs are hemi-substrates. Moderate OP hydrolase (OPase) activity has been observed for certain natural ChEs and for G117H-based human BChE mutants made by site-directed mutagenesis. However, before mutated ChEs can become operational catalytic bioscavengers their dephosphylation rate constant must be increased by several orders of magnitude. New strategies for converting ChEs into fast OPase are based either on combinational approaches or on computer redesign of enzyme. The keystone for rational conversion of ChEs into OPases is to understand the reaction mechanisms with OPs. In the present work we propose that efficient OP hydrolysis can be achieved by re-designing the configuration of enzyme active center residues and by creating specific routes for attack of water molecules and proton transfer. Four directions for nucleophilic attack of water on phosphorus atom were defined. Changes must lead to a novel enzyme, wherein OP hydrolysis wins over competing aging reactions. Kinetic, crystallographic, and computational data have been accumulated that describe mechanisms of reactions involving ChEs. From these studies, it appears that introducing

  17. Optimization of Cholinesterase-Based Catalytic Bioscavengers Against Organophosphorus Agents

    Directory of Open Access Journals (Sweden)

    Sofya V. Lushchekina

    2018-03-01

    Full Text Available Organophosphorus agents (OPs are irreversible inhibitors of acetylcholinesterase (AChE. OP poisoning causes major cholinergic syndrome. Current medical counter-measures mitigate the acute effects but have limited action against OP-induced brain damage. Bioscavengers are appealing alternative therapeutic approach because they neutralize OPs in bloodstream before they reach physiological targets. First generation bioscavengers are stoichiometric bioscavengers. However, stoichiometric neutralization requires administration of huge doses of enzyme. Second generation bioscavengers are catalytic bioscavengers capable of detoxifying OPs with a turnover. High bimolecular rate constants (kcat/Km > 106 M−1min−1 are required, so that low enzyme doses can be administered. Cholinesterases (ChE are attractive candidates because OPs are hemi-substrates. Moderate OP hydrolase (OPase activity has been observed for certain natural ChEs and for G117H-based human BChE mutants made by site-directed mutagenesis. However, before mutated ChEs can become operational catalytic bioscavengers their dephosphylation rate constant must be increased by several orders of magnitude. New strategies for converting ChEs into fast OPase are based either on combinational approaches or on computer redesign of enzyme. The keystone for rational conversion of ChEs into OPases is to understand the reaction mechanisms with OPs. In the present work we propose that efficient OP hydrolysis can be achieved by re-designing the configuration of enzyme active center residues and by creating specific routes for attack of water molecules and proton transfer. Four directions for nucleophilic attack of water on phosphorus atom were defined. Changes must lead to a novel enzyme, wherein OP hydrolysis wins over competing aging reactions. Kinetic, crystallographic, and computational data have been accumulated that describe mechanisms of reactions involving ChEs. From these studies, it appears that

  18. Chlorination of organophosphorus pesticides in natural waters

    Energy Technology Data Exchange (ETDEWEB)

    Acero, Juan L. [Departamento de Ingenieria Quimica y Energetica, Universidad de Extremadura, 06071 Badajoz (Spain)], E-mail: jlacero@unex.es; Benitez, F. Javier; Real, Francisco J.; Gonzalez, Manuel [Departamento de Ingenieria Quimica y Energetica, Universidad de Extremadura, 06071 Badajoz (Spain)

    2008-05-01

    Unknown second-order rate constants for the reactions of three organophosphorus pesticides (chlorpyrifos, chlorfenvinfos and diazinon) with chlorine were determined in the present study, and the influence of pH and temperature was established. It was found that an increase in the pH provides a negative effect on the pesticides degradation rates. Apparent second-order rate constants at 20 {sup o}C and pH 7 were determined to be 110.9, 0.004 and 191.6 M{sup -1} s{sup -1} for chlorpyrifos, chlorfenvinfos and diazinon, respectively. A higher reactivity of chlorine with the phosphorothioate group (chlorpyrifos and diazinon) than with the phosphate moiety (chlorfenvinfos) could explain these results. Intrinsic rate constant for the elementary reactions of chlorine species with chlorpyrifos and diazinon were also calculated, leading to the conclusion that the reaction between hypochlorous acid and the pesticide is predominant at neutral pH. The elimination of these pesticides in surface waters was also investigated. A chlorine dose of 2.5 mg L{sup -1} was enough to oxidize chlorpyrifos and diazinon almost completely, with a formation of trihalomethanes below the EU standard for drinking water. However, the removal of chlorfenvinfos was not appreciable. Therefore, chlorination is a feasible option for the removal of organophosphorus pesticides with phosphorothioate group during oxidation and disinfection processes, but not for the elimination of pesticides with phosphate moiety.

  19. Chlorination of organophosphorus pesticides in natural waters

    International Nuclear Information System (INIS)

    Acero, Juan L.; Benitez, F. Javier; Real, Francisco J.; Gonzalez, Manuel

    2008-01-01

    Unknown second-order rate constants for the reactions of three organophosphorus pesticides (chlorpyrifos, chlorfenvinfos and diazinon) with chlorine were determined in the present study, and the influence of pH and temperature was established. It was found that an increase in the pH provides a negative effect on the pesticides degradation rates. Apparent second-order rate constants at 20 o C and pH 7 were determined to be 110.9, 0.004 and 191.6 M -1 s -1 for chlorpyrifos, chlorfenvinfos and diazinon, respectively. A higher reactivity of chlorine with the phosphorothioate group (chlorpyrifos and diazinon) than with the phosphate moiety (chlorfenvinfos) could explain these results. Intrinsic rate constant for the elementary reactions of chlorine species with chlorpyrifos and diazinon were also calculated, leading to the conclusion that the reaction between hypochlorous acid and the pesticide is predominant at neutral pH. The elimination of these pesticides in surface waters was also investigated. A chlorine dose of 2.5 mg L -1 was enough to oxidize chlorpyrifos and diazinon almost completely, with a formation of trihalomethanes below the EU standard for drinking water. However, the removal of chlorfenvinfos was not appreciable. Therefore, chlorination is a feasible option for the removal of organophosphorus pesticides with phosphorothioate group during oxidation and disinfection processes, but not for the elimination of pesticides with phosphate moiety

  20. QSAR for cholinesterase inhibition by organophosphorus esters and CNDO/2 calculations for organophosphorus ester hydrolysis

    Science.gov (United States)

    Johnson, H.; Kenley, R. A.; Rynard, C.; Golub, M. A.

    1985-01-01

    Quantitative structure-activity relationships were derived for acetyl- and butyrylcholinesterase inhibition by various organophosphorus esters. Bimolecular inhibition rate constants correlate well with hydrophobic substituent constants, and with the presence or absence of catonic groups on the inhibitor, but not with steric substituent constants. CNDO/2 calculations were performed on a separate set of organophosphorus esters, RR'P(O)X, where R and R' are alkyl and/or alkoxy groups and X is fluorine, chlorine or a phenoxy group. For each subset with the same X, the CNDO-derived net atomic charge at the central phosphorus atom in the ester correlates well with the alkaline hydrolysis rate constant. For the whole set of esters with different X, two equations were derived that relate either charge and leaving group steric bulk, or orbital energy and bond order to the hydrogen hydrolysis rate constant.

  1. Treatment Strategies for the NMDA Component of Organophosphorus Convulsions

    National Research Council Canada - National Science Library

    Peterson, Steven

    2003-01-01

    ...) induced status epilepticus (SE) used here as a model of organophosphorus nerve agents. The nonbarbiturate anesthetic propofol was found to induce significant anticonvulsant and neuroprotectant effects in Li-pilo SE...

  2. [Decontamination of organophosphorus compounds: Towards new alternatives].

    Science.gov (United States)

    Poirier, L; Jacquet, P; Elias, M; Daudé, D; Chabrière, E

    2017-05-01

    Organophosphorus coumpounds (OP) are toxic chemicals mainly used for agricultural purpose such as insecticides and were also developed and used as warfare nerve agents. OP are inhibitors of acetylcholinesterase, a key enzyme involved in the regulation of the central nervous system. Chemical, physical and biological approaches have been considered to decontaminate OP. This review summarizes the current and emerging strategies that are investigated to tackle this issue with a special emphasis on enzymatic remediation methods. During the last decade, many studies have been dedicated to the development of biocatalysts for OP removal. Among these, recent reports have pointed out the promising enzyme SsoPox isolated from the archaea Sulfolobus solfataricus. Considering both its intrinsic stability and activity, this hyperthermostable enzyme is highly appealing for the decontamination of OP. Copyright © 2017 Académie Nationale de Pharmacie. All rights reserved.

  3. The Vital Function of Fe3O4@Au nanocomposites for Hydrolase Biosensor Design and Its Application in Detection of Methyl Parathion

    Energy Technology Data Exchange (ETDEWEB)

    Zhao, Yuting; Zhang, Weiying; Lin, Yuehe; Du, Dan

    2013-02-04

    A nanocomposite of gold nanoparticles (AuNPs) decorating a magnetic Fe3O4 core was synthesized using cysteamine (SH–NH2) as linker, and characterized by TEM, XPS, UV and electrochemistry. Then a hydrolase biosensor, based on self-assembly of methyl parathion hydrolase (MPH) on the Fe3O4@Au nanocomposite, was developed for sensitive and selective detection of the organophosphorus pesticide (OP) methyl parathion. The magnetic nanocomposite provides an easy way to construct the enzyme biosensor by simply exerting an external magnetic field, and also provides a simple way to renew the electrode surface by removing the magnet. Unlike inhibition-based enzyme biosensors, the hydrolase is not poisoned by OPs and thus is reusable for continuous measurement. AuNPs not only provide a large surface area, high loading efficiency and fast electron transfer, but also stabilize the enzyme through electrostatic interactions. The MPH biosensor shows rapid response and high selectivity for detection of methyl parathion, with a linear range from 0.5 to 1000 ng/mL and a detection limit of 0.1 ng/mL. It also shows acceptable reproducibility and stability. The simplicity and ease of operation of the proposed method has great potential for on-site detection of P–S containing pesticides and provides a promising strategy to construct a robust biosensor.

  4. Cytosolic cholesterol ester hydrolase in adrenal cortex

    OpenAIRE

    Tocher, Douglas R.

    1983-01-01

    Cholesterol ester hydrolase (CEH) in adrenocortical cytosol was known to be phosphorylated and activated, in response to ACTH in a cAMPdependent protein kinase mediated process. The purification of CEH from bovine adrenocortical cytosol was attempted. The use of detergents to solubilise the enzyme from lipid-rich aggregates was investigated and sodium cholate was found to be effective. A purification procedure using cholate solubilised enzyme was developed. The detergent int...

  5. Production of Self-Purifying Proteins in a Variety of Expression Hosts with Focus on Organophosphorus Hydrolase

    Science.gov (United States)

    2012-08-17

    Manley ,  R.G.  Options  for...0.0015 0.001 0 .0005 0 4 Average Product Yields .... ..... ... • • 5 6 7 8 9 ELP (SOX) Amino Acids • 10 11 12 160 140 "’C 120 -0 LL ...0.005 0 4 5 6 7 8 9 10 11 12 ELP Length (SOX) Amino Acids so 45 "’C 40 -0 35 LL c:: 0 30 ·-..... 25 ro u 20 ·-’+-·-s... ::s 15 0.. 10

  6. FLOW INJECTION AMPEROMETRIC DETECTION OF OP NERVE AGENTS BASED ON AN ORGANOPHOSPHORUS-HYDROLASE BIOSENSOR DETECTOR. (R828160)

    Science.gov (United States)

    The perspectives, information and conclusions conveyed in research project abstracts, progress reports, final reports, journal abstracts and journal publications convey the viewpoints of the principal investigator and may not represent the views and policies of ORD and EPA. Concl...

  7. A 1000-L Scale-Up Fermentation of Escherichia Coli Containing PVSEOP7 for Production of Organophosphorus Hydrolase

    National Research Council Canada - National Science Library

    Lukens, Dennis C; Rastogi, Vipin K; Cheng, Tu-c; DeFrank, Joseph J; Valdes, James J; Kim, Michael H

    2003-01-01

    .... coli XL1 containing pVSEOP7. The specific OPH activity was monitored during each 20-L batch fermentation culture by assaying several times between the IPTG induction point (OD of 0.4 to 0.5 at 600 nm...

  8. Biodegradation of organophosphorus pesticides by soil bacteria

    Science.gov (United States)

    de Pasquale, C.; Fodale, R.; Lo Piccolo, L.; Palazzolo, E.; Alonzo, G.; Quatrini, P.

    2009-04-01

    A number of studies in the 1980s and 1990s showed that crop-protection products, applied to drained fields, could move downwards through the soil profile and to the groundwater. Organophosphorus insecticides (OPs) are used all over the world for crop protection, for other agricultural practices such as sheep dipping and, in aquaculture, for the control of sea lice. Ops besides showing a specific neurotoxicity and have also been related to various modern diseases, including Creutzfeldt-Jakob (CJD) and the Gulf War syndrome. Although OPs are less persistent than Organoclorine pesticides (OCs), they still constitute an environmental risks thus increasing the social concern about their levels in soils, surface waters, and ground waters. Degradation of OPs by microorganisms has been assessed for a few bacterial strains. In the present study the OPs degrading potential of indigenous soil microorganisms was investigated. Using enrichment cultures in which parathion was the only C and energy sources many bacterial strains were isolated from OPs contaminated and pristine agricultural soils characterized by different physico-chemical properties. More than 40 potential OPs degraders were isolated and grouped in operational taxonomic units (OTU) using analysis of polymorphism showed by the ribosomal internal transcribed spacer (ITS). Partial sequencing of 16S rRNA gene of representative isolates of each OTU revealed that most of them belong to Proteobacteria and Actinobacteria. All the analyzed soils showed the presence of putative OPs degraders: the highest diversity was found in organic cultivated soils, the lowest in chemically cultivated soils. Degradation of different OPs, characterized by different physical and chemical properties, was obtained by different selected representative strains using SPME GC-MS analysis on water and soil microcosms. The results showed that, after the incubation period, the amount of pesticide residues were in the range 20-80%. Some of the

  9. Study of Serum Amylase and Serum Cholinesterase in Organophosphorus Poisoning

    Directory of Open Access Journals (Sweden)

    Sharan Badiger

    2016-04-01

    Full Text Available Background: Poisoning due to organophosphorus compounds is most commonly seen. Earlier plasma cholinesterase level was used to assess the severity of poisoning. Presently serum amylase is being recommended as a better indicator of severity. Aims and Objectives: To study plasma cholinesterase and serum amylase levels in acute organophosphorus and to correlate serum amylase levels with clinical severity and outcome. Material and Methods: A total of 80 patients in the study admitted to a tertiary care centre within 24 hours with a history of organophosphorus poisoning were included in study. Estimation of plasma cholinesterase and serum rd amylase was done at the time of admission, and on 3 th day and on 5 day. Results: Occurrence of organophosphorus poisoning was more common among age group 21-30 years and among males (57.5%. They were 25 (31.2% farmers, 23 (28.8% st u d e n ts, a n d 2 2 ( 2 7 . 5% h o u s ewi v e s. Monocrotophos (45.0% was commonly used compound. Mean value of plasma cholinesterase and serum amylase at admission are 3693 U/L, and 185.4 U/L. There was significant inhibition of plasma cholinesterase and elevation of serum amylase at th admission with return to normal values on 5 day. Conclusion: Plasma cholinesterase inhibition 200 U/L has been associated with poor prognosis and proneness to respiratory failure.

  10. Acute organophosphorus compound poisoning in cattle: A case report

    African Journals Online (AJOL)

    A case of an acute organophosphorus compound, GOLDFLEECE poisoning involving 39 cattle at Abubakar Tafawa Balewa University, Bauchi is reported. The animals were overexposed to the compound following routine tick spray. Within 15 minutes after the spray of the compound, 26 animals were recumbent showing ...

  11. Acute organo-phosphorus pesticide poisoning in North Karnataka ...

    African Journals Online (AJOL)

    Background: Pesticide poisoning is an important cause of morbidity and mortality in India. Objectives: To assess the oxidative damage, hemoglobin level and leukocyte count in acute organophosphorus pesticide poisoning. Methods: Plasma cholinesterase was assessed as a toxicity marker. Oxidative damage was ...

  12. Bioprospecting metagenomics of decaying wood: mining for new glycoside hydrolases

    Directory of Open Access Journals (Sweden)

    Li Luen-Luen

    2011-08-01

    Full Text Available Abstract Background To efficiently deconstruct recalcitrant plant biomass to fermentable sugars in industrial processes, biocatalysts of higher performance and lower cost are required. The genetic diversity found in the metagenomes of natural microbial biomass decay communities may harbor such enzymes. Our goal was to discover and characterize new glycoside hydrolases (GHases from microbial biomass decay communities, especially those from unknown or never previously cultivated microorganisms. Results From the metagenome sequences of an anaerobic microbial community actively decaying poplar biomass, we identified approximately 4,000 GHase homologs. Based on homology to GHase families/activities of interest and the quality of the sequences, candidates were selected for full-length cloning and subsequent expression. As an alternative strategy, a metagenome expression library was constructed and screened for GHase activities. These combined efforts resulted in the cloning of four novel GHases that could be successfully expressed in Escherichia coli. Further characterization showed that two enzymes showed significant activity on p-nitrophenyl-α-L-arabinofuranoside, one enzyme had significant activity against p-nitrophenyl-β-D-glucopyranoside, and one enzyme showed significant activity against p-nitrophenyl-β-D-xylopyranoside. Enzymes were also tested in the presence of ionic liquids. Conclusions Metagenomics provides a good resource for mining novel biomass degrading enzymes and for screening of cellulolytic enzyme activities. The four GHases that were cloned may have potential application for deconstruction of biomass pretreated with ionic liquids, as they remain active in the presence of up to 20% ionic liquid (except for 1-ethyl-3-methylimidazolium diethyl phosphate. Alternatively, ionic liquids might be used to immobilize or stabilize these enzymes for minimal solvent processing of biomass.

  13. Hydrolase activity in Jerusalem artichoke and chicory

    Energy Technology Data Exchange (ETDEWEB)

    Klaushofer, H.; Abraham, B.; Leichtfried, G.

    1988-03-01

    Post-harvest storage of chicory and Jerusalem artichoke and overwintering of Jerusalem artichoke in the soil cause a more or less pronounced shortening of the fructan chain, depending on the variety. The proportion of fructose in the total fructan thus shifts towards glucose. This reduction on the fructose/glucose ratio is undesirable if the intention is to obtain a sweetener of high fructose content. In this work an attempt was made, via the quantity of fructose formed after a 4(3)-hour reaction of a tuber (root) extract with inulin, to assign a characteristic value to the depolymerization tendency of the material in question. However, since the plant extract not only contains enzymes (hydrolase A and B) that shorten the fructan chains but the activity of fructosyltransferase (SST, FFT) and enzymes of microbial origin (inulinase II, invertase) must also be considered, the concept of 'hydrolase activity' used by the authors is essentially an expression of 'total activity'. The activity unit (EU) is defined as the ability to split of 1 ..mu..mol of fructose from (chicory) inulin per minute under experimental conditions. Values of 0.25 to 0.77 EU/g dry solids were found in Jerusalem artichoke. Considerable differences may occur between varieties from the same cultivated area and the same harvest period. With one and the same variety, the activity appears to be subject to marked yearly fluctuations, so that at present, because of hydrolase activity, nothing certain can be said about the depolymerization tendency of a variety.

  14. Competitive immunochromatographic assay for the detection of the organophosphorus pesticide chlorpyrifos

    Science.gov (United States)

    Kim, Young Ah; Lee, Eun-Hye; Kim, Kwang-Ok; Lee, Yong Tae; Hammock, Bruce D.; Lee, Hye-Sung

    2014-01-01

    An immunochromatographic assay (ICA) based on competitive antigen-coated format using colloidal gold as the label was developed for the detection of the organophosphorus insecticide chlorpyrifos. The ICA test strip consisted of a membrane with a detection zone, a sample pad and an absorbent pad. The membrane was separately coated with chlorpyrifos hapten-OVA conjugate (test line) and anti-mouse IgG (control line). Based on the fact that the competition is between the migrating analyte in the sample and the analyte hapten immobilized on the test strip for the binding sites of the antibody-colloidal gold (Ab-CG) conjugate migrating on the test strip, this study suggests that the relative migration speed between the two migrating substances is a critically important factor for the sensitive detection by competitive ICA. This criterion was utilized for the confirmation of appropriateness of a nitrocellulose (NC) membrane for chlorpyrifos ICA. The detection limit of the ICA for chlorpyrifos standard and chlorpyrifos spiked into agricultural samples were 10 and 50 ng mL−1, respectively. The assay time for the ICA test was less than 10 min, suitable for rapid on-site testing of chlorpyrifos. PMID:21504817

  15. Zirconium(IV) functionalized magnetic nanocomposites for extraction of organophosphorus pesticides from environmental water samples.

    Science.gov (United States)

    Jiang, Li; Huang, Tengjun; Feng, Shun; Wang, Jide

    2016-07-22

    The widespread use of organophosphate pesticides (OPPs) in agriculture leads to residue accumulation in the environment which is dangerous to human health and disrupts the ecological balance. In this work, one nanocomposite immobilized zirconium (Zr, IV) was prepared and used as the affinity probes to quickly and selectively extract organophosphorus pesticides (OPPs) from water samples. The Fe3O4-ethylenediamine tetraacetic acid (EDTA)@Zr(IV) nanocomposites (NPs) were prepared by simply mixing Zr(IV) ions with Fe3O4-EDTA NPs synthesized by one-pot chemical co-precipitation method. The immobilized Zr(IV) ions were further utilized to capture OPPs based on their high affinity for the phosphate moiety in OPPs. Coupled with GC-MS, four OPPs were used as models to demonstrate the feasibility of this approach. Under the optimum conditions, the limits of detection for target OPPs were in the range of 0.10-10.30ngmL(-1) with relative standard deviations (RSDs) of 0.61-4.40% (n=3), respectively. The linear ranges were over three orders of magnitudes (correlation coefficients, R(2)>0.9995). The Fe3O4-EDTA@Zr(IV) NPs were successfully applied to extract OPPs samples with recoveries of 86.95-112.60% and RSDs of 1.20-10.42% (n=3) from two spiked real water. By the proposed method, the matrix interference could be effectively eliminated. We hope our finding can provide a promising alternative for the fast extraction of OPPs from complex real samples. Copyright © 2016 Elsevier B.V. All rights reserved.

  16. Denaturation/Renaturation of Organophosphorus Acid Anhydrolase (OPAA) Using Guanidinium Hydrochloride and Urea

    National Research Council Canada - National Science Library

    Ong, K. K; Sun, Z; Cheng, T. C; Wei, Y; Yuan, J. M; Yin, R

    2004-01-01

    .... Using organophosphorus acid anhydrolase (OPAA) as the model protein, a guanidinium hydrochloride and urea denaturation/renaturation study was conducted and measured both optically and enzymatically...

  17. Organophosphorus pentavalent compounds: history, synthetic methods of preparation and application as insecticides and antitumor agents

    International Nuclear Information System (INIS)

    Santos, Viviane Martins Rebello dos; Donnici, Claudio Luis; DaCosta, Joao Batista Neves; Caixeiro, Janaina Marques Rodrigues

    2007-01-01

    This paper is a review of the history, synthesis and application of organophosphorus compounds, especially of those of pentavalent phosphorus, such as phosphoramidates, phosphorothioates, phosphonates and phosphonic acids with insecticide and anticancer activities. The organophosphorus compounds with agrochemical applications show great structural variety, They include not only insecticides, but also fungicides, herbicides, and others. The large variety of commercially available organophosphorus pesticides is remarkable. Even more interesting is the high efficiency of some organophosphorus compounds as anticancer agents such as cyclophosphamide and its derivatives. (author)

  18. Immobilized enzymes and cells

    Energy Technology Data Exchange (ETDEWEB)

    Bucke, C; Wiseman, A

    1981-04-04

    This article reviews the current state of the art of enzyme and cell immobilization and suggests advances which might be made during the 1980's. Current uses of immobilized enzymes include the use of glucoamylase in the production of glucose syrups from starch and glucose isomerase in the production of high fructose corn syrup. Possibilities for future uses of immobilized enzymes and cells include the utilization of whey and the production of ethanol.

  19. Biodegradation and Utilization of Organophosphorus Pesticide Malathion by Cyanobacteria

    Directory of Open Access Journals (Sweden)

    Wael M. Ibrahim

    2014-01-01

    Full Text Available Three strains of filamentous Cyanobacteria were used to study their growth and utilization of organophosphorus pesticide malathion. A sharp decrease in the growth of the algal strains was observed by increasing the concentration of malathion. Amongst them Nostoc muscorum tolerated different concentrations and was recorded as the highest efficient strain for biodegradation (91% of this compound. Moreover, carbohydrate and protein content of their cells overtopped the other strains especially at higher concentrations. The algal strains were further subjected to grow under P-limitation in absence and presence of malathion. Although, the algal growth under P-limitation recorded a very poor level, a massive enhanced growth and phosphorous content of cells were obtained when the P-limited medium was amended with malathion. This study clarified that N. muscorum with its capability to utilize malathion as a sole phosphorous source is considered as an inexpensive and efficient biotechnology for remediation of organophosphorus pesticide from contaminated wastewater.

  20. Acute organophosphorus poisoning complicated by acute coronary syndrome.

    Science.gov (United States)

    Pankaj, Madhu; Krishna, Kavita

    2014-07-01

    We report a case of 30 year old alcoholic male admitted with vomiting, drowsiness, limb weakness and fasciculations after alleged history of consumption of 30 ml of chlorpyriphos insecticide. He had low serum cholinesterase levels. With standard treatment for organophosphorus poisoning (OPP), he improved gradually until day 5, when he developed neck and limb weakness and respiratory distress. This intermediate syndrome was treated with oximes, atropine and artificial ventilation. During treatment, his ECG showed fresh changes of ST elevation. High CPK & CPK-MB levels, septal hypokinesia on 2D echo suggested acute coronary syndrome. Coronary angiography was postponed due to his bedridden and obtunded status. The patient finally recovered fully by day 15 and was discharged. Acute coronary syndrome is a rare occurrence in OP poisoning. The present case thus emphasises the need for careful electrocardiographic and enzymatic monitoring of all patients of organophosphorus poisoning to prevent potential cardiac complication which can prove fatal.

  1. Novel organophosphorus compounds; synthesis, spectroscopy and X-ray crystallography

    Czech Academy of Sciences Publication Activity Database

    Shariatinia, Z.; Sohrabi, M.; Yousefi, M.; Kovaľ, Tomáš; Dušek, Michal

    2012-01-01

    Roč. 11, č. 2 (2012), s. 125-133 ISSN 1024-1221 Grant - others:AV ČR(CZ) AP0701 Program:Akademická prémie - Praemium Academiae Institutional research plan: CEZ:AV0Z10100521 Keywords : organophosphorus compounds * NMR * X-ray crystallography * hydrogen bond Subject RIV: BM - Solid Matter Physics ; Magnetism Impact factor: 0.686, year: 2012

  2. The application of green chemistry methods in organophosphorus synthesis

    International Nuclear Information System (INIS)

    Odinets, Irina L; Matveeva, E V

    2012-01-01

    Data concerning the synthesis of organophosphorus compounds in ionic liquids, in water and under solvent-free conditions are considered and summarized. It is shown that this strategy, which complies with the definition of green chemistry, has advantages in terms of the rate of the process and the yields of target products as compared with syntheses in common organic solvents. The Wittig, Horner–Wadsworth–Emmons, Kabachnik–Fields, Arbuzov and Michaelis reactions are considered as examples. The bibliography includes 178 references.

  3. Improvement of the homogeneity of protein-imprinted polymer films by orientated immobilization of the template

    International Nuclear Information System (INIS)

    Liu Lijian; Zheng Jingjing; Fang Guijie; Xie Weihong

    2012-01-01

    Highlights: ► MPH was genetically modified at its C-terminal with (Gly-Ser) 5 –Cys. ► MPH-L was immobilized with fixed orientation via disulfide chemistry. ► The immobilized MPH-L retained the activity of MPH. ► MPH-L formed a homogeneous template. ► Homogeneous MIP film was obtained with orientated immobilization of the template. - Abstract: A method for preparing homogeneous protein-imprinted polymer films with orientated immobilization of template is described. The template methyl parathion hydrolase (MPH) was modified with a peptide linker (Gly-Ser) 5 –Cys and was immobilized on a cover glass with a fixed orientation via the linker. The activity of the fusion enzyme (MPH-L) was evaluated by determining the product's absorbance at 405 nm (A 405 ). Both the free and the immobilized MPH-L showed higher retention of the bioactivity than the wide type enzyme (MPH-W) as revealed by the A 405 values for MPH-L free /MPH-W free (1.159/1.111) and for MPH-L immobilized /MPH-W immobilized (0.348/0.118). The immobilized MPH-L also formed a more homogeneous template stamp compared to the immobilized MPH-W. The molecularly imprinted polymer films prepared with the immobilized MPH-L exhibited high homogeneity with low Std. Deviations of 80 and 200 from the CL intensity mean volumes which were observed for batch-prepared films and an individual film, respectively. MPH-L-imprinted polymer film also had a larger template binding capacity indicated by higher CL intensity mean volume of 3900 INT over 2500 INT for MPH-W-imprinted films. The imprinted film prepared with the orientated immobilization of template showed an imprinting factor of 1.7, while the controls did not show an imprinting effect.

  4. Lysophosphatidic acids are new substrates for the phosphatase domain of soluble epoxide hydrolase[S

    Science.gov (United States)

    Oguro, Ami; Imaoka, Susumu

    2012-01-01

    Soluble epoxide hydrolase (sEH) is a bifunctional enzyme that has a C-terminus epoxide hydrolase domain and an N-terminus phosphatase domain. The endogenous substrates of epoxide hydrolase are known to be epoxyeicosatrienoic acids, but the endogenous substrates of the phosphatase activity are not well understood. In this study, to explore the substrates of sEH, we investigated the inhibition of the phosphatase activity of sEH toward 4-methylumbelliferyl phosphate by using lecithin and its hydrolyzed products. Although lecithin itself did not inhibit the phosphatase activity, the hydrolyzed lecithin significantly inhibited it, suggesting that lysophospholipid or fatty acid can inhibit it. Next, we investigated the inhibition of phosphatase activity by lysophosphatidyl choline, palmitoyl lysophosphatidic acid, monopalmitoyl glycerol, and palmitic acid. Palmitoyl lysophosphatidic acid and fatty acid efficiently inhibited phosphatase activity, suggesting that lysophosphatidic acids (LPAs) are substrates for the phosphatase activity of sEH. As expected, palmitoyl, stearoyl, oleoyl, and arachidonoyl LPAs were efficiently dephosphorylated by sEH (Km, 3–7 μM; Vmax, 150–193 nmol/min/mg). These results suggest that LPAs are substrates of sEH, which may regulate physiological functions of cells via their metabolism. PMID:22217705

  5. Glycoside Hydrolases across Environmental Microbial Communities.

    Directory of Open Access Journals (Sweden)

    Renaud Berlemont

    2016-12-01

    Full Text Available Across many environments microbial glycoside hydrolases support the enzymatic processing of carbohydrates, a critical function in many ecosystems. Little is known about how the microbial composition of a community and the potential for carbohydrate processing relate to each other. Here, using 1,934 metagenomic datasets, we linked changes in community composition to variation of potential for carbohydrate processing across environments. We were able to show that each ecosystem-type displays a specific potential for carbohydrate utilization. Most of this potential was associated with just 77 bacterial genera. The GH content in bacterial genera is best described by their taxonomic affiliation. Across metagenomes, fluctuations of the microbial community structure and GH potential for carbohydrate utilization were correlated. Our analysis reveals that both deterministic and stochastic processes contribute to the assembly of complex microbial communities.

  6. Immobilized waste leaching

    International Nuclear Information System (INIS)

    Suarez, A.A.

    1989-01-01

    The main mechanism by which the immobilized radioactive materials can return to biosphere is the leaching due to the intrusion of water into the repositories. Some mathematical models and experiments utilized to evaluate the leaching rates in different immobilization matrices are described. (author) [pt

  7. Novel microbial epoxide hydrolases for biohydrolysis of glycidyl derivatives

    Czech Academy of Sciences Publication Activity Database

    Kotík, Michael; Břicháč, Jiří; Kyslík, Pavel

    2005-01-01

    Roč. 120, - (2005), s. 364-375 ISSN 0168-1656 Institutional research plan: CEZ:AV0Z5020903 Keywords : screening * epoxide hydrolase * biotransformation Subject RIV: EE - Microbiology, Virology Impact factor: 2.687, year: 2005

  8. Use of full recovery hydrolasing equipment for facility decommissioning - 16325

    International Nuclear Information System (INIS)

    Martin, Scott A.; Adams, Scott R.

    2009-01-01

    The removal of surface contamination is a major challenge for nearly all nuclear facilities undergoing, or awaiting, decommissioning. Conventional means of surface decontamination can expose workers to unnecessary hazards, and are often not fit-for-purpose due to size constraints or weight restrictions. Additionally, conventional methods are not always easily deployed remotely due to their complexity or required services. The use of ultra high pressure water for surface decontamination, known as hydrolasing, is recognized as a technology which can be used in various applications requiring surface removal. Hydrolasing is an advantageous technology for many reasons including its versatility, overall simplicity and relative ease of remote deployment. For the nuclear industry, one of the largest challenges with regards to the use of hydrolasing is the requirement for the full recovery of the injected water and removed solids. For nonnuclear applications, there is often no requirement for recovery of the liquid and solid waste, which has led to few system designs which will recover the waste in full. S.A. Robotics' experience with the deployment of ultra high pressure water systems for nuclear applications has shown that full recovery of injected water and removed solids is achievable in both underwater and in-air applications. Innovative equipment and system design have allowed S.A. Robotics' hydrolasing systems to achieve near 100% solid and liquid recovery during concrete hydrolasing. This technology has been deployed for Fluor Hanford at Hanford's K-Basins, as well as for UKAEA as part of the Windscale Piles decommissioning project. The purpose of this paper is to provide a short description of the hydrolasing process and the associated waste issues, describe the unique design features of S.A. Robotics' hydrolasing systems which combat these issues, and provide an overview of two of the hydrolasing projects that S.A. Robotics has completed. (authors)

  9. Plutonium Disposition by Immobilization

    International Nuclear Information System (INIS)

    Gould, T.; DiSabatino, A.; Mitchell, M.

    2000-01-01

    The ultimate goal of the Department of Energy (DOE) Immobilization Project is to develop, construct, and operate facilities that will immobilize between 17 to 50 tonnes (MT) of U.S. surplus weapons-usable plutonium materials in waste forms that meet the ''spent fuel'' standard and are acceptable for disposal in a geologic repository. Using the ceramic can-in-canister technology selected for immobilization, surplus plutonium materials will be chemically combined into ceramic forms which will be encapsulated within large canisters of high level waste (HLW) glass. Deployment of the immobilization capability should occur by 2008 and be completed within 10 years. In support of this goal, the DOE Office of Fissile Materials Disposition (MD) is conducting development and testing (D and T) activities at four DOE laboratories under the technical leadership of Lawrence Livermore National Laboratory (LLNL). The Savannah River Site has been selected as the site for the planned Plutonium Immobilization Plant (PIP). The D and T effort, now in its third year, will establish the technical bases for the design, construction, and operation of the U. S. capability to immobilize surplus plutonium in a suitable and cost-effective manner. Based on the D and T effort and on the development of a conceptual design of the PIP, automation is expected to play a key role in the design and operation of the Immobilization Plant. Automation and remote handling are needed to achieve required dose reduction and to enhance operational efficiency

  10. Production, enrichment and immobilization of a metagenome-derived epoxide hydrolase

    Czech Academy of Sciences Publication Activity Database

    Grulich, Michal; Maršálek, Jaroslav; Kyslík, Pavel; Štěpánek, Václav; Kotík, Michael

    2011-01-01

    Roč. 46, č. 2 (2011), s. 526-532 ISSN 1359-5113 R&D Projects: GA ČR GAP207/10/0135; GA ČR GAP504/10/0137 Institutional research plan: CEZ:AV0Z50200510 Keywords : Overexpression * Fed-batch * Aqueous two-phase system Subject RIV: EE - Microbiology, Virology Impact factor: 2.627, year: 2011

  11. The brain imaging study of the organophosphorus pesticides poisoning

    International Nuclear Information System (INIS)

    Yang Yanmei; Liu Huaijun; Li Shuling; Wang Yongsheng; Huang Boyuan; Chi Cen; Shi Zhenyang; Cui Caixia; Zhou Lixia; Liu Runtian

    2004-01-01

    Objective: To summarize the CT and MR imaging findings in acute organophosphorus pesticides poisoning patients, and to improve the early diagnostic ability. Methods: The imaging of 34 patients of organophosphorus pesticides poisoning was analyzed, the poisons were all taken orally. The pesticides included methamidophos (12 cases), omethoate (15 cases), DDV (3 cases), and methylparathion (4 cases). According to the diagnosis and classification diagnosis criterion of acute organophosphorus pesticides poisoning, the patients were divided into two groups: mild or moderate grade group (24 cases) and severe grade group (10 cases). The relationship between the clinic grade and CT and MRI findings was studied. Results: in the severe grade group, 4 patients showed brain edema, presenting as sulcus and fissure flattened or disappeared, and ventricles and cisterns narrowed or closed 2-3 days after poisoning. In 3 patients 3 days to 3 months after poisoning, bilateral basal ganglion and cerebral cortex showed prolonged T 1 and T 2 signals, and high signal intensity was detected on FLAIR, and bilateral basal ganglion low density was revealed on CT. T 1 relaxation was shortened, T 2 WI and FLAIR imaging showed high signal intensity in 1 patient. The imaging of 1 patient 6 months after poisoning showed the cerebral sulcus, fissure and ventricle were enlarged. CT and MRI in the mild or moderate group were normal. By the Fisher's exact probabilities test, the imaging exhibition difference between the severe grade and mild or moderate grade patients was significant. Conclusion: The CT and MRI can reflect the brain injury after poisoning, and the imaging exhibitions were various. The imaging information can provide credible foundation for the therapy for lightening the brain edema and nourishing the brain cell

  12. Multifunctional organophosphorus extractants: a status report on development and applications

    International Nuclear Information System (INIS)

    Schulz, W.W.; Horwitz, E.P.

    1988-01-01

    Up-to-date state of the development of science and technology of multifunctional organophosphorus extractants is considered. The detailed classification of these extractants is presented. They attracted pasticular interest because of affinity of some bifunctional phosphonates, phosphine oxides, carbamoylalkylphosphonates to trivalent Am, tetravalent and hexavalent actinides, trivalent lanthanides in strong mineral acids, and because of ability of some alkylpyrophosphoric acids to extract effectively U(4) from concentrated solutions of phosphoric acid. Application of these extractants for analytic purposes and in the field of nuclear technology is considered

  13. [Meta-analysis of association between organophosphorus pesticides and aplastic anemia].

    Science.gov (United States)

    Zhang, Ji; Yang, Tubao

    2015-09-01

    To evaluate the association between organophosphorus pesticides and aplastic anemia, and provide scientific evidence for the primary prevention of aplastic anemia. The published papers of case control studies on the association between organophosphorus pesticides and aplastic anemia from January 1990 to August 2014 were collected from Chinese BioMedical Literature Base (CBM), Chinese National Knowledge Infrastructure (CNKI), PubMed and EMBASE. The papers which met the inclusion criteria were evaluated. The pooled odds ratios (OR) and 95% confidence interval (CI) of organophosphorus pesticides were calculated with software Review Manager 5.0. Subgroup analysis were conducted for different population and different usage of organophosphorus pesticides. A total of 9 papers were selected, involving 5 833 subjects (1 404 cases and 4 429 controls). The results showed that organophosphorus pesticides could increase the risk of aplastic anemia (OR=1.97, 95% CI: 1.60-2.44) . Subgroup analysis showed that Asian (OR=2.01, 95% CI: 1.52-2.66) had higher risk of aplastic anemia than American or European (OR=1.93, 95% CI: 1.39-2.67) . Using pure organophosphorus pesticides (OR=2.15, 95% CI: 1.60-2.88) was more prone to cause aplastic anemia than using the mixture of organophosphorus pesticides (OR=1.82, 95% CI: 1.34-2.47). The analysis indicated that organophosphorus pesticides might be a risk factor for aplastic anemia. Reducing organophosphorus pesticides exposure in daily life and industrial or agricultural production could prevent the incidence of aplastic anemia.

  14. Acute myocardial infarction: Can it be a complication of acute organophosphorus compound poisoning?

    Directory of Open Access Journals (Sweden)

    P Joshi

    2013-01-01

    Full Text Available Organophosphorus compounds are used as pesticides and represent a common cause of poisoning in developing countries including India due to their widespread availability and use. Toxicity due to these agents can affect many organs including heart. Here, we report a case of acute organophosphorus poisoning (parathion, followed by acute myocardial infarction; documented by clinical features, electrocardiographic changes, and elevated cardiac enzymes. Myocardial infarction has been rarely reported with organophosphorus compounds exposure, thus awareness of this complication can reduce morbidity and mortality.

  15. Levels of organophosphorus pesticides in medicinal plants commonly consumed in Iran

    Directory of Open Access Journals (Sweden)

    Sarkhail Parisa

    2012-08-01

    Full Text Available Abstract The frequent occurrence of pesticide residues in herbal materials was indicated by previous studies. In this study, the concentration of some of the organophosphorus pesticides including parathion, malathion, diazinon and pirimiphos methyl in different kinds of medicinal plants were determined. The samples were collected randomly from ten local markets of different areas of Iran. At the detection limit of 0.5 ng g-1, parathion and pirimiphos methyl were not detected in any of the samples. Some amounts of malathion and diazinon were found in Zataria, Matricaria chamomile, Spearmint and Cumin Seed samples while, the concentrations of target organophosphorus pesticides in Borage samples were below the detection limits of the methods which could be a result of intensive transformation of organophosphorus pesticides by Borage. In addition the organophosphorus pesticides were detected in all of the samples below the maximum residue levels (MRLs proposed by the international organizations.

  16. UPTAKE AND PHYTOTRANSFORMATION OF ORGANOPHOSPHORUS PESTICIDES BY AXENICALLY CULTIVATED AQUATIC PLANTS

    Science.gov (United States)

    The uptake and phytotransformation of organophosphorus (OP) pesticides (malathion, demeton-S-methyl, and crufomate) was investigated in vitro using the axenically aquatic cultivated plants parrot feather (Myriophyllum aquaticum), duckweed (Spirodela oligorrhiza L.), and elodea (E...

  17. Modulation of Immune Response by Organophosphorus Pesticides: Fishes as a Potential Model in Immunotoxicology

    Science.gov (United States)

    Díaz-Resendiz, K. J. G.; Toledo-Ibarra, G. A.; Girón-Pérez, M. I.

    2015-01-01

    Immune response is modulated by different substances that are present in the environment. Nevertheless, some of these may cause an immunotoxic effect. In this paper, the effect of organophosphorus pesticides (frequent substances spilled in aquatic ecosystems) on the immune system of fishes and in immunotoxicology is reviewed. Furthermore, some cellular and molecular mechanisms that might be involved in immunoregulation mechanisms of organophosphorus pesticides are discussed. PMID:25973431

  18. Modulation of Immune Response by Organophosphorus Pesticides: Fishes as a Potential Model in Immunotoxicology

    Directory of Open Access Journals (Sweden)

    K. J. G. Díaz-Resendiz

    2015-01-01

    Full Text Available Immune response is modulated by different substances that are present in the environment. Nevertheless, some of these may cause an immunotoxic effect. In this paper, the effect of organophosphorus pesticides (frequent substances spilled in aquatic ecosystems on the immune system of fishes and in immunotoxicology is reviewed. Furthermore, some cellular and molecular mechanisms that might be involved in immunoregulation mechanisms of organophosphorus pesticides are discussed.

  19. Immobilization of microorganisms. Part 1. Preparation of immobilized Lactobacillus bulgaricus

    Energy Technology Data Exchange (ETDEWEB)

    Lee, K H

    1981-01-01

    The immobilization of Lactobacillus bulgaricus on polyacrylamide and on alginate beads was investigated. The most active immobilized cells were obtained by entrapment in Ca alginate beads. These immobilized microbial cells, when introduced into 4.5% lactose solution and whey solution showed maximum relative activity of 28% for lactose and 18% for whey compared to free cells.

  20. Limb immobilization and corticobasal syndrome.

    Science.gov (United States)

    Graff-Radford, Jonathan; Boeve, Bradley F; Drubach, Daniel A; Knopman, David S; Ahlskog, J Eric; Golden, Erin C; Drubach, Dina I; Petersen, Ronald C; Josephs, Keith A

    2012-12-01

    Recently, we evaluated two patients with corticobasal syndrome (CBS) who reported symptom onset after limb immobilization. Our objective was to investigate the association between trauma, immobilization and CBS. The charts of forty-four consecutive CBS patients seen in the Mayo Clinic Alzheimer Disease Research Center were reviewed with attention to trauma and limb immobilization. 10 CBS patients (23%) had immobilization or trauma on the most affected limb preceding the onset or acceleration of symptoms. The median age at onset was 61. Six patients manifested their first symptoms after immobilization from surgery or fracture with one after leg trauma. Four patients had pre-existing symptoms of limb dysfunction but significantly worsened after immobilization or surgery. 23 percent of patients had immobilization or trauma of the affected limb. This might have implications for management of CBS, for avoiding injury, limiting immobilization and increasing movement in the affected limb. Copyright © 2012 Elsevier Ltd. All rights reserved.

  1. Innovative approach for the electrochemical detection of non-electroactive organophosphorus pesticides using oxime as electroactive probe

    International Nuclear Information System (INIS)

    Dong, Jing; Hou, Juying; Jiang, Jianxia; Ai, Shiyun

    2015-01-01

    Highlights: • Novel approach for electrochemical detection of non-electroactive OPs was proposed. • PAM was used as electroactive probe for the first time. • The detection system displayed high sensitivity and promptness. • The developed sensor was used in real samples with satisfactory results. - Abstract: An innovative approach for sensitive and simple electrochemical detection of non-electroactive organophosphorus pesticides (OPs) was described in this report. The novel strategy emphasized the fabrication of an oxime-based sensor via attaching pralidoxime (PAM) on graphene quantum dots (GQDs) modified glassy carbon electrode. The introduction of GQDs significantly increased the effective electrode area, and then enlarged the immobilization quantity of PAM. Thus, the oxidation current of PAM was obviously increased. Relying on the nucleophilic substitution reaction between oxime and OPs, fenthion was detected using PAM as the electroactive probe. Under optimum conditions, the difference of oxidation current of PAM was proportional to fenthion concentration over the range from 1.0 × 10 −11 M to 5.0 × 10 −7 M with a detection limit of 6.8 × 10 −12 M (S/N = 3). Moreover, the favorable detection performance in water and soil samples heralded the promising applications in on-site OPs detection

  2. Organophosphorus flame retardants and plasticizers in the atmosphere of the North Sea

    International Nuclear Information System (INIS)

    Moeller, Axel; Xie Zhiyong; Caba, Armando; Sturm, Renate; Ebinghaus, Ralf

    2011-01-01

    Air samples collected in the German part of the North Sea from March to July 2010 were investigated for organophosphorus compounds (OPs) being applied as flame retardants and plasticizers. The Σ 8 OPs concentration ranged from 110 to 1400 pg m -3 while tris(2-chloroisopropyl) phosphate (TCPP) dominated all samples with individual concentrations up to 1200 pg m -3 . The highest concentrations were observed in continental air masses showing the high influence of industrialized regions including production sites on atmospheric emissions and concentrations. The occurrence of OPs even in oceanic/Arctic air masses shows that OPs can undergo long-range atmospheric transport. Dry particle-bound deposition fluxes from 9 to 240 ng m -2 d -1 for Σ 8 OPs were estimated leading to a minimum annual flux of 710 ± 580 kg y -1 OPs into the German North Sea. This study presents the first occurrence of OPs in the marine atmosphere together with important information on their long-range transport potential. - Highlights: → Organophosphorus flame retardants are detected for the first time in the marine atmosphere. → Organophosphorus compounds can undergo medium to long-range atmospheric transport. → Western Europe emits organophosphorus compounds to the marine atmosphere. → Marine air levels of organophosphorus flame retardants range up to 1 ng/m 3 . - Organophosphorus flame retardants, in particular tris(2-chloroisopropyl) phosphate, are emitted into the North Sea atmosphere by Western European countries.

  3. Membranes suited for immobilizing biomolecules

    NARCIS (Netherlands)

    2009-01-01

    The present invention relates to flow-through membranes suitable for the immobilization of biomols., methods for the prepn. of such membranes and the use of such membranes for the immobilization of biomols. and subsequent detection of immobilized biomols. The invention concerns a flow-through

  4. Determination of organophosphorus pesticide residues in tomatoes by gas chromatography

    International Nuclear Information System (INIS)

    Souissi, Sihem

    2010-01-01

    Chloropyriphos and malathion are two organophosphorus pesticides from many others pesticides widely used by famers in agriculture .Because of their bad effect on human health, officials standards are set by the international organisations and communities to ensure safer food for consumer .In the same way, scientists over the world are working hard to develop new detection techniques responding to the international requirements. In this study, an ' IAEA-ethylacetate method ', an adaptation of the popular QuEChERS multi residue method, was optimized to analyse chloropyriphos and Malathion residues in tomatoes .Ethyl-Acetate was used as an extraction solvent the PSA was kept for the clean up procedure. GC-NPD is used for samples analysis .The method optimized is specifique, selective with a recovery averaged more than 70 pour cent. A complete validation of the method is necessary to be used for routine analysis.

  5. Fluorescent Chemosensors for Toxic Organophosphorus Pesticides: A Review

    Directory of Open Access Journals (Sweden)

    Kenneth Fletcher

    2010-07-01

    Full Text Available Many organophosphorus (OP based compounds are highly toxic and powerful inhibitors of cholinesterases that generate serious environmental and human health concerns. Organothiophosphates with a thiophosphoryl (P=S functional group constitute a broad class of these widely used pesticides. They are related to the more reactive phosphoryl (P=O organophosphates, which include very lethal nerve agents and chemical warfare agents, such as, VX, Soman and Sarin. Unfortunately, widespread and frequent commercial use of OP-based compounds in agricultural lands has resulted in their presence as residues in crops, livestock, and poultry products and also led to their migration into aquifers. Thus, the design of new sensors with improved analyte selectivity and sensitivity is of paramount importance in this area. Herein, we review recent advances in the development of fluorescent chemosensors for toxic OP pesticides and related compounds. We also discuss challenges and progress towards the design of future chemosensors with dual modes for signal transduction.

  6. Enantioselectivity of a recombinant epoxide hydrolase from Agrobacterium radiobacter

    NARCIS (Netherlands)

    Lutje Spelberg, Jeffrey H.; Rink, Rick; Kellogg, Richard M.; Janssen, Dick B.

    1998-01-01

    The recombinant epoxide hydrolase from Agrobacterium radiobacter AD1 was used to obtain enantiomerically pure epoxides by means of a kinetic resolution. Epoxides such as styrene oxide and various derivatives thereof and phenyl glycidyl ether were obtained in high enantiomeric excess and in

  7. Properties of epoxide hydrolase from the yeast Rhodotorula glutinis

    NARCIS (Netherlands)

    Ariës-Kronenburg, N.A.E.

    2002-01-01

    Epoxide hydrolases are ubiquitous enzymes that can be found in nearly all living organisms. Some of the enzymes play an important role in detoxifying xenobiotic and metabolic compounds. Others are important in the growth of organisms like

  8. Further characterization of intestinal lactase/phlorizin hydrolase

    DEFF Research Database (Denmark)

    Skovbjerg, H; Norén, O; Sjöström, H

    1982-01-01

    Pig intestinal lactase/phlorizin hydrolase (EC 3.2.1.23/62) was purified in its amphiphilic form by immunoadsorbent chromatography. The purified enzyme was free of other known brush border enzymes and appeared homogeneous in immunoelectrophoresis and polyacrylamide gel electrophoresis in the pres......Pig intestinal lactase/phlorizin hydrolase (EC 3.2.1.23/62) was purified in its amphiphilic form by immunoadsorbent chromatography. The purified enzyme was free of other known brush border enzymes and appeared homogeneous in immunoelectrophoresis and polyacrylamide gel electrophoresis...... in the presence of SDS. Pig lactase/phlorizin hydrolase was shown to have the same quaternary structure as the human enzyme, i.e., built up of two polypeptides of the same molecular weight (160000). In addition to hydrolyzing lactose, phlorizin and a number of synthetic substrates, both the human and the pig...... membranes (basolateral and intracellular membranes) exhibited in SDS-polyacrylamide gel electrophoresis the same size of constituent polypeptides and the same catalytic and immunological properties as a normal brush border lactase/phlorizin hydrolase....

  9. Identification and characterization of some Aspergillus pectinolytic glycoside hydrolases

    NARCIS (Netherlands)

    Zandleven, J.S.

    2006-01-01

    Keywords: Aspergillusniger , Arabidopsis thaliana , homogalacturonan, rhamnogalacturonan, xylogalacturonan, xylogalacturonan hydrolase, exo-polygalacturonasePectinases are used for many food

  10. Method for enhancing amidohydrolase activity of fatty acid amide hydrolase

    Science.gov (United States)

    John, George; Nagarajan, Subbiah; Chapman, Kent; Faure, Lionel; Koulen, Peter

    2017-12-26

    A method for enhancing amidohydrolase activity of Fatty Acid Amide Hydrolase (FAAH) is disclosed. The method comprising administering a phenoxyacyl-ethanolamide that causes the enhanced activity. The enhanced activity can have numerous effects on biological organisms including, for example, enhancing the growth of certain seedlings.

  11. Method for enhancing amidohydrolase activity of fatty acid amide hydrolase

    Science.gov (United States)

    John, George; Nagarajan, Subbiah; Chapman, Kent; Faure, Lionel; Koulen, Peter

    2016-10-25

    A method for enhancing amidohydrolase activity of Fatty Acid Amide Hydrolase (FAAH) is disclosed. The method comprising administering a phenoxyacylethanolamide that causes the enhanced activity. The enhanced activity can have numerous effects on biological organisms including, for example, enhancing the growth of certain seedlings. The subject matter disclosed herein relates to enhancers of amidohydrolase activity.

  12. Hydrolase stabilization via entanglement in poly(propylene sulfide) nanoparticles: stability towards reactive oxygen species

    International Nuclear Information System (INIS)

    Allen, Brett L; Johnson, Jermaine D; Walker, Jeremy P

    2012-01-01

    In the advancement of green syntheses and sustainable reactions, enzymatic biocatalysis offers extremely high reaction rates and selectivity that goes far beyond the reach of chemical catalysts; however, these enzymes suffer from typical environmental constraints, e.g. operational temperature, pH and tolerance to oxidative environments. A common hydrolase enzyme, diisopropylfluorophosphatase (DFPase, EC 3.1.8.2), has demonstrated a pronounced efficacy for the hydrolysis of a variety of substrates for potential toxin remediation, but suffers from the aforementioned limitations. As a means to enhance DFPase’s stability in oxidative environments, enzymatic covalent immobilization within the polymeric matrix of poly(propylene sulfide) (PPS) nanoparticles was performed. By modifying the enzyme’s exposed lysine residues via thiolation, DFPase is utilized as a comonomer/crosslinker in a mild emulsion polymerization. The resultant polymeric polysulfide shell acts as a ‘sacrificial barrier’ by first oxidizing to polysulfoxides and polysulfones, rendering DFPase in an active state. DFPase–PPS nanoparticles thus retain activity upon exposure to as high as 50 parts per million (ppm) of hypochlorous acid (HOCl), while native DFPase is observed as inactive at 500 parts per billion (ppb). This trend is also confirmed by enzyme-generated (chloroperoxidase (CPO), EC 1.11.1.10) reactive oxygen species (ROS) including both HOCl (3 ppm) and ClO 2 (100 ppm). (paper)

  13. A remote but significant sequence homology between glycoside hydrolase clan GH-H and glycoside hydrolase family GH 31

    DEFF Research Database (Denmark)

    Janecek, S.; Svensson, Birte; MacGregor, E.A.

    2007-01-01

    Although both the α-amylase super-family, i.e. the glycoside hydrolase (GH) clan GH-H (the GH families 13, 70 and 77), and family GH31 share some characteristics, their different catalytic machinery prevents classification of GH31 in clan GH-H. A significant but remote evolutionary relatedness is...

  14. Simultaneous detection of dual biomarkers from humans exposed to organophosphorus pesticides by combination of immunochromatographic test strip and ellman assay.

    Science.gov (United States)

    Yang, Mingming; Zhao, Yuting; Wang, Limin; Paulsen, Michael; Simpson, Christopher D; Liu, Fengquan; Du, Dan; Lin, Yuehe

    2018-05-01

    A novel sandwich immunoassay based immunochromatographic test strip (ICTS) has been developed for simultaneously measuring both butyrylcholinesterase (BChE) activity and the total amount of BChE (including inhibited and active enzyme) from 70 μLpost-exposure human plasma sample. The principle of this method is based on the BChE monoclonal antibody (MAb) capable of acting as both capture antibody and detection antibody. The BChE MAb which was immobilized on the test line was able to recognize both organophosphorus BChE adducts (OP-BChE) and BChE and provided equal binding affinity, permitting detection of the total enzyme amount in post-exposure human plasma samples. The formed immunocomplexes on the test line can further be excised from the test-strip for subsequent off-line measurement of BChE activity using the Ellman assay. Therefore, dual biomarkers of BChE activity and phosphorylation (OP-BChE) will be obtained simultaneously. The whole sandwich-immunoassay was performed on one ICTS, greatly reducing analytical time. The ICTS sensor showed excellent linear responses for assaying total amount of BChE and active BChE ranging from 0.22 to 3.58nM and 0.22-7.17nM, respectively. Both the signal detection limits are 0.10nM. We validated the practical application of the proposed method to measure 124 human plasma samples from orchard workers and cotton farmers with long-term exposure to organophosphorus pesticides (OPs). The results were in highly agreement with LC/MS/MS which verified our method is extremely accurate. Combining the portability and rapidity of test strip and the compatibility of BChE MAb as both capture antibody and detection antibody, the developed method provides a baseline-free, low-cost and rapid tool for in-field monitoring of OP exposures. Copyright © 2018 Elsevier B.V. All rights reserved.

  15. BIOSENSOR FOR DIRECT DETERMINATION OF ORGANOPHOSPHATE NERVE AGENTS. 1. POTENTIOMETRIC ENZYME ELECTRODE. (R823663)

    Science.gov (United States)

    A potentiometric enzyme electrode for the direct measurement of organophosphate (OP)nerve agents was developed. The basic element of this enzyme electrode was a pH electrodemodified with an immobilized organophosphorus hydrolase (OPH) layer formed by cross-linkingOPH ...

  16. Improvement of the homogeneity of protein-imprinted polymer films by orientated immobilization of the template

    Energy Technology Data Exchange (ETDEWEB)

    Liu Lijian; Zheng Jingjing; Fang Guijie [Key Laboratory of Fermentation Engineering (Ministry of Education), College of Bioengineering, Hubei University of Technology, Nanhu Li Jia Dun 1, Wuhan 430068 (China); Xie Weihong, E-mail: weihong.xie@yahoo.com.cn [Key Laboratory of Fermentation Engineering (Ministry of Education), College of Bioengineering, Hubei University of Technology, Nanhu Li Jia Dun 1, Wuhan 430068 (China)

    2012-05-13

    Highlights: Black-Right-Pointing-Pointer MPH was genetically modified at its C-terminal with (Gly-Ser){sub 5}-Cys. Black-Right-Pointing-Pointer MPH-L was immobilized with fixed orientation via disulfide chemistry. Black-Right-Pointing-Pointer The immobilized MPH-L retained the activity of MPH. Black-Right-Pointing-Pointer MPH-L formed a homogeneous template. Black-Right-Pointing-Pointer Homogeneous MIP film was obtained with orientated immobilization of the template. - Abstract: A method for preparing homogeneous protein-imprinted polymer films with orientated immobilization of template is described. The template methyl parathion hydrolase (MPH) was modified with a peptide linker (Gly-Ser){sub 5}-Cys and was immobilized on a cover glass with a fixed orientation via the linker. The activity of the fusion enzyme (MPH-L) was evaluated by determining the product's absorbance at 405 nm (A{sub 405}). Both the free and the immobilized MPH-L showed higher retention of the bioactivity than the wide type enzyme (MPH-W) as revealed by the A{sub 405} values for MPH-L{sub free}/MPH-W{sub free} (1.159/1.111) and for MPH-L{sub immobilized}/MPH-W{sub immobilized} (0.348/0.118). The immobilized MPH-L also formed a more homogeneous template stamp compared to the immobilized MPH-W. The molecularly imprinted polymer films prepared with the immobilized MPH-L exhibited high homogeneity with low Std. Deviations of 80 and 200 from the CL intensity mean volumes which were observed for batch-prepared films and an individual film, respectively. MPH-L-imprinted polymer film also had a larger template binding capacity indicated by higher CL intensity mean volume of 3900 INT over 2500 INT for MPH-W-imprinted films. The imprinted film prepared with the orientated immobilization of template showed an imprinting factor of 1.7, while the controls did not show an imprinting effect.

  17. Poly(aspartic acid) (PAA) hydrolases and PAA biodegradation: current knowledge and impact on applications.

    Science.gov (United States)

    Hiraishi, Tomohiro

    2016-02-01

    Thermally synthesized poly(aspartic acid) (tPAA) is a bio-based, biocompatible, biodegradable, and water-soluble polymer that has a high proportion of β-Asp units and equivalent moles of D- and L-Asp units. Poly(aspartic acid) (PAA) hydrolase-1 and hydrolase-2 are tPAA biodegradation enzymes purified from Gram-negative bacteria. PAA hydrolase-1 selectively cleaves amide bonds between β-Asp units via an endo-type process, whereas PAA hydrolase-2 catalyzes the exo-type hydrolysis of the products of tPAA hydrolysis by PAA hydrolase-1. The novel reactivity of PAA hydrolase-1 makes it a good candidate for a biocatalyst in β-peptide synthesis. This mini-review gives an overview of PAA hydrolases with emphasis on their biochemical and functional properties, in particular, PAA hydrolase-1. Functionally related enzymes, such as poly(R-3-hydroxybutyrate) depolymerases and β-aminopeptidases, are compared to PAA hydrolases. This mini-review also provides findings that offer an insight into the catalytic mechanisms of PAA hydrolase-1 from Pedobacter sp. KP-2.

  18. Crystallization of mouse S-adenosyl-l-homocysteine hydrolase

    International Nuclear Information System (INIS)

    Ishihara, Masaaki; Kusakabe, Yoshio; Ohsumichi, Tsuyoshi; Tanaka, Nobutada; Nakanishi, Masayuki; Kitade, Yukio; Nakamura, Kazuo T.

    2010-01-01

    Mouse S-adenosyl-l-homocysteine hydrolase has been crystallized in the presence of the reaction product adenosine. Diffraction data to 1.55 Å resolution were collected using synchrotron radiation. S-Adenosyl-l-homocysteine hydrolase (SAHH; EC 3.3.1.1) catalyzes the reversible hydrolysis of S-adenosyl-l-homocysteine to adenosine and l-homocysteine. For crystallographic investigations, mouse SAHH (MmSAHH) was overexpressed in bacterial cells and crystallized using the hanging-drop vapour-diffusion method in the presence of the reaction product adenosine. X-ray diffraction data to 1.55 Å resolution were collected from an orthorhombic crystal form belonging to space group I222 with unit-cell parameters a = 100.64, b = 104.44, c = 177.31 Å. Structural analysis by molecular replacement is in progress

  19. Evaluation of fish models of soluble epoxide hydrolase inhibition.

    OpenAIRE

    Newman, J W; Denton, D L; Morisseau, C; Koger, C S; Wheelock, C E; Hinton, D E; Hammock, B D

    2001-01-01

    Substituted ureas and carbamates are mechanistic inhibitors of the soluble epoxide hydrolase (sEH). We screened a set of chemicals containing these functionalities in larval fathead minnow (Pimphales promelas) and embryo/larval golden medaka (Oryzias latipes) models to evaluate the utility of these systems for investigating sEH inhibition in vivo. Both fathead minnow and medaka sEHs were functionally similar to the tested mammalian orthologs (murine and human) with respect to substrate hydrol...

  20. Structural insight into catalytic mechanism of PET hydrolase

    OpenAIRE

    Han, Xu; Liu, Weidong; Huang, Jian-Wen; Ma, Jiantao; Zheng, Yingying; Ko, Tzu-Ping; Xu, Limin; Cheng, Ya-Shan; Chen, Chun-Chi; Guo, Rey-Ting

    2017-01-01

    PET hydrolase (PETase), which hydrolyzes polyethylene terephthalate (PET) into soluble building blocks, provides an attractive avenue for the bioconversion of plastics. Here we present the structures of a novel PETase from the PET-consuming microbe Ideonella sakaiensis in complex with substrate and product analogs. Through structural analyses, mutagenesis, and activity measurements, a substrate-binding mode is proposed, and several features critical for catalysis are elucidated.

  1. Structural insight into catalytic mechanism of PET hydrolase.

    Science.gov (United States)

    Han, Xu; Liu, Weidong; Huang, Jian-Wen; Ma, Jiantao; Zheng, Yingying; Ko, Tzu-Ping; Xu, Limin; Cheng, Ya-Shan; Chen, Chun-Chi; Guo, Rey-Ting

    2017-12-13

    PET hydrolase (PETase), which hydrolyzes polyethylene terephthalate (PET) into soluble building blocks, provides an attractive avenue for the bioconversion of plastics. Here we present the structures of a novel PETase from the PET-consuming microbe Ideonella sakaiensis in complex with substrate and product analogs. Through structural analyses, mutagenesis, and activity measurements, a substrate-binding mode is proposed, and several features critical for catalysis are elucidated.

  2. Inhibition of Xenobiotic-Degrading Hydrolases by Organophosphinates

    Science.gov (United States)

    1986-07-01

    M 4 Q r 000 44 Table 11. Purification of arylester hydrolase Specific Total Total Activity Volume Activity Proteina (Umoles/ Purifi- Fraction (mL...did get re-adjusted after the sample was applied. After the sample was applied the column was washed with the above MES buffer an.+eluted with 100 ml...Lieske (94) and compared them to the reversed phase HPLC retention times we have previously reported (16). We get an excellent linear correlation

  3. Immobilization of enzymes by radiation

    International Nuclear Information System (INIS)

    Kaetsu, I.; Kumakura, M.; Yoshida, M.; Asano, M.; Himei, M.; Tamura, M.; Hayashi, K.

    1979-01-01

    Immobilization of various enzymes was performed by radiation-induced polymerization of glass-forming monomers at low temperatures. Alpha-amylase and glucoamylase were effectively immobilized in hydrophilic polymer carrier such as poly(2-hydroxyethyl methacrylate) and also in rather hydrophobic carrier such as poly(tetraethylene-glycol diacrylate). Immobilized human hemoglobin underwent the reversible oxygenation concomitantly with change of oxygen concentration outside of the matrices. (author)

  4. Effects of immobilization on spermiogenesis

    Science.gov (United States)

    Meitner, E. R.

    1980-01-01

    The influence of immobilization stress on spermiogenesis in rats was investigated. After 96 hour immobilization, histological changes began to manifest themselves in the form of practically complete disappearance of cell population of the wall of seminiferous tubule as well as a markedly increased number of cells with pathologic mitoses. Enzymological investigations showed various changes of activity (of acid and alkaline phosphatase and nonspecific esterase) in the 24, 48, and 96 hour immobilization groups.

  5. Clinical emergency treatment of 68 critical patients with severe organophosphorus poisoning and prognosis analysis after rescue.

    Science.gov (United States)

    Dong, Hui; Weng, Yi-Bing; Zhen, Gen-Shen; Li, Feng-Jie; Jin, Ai-Chun; Liu, Jie

    2017-06-01

    This study reports the clinical emergency treatment of 68 critical patients with severe organophosphorus poisoning, and analyzes the prognosis after rescue.The general data of 68 patients with severe organophosphorus poisoning treated in our hospital were retrospectively analyzed. These patients were divided into 2 groups: treatment group, and control group. Patients in the control group received routine emergency treatment, while patients in the treatment group additionally received hemoperfusion plus hemodialysis on the basis of routine emergency treatment. The curative effects in these 2 groups and the prognosis after rescue were compared.Compared with the control group, atropinization time, recovery time of cholinesterase activity, recovery time of consciousness, extubation time, and length of hospital stay were shorter (P poisoning rebound rate was significantly lower (P treatment group.Hemoperfusion and hemodialysis on the basis of routine emergency treatment for critical patients with organophosphorus poisoning can improve rescue outcomes and improve the prognosis of patients, which should be popularized.

  6. Organophosphorus reagents in actinide separations: Unique tools for production, cleanup and disposal

    International Nuclear Information System (INIS)

    Nash, K. L.

    2000-01-01

    Interactions of actinide ions with phosphate and organophosphorus reagents have figured prominently in nuclear science and technology, particularly in the hydrometallurgical processing of irradiated nuclear fuel. Actinide interactions with phosphorus-containing species impact all aspects from the stability of naturally occurring actinides in phosphate mineral phases through the application of the bismuth phosphate and PUREX processes for large-scale production of transuranic elements to the development of analytical separation and environment restoration processes based on new organophosphorus reagents. In this report, an overview of the unique role of organophosphorus compounds in actinide production, disposal, and environment restoration is presented. The broad utility of these reagents and their unique chemical properties is emphasized

  7. Structure–efficiency relationships of cyclodextrin scavengers in the hydrolytic degradation of organophosphorus compounds

    Directory of Open Access Journals (Sweden)

    Sophie Letort

    2017-03-01

    Full Text Available New derivatives of cyclodextrins were prepared in order to determine the relative importance of the structural key elements involved in the degradation of organophosphorus nerve agents. To avoid a competitive inclusion between the organophosphorus substrate and the iodosobenzoate group, responsible for its degradation, the latter group had to be covalently bound to the cyclodextrin scaffold. Although the presence of the α nucleophile iodosobenzoate was a determinant in the hydrolysis process, an imidazole group was added to get a synergistic effect towards the degradation of the agents. The degradation efficiency was found to be dependent on the relative position of the heterocycle towards the reactive group as well as on the nature of the organophosphorus derivative.

  8. A systems-level approach for investigating organophosphorus pesticide toxicity.

    Science.gov (United States)

    Zhu, Jingbo; Wang, Jing; Ding, Yan; Liu, Baoyue; Xiao, Wei

    2018-03-01

    The full understanding of the single and joint toxicity of a variety of organophosphorus (OP) pesticides is still unavailable, because of the extreme complex mechanism of action. This study established a systems-level approach based on systems toxicology to investigate OP pesticide toxicity by incorporating ADME/T properties, protein prediction, and network and pathway analysis. The results showed that most OP pesticides are highly toxic according to the ADME/T parameters, and can interact with significant receptor proteins to cooperatively lead to various diseases by the established OP pesticide -protein and protein-disease networks. Furthermore, the studies that multiple OP pesticides potentially act on the same receptor proteins and/or the functionally diverse proteins explained that multiple OP pesticides could mutually enhance toxicological synergy or additive on a molecular/systematic level. To the end, the integrated pathways revealed the mechanism of toxicity of the interaction of OP pesticides and elucidated the pathogenesis induced by OP pesticides. This study demonstrates a systems-level approach for investigating OP pesticide toxicity that can be further applied to risk assessments of various toxins, which is of significant interest to food security and environmental protection. Copyright © 2017 Elsevier Inc. All rights reserved.

  9. Detection of Organophosphorus Pesticides with Colorimetry and Computer Image Analysis.

    Science.gov (United States)

    Li, Yanjie; Hou, Changjun; Lei, Jincan; Deng, Bo; Huang, Jing; Yang, Mei

    2016-01-01

    Organophosphorus pesticides (OPs) represent a very important class of pesticides that are widely used in agriculture because of their relatively high-performance and moderate environmental persistence, hence the sensitive and specific detection of OPs is highly significant. Based on the inhibitory effect of acetylcholinesterase (AChE) induced by inhibitors, including OPs and carbamates, a colorimetric analysis was used for detection of OPs with computer image analysis of color density in CMYK (cyan, magenta, yellow and black) color space and non-linear modeling. The results showed that there was a gradually weakened trend of yellow intensity with the increase of the concentration of dichlorvos. The quantitative analysis of dichlorvos was achieved by Artificial Neural Network (ANN) modeling, and the results showed that the established model had a good predictive ability between training sets and predictive sets. Real cabbage samples containing dichlorvos were detected by colorimetry and gas chromatography (GC), respectively. The results showed that there was no significant difference between colorimetry and GC (P > 0.05). The experiments of accuracy, precision and repeatability revealed good performance for detection of OPs. AChE can also be inhibited by carbamates, and therefore this method has potential applications in real samples for OPs and carbamates because of high selectivity and sensitivity.

  10. Plutonium and americium extraction studies with bifunctional organophosphorus extractants

    International Nuclear Information System (INIS)

    Navratil, J.D.

    1985-01-01

    Neutral bifunctional organophosphorus extractants, such as octylphenyl-N,N-diisobutylcarbamoylmethylphosphine oxide (CMPO) and dihexyl-N,N-diethylcarbamoylmethylphosphonate (CMP), are under study at the Rocky Flats Plant (RFP) to remove plutonium and americium from the 7M nitric acid waste. These compounds extract trivalent actinides from strong nitric acid, a property which distinguishes them from monofunctional organiphosphorus reagents. Furthermore, the reagents extract hydroytic plutonium (IV) polymer which is present in the acid waste stream. The compounds extract trivalent actinides with a 3:1 stoichiometry, whereas tetra- and hexavalent actinides extract with a stoichiometry of 2:1. Preliminary studies indicate that the extracted plutonium polymer complex contains one to two molecules of CMP per plutonium ion and the plutonium(IV) maintains a polymeric structure. Recent studies by Horwitz and co-workers conclude that the CMPO and CMP reagents behave as monodentate ligands. At RFP, three techniques are being tested for using CMP and CMPO to remove plutonium and americium from nitric acid waste streams. The different techniques are liquid-liquid extraction, extraction chromatography, and solid-supported liquid membranes. Recent tests of the last two techniques will be briefly described. In all the experiments, CMP was an 84% pure material from Bray Oil Co. and CMPO was 98% pure from M and T Chemicals

  11. Neurotoxicity in Preclinical Models of Occupational Exposure to Organophosphorus Compounds

    Science.gov (United States)

    Voorhees, Jaymie R.; Rohlman, Diane S.; Lein, Pamela J.; Pieper, Andrew A.

    2017-01-01

    Organophosphorus (OPs) compounds are widely used as insecticides, plasticizers, and fuel additives. These compounds potently inhibit acetylcholinesterase (AChE), the enzyme that inactivates acetylcholine at neuronal synapses, and acute exposure to high OP levels can cause cholinergic crisis in humans and animals. Evidence further suggests that repeated exposure to lower OP levels insufficient to cause cholinergic crisis, frequently encountered in the occupational setting, also pose serious risks to people. For example, multiple epidemiological studies have identified associations between occupational OP exposure and neurodegenerative disease, psychiatric illness, and sensorimotor deficits. Rigorous scientific investigation of the basic science mechanisms underlying these epidemiological findings requires valid preclinical models in which tightly-regulated exposure paradigms can be correlated with neurotoxicity. Here, we review the experimental models of occupational OP exposure currently used in the field. We found that animal studies simulating occupational OP exposures do indeed show evidence of neurotoxicity, and that utilization of these models is helping illuminate the mechanisms underlying OP-induced neurological sequelae. Still, further work is necessary to evaluate exposure levels, protection methods, and treatment strategies, which taken together could serve to modify guidelines for improving workplace conditions globally. PMID:28149268

  12. ANALYSIS OF ORGANOPHOSPHORUS POISONING, AT TERTIARY CARE HOSPITAL: A REPORT

    Directory of Open Access Journals (Sweden)

    Shakuntala

    2015-01-01

    Full Text Available BACKGROUND: Organophosphorus (OP compounds are the most common suicidal poison in developing countries and mortality continues to be high. The present study was aimed to know the pattern and outcome of the OP poisoning. METHODOLOGY: A record based retrospective study from January 2013 - December 2013 was Conducted in a tertiary care hospital and data regarding age, gender, domicile, type of poison, manner of poisoning, seasonal trends, marital status, motive behind poisoning , socio - economic status and outcome was collected in a pre - structured Performa. All data were documented, analyzed and interpreted as per the laid down protocol. RESULTS : out of total 1575 cases of OP compound poisoning, 71.73% (1130 were male, 28.27% (445 were female, 34.6% were in the age group 21 - 30 years, 70.95% were of low socio - economic status, Occupation wise agricultural workers were on top of the list (70.07%, The commonest (93.78% motive behind poisoning was suicidal in both males and females, Financial problem was one of the commonest (51.22% reasons of poisoning. The mortality rate in our study was 13.47%. CONCLUSION : Y oung and adult males of Low socio - economic class, rural, both literate and illiterate agriculturists commonly abuse this substance to commit suicide

  13. Differences between organophosphorus insecticides in human self-poisoning: a prospective cohort study.

    Science.gov (United States)

    Eddleston, Michael; Eyer, Peter; Worek, Franz; Mohamed, Fahim; Senarathna, Lalith; von Meyer, Ludwig; Juszczak, Edmund; Hittarage, Ariyasena; Azhar, Shifa; Dissanayake, Wasantha; Sheriff, M H Rezvi; Szinicz, Ladislaus; Dawson, Andrew H; Buckley, Nick A

    Although more than 100 organophosphorus insecticides exist, organophosphorus poisoning is usually regarded as a single entity, distinguished only by the compound's lethal dose in animals. We aimed to determine whether the three most common organophosphorus insecticides used for self-poisoning in Sri Lanka differ in the clinical features and severity of poisoning they cause. We prospectively studied 802 patients with chlorpyrifos, dimethoate, or fenthion self-poisoning admitted to three hospitals. Blood cholinesterase activity and insecticide concentration were measured to determine the compound and the patients' response to insecticide and therapy. We recorded clinical outcomes for each patient. Compared with chlorpyrifos (35 of 439, 8.0%), the proportion dying was significantly higher with dimethoate (61 of 264, 23.1%, odds ratio [OR] 3.5, 95% CI 2.2-5.4) or fenthion (16 of 99, 16.2%, OR 2.2, 1.2-4.2), as was the proportion requiring endotracheal intubation (66 of 439 for chlorpyrifos, 15.0%; 93 of 264 for dimethoate, 35.2%, OR 3.1, 2.1-4.4; 31 of 99 for fenthion, 31.3%, 2.6, 1.6-4.2). Dimethoate-poisoned patients died sooner than those ingesting other pesticides and often from hypotensive shock. Fenthion poisoning initially caused few symptoms but many patients subsequently required intubation. Acetylcholinesterase inhibited by fenthion or dimethoate responded poorly to pralidoxime treatment compared with chlorpyrifos-inhibited acetylcholinesterase. Organophosphorus insecticide poisoning is not a single entity, with substantial variability in clinical course, response to oximes, and outcome. Animal toxicity does not predict human toxicity since, although chlorpyrifos is generally the most toxic in rats, it is least toxic in people. Each organophosphorus insecticide should be considered as an individual poison and, consequently, patients might benefit from management protocols developed for particular organophosphorus insecticides.

  14. Annotation and comparative analysis of the glycoside hydrolase genes in Brachypodium distachyon

    Directory of Open Access Journals (Sweden)

    Wu Jiajie

    2010-10-01

    Full Text Available Abstract Background Glycoside hydrolases cleave the bond between a carbohydrate and another carbohydrate, a protein, lipid or other moiety. Genes encoding glycoside hydrolases are found in a wide range of organisms, from archea to animals, and are relatively abundant in plant genomes. In plants, these enzymes are involved in diverse processes, including starch metabolism, defense, and cell-wall remodeling. Glycoside hydrolase genes have been previously cataloged for Oryza sativa (rice, the model dicotyledonous plant Arabidopsis thaliana, and the fast-growing tree Populus trichocarpa (poplar. To improve our understanding of glycoside hydrolases in plants generally and in grasses specifically, we annotated the glycoside hydrolase genes in the grasses Brachypodium distachyon (an emerging monocotyledonous model and Sorghum bicolor (sorghum. We then compared the glycoside hydrolases across species, at the levels of the whole genome and individual glycoside hydrolase families. Results We identified 356 glycoside hydrolase genes in Brachypodium and 404 in sorghum. The corresponding proteins fell into the same 34 families that are represented in rice, Arabidopsis, and poplar, helping to define a glycoside hydrolase family profile which may be common to flowering plants. For several glycoside hydrolase familes (GH5, GH13, GH18, GH19, GH28, and GH51, we present a detailed literature review together with an examination of the family structures. This analysis of individual families revealed both similarities and distinctions between monocots and eudicots, as well as between species. Shared evolutionary histories appear to be modified by lineage-specific expansions or deletions. Within GH families, the Brachypodium and sorghum proteins generally cluster with those from other monocots. Conclusions This work provides the foundation for further comparative and functional analyses of plant glycoside hydrolases. Defining the Brachypodium glycoside hydrolases sets

  15. Production of tannase by the immobilized cells of Bacillus licheniformis KBR6 in Ca-alginate beads.

    Science.gov (United States)

    Mohapatra, P K D; Mondal, K C; Pati, B R

    2007-06-01

    The present study was aimed at finding the optimal conditions for immobilization of Bacillus licheniformis KBR6 cells in calcium-alginate (Ca-alginate) beads and determining the operational stability during the production of tannin-acyl-hydrolase (tannase) under semicontinous cultivation. The active cells of B. licheniformis KBR6 were immobilized in Ca-alginate and used for the production of tannase. The influence of alginate concentration (5, 10, 20 and 30 g l(-1)) and initial cell loading on enzyme production were studied. The production of tannase increased significantly with increasing alginate concentration and reached a maximum enzyme yield of 0.56 +/- 0.03 U ml(-1) at 20 g l(-1). This was about 1.70-fold higher than that obtained by free cells. The immobilized cells produced tannase consistently over 13 repeated cycles and reached a maximum level at the third cycle. Scanning electron microscope study indicated that the cells in Ca-alginate beads remain in normal shape. The Ca-alginate entrapment is a promising immobilization method of B. licheniformis KBR6 for repeated tannase production. Tannase production by immobilized cells is superior to that of free cells because it leads to higher volumetric activities within the same period of fermentation. This is the first report of tannase production from immobilized bacterial cells. The bacterium under study can produce higher amounts of tannase with respect to other fungal strains within a short cultivation period.

  16. Biodegradation of chlorobenzene using immobilized crude extracts ...

    African Journals Online (AJOL)

    SERVER

    2007-10-04

    Oct 4, 2007 ... immobilized crude extracts were reused for all other experiments and found that immobilization .... India which are of analytical reagent grade. .... 9. 60. 3. 1. Figure 3. Degradation of chlorobenzene by immobilized crude.

  17. Supramolecular protein immobilization on lipid bilayers

    NARCIS (Netherlands)

    Bosmans, R.P.G.; Hendriksen, W.E.; Verheijden, Mark Lloyd; Eelkema, R.; Jonkheijm, Pascal; van Esch, J.H.; Brunsveld, Luc

    2015-01-01

    Protein immobilization on surfaces, and on lipid bilayers specifically, has great potential in biomolecular and biotechnological research. Of current special interest is the immobilization of proteins using supramolecular noncovalent interactions. This allows for a reversible immobilization and

  18. Iodine immobilization in apatites

    International Nuclear Information System (INIS)

    Audubert, F.; Lartigue, J.E.

    2000-01-01

    In the context of a scientific program on long-lived radionuclide conditioning, a matrix for iodine 129 immobilization has been studied. A lead vanado-phosphate apatite was prepared from the melt of lead vanado-phosphate Pb 3 (VO 4 ) 1.6 (PO 4 ) 0.4 and lead iodide PbI 2 in stoichiometric proportions by calcination at 700 deg. C during 3 hours. Natural sintering of this apatite is not possible because the product decomposition occurs at 400 deg. C. Reactive sintering is the solution. The principle depends on the coating of lead iodide with lead vanado-phosphate. Lead vanado-phosphate coating is used as iodo-apatite reactant and as dense covering to confine iodine during synthesis. So the best condition to immobilize iodine during iodo-apatite synthesis is a reactive sintering at 700 deg. C under 25 MPa. We obtained an iodo-apatite surrounded with dense lead vanadate. Leaching behaviour of the matrix synthesized by solid-solid reaction is under progress in order to determine chemical durability, basic mechanisms of the iodo-apatite alteration and kinetic rate law. Iodo-apatite dissolution rates were pH and temperature dependent. We obtained a rate of 2.5 10 -3 g.m -2 .d -1 at 90 deg. C in initially de-ionised water. (authors)

  19. BIOSENSOR FOR DIRECT DETERMINATION OF ORGANOPHOSPHATE NERVE AGENTS USING RECOMBINANT ESCHERICHIA COLI WITH SURFACE-EXPRESSED ORGANOPHOSPHORUS HYDROLASE. 1. POTENTIOMETRIC MICROBIAL ELECTRODE. (R823663)

    Science.gov (United States)

    The perspectives, information and conclusions conveyed in research project abstracts, progress reports, final reports, journal abstracts and journal publications convey the viewpoints of the principal investigator and may not represent the views and policies of ORD and EPA. Concl...

  20. AMPEROMETRIC MICROBIAL BIOSENSOR FOR DIRECT DETERMINATION OF ORGANOPHOSPHATE NERVE AGENTS USING RECOMBINANT MORAXELLA SP. WITH SURFACE EXPRESSED ORGANOPHOSPHORUS HYDROLASE. (R828160)

    Science.gov (United States)

    The perspectives, information and conclusions conveyed in research project abstracts, progress reports, final reports, journal abstracts and journal publications convey the viewpoints of the principal investigator and may not represent the views and policies of ORD and EPA. Concl...

  1. MICROBIAL BIOSENSOR FOR DIRECT DETERMINATION OF ORGANOPHOSPHATE NERVE AGENTS USING RECOMBINANT ESCHERICHIA COLI WITH SURFACE-EXPRESSED ORGANOPHOSPHORUS HYDROLASE. 2. FIBER-OPTIC MICROBIAL BIOSENSOR. (R823663)

    Science.gov (United States)

    The perspectives, information and conclusions conveyed in research project abstracts, progress reports, final reports, journal abstracts and journal publications convey the viewpoints of the principal investigator and may not represent the views and policies of ORD and EPA. Concl...

  2. Assessing attitudes toward spinal immobilization.

    Science.gov (United States)

    Bouland, Andrew J; Jenkins, J Lee; Levy, Matthew J

    2013-10-01

    Prospective studies have improved knowledge of prehospital spinal immobilization. The opinion of Emergency Medical Services (EMS) providers regarding spinal immobilization is unknown, as is their knowledge of recent research advances. To examine the attitudes, knowledge, and comfort of prehospital and Emergency Department (ED) EMS providers regarding spinal immobilization performed under a non-selective protocol. An online survey was conducted from May to July of 2011. Participants were drawn from the Howard County Department of Fire and Rescue Services and the Howard County General Hospital ED. The survey included multiple choice questions and responses on a modified Likert scale. Correlation analysis and descriptive data were used to analyze results. Comfort using the Kendrick Extrication Device was low among ED providers. Experienced providers were more likely to indicate comfort using this device. Respondents often believed that spinal immobilization is appropriate in the management of penetrating trauma to the chest and abdomen. Reported use of padding decreased along with the frequency with which providers practice and encounter immobilized patients. Respondents often indicated that they perform spinal immobilization due solely to mechanism of injury. Providers who feel as if spinal immobilization is often performed unnecessarily were more likely to agree that immobilization causes an unnecessary delay in patient care. The results demonstrate the need for improved EMS education in the use of the Kendrick Extrication Device, backboard padding, and spinal immobilization in the management of penetrating trauma. The attitudes highlighted in this study are relevant to the implementation of a selective spinal immobilization protocol. Copyright © 2013 Elsevier Inc. All rights reserved.

  3. Organophosphorus flame retardants – Toxicity and influence on human health

    Directory of Open Access Journals (Sweden)

    Elżbieta Bruchajzer

    2015-06-01

    Full Text Available Organophosphorus flame retardants (flame retardants, FRs have been used for several decades in many industries, including the production of dyes, varnishes, adhesives, synthetic resins, polyvinyl chloride, hydraulic fluids, plastics and textiles. Their importance in recent times has increased due to i.a., significantly reduced use of polybrominated diphenyl ethers (PBDEs – persistent organic pollutants, dangerous for the environment. The aim of this study was to review the available literature data concerning phosphorous FRs primarily for neurotoxic, fertility, reproductive and carcinogenic effects. The analysis concerned the following most commonly used substances: tris(2-ethylhexylphosphate (TEHP, tris(2-butoxyethylphosphate (TBEP, triphenyl phosphate (TPP, tris(2-chloroethylphosphate (TCEP, tetrakis(hydroxymethyl-phosphonium chloride (THPC, tributyl phosphate (TBP, tricresyl phosphate (TCP, tris(2-chloroisopropylphosphate (TCPP, tris(1,3-dichloroisopropylphosphate (TDCP and tetrakis(hydroxymethyl phosphonium sulphate (THPS. In animal studies neurotoxic effects were found after exposure to TBEP, THPC, TBP and TCP, while in humans they were observed only after exposure to TCP. TCEP, THPS, TBP, TCP and TDCP caused disorders in fertility and/or fetal development of animals. Adverse effects on reproduction in humans may be caused by TPP, TCP, and TDCP. In laboratory animals the development of tumors was observed after high doses of TEHP, TCEP, TBP and TDCP. None of these compounds is classified as a human carcinogen. The environmental toxicity of phosphate FRs is low (except for TPP, TCEP and TBEP. They are not stable compounds, in living organisms they are metabolised and quickly excreted. Therefore, they can be used as an alternative to PBDEs. Med. Pr. 2015;66(2:235–264

  4. Degradation of organophosphorus compounds by X-ray irradiation

    International Nuclear Information System (INIS)

    Trebse, P.; Arcon, I.

    2002-01-01

    Complete text of publication follows. Our research presented in this contribution aims to elucidate the degradation mechanisms of organophosphate pesticides as organic pollutants by X-ray irradiation. Diazinon, one of the most widely used pesticides in Slovenia, has been chosen as a model compound for the study of radiation induced degradation of organophosphorus pesticides. Recent studies have shown that the degradation of the pesticide at normal conditions (room temperature, exposure to daylight) is strongly enhanced when the pesticide is exposed to UV light (Hg lamp, λ=254 nm, XeCl excimer laser, λ=308 nm). In our study we irradiated the pesticide in aqueous media with a white x-ray beam from a conventional x-ray source. Mo X-ray tube operating at the high voltage of 55 kV and a current of 45 mA was used. The flux of the continuous X-ray beam was stabilized within 1%. Saturated water solution of the pesticide (volume: 4mL, conc. of 40 mg L -1 ) was inserted in 1 cm long lucite cell with 1 mm thick lucite windows. The whole volume of the solution in the cell was exposed to the unfiltered X-ray beam. The dose rate on the sample was about 1 mGy/s. Different irradiation times between 30 min to 120 min were chosen to study the dependence of the pesticide decomposition with the absorbed dose. Solid phase extraction was employed for sample extraction from the solution, and gas chromatography was used for the identification and quantification of the compounds. The results show that the concentration of the pesticide in the solution decreases exponentially with the exposure time, i.e. with the absorbed dose. At irradiation conditions described above, the time constant of the exponential decrease was 74 min

  5. Cognitive decline, mortality, and organophosphorus exposure in aging Mexican Americans.

    Science.gov (United States)

    Paul, Kimberly C; Ling, Chenxiao; Lee, Anne; To, Tu My; Cockburn, Myles; Haan, Mary; Ritz, Beate

    2018-01-01

    Cognitive impairment is a major health concern among older Mexican Americans, associated with significant morbidity and mortality, and may be influenced by environmental exposures. To investigate whether agricultural based ambient organophosphorus (OP) exposure influences 1) the rate of cognitive decline and mortality and 2) whether these associations are mediated through metabolic or inflammatory biomarkers. In a subset of older Mexican Americans from the Sacramento Area Latino Study on Aging (n = 430), who completed modified mini-mental state exams (3MSE) up to 7 times (1998-2007), we examined the relationship between estimated ambient OP exposures and cognitive decline (linear repeated measures model) and time to dementia or being cognitively impaired but not demented (CIND) and time to mortality (cox proportional hazards model). We then explored metabolic and inflammatory biomarkers as potential mediators of these relationships (additive hazards mediation). OP exposures at residential addresses were estimated with a geographic information system (GIS) based exposure assessment tool. Participants with high OP exposure in the five years prior to baseline experienced faster cognitive decline (β = 0.038, p = 0.02) and higher mortality over follow-up (HR = 1.91, 95% CI = 1.12, 3.26). The direct effect of OP exposure was estimated at 241 (95% CI = 27-455) additional deaths per 100,000 person-years, and the proportion mediated through the metabolic hormone adiponectin was estimated to be 4% 1.5-19.2). No other biomarkers were associated with OP exposure. Our study provides support for the involvement of OP pesticides in cognitive decline and mortality among older Mexican Americans, possibly through biologic pathways involving adiponectin. Copyright © 2017 Elsevier Inc. All rights reserved.

  6. Blood cholinesterases as human biomarkers of organophosphorus pesticide exposure.

    Science.gov (United States)

    Nigg, H N; Knaak, J B

    2000-01-01

    The organophosphorus pesticides of this review were discovered in 1936 during the search for a replacement for nicotine for cockroach control. The basic biochemical characteristics of RBC AChE and BChE were determined in the 1940s. The mechanism of inhibition of both enzymes and other serine esterases was known in the 1940s and, in general, defined in the 1950s. In 1949, the death of a parathion mixer-loader dictated blood enzyme monitoring to prevent acute illness from organophosphorus pesticide intoxication. However, many of the chemical and biochemical steps for serine enzyme inhibition by OP compounds remain unknown today. The possible mechanisms of this inhibition are presented kinetically beginning with simple (by comparison) Michaelis-Menten substrate enzyme interaction kinetics. As complicated as the inhibition kinetics appear here, PBPK model kinetics will be more complex. The determination of inter- and intraindividual variation in RBC ChE and BChE was recognized early as critical knowledge for a blood esterase monitoring program. Because of the relatively constant production of RBCs, variation in RBC AChE was determined by about 1970. The source of plasma (or serum) BChE was shown to be the liver in the 1960s with the change in BChE phenotype to the donor in liver transplant patients. BChE activity was more variable than RBC AChE, and only in the 1990s have BChE individual variation questions been answered. We have reviewed the chemistry, metabolism, and toxicity of organophosphorus insecticides along with their inhibitory action toward tissue acetyl- and butyrylcholinesterases. On the basis of the review, a monitoring program for individuals mixing-loading and applying OP pesticides for commercial applicators was recommended. Approximately 41 OPs are currently registered for use by USEPA in the United States. Under agricultural working conditions, OPs primarily are absorbed through the skin. Liver P-450 isozymes catalyze the desulfurization of

  7. HLW immobilization in glass

    International Nuclear Information System (INIS)

    Leroy, P.; Jacquet-Francillon, N.; Runge, S.

    1992-01-01

    The immobilization of High Level Waste in glass in France is a long history which started as early as in the 1950's. More than 30 years of Research and Development have been invested in that field. Two industrial facilities are operating (AVM and R7) and a third one (T7), under cold testing, is planned to start active operation in the mid-92. While vitrification has been demonstrated to be an industrially mastered process, the question of the quality of the final waste product, i.e. the HLW glass, must be addressed. The scope of the present paper is to focus on the latter point from both standpoints of the R and D and of the industrial reality

  8. Dietary cumulative acute risk assessment of organophosphorus, carbamates and pyrethroids insecticides for the Brazilian population.

    NARCIS (Netherlands)

    Jardim, Andreia Nunes Oliveira; Brito, Alessandra Page; van Donkersgoed, Gerda; Boon, Polly E; Caldas, Eloisa Dutra

    Cumulative acute dietary risk assessments of organophosphorus (OPs), carbamates (CBs) and pyrethroids (PYs) were conducted for the Brazilian population. Residue data for 30786 samples of 30 foods were obtained from two national monitoring programs and one University laboratory, and consumption data

  9. Infrared Spectroscopic Observations on the Fate of Organophosphorus Compounds Exposed to Atmospheric Moisture. Part 3

    Science.gov (United States)

    2007-05-01

    FATE OF ORGANOPHOSPHORUS COMPOUNDS EXPOSED TO ATMOSPHERIC MOISTURE PART III. PHOSPHINES, PHOSPHITES , PHOSPHONITES, PHOSPHINITES, PHOSPHORIC ACIDS ...The investigation continues with Phosphines, Phosphites , Phosphonites, Phosphinites, Phosphoric Acids , Phosphonic Acids , Phosphinic Acids , Phosphine...infrared spectrum of di-(2-ethylhexyl) phosphoric acid as a liquid film between KBr windows is given in Figure 104. The band assignments are as follows

  10. Monoclonal antibody-based broad-specificity immunoassay for monitoring organophosphorus pesticides in environmental water samples

    Science.gov (United States)

    The extensive use of organophosphorus pesticides (OPs) in agriculture and domestic settings can result in widespread water contamination. The development of easy-to-use and rapid-screening immunoassay methods in a class-selective manner is a topic of considerable environmental interest. In this wo...

  11. Determination of organophosphorus acids by thermo-spray liquid chromatography-mass spectrometry

    NARCIS (Netherlands)

    Wils, E.R.J.; Hulst, A.G.

    1988-01-01

    The determination of thirteen organophosphorus acids, hydrolysis products of nerve agents and pesticides, by a combination of ion-pair liquid chromatography on a reversed-phase C18 column and thermospray mass spectrometry was investigated. Ammonium acetate and three tetraalkylammonium salts with

  12. RESEARCH OF HEAVY METALS, ORGANOCHLORINE AND ORGANOPHOSPHORUS PESTICIDES IN POWDERED INFANT FORMULA

    Directory of Open Access Journals (Sweden)

    M.C. Abete

    2009-02-01

    Full Text Available During the period between october 2007 and november 2008 were collected 60 samples of powdered infant formula. The analysis for the detection of heavy metals, organochlorine and organophosphorus pesticides show that the environmental situation is under control and powdered infant formula satisfies this health requisite.

  13. Tracing organophosphorus and brominated flame retardants and plasticizers in an estuarine food web

    NARCIS (Netherlands)

    Brandsma, S.H.; Leonards, P.E.G.; Leslie, H.A.; de Boer, J.

    2015-01-01

    Nine organophosphorus flame retardants (PFRs) were detected in a pelagic and benthic food web of the Western Scheldt estuary, The Netherlands. Concentrations of several PFRs were an order of magnitude higher than those of the brominated flame retardants (BFRs). However, the detection frequency of

  14. Efficient Degumming of Rice Bran Oil by Immobilized PLA1 from Thermomyces lanuginosus

    Directory of Open Access Journals (Sweden)

    Tripti Singhania

    2015-01-01

    Full Text Available Phospholipase A1 (PLA1 immobilized in calcium alginate can effectively overcome the mass transfer resistance at the lipid-water interface making more room for the enzyme to separate itself from the products of reaction and to bind with the next available molecule at the interface. The reaction of an immobilized PLA1 hydrolase from Thermomyces lanuginosus was comparatively faster than of its free form. The rate of phospholipid hydrolysis by PLA1 was studied in calcium-rich and calcium-depleted environments; and the extent of phosphorus removed from the crude rice bran oil as well as the amount of free fatty acids produced during the reaction were used as indices for analysing the rate of enzymatic hydrolysis under standard conditions of pH, temperature, time of incubation and agitation. The immobilized PLA1 was found to be superior in removing phosphorus in the presencem of 10 mM bivalent calcium ions in a solution. As compared to a maximum of 72.52 % phosphorus removed by 0.01 kg of free enzyme per kg of oil, the same amount of immobilized PLA1 removed phosphorus from oil by 94.12 % under the same experimental conditions (pH=6, 60 °C, 1-hour incubation. Both the free PLA1 and its immobilized form had shown extended rates of hydrolysis in a calcium-rich environment. The mass fractions of free fatty acids produced by the free enzyme and by its immobilized form were 14.9 and 14.16 %, respectively, under the above experimental conditions. The removal of phosphorusfrom oil was accompanied by a signifi cant reduction in colour and restoration of iodine value to the desired level.

  15. Immobilization of cholesterol esterase in mesoporous silica materials and its hydrolytic activity toward diethyl phthalate

    Energy Technology Data Exchange (ETDEWEB)

    Orita, Toru, E-mail: nqj45366@nifty.com [Division of Chemistry for Materials, Graduate School of Engineering, Mie University, 1577 Kurimamachiya-cho, Tsu, Mie 514-8570 (Japan); Taiyo Kagaku Co. Ltd., 800 Yamada-cho, Yokkaichi, Mie 512-1111 (Japan); Tomita, Masahiro [Division of Chemistry for Materials, Graduate School of Engineering, Mie University, 1577 Kurimamachiya-cho, Tsu, Mie 514-8570 (Japan); Saito, Takao; Nishida, Nasakazu; Kato, Katsuya [National Institute of Advanced Industrial Science and Technology, 2266-78 Anagahora, Moriyamaku, Nagoya, Aichi 463-8560 (Japan)

    2012-05-01

    Cholesterol esterase (CE, cholesteryl ester hydrolase, EC 3.1.1.13) from porcine pancreas (molecular weight 400-500 kDa) exhibits hydrolytic activity toward various toxic organic phthalate esters. CE was confined in the nanospace (diameter 3-30 nm) of five types of mesoporous silica (MPS) that differ in structural properties such as pore diameter, pore volume, and particle morphology. These structural properties were characterized by transmission electron microscopy, small-angle X-ray diffraction, N{sub 2} adsorption-desorption experiments, solid-state {sup 13}C nuclear magnetic resonance (NMR), and solid-state {sup 29}Si NMR. Catalytic activities of immobilized and free CE were evaluated by the hydrolysis of diethyl phthalate in phosphate buffer solutions containing an organic cosolvent. Optimal activity recovery was achieved when CE was immobilized in n-decane-functionalized MPS, which had a large pore size (22.5 nm). The immobilization also protected against effects of temperature within the range 30 Degree-Sign C-60 Degree-Sign C; CE immobilized in n-decyl-functionalized MPS exhibited better thermal stability than in non-functionalized MPS or free CE. Moreover, it retained approximately 60% of its catalytic activity even after six catalytic cycles. - Highlights: Black-Right-Pointing-Pointer The highest activity of immobilized CE was shown in MPS with a pore size of 22.5 nm. Black-Right-Pointing-Pointer Catalytic efficiency improved when MPS was functionalized by n-decyl substitution. Black-Right-Pointing-Pointer Immobilized CE exhibited good thermal stability and reusability. Black-Right-Pointing-Pointer Organic co-solvent and the substrate structures affected enzyme activities.

  16. Autolysis of dairy leuconostocs and detection of peptidoglycan hydrolases by renaturing SDS-PAGE.

    Science.gov (United States)

    Cibik, R; Chapot-Chartier, M P

    2000-11-01

    The autolysis of lactic acid bacteria plays a major role during cheese ripening. The aim of this study was to evaluate the autolytic properties and peptidoglycan hydrolase content of dairy leuconostocs. Autolysis of 59 strains of dairy Leuconostoc was examined under starvation conditions in potassium phosphate buffer. The ability of dairy leuconostocs to lyse is strain dependant and not related to the species. The peptidoglycan hydrolase profile of Leuc. mesenteroides subsp. mesenteroides 10L was analysed by renaturing gel electrophoresis. Two major activity bands migrating at 41 and 52 kDa were observed. According to the specificity analysis, strain 10L seems to contain a glycosidase and an N-acetyl-muramyl-L-alanine amidase, or an endopeptidase. The peptidoglycan hydrolase profiles of various Leuconostoc species were also compared. Several peptidoglycan hydrolase activities could be detected in the different Leuconostoc species. Further characterization of the peptidoglycan hydrolases will help to control autolysis of leuconostocs in cheese.

  17. Degradation of Polyester Polyurethane by Bacterial Polyester Hydrolases

    Directory of Open Access Journals (Sweden)

    Juliane Schmidt

    2017-02-01

    Full Text Available Polyurethanes (PU are widely used synthetic polymers. The growing amount of PU used industrially has resulted in a worldwide increase of plastic wastes. The related environmental pollution as well as the limited availability of the raw materials based on petrochemicals requires novel solutions for their efficient degradation and recycling. The degradation of the polyester PU Impranil DLN by the polyester hydrolases LC cutinase (LCC, TfCut2, Tcur1278 and Tcur0390 was analyzed using a turbidimetric assay. The highest hydrolysis rates were obtained with TfCut2 and Tcur0390. TfCut2 also showed a significantly higher substrate affinity for Impranil DLN than the other three enzymes, indicated by a higher adsorption constant K. Significant weight losses of the solid thermoplastic polyester PU (TPU Elastollan B85A-10 and C85A-10 were detected as a result of the enzymatic degradation by all four polyester hydrolases. Within a reaction time of 200 h at 70 °C, LCC caused weight losses of up to 4.9% and 4.1% of Elastollan B85A-10 and C85A-10, respectively. Gel permeation chromatography confirmed a preferential degradation of the larger polymer chains. Scanning electron microscopy revealed cracks at the surface of the TPU cubes as a result of enzymatic surface erosion. Analysis by Fourier transform infrared spectroscopy indicated that the observed weight losses were a result of the cleavage of ester bonds of the polyester TPU.

  18. High-level-waste immobilization

    International Nuclear Information System (INIS)

    Crandall, J.L.

    1982-01-01

    Analysis of risks, environmental effects, process feasibility, and costs for disposal of immobilized high-level wastes in geologic repositories indicates that the disposal system safety has a low sensitivity to the choice of the waste disposal form

  19. [On necessity to modify biochemical methods for detecting organophosphorus componds in chemical weapons extinction objects (review of literature)].

    Science.gov (United States)

    Prokofieva, D S; Shmurak, V I; Sadovnikov, S V; Gontcharov, N V

    2015-01-01

    The article covers problems of biochemical methods assessing organophosphorus toxic compounds in objects of chemical weapons extinction. The authors present results of works developing new, more specific and selective biochemical methods.

  20. Comparison of the Developmental and Acute Neurotoxicity of a Library of Organophosphorus Pesticides Using a Vertebrate Behavioral Assay

    Science.gov (United States)

    The U.S. Environmental Protection Agency is evaluating methods to screen and prioritize organophosphorus pesticides for neurotoxicity using behavioral tests in an in vivo, vertebrate, medium-throughput model (zebrafish; Danio rerio). Our behavioral testing paradigm assesses the e...

  1. Status of plutonium ceramic immobilization processes and immobilization forms

    Energy Technology Data Exchange (ETDEWEB)

    Ebbinghaus, B.B.; Van Konynenburg, R.A. [Lawrence Livermore National Lab., CA (United States); Vance, E.R.; Jostsons, A. [Australian Nuclear Science and Technology Organization, Menai (Australia)] [and others

    1996-05-01

    Immobilization in a ceramic followed by permanent emplacement in a repository or borehole is one of the alternatives currently being considered by the Fissile Materials Disposition Program for the ultimate disposal of excess weapons-grade plutonium. To make Pu recovery more difficult, radioactive cesium may also be incorporated into the immobilization form. Valuable data are already available for ceramics form R&D efforts to immobilize high-level and mixed wastes. Ceramics have a high capacity for actinides, cesium, and some neutron absorbers. A unique characteristic of ceramics is the existence of mineral analogues found in nature that have demonstrated actinide immobilization over geologic time periods. The ceramic form currently being considered for plutonium disposition is a synthetic rock (SYNROC) material composed primarily of zirconolite (CaZrTi{sub 2}O{sub 7}), the desired actinide host phase, with lesser amounts of hollandite (BaAl{sub 2}Ti{sub 6}O{sub 16}) and rutile (TiO{sub 2}). Alternative actinide host phases are also being considered. These include pyrochlore (Gd{sub 2}Ti{sub 2}O{sub 7}), zircon (ZrSiO{sub 4}), and monazite (CePO{sub 4}), to name a few of the most promising. R&D activities to address important technical issues are discussed. Primarily these include moderate scale hot press fabrications with plutonium, direct loading of PuO{sub 2} powder, cold press and sinter fabrication methods, and immobilization form formulation issues.

  2. Status of plutonium ceramic immobilization processes and immobilization forms

    International Nuclear Information System (INIS)

    Ebbinghaus, B.B.; Van Konynenburg, R.A.; Vance, E.R.; Jostsons, A.

    1996-01-01

    Immobilization in a ceramic followed by permanent emplacement in a repository or borehole is one of the alternatives currently being considered by the Fissile Materials Disposition Program for the ultimate disposal of excess weapons-grade plutonium. To make Pu recovery more difficult, radioactive cesium may also be incorporated into the immobilization form. Valuable data are already available for ceramics form R ampersand D efforts to immobilize high-level and mixed wastes. Ceramics have a high capacity for actinides, cesium, and some neutron absorbers. A unique characteristic of ceramics is the existence of mineral analogues found in nature that have demonstrated actinide immobilization over geologic time periods. The ceramic form currently being considered for plutonium disposition is a synthetic rock (SYNROC) material composed primarily of zirconolite (CaZrTi 2 O 7 ), the desired actinide host phase, with lesser amounts of hollandite (BaAl 2 Ti 6 O 16 ) and rutile (TiO 2 ). Alternative actinide host phases are also being considered. These include pyrochlore (Gd 2 Ti 2 O 7 ), zircon (ZrSiO 4 ), and monazite (CePO 4 ), to name a few of the most promising. R ampersand D activities to address important technical issues are discussed. Primarily these include moderate scale hot press fabrications with plutonium, direct loading of PuO 2 powder, cold press and sinter fabrication methods, and immobilization form formulation issues

  3. Binding affinity and adhesion force of organophosphate hydrolase enzyme with soil particles related to the isoelectric point of the enzyme.

    Science.gov (United States)

    Islam, Shah Md Asraful; Yeasmin, Shabina; Islam, Md Saiful; Islam, Md Shariful

    2017-07-01

    The binding affinity of organophosphate hydrolase enzyme (OphB) with soil particles in relation to the isoelectric point (pI) was studied. Immobilization of OphB with soil particles was observed by confocal microscopy, Fourier transform infrared spectroscopy (FT-IR), and Atomic force microscopy (AFM). The calculated pI of OphB enzyme was increased from 8.69 to 8.89, 9.04 and 9.16 by the single, double and triple mutant of OphB enzyme, respectively through the replacement of negatively charged aspartate with positively charged histidine. Practically, the binding affinity was increased to 5.30%, 11.50%, and 16.80% for single, double and triple mutants, respectively. In contrast, enzyme activity of OphB did not change by the mutation of the enzyme. On the other hand, adhesion forces were gradually increased for wild type OphB enzyme (90 pN) to 96, 100 and 104 pN for single, double and triple mutants of OphB enzyme, respectively. There was an increasing trend of binding affinity and adhesion force by the increase of isoelectric point (pI) of OphB enzyme. Copyright © 2017 Elsevier Inc. All rights reserved.

  4. Cloning, recombinant production, crystallization and preliminary X-ray diffraction studies of a family 84 glycoside hydrolase from Clostridium perfringens

    International Nuclear Information System (INIS)

    Ficko-Blean, Elizabeth; Boraston, Alisdair B.

    2005-01-01

    Crystallization of a family 84 glycoside hydrolase, a putative virulence factor, secreted by C. perfringens is reported. Clostridium perfringens is a ubiquitous environmental organism that is capable of causing a variety of diseases in mammals, including gas gangrene and necrotic enteritis in humans. The activity of a secreted hyaluronidase, attributed to the NagH protein, contributes to the pathogenicity of this organism. The family 84 catalytic module of one of the three homologues of NagH found in C. perfringens (ATCC 13124) has been cloned. The 69 kDa catalytic module of NagJ, here called GH84C, was overproduced in Escherichia coli and purified by immobilized metal-affinity chromatography (IMAC). Crystals belonging to space group I222 or I2 1 2 1 2 1 with unit-cell parameters a = 130.39, b = 150.05, c = 155.43 Å were obtained that diffracted to 2.1 Å. Selenomethionyl crystals have also been produced, leading to the possibility of solving the phase problem by MAD using synchrotron radiation

  5. Crystal structure of bile salt hydrolase from Lactobacillus salivarius.

    Science.gov (United States)

    Xu, Fuzhou; Guo, Fangfang; Hu, Xiao Jian; Lin, Jun

    2016-05-01

    Bile salt hydrolase (BSH) is a gut-bacterial enzyme that negatively influences host fat digestion and energy harvesting. The BSH enzyme activity functions as a gateway reaction in the small intestine by the deconjugation of glycine-conjugated or taurine-conjugated bile acids. Extensive gut-microbiota studies have suggested that BSH is a key mechanistic microbiome target for the development of novel non-antibiotic food additives to improve animal feed production and for the design of new measures to control obesity in humans. However, research on BSH is still in its infancy, particularly in terms of the structural basis of BSH function, which has hampered the development of BSH-based strategies for improving human and animal health. As an initial step towards the structure-function analysis of BSH, C-terminally His-tagged BSH from Lactobacillus salivarius NRRL B-30514 was crystallized in this study. The 1.90 Å resolution crystal structure of L. salivarius BSH was determined by molecular replacement using the structure of Clostridium perfringens BSH as a starting model. It revealed this BSH to be a member of the N-terminal nucleophile hydrolase superfamily. Crystals of apo BSH belonged to space group P21212, with unit-cell parameters a = 90.79, b = 87.35, c = 86.76 Å (PDB entry 5hke). Two BSH molecules packed perfectly as a dimer in one asymmetric unit. Comparative structural analysis of L. salivarius BSH also identified potential residues that contribute to catalysis and substrate specificity.

  6. Immobilization needs and technology programs

    International Nuclear Information System (INIS)

    Gray, L.W.; Kan, T.; Shaw, H.; Armantrout, G.

    1995-01-01

    In the aftermath of the Cold War, the US and Russia agreed to large reductions in nuclear weapons. To aid in the selection of long-term management options, DOE has undertaken a multifaceted study to select options for storage and disposition of plutonium in keeping with US policy that plutonium must be subjected to the highest standards of safety, security, and accountability. One alternative being considered is immobilization. To arrive at a suitable immobilization form, we first reviewed published information on high-level waste immobilization technologies and identified 72 possible plutonium immobilization forms to be prescreened. Surviving forms were further screened using multi-attribute utility analysis to determine the most promising technology families. Promising immobilization families were further evaluated to identify chemical, engineering, environmental, safety, and health problems that remain to be solved prior to making technical decisions as to the viability of using the form for long- term disposition of plutonium. From this evaluation, a detailed research and development plan has been developed to provide answers to these remaining questions

  7. Immobilization of cellulase by radiation polymerization

    International Nuclear Information System (INIS)

    Kumakura, M.; Kaetsu, I.

    1983-01-01

    Immobilization of cellulase by radiation polymerization at low temperatures was studied. The enzymatic activity of immobilized cellulase pellets varied with the monomer, enzyme concentration, and the thickness of immobilized cellulase pellets. The optimum monomer concentration in the immobilization of cellulase was 30-50% at the pellet thickness of 1.0 mm, in which the enzymatic activity was 50%. The enzymatic activity of immobilized cellulase pellets was examined using various substrates such as cellobiose, carboxymethylcellulose, and paper pretreated by radiation. It was found that irradiated paper can be hydrolyzed by immobilized cellulase pellets. (author)

  8. Comparative study on cleanup procedures for the determination of organophosphorus pesticides in vegetables

    International Nuclear Information System (INIS)

    Alvin, Chai Lian Kuet; Lau, Seng

    2008-01-01

    A study was carried out to compare the cleanup procedures for the determination of organophosphorus pesticides in vegetables. Eleven organophosphorus pesticides were extracted with acetone and methylene chloride. Extracts were cleanup by solid-phase extraction (SPE) mixed-mode column using quaternary amine and aminopropyl (SAX/ NH 2 ) or octadecyl (C 18 ) sorbents. The pesticides were determined by gas chromatography with flame photometric detector. The recovery results obtained from the SPE SAX/ NH 2 and C 18 cleanups in carrot, cucumber and green mustard samples were in the range of 71.0 % to 115 %. Lower recoveries were obtained for polar pesticides, methamidophos and dimethoate. These results were compared to the method currently used in the laboratory which does not include any cleanup. (author)

  9. Calcium uptake by sarcoplasmic reticulum in the presence of organophosphorus insecticide methyl-parathion

    International Nuclear Information System (INIS)

    Blasiak, J.

    1995-01-01

    Using an isotope labelling technique it has been shown that an organophosphorus insecticide methyl parathion (0,0-diethyl 0-4-nitrophenyl phosphorothionate) depressed calcium uptake by sarcoplasmic reticulum isolated from rabbit hind leg muscle. The effect was significant for insecticide concentrations of 50 and 100 μM and was dose-dependent. The insecticide exerted a more pronounced effect on calcium uptake in the presence of ATP in the reticulum environment than in the absence of ATP. The inhibitory action of methyl parathion on Ca 2+ accumulation by sarcoplasmic reticulum can cause a rise in myoplasmic free Ca 2+ , the essential prerequisite for contracture activation. Because methyl parathion, as well as other organophosphorus insecticides, is primarily neurotoxic, evidence of non-specific effect could be important for assessing its environmental safety. (author). 20 refs, 2 figs

  10. Compositional profile of α / β-hydrolase fold proteins in mangrove soil metagenomes: prevalence of epoxide hydrolases and haloalkane dehalogenases in oil-contaminated sites.

    Science.gov (United States)

    Jiménez, Diego Javier; Dini-Andreote, Francisco; Ottoni, Júlia Ronzella; de Oliveira, Valéria Maia; van Elsas, Jan Dirk; Andreote, Fernando Dini

    2015-05-01

    The occurrence of genes encoding biotechnologically relevant α/β-hydrolases in mangrove soil microbial communities was assessed using data obtained by whole-metagenome sequencing of four mangroves areas, denoted BrMgv01 to BrMgv04, in São Paulo, Brazil. The sequences (215 Mb in total) were filtered based on local amino acid alignments against the Lipase Engineering Database. In total, 5923 unassembled sequences were affiliated with 30 different α/β-hydrolase fold superfamilies. The most abundant predicted proteins encompassed cytosolic hydrolases (abH08; ∼ 23%), microsomal hydrolases (abH09; ∼ 12%) and Moraxella lipase-like proteins (abH04 and abH01; mangroves BrMgv01-02-03. This suggested selection and putative involvement in local degradation/detoxification of the pollutants. Seven sequences that were annotated as genes for putative epoxide hydrolases and five for putative haloalkane dehalogenases were found in a fosmid library generated from BrMgv02 DNA. The latter enzymes were predicted to belong to Actinobacteria, Deinococcus-Thermus, Planctomycetes and Proteobacteria. Our integrated approach thus identified 12 genes (complete and/or partial) that may encode hitherto undescribed enzymes. The low amino acid identity (< 60%) with already-described genes opens perspectives for both production in an expression host and genetic screening of metagenomes. © 2014 The Authors. Microbial Biotechnology published by John Wiley & Sons Ltd and Society for Applied Microbiology.

  11. Compositional profile of α/β-hydrolase fold proteins in mangrove soil metagenomes: prevalence of epoxide hydrolases and haloalkane dehalogenases in oil-contaminated sites

    Science.gov (United States)

    Jiménez, Diego Javier; Dini-Andreote, Francisco; Ottoni, Júlia Ronzella; de Oliveira, Valéria Maia; van Elsas, Jan Dirk; Andreote, Fernando Dini

    2015-01-01

    The occurrence of genes encoding biotechnologically relevant α/β-hydrolases in mangrove soil microbial communities was assessed using data obtained by whole-metagenome sequencing of four mangroves areas, denoted BrMgv01 to BrMgv04, in São Paulo, Brazil. The sequences (215 Mb in total) were filtered based on local amino acid alignments against the Lipase Engineering Database. In total, 5923 unassembled sequences were affiliated with 30 different α/β-hydrolase fold superfamilies. The most abundant predicted proteins encompassed cytosolic hydrolases (abH08; ∼ 23%), microsomal hydrolases (abH09; ∼ 12%) and Moraxella lipase-like proteins (abH04 and abH01; mangroves BrMgv01-02-03. This suggested selection and putative involvement in local degradation/detoxification of the pollutants. Seven sequences that were annotated as genes for putative epoxide hydrolases and five for putative haloalkane dehalogenases were found in a fosmid library generated from BrMgv02 DNA. The latter enzymes were predicted to belong to Actinobacteria, Deinococcus-Thermus, Planctomycetes and Proteobacteria. Our integrated approach thus identified 12 genes (complete and/or partial) that may encode hitherto undescribed enzymes. The low amino acid identity (< 60%) with already-described genes opens perspectives for both production in an expression host and genetic screening of metagenomes. PMID:25171437

  12. Organophosphorus insecticides: Toxic effects and bioanalytical tests for evaluating toxicity during degradation processes

    Directory of Open Access Journals (Sweden)

    Čolović Mirjana B.

    2013-01-01

    Full Text Available Organophosphorus insecticides have been the most applied group of insecticides for the last two decades. Their main toxic effects are related to irreversible inactivation of acetylcholinesterase (AChE. Actually, they covalently bind to serine OH group in the enzyme active site forming phosphorylated enzyme that cannot hydrolyze acetylcholine. Organophosphorus insecticides in the environment undergo the natural degradation pathway including mainly homogeneous and heterogeneous hydrolysis (especially at high pH generating non-inhibiting products. Additionally, thio organophosphates are easily oxidized by naturally present oxidants and UV light, forming more toxic and stable oxons. Thus, oxidative degradation procedures, generally referred as advanced oxidation processes (AOP, have been applied for their efficient removal from contaminated waters. The most applied bioassays to monitor the organophosphate toxicity i.e. the detoxification degree during AOP are Vibrio fischeri and AChE bioassays. Vibrio fischeri toxicity test exploits bioluminescence as the measure of luciferase activity of this marine bacterium, whereas AChE bioassay is based on AChE activity inhibition. Both bioanalytical techniques are rapid (several minutes, simple, sensitive and reproducible. Vibrio fischeri test seems to be a versatile indicator of toxic compounds generated in AOP for organophosphorus insecticides degradation. However, detection of neurotoxic AChE inhibitors, which can be formed in AOP of some organophosphates, requires AChE bioassays. Therefore, AChE toxicity test is more appropriate for monitoring the degradation processes of thio organophosphates, because more toxic oxo organophosphates might be formed and overlooked by Vibrio fischeri bioluminescence inhibition. In addition, during organophosphates removal by AOP, compounds with strong genotoxic potential may be formed, which cannot be detected by standard toxicity tests. For this reason, determination of

  13. Organophosphorus acid anhydrolase from Alteromonas macleodii: structural study and functional relationship to prolidases

    Czech Academy of Sciences Publication Activity Database

    Štěpánková, Andrea; Dušková, Jarmila; Skálová, Tereza; Hašek, Jindřich; Koval, Tomáš; Ostergaard, L. H.; Dohnálek, Jan

    2013-01-01

    Roč. 69, č. 4 (2013), s. 346-354 ISSN 1744-3091 R&D Projects: GA ČR GA310/09/1407; GA ČR GA305/07/1073; GA MŠk EE2.3.30.0029 Institutional research plan: CEZ:AV0Z40500505 Institutional support: RVO:61389013 Keywords : organophosphorus acid anhydrolase * prolidases * bifunctional Subject RIV: CE - Biochemistry Impact factor: 0.568, year: 2013

  14. A Common Mechanism for Resistance to Oxime Reactivation of Acetylcholinesterase Inhibited by Organophosphorus Compounds

    Science.gov (United States)

    2013-01-01

    reactivated than AChE conjugates inhibited by the corresponding Rp enantiomers and this effect is enhanced as the size of the O-alkyl substituents of OP...Organophosphates and Carbamates, Butterworth & Heinemann , Oxford, 1992. pp. 555–577. [2] P. Taylor, Anticholinesterase agents, in: L.L. Brunton, J.S...application of the Hammett equation with the constants rph in the chemistry of organophosphorus compounds, Russ. Chem. Rev. 38 (1969) 795–811. [13

  15. Immobile Complex Verbs in Germanic

    DEFF Research Database (Denmark)

    Vikner, Sten

    2005-01-01

    the V° requirements or the V* requirements. Haider (1993, p. 62) and Koopman (1995), who also discuss such immobile verbs, only account for verbs with two prefix-like parts (e.g., German uraufführen ‘to perform (a play) for the first time' or Dutch herinvoeren ‘to reintroduce'), not for the more...... frequent type with only one prefix-like part (e.g., German bauchreden/Dutch buikspreken ‘to ventriloquize'). This analysis will try to account not only for the data discussed in Haider (1993) and Koopman (1995) but also for the following: - why immobile verbs include verbs with only one prefix-like part...... are immobile, - why such verbs are not found in Germanic VO-languages such as English and Scandinavian....

  16. Long Alkyl Chain Organophosphorus Coupling Agents for in Situ Surface Functionalization by Reactive Milling

    Directory of Open Access Journals (Sweden)

    Annika Betke

    2014-08-01

    Full Text Available Innovative synthetic approaches should be simple and environmentally friendly. Here, we present the surface modification of inorganic submicrometer particles with long alkyl chain organophosphorus coupling agents without the need of a solvent, which makes the technique environmentally friendly. In addition, it is of great benefit to realize two goals in one step: size reduction and, simultaneously, surface functionalization. A top-down approach for the synthesis of metal oxide particles with in situ surface functionalization is used to modify titania with long alkyl chain organophosphorus coupling agents. A high energy planetary ball mill was used to perform reactive milling using titania as inorganic pigment and long alkyl chain organophosphorus coupling agents like dodecyl and octadecyl phosphonic acid. The final products were characterized by IR, NMR and X-ray fluorescence spectroscopy, thermal and elemental analysis as well as by X-ray powder diffraction and scanning electron microscopy. The process entailed a tribochemical phase transformation from the starting material anatase to a high-pressure modification of titania and the thermodynamically more stable rutile depending on the process parameters. Furthermore, the particles show sizes between 100 nm and 300 nm and a degree of surface coverage up to 0.8 mmol phosphonate per gram.

  17. Immobilization of acid digestion residue

    International Nuclear Information System (INIS)

    Greenhalgh, W.O.; Allen, C.R.

    1983-01-01

    Acid digestion treatment of nuclear waste is similar to incineration processes and results in the bulk of the waste being reduced in volume and weight to some residual solids termed residue. The residue is composed of various dispersible solid materials and typically contains the resultant radioactivity from the waste. This report describes the immobilization of the residue in portland cement, borosilicate glass, and some other waste forms. Diagrams showing the cement and glass virtification parameters are included in the report as well as process steps and candidate waste product forms. Cement immobilization is simplest and probably least expensive; glass vitrification exhibits the best overall volume reduction ratio

  18. Les lipases sont des hydrolases atypiques : principales caractéristiques et applications

    Directory of Open Access Journals (Sweden)

    Fickers P.

    2008-01-01

    Full Text Available ipases are atypical hydrolases: principal characteristics and applications. Due to their kinetic and substrate specificities, triacylglycerol acyl-hydrolases or lipases are atypical enzymes. In function of their microenvironment, lipases are able to act as hydrolases in aqueous solution or as biocatalysts in organic synthesis. As hydrolases, they are responsible of the triglycerids catabolism into fatty acids and glycerol. In many organisms, this reaction plays a major role in the fat and lipid metabolism. In addition, lipases are also able to hydrolyse phospholipids and cholesterol esters. In organic solvent, lipases could catalyse reactions such as esterifications, acidolysis or alcoolysis with enantio-, regio- and chimioselectivity. Lipases form a mixed class of enzyme due to their animal, vegetal or microbial origins. All those properties led to the development of many applications in the food and chemical industries but also in the medical and therapeutic field.

  19. Dysregulation of soluble epoxide hydrolase and lipidomic profiles in anorexia nervosa

    KAUST Repository

    Shih, P. B.; Yang, J.; Morisseau, C.; German, J. B.; Scott-Van Zeeland, A. A.; Armando, A. M.; Quehenberger, O.; Bergen, A. W.; Magistretti, Pierre J.; Berrettini, W.; Halmi, K. A.; Schork, N.; Hammock, B. D.; Kaye, W.

    2015-01-01

    Individuals with anorexia nervosa (AN) restrict eating and become emaciated. They tend to have an aversion to foods rich in fat. Because epoxide hydrolase 2 (EPHX2) was identified as a novel AN susceptibility gene, and because its protein product

  20. Purification and characterisation of a novel enantioselective epoxide hydrolase from Aspergillus niger M200

    Czech Academy of Sciences Publication Activity Database

    Kotík, Michael; Kyslík, Pavel

    2006-01-01

    Roč. 1760, - (2006), s. 245-252 ISSN 0006-3002 Institutional research plan: CEZ:AV0Z50200510 Keywords : epoxide hydrolase * enantioselectivity * aspergillus niger Subject RIV: EE - Microbiology, Virology

  1. α-Amylase: an enzyme specificity found in various families of glycoside hydrolases

    DEFF Research Database (Denmark)

    Janeček, Štefan; Svensson, Birte; MacGregor, E. Ann

    2014-01-01

    of all carbohydrate-active enzymes, it is one of the most frequently occurring glycoside hydrolases (GH). α-Amylase is the main representative of family GH13, but it is probably also present in the families GH57 and GH119, and possibly even in GH126. Family GH13, known generally as the main α...... investigation because of an obvious, but unexpected, homology with inverting β-glucan-active hydrolases....

  2. HYDROLASING OF CONTAMINATED UNDERWATER BASIN SURFACES AT THE HANFORD K AREA

    International Nuclear Information System (INIS)

    CHRONISTER, G.B.

    2005-01-01

    This paper discusses selecting and implementing hydrolasing technology to reduce radioactive contamination in preparing to dispose of the K Basins; two highly contaminated concrete basins at the Hanford Site. A large collection of spent nuclear fuel stored for many years underwater at the K Basins has been removed to stable, dry, safe storage. Remediation activities have begun for the remaining highly contaminated water. sludge, and concrete basin structures. Hydrolasing will be used to decontaminate and prepare the basin structures for disposal

  3. Radiation immobilization of catalase and its application

    International Nuclear Information System (INIS)

    Wang Guanghui; Ha Hongfei; Wang Xia; Wu Jilan

    1988-01-01

    Catalase was immobilized by a chemical method on porous polyacrylamide particles produced by radiation polymerization of acrylamide monomer at low temperature (-78 0 C). Activity of immobilized catalase was enhanced distinctly by joining a chemical arm to the support. The method of recovery of catalase activity on immobilized polymer was found by soaking it in certain buffer. The treatment of H 2 O 2 both in aqueous solution and alcoholic solution by using the immobilized catalase was performed. (author)

  4. A STUDY OF PREDICTING THE NEED FOR VENTILATOR SUPPORT AND OUTCOME IN ORGANOPHOSPHORUS POISONING

    Directory of Open Access Journals (Sweden)

    Kalinga Bommankatte Eranaik

    2017-04-01

    Full Text Available BACKGROUND Organophosphorus compound poisoning is the most common poisonings in India because of easy availability, often requiring ICU care and ventilator support. Clinical research has indicated that respiratory failure is the most important cause of death due to Organophosphorus poisoning. It results in respiratory muscle weakness, pulmonary oedema, respiratory depression, increased secretions and bronchospasm. These complications and death can be prevented with timely Institution of ventilator support. The aim of present study was to identify the factors and predicting the need for ventilator support and outcome. Aim of the Study- To predict the need for ventilator support and outcome in organophosphate poisoning. MATERIALS AND METHODS Seventy consecutive patients admitted with a history of organophosphorus poisoning at KIMS, Hubli were taken for study after considering the inclusion and exclusion criteria. Detailed history, confirmation of poisoning, examination and other than routine investigations serum pseudocholinesterase and arterial blood gas analysis was done. The severity of organophosphorus poisoning was graded as mild, moderate and severe based on the factors which influence the need for ventilator support. RESULTS This study was conducted in 70 patients, out of which 48 (68.6% were male patients and 22 (31.4% were female patients. Among them 37 (53% patients required ventilation and 33 (47% expired. Chlorpyrifos, Dichlorvos and Monocrotophos were most commonly consumed poisons. 74% patients who consumed these compounds required ventilator support and 73% patients expired. 100% of patients presented with pin point pupil, fasciculation score > 4, respiratory rate > 20, GCS score < 7 and severe grade of poisoning required ventilator support and pseudocholinesterase < 900 U/L, 70% of metabolic acidosis and atropine requirement more than 180 mg within 48 hours required ventilator support and associated with high mortality. CONCLUSION

  5. Regulation of calcium release from the endoplasmic reticulum by the serine hydrolase ABHD2.

    Science.gov (United States)

    Yun, Bogeon; Lee, HeeJung; Powell, Roger; Reisdorph, Nichole; Ewing, Heather; Gelb, Michael H; Hsu, Ku-Lung; Cravatt, Benjamin F; Leslie, Christina C

    2017-09-02

    The serine hydrolase inhibitors pyrrophenone and KT195 inhibit cell death induced by A23187 and H 2 O 2 by blocking the release of calcium from the endoplasmic reticulum and mitochondrial calcium uptake. The effect of pyrrophenone and KT195 on these processes is not due to inhibition of their known targets, cytosolic phospholipase A 2 and α/β-hydrolase domain-containing (ABHD) 6, respectively, but represent off-target effects. To identify targets of KT195, fibroblasts were treated with KT195-alkyne to covalently label protein targets followed by click chemistry with biotin azide, enrichment on streptavidin beads and tryptic peptide analysis by mass spectrometry. Although several serine hydrolases were identified, α/β-hydrolase domain-containing 2 (ABHD2) was the only target in which both KT195 and pyrrophenone competed for binding to KT195-alkyne. ABHD2 is a serine hydrolase with a predicted transmembrane domain consistent with its pull-down from the membrane proteome. Subcellular fractionation showed localization of ABHD2 to the endoplasmic reticulum but not to mitochondria or mitochondrial-associated membranes. Knockdown of ABHD2 with shRNA attenuated calcium release from the endoplasmic reticulum, mitochondrial calcium uptake and cell death in fibroblasts stimulated with A23187. The results describe a novel mechanism for regulating calcium transfer from the endoplasmic reticulum to mitochondria that involves the serine hydrolase ABHD2. Copyright © 2017 Elsevier Inc. All rights reserved.

  6. Immobilization and characterization of inulinase from Ulocladium

    Indian Academy of Sciences (India)

    Ulocladium atrum inulinase was immobilized on different composite membranes composed of chitosan/nonwoven fabrics. Km values of free and immobilized U. atrum inulinase on different composite membranes were calculated. The enzyme had optimum pH at 5.6 for free and immobilized U. atrum inulinase on polyester ...

  7. Immobilization of Mitochondria on Graphene

    Science.gov (United States)

    2013-08-29

    poly-L-lysine has also been reported for immobilization of yeast mitochondria. Coating was performed by repetitive washing of cover slips with 0.02...of Poly-L-lysine Applications of PLL PLL is a production of bacterial fermentation and is used as a food preservative. In biology, PLL is used in

  8. Expression of Nudix hydrolase genes in barley under UV irradiation

    Science.gov (United States)

    Tanaka, Sayuri; Sugimoto, Manabu; Kihara, Makoto

    Seed storage and cultivation should be necessary to self-supply foods when astronauts would stay and investigate during long-term space travel and habitation in the bases on the Moon and Mars. Thought the sunlight is the most importance to plants, both as the ultimate energy source and as an environmental signal regulating growth and development, UV presenting the sunlight can damage many aspects of plant processes at the physiological and DNA level. Especially UV-C, which is eliminated by the stratospheric ozone layer, is suspected to be extremely harmful and give a deadly injury to plants in space. However, the defense mechanism against UV-C irradiation damage in plant cells has not been clear. In this study, we investigated the expression of Nudix hydrolases, which defense plants from biotic / abiotic stress, in barley under UV irradiation. The genes encoding the amino acid sequences, which show homology to those of 28 kinds of Nudix hydrolases in Arabidopsis thaliana, were identified in the barley full-length cDNA library. BLAST analysis showed 14 kinds of barley genes (HvNUDX1-14), which encode the Nudix motif sequence. A phylogenetic tree showed that HvNUDX1, HvNUDX7, HvNUDX9 and HvNUDX11 belonged to the ADP-ribose pyrophosphohydrolase, ADP-sugar pyrophosphohydrolase, NAD(P)H pyrophosphohydrolase and FAD pyrophosphohydrolase subfamilies, respectively, HvNUDX3, HvNUDX6, and HvNUDX8 belonged to the Ap _{n}A pyrophosphohydrolase subfamilies, HvNUDX5 and HvNUDX14 belonged to the coenzyme A pyrophosphohydrolase subfamilies, HvNUDX12 and HvNUDX13 belonged to the Ap _{4}A pyrophosphohydrolase subfamilies. Induction of HvNUDX genes by UV-A (340nm), UV-B (312nm), and UV-C (260nm) were analyzed by quantitative RT-PCR. The results showed that HvNUDX4 was induced by UV-A and UV-B, HvNUDX6 was induced by UV-B and UV-C, and HvNUDX7 and HvNUDX14 were induced by UV-C, significantly. Our results suggest that the response of HvNUDXs to UV irradiation is different by UV

  9. Epoxide hydrolase affects estrogen production in the human ovary.

    Science.gov (United States)

    Hattori, N; Fujiwara, H; Maeda, M; Fujii, S; Ueda, M

    2000-09-01

    To investigate the mechanisms of ovarian cell differentiation, we raised a new monoclonal antibody, HCL-3, which reacted with human luteal cells. It also reacted with human and porcine hepatocytes. The immunoaffinity-purified HCL-3 antigen from human corpora lutea (CL) was shown to be a 46-kDa protein. The N-terminal 22 amino acids of the 46-kDa protein from porcine liver exhibited high homology (82%) to human microsomal epoxide hydrolase (mEH). The purified HCL-3 antigen from human CL or porcine liver showed EH enzyme activity, confirming that HCL-3 antigen is identical to mEH, which is reported to detoxify the toxic substrates in the liver. In human follicles, mEH was immunohistochemically detected on granulosa and theca interna cells. In the menstrual and pregnant CL, mEH was also expressed on large and small luteal cells. A competitive inhibitor of EH, 1,2-epoxy-3,3,3-trichloropropane, inhibited the conversion of estradiol from testosterone by granulosa cells cultured in vitro, indicating the involvement of mEH in ovarian estrogen production. Because anticonvulsant sodium valproate and its analogues were reported to inhibit EH enzyme activity, these findings provide a new insight into the etiology of endocrine disorders that are frequently observed among epileptic patients taking anticonvulsant drugs.

  10. Microfluidic glycosyl hydrolase screening for biomass-to-biofuel conversion.

    Science.gov (United States)

    Bharadwaj, Rajiv; Chen, Zhiwei; Datta, Supratim; Holmes, Bradley M; Sapra, Rajat; Simmons, Blake A; Adams, Paul D; Singh, Anup K

    2010-11-15

    The hydrolysis of biomass to fermentable sugars using glycosyl hydrolases such as cellulases and hemicellulases is a limiting and costly step in the conversion of biomass to biofuels. Enhancement in hydrolysis efficiency is necessary and requires improvement in both enzymes and processing strategies. Advances in both areas in turn strongly depend on the progress in developing high-throughput assays to rapidly and quantitatively screen a large number of enzymes and processing conditions. For example, the characterization of various cellodextrins and xylooligomers produced during the time course of saccharification is important in the design of suitable reactors, enzyme cocktail compositions, and biomass pretreatment schemes. We have developed a microfluidic-chip-based assay for rapid and precise characterization of glycans and xylans resulting from biomass hydrolysis. The technique enables multiplexed separation of soluble cellodextrins and xylose oligomers in around 1 min (10-fold faster than HPLC). The microfluidic device was used to elucidate the mode of action of Tm_Cel5A, a novel cellulase from hyperthermophile Thermotoga maritima . The results demonstrate that the cellulase is active at 80 °C and effectively hydrolyzes cellodextrins and ionic-liquid-pretreated switchgrass and Avicel to glucose, cellobiose, and cellotriose. The proposed microscale approach is ideal for quantitative large-scale screening of enzyme libraries for biomass hydrolysis, for development of energy feedstocks, and for polysaccharide sequencing.

  11. Heterologous expression of the methyl carbamate-degrading hydrolase MCD.

    Science.gov (United States)

    Naqvi, Tatheer; Cheesman, Matthew J; Williams, Michelle R; Campbell, Peter M; Ahmed, Safia; Russell, Robyn J; Scott, Colin; Oakeshott, John G

    2009-10-26

    The methyl carbamate-degrading hydrolase (MCD) of Achromobacter WM111 has considerable potential as a pesticide bioremediation agent. However this potential has been unrealisable until now because of an inability to express MCD in heterologous hosts such as Escherichia coli. Herein, we describe the first successful attempt to express appreciable quantities of MCD in active form in E. coli, and the subsequent characterisation of the heterologously expressed material. We find that the properties of this material closely match the previously reported properties of MCD produced from Achromobacter WM111. This includes the presence of two distinct forms of the enzyme that we show are most likely due to the presence of two functional translational start sites. The purified enzyme catalyses the hydrolysis of a carbamate (carbaryl), a carboxyl ester (alpha-naphthyl acetate) and a phophotriester (dimethyl umbelliferyl phosphate) and it is relatively resistant to thermal and solvent-mediated denaturation. The robust nature and catalytic promiscuity of MCD suggest that it could be exploited for various biotechnological applications.

  12. Hepatic cholesterol ester hydrolase in human liver disease.

    Science.gov (United States)

    Simon, J B; Poon, R W

    1978-09-01

    Human liver contains an acid cholesterol ester hydrolase (CEH) of presumed lysosomal origin, but its significance is unknown. We developed a modified CEH radioassay suitable for needle biopsy specimens and measured hepatic activity of this enzyme in 69 patients undergoing percutaneous liver biopsy. Histologically normal livers hydrolyzed 5.80 +/- 0.78 SEM mumoles of cholesterol ester per hr per g of liver protein (n, 10). Values were similar in alcoholic liver disease (n, 17), obstructive jaundice (n, 9), and miscellaneous hepatic disorders (n, 21). In contrast, mean hepatic CEH activity was more than 3-fold elevated in 12 patients with acute hepatitis, 21.05 +/- 2.45 SEM mumoles per hr per g of protein (P less than 0.01). In 2 patients studied serially, CEH returned to normal as hepatitis resolved. CEH activity in all patients paralleled SGOT levels (r, 0.84; P less than 0.01). There was no correlation with serum levels of free or esterified cholesterol nor with serum activity of lecithin-cholesterol acyltransferase, the enzyme responsible for cholesterol esterification in plasma. These studies confirm the presence of CEH activity in human liver and show markedly increased activity in acute hepatitis. The pathogenesis and clinical significance of altered hepatic CEH activity in liver disease require further study.

  13. Fractionation and Characterization of Tannin Acyl Hydrolase from Aspergillus niger

    Directory of Open Access Journals (Sweden)

    YUNITA ARIAN SANI ANWAR

    2009-09-01

    Full Text Available We previously produced tannin acyl hydrolase (tannase from Aspergillus niger isolated from cacao pod. In the present study the enzyme was subjected to fractionation by ammonium sulphate followed by dialysis process. The saturation level of ammonium sulphate used was 30-80% where the best enzyme activity was obtained at the saturation level of 60%. Compared to that of crude enzyme, specific activity of tannase after dialysis was four folds. Characterization results showed that optimum activity was at 35-50 oC and pH 6. Tannase was activated by K+ and Na+ at concentration of 0.01 and 0.05 M respectively. Mg2+ was found activate tannase only at 0.01 M. Addition of metal ions like Zn2+, Cu2+, Ca2+, Mn2+ and Fe2+ inhibited the enzyme activity. Kinetics analysis of various substrates tested showed that the Km value of tannic acid and gallotannin was 0.401 and 6.611 mM respectively. Vmax value of tannic acid was 10.804 U/ml and of gallotannin was 12.406 U/ml. Based on Michaelis-Menten constant (Km, the tannase obtained in the present study was more active in hydrolysing depside bonds rather than ester bonds.

  14. Fractionation and Characterization of Tannin Acyl Hydrolase from Aspergillus niger

    Directory of Open Access Journals (Sweden)

    YUNITA ARIAN SANI ANWAR

    2009-09-01

    Full Text Available We previously produced tannin acyl hydrolase (tannase from Aspergillus niger isolated from cacao pod. In the present study the enzyme was subjected to fractionation by ammonium sulphate followed by dialysis process. The saturation level of ammonium sulphate used was 30–80% where the best enzyme activity was obtained at the saturation level of 60%. Compared to that of crude enzyme, specific activity of tannase after dialysis was four folds. Characterization results showed that optimum activity was at 35–50 °C and pH 6. Tannase was activated by K+ and Na+ at concentration of 0.01 and 0.05 M respectively. Mg2+ was found activate tannase only at 0.01 M. Addition of metal ions like Zn2+, Cu2+, Ca2+, Mn2+ and Fe2+ inhibited the enzyme activity. Kinetics analysis of various substrates tested showed that the Km value of tannic acid and gallotannin was 0.401 and 6.611 mM respectively. Vmax value of tannic acid was 10.804 U/ml and of gallotannin was 12.406 U/ml. Based on Michaelis-Menten constant (Km, the tannase obtained in the present study was more active in hydrolysing depside bonds rather than ester bonds.

  15. Ubiquitin C-Terminal Hydrolase L1 in Tumorigenesis

    Directory of Open Access Journals (Sweden)

    Jennifer Hurst-Kennedy

    2012-01-01

    Full Text Available Ubiquitin carboxyl-terminal hydrolase L1 (UCH-L1, aka PGP9.5 is an abundant, neuronal deubiquitinating enzyme that has also been suggested to possess E3 ubiquitin-protein ligase activity and/or stabilize ubiquitin monomers in vivo. Recent evidence implicates dysregulation of UCH-L1 in the pathogenesis and progression of human cancers. Although typically only expressed in neurons, high levels of UCH-L1 have been found in many nonneuronal tumors, including breast, colorectal, and pancreatic carcinomas. UCH-L1 has also been implicated in the regulation of metastasis and cell growth during the progression of nonsmall cell lung carcinoma, colorectal cancer, and lymphoma. Together these studies suggest UCH-L1 has a potent oncogenic role and drives tumor development. Conversely, others have observed promoter methylation-mediated silencing of UCH-L1 in certain tumor subtypes, suggesting a potential tumor suppressor role for UCH-L1. In this paper, we provide an overview of the evidence supporting the involvement of UCH-L1 in tumor development and discuss the potential mechanisms of action of UCH-L1 in oncogenesis.

  16. Soluble epoxide hydrolase inhibitory activity of anthraquinone components from Aloe.

    Science.gov (United States)

    Sun, Ya Nan; Kim, Jang Hoon; Li, Wei; Jo, A Reum; Yan, Xi Tao; Yang, Seo Young; Kim, Young Ho

    2015-10-15

    Aloe is a short-stemmed succulent herb widely used in traditional medicine to treat various diseases and as raw material in cosmetics and heath foods. In this study, we isolated and identified two new anthraquinone derivatives, aloinoside C (6) and aloinoside D (7), together with six known compounds from an aqueous dissolved Aloe exudate. Their structures were identified by spectroscopic analysis. The inhibitory effects of the isolated compounds on soluble epoxide hydrolase (sEH) were evaluated. Compounds 1-8 inhibited sEH activity potently, with IC50 values ranging from 4.1±0.6 to 41.1±4.2 μM. A kinetic analysis of compounds 1-8 revealed that the inhibitory actions of compounds 1, 6 and 8 were non-competitive, whereas those of compounds 2-5 and 7 were the mixed-type. Molecular docking increases our understanding of receptor-ligand binding of all compounds. These results demonstrate that compounds 1-8 from Aloe are potential sEH inhibitors. Copyright © 2015 Elsevier Ltd. All rights reserved.

  17. Biodiesel production with immobilized lipase: A review.

    Science.gov (United States)

    Tan, Tianwei; Lu, Jike; Nie, Kaili; Deng, Li; Wang, Fang

    2010-01-01

    Fatty acid alkyl esters, also called biodiesel, are environmentally friendly and show great potential as an alternative liquid fuel. Biodiesel is produced by transesterification of oils or fats with chemical catalysts or lipase. Immobilized lipase as the biocatalyst draws high attention because that process is "greener". This article reviews the current status of biodiesel production with immobilized lipase, including various lipases, immobilization methods, various feedstocks, lipase inactivation caused by short chain alcohols and large scale industrialization. Adsorption is still the most widely employed method for lipase immobilization. There are two kinds of lipase used most frequently especially for large scale industrialization. One is Candida antartica lipase immobilized on acrylic resin, and the other is Candida sp. 99-125 lipase immobilized on inexpensive textile membranes. However, to further reduce the cost of biodiesel production, new immobilization techniques with higher activity and stability still need to be explored. Copyright 2010 Elsevier Inc. All rights reserved.

  18. Compositional profile of α / β-hydrolase fold proteins in mangrove soil metagenomes : Prevalence of epoxide hydrolases and haloalkane dehalogenases in oil-contaminated sites

    NARCIS (Netherlands)

    Jiménez Avella, Diego; Dini Andreote, Francisco; Ottoni, Júlia Ronzella; de Oliveira, Valéria Maia; van Elsas, Jan Dirk; Andreote, Fernando Dini

    The occurrence of genes encoding biotechnologically relevant α/β-hydrolases in mangrove soil microbial communities was assessed using data obtained by whole-metagenome sequencing of four mangroves areas, denoted BrMgv01 to BrMgv04, in São Paulo, Brazil. The sequences (215 Mb in total) were filtered

  19. The apo structure of sucrose hydrolase from Xanthomonas campestris pv. campestris shows an open active-site groove

    DEFF Research Database (Denmark)

    Champion, Elise; Remaud-Simeon, Magali; Skov, Lars Kobberøe

    2009-01-01

    Glycoside hydrolase family 13 (GH-13) mainly contains starch-degrading or starch-modifying enzymes. Sucrose hydrolases utilize sucrose instead of amylose as the primary glucosyl donor. Here, the catalytic properties and X-ray structure of sucrose hydrolase from Xanthomonas campestris pv. campestris...... of GH-13. Comparisons with structures of the highly similar sucrose hydrolase from X. axonopodis pv. glycines most notably showed that residues Arg516 and Asp138, which form a salt bridge in the X. axonopodis sucrose complex and define part of the subsite -1 glucosyl-binding determinants...

  20. Immobilization of iodine in concrete

    Science.gov (United States)

    Clark, Walter E.; Thompson, Clarence T.

    1977-04-12

    A method for immobilizing fission product radioactive iodine recovered from irradiated nuclear fuel comprises combining material comprising water, Portland cement and about 3-20 wt. % iodine as Ba(IO.sub.3).sub.2 to provide a fluid mixture and allowing the fluid mixture to harden, said Ba(IO.sub.3).sub.2 comprising said radioactive iodine. An article for solid waste disposal comprises concrete prepared by this method. BACKGROUND OF THE INVENTION This invention was made in the course of, or under a contract with the Energy Research and Development Administration. It relates in general to reactor waste solidification and more specifically to the immobilization of fission product radioactive iodine recovered from irradiated nuclear fuel for underground storage.

  1. Contaminant immobilization via microbial activity

    International Nuclear Information System (INIS)

    1991-11-01

    The aim of this study was to search the literature to identify biological techniques that could be applied to the restoration of contaminated groundwaters near uranium milling sites. Through bioremediation it was hypothesized that the hazardous heavy metals could be immobilized in a stable, low-solubility form, thereby halting their progress in the migrating groundwater. Three basic mechanisms were examined: reduction of heavy metals by microbially produced hydrogen sulfide; direct microbial mediated reduction; and biosorption

  2. Immobilization of iodine in concrete

    International Nuclear Information System (INIS)

    Clark, W.E.; Thompson, C.T.

    1977-01-01

    A method for immobilizing fission product radioactive iodine recovered from irradiated nuclear fuel comprises combining material comprising water, Portland cement and about 3 to 20 wt percent iodine as Ba(IO 3 ) 2 to provide a fluid mixture and allowing the fluid mixture to harden, said Ba(IO 3 ) 2 comprising said radioactive iodine. An article for solid waste disposal comprises concrete prepared by this method. 10 claims, 2 figures

  3. Levels and distribution of organophosphorus flame retardants and plasticizers in fishes from Manila Bay, the Philippines

    International Nuclear Information System (INIS)

    Kim, Joon-Woo; Isobe, Tomohiko; Chang, Kwang-Hyeon; Amano, Atsuko; Maneja, Rommel H.; Zamora, Peter B.; Siringan, Fernando P.; Tanabe, Shinsuke

    2011-01-01

    Organophosphorus compounds (OPCs) and stable isotope ratios (δ 13 C and δ 15 N) were determined in 58 fishes belonging to 20 species collected from Manila Bay, the Philippines. OPCs were detected in most of the samples and found up to μg/g lw (lipid weight) level, suggesting their ubiquitous presence in the coastal marine environment of the Philippines. Higher levels (>1000 ng/g lw) of total OPCs were determined in yellowstriped goatfish, silver sillago, tripletail wrasse and bumpnose trevally indicates either their active uptake from ambient water or lower metabolic capacity of these species. Levels of triphenyl phosphate (TPhP) in demersal species showed a positive correlation with δ 15 N, indicating that TPhP was adsorbed onto the particle, settled down to the bottom sediment and accumulated through the benthic food web rather than the pelagic. Estimated dietary intake of OPCs in Manila Bay fishes were four to five orders of magnitude lower than the proposed reference dose (RfD). - Highlights: → Organophosphorus compounds (OPCs) were determined in fish from Manila Bay. → OPCs were detected up to μg/g lw, suggesting ubiquitous environmental contamination. → Among the 9 targeted OPCs, TEHP and TEP were found as the predominant compounds. → Estimated dietary intake through fish consumption was 4-5 orders of magnitude lower than RfD. → This is the first report on OPCs pollution in marine environment of Southeast Asia. - Occurrence and bioaccumulation of organophosphorus compounds (OPCs) were determined in fishes from Manila Bay.

  4. Determination of Twenty Organophosphorus Pesticides in Wheat Samples from Different Regions of Iran

    Directory of Open Access Journals (Sweden)

    Attaollah Shakoori *

    2017-09-01

    Full Text Available Background: Organophosphorus pesticides are widely used in agriculture, homes, gardens, and veterinary practices. Extensive application of pesticides in agriculture often results in residues of these compounds being absorbed into the foods, including wheat. The aim of this study was to evaluate the residue levels of 20 organophosphorus pesticides in wheat samples collected from different regions of Iran. Methods: This research reports a rapid, specific and sensitive multiresidue method based on the Quick Easy Cheap Effective Rugged and Safe (QuEChERS sample preparation method and gas chromatography with mass spectrometric detection in the selected ion monitoring mode (GC–SIM–MS to evaluate 20 organophosphorus pesticides in wheat samples. Results: In the concentration range of 20-200 ng/g, the calibration curves for each analyte was linear with a determination coefficient (R2 of 0.993 to 0.999. The limits of detection (LODs and quantitation (LOQs were between 2.5-6.7 and 7.5-20 ng/g, respectively. The mean recoveries obtained for three fortification levels (25, 50 and 100 ng/g, five replicates each were 80-114% with a satisfactory precision (RSD<20%. 31.1% samples contained residues of one or more target compounds. Chlorpyrifos was the most common residue (17.8%, followed by pirimiphos-methyl (6.7%, diazinon (4.4%, chlorpyrifos-methyl (1.1% and malathion (1.1%. Conclusion: Among the detected pesticides, only diazinon and malathion are permitted pesticides for wheat production in Iran. However, their concentrations were below the maximum residue levels (MRLs established by the Iranian National Standard Organization (INSO.

  5. Evaluation of fish models of soluble epoxide hydrolase inhibition.

    Science.gov (United States)

    Newman, J W; Denton, D L; Morisseau, C; Koger, C S; Wheelock, C E; Hinton, D E; Hammock, B D

    2001-01-01

    Substituted ureas and carbamates are mechanistic inhibitors of the soluble epoxide hydrolase (sEH). We screened a set of chemicals containing these functionalities in larval fathead minnow (Pimphales promelas) and embryo/larval golden medaka (Oryzias latipes) models to evaluate the utility of these systems for investigating sEH inhibition in vivo. Both fathead minnow and medaka sEHs were functionally similar to the tested mammalian orthologs (murine and human) with respect to substrate hydrolysis and inhibitor susceptibility. Low lethality was observed in either larval or embryonic fish exposed to diuron [N-(3,4-dichlorophenyl), N'-dimethyl urea], desmethyl diuron [N-(3,4-dichlorophenyl), N'-methyl urea], or siduron [N-(1-methylcyclohexyl), N'-phenyl urea]. Dose-dependent inhibition of sEH was a sublethal effect of substituted urea exposure with the potency of siduron diuron = diuron, differing from the observed in vitro sEH inhibition potency of siduron > desmethyl diuron > diuron. Further, siduron exposure synergized the toxicity of trans-stilbene oxide in fathead minnows. Medaka embryos exposed to diuron, desmethyl diuron, or siduron displayed dose-dependent delays in hatch, and elevated concentrations of diuron and desmethyl diuron produced developmental toxicity. The dose-dependent toxicity and in vivo sEH inhibition correlated, suggesting a potential, albeit undefined, relationship between these factors. Additionally, the observed inversion of in vitro to in vivo potency suggests that these fish models may provide tools for investigating the in vivo stability of in vitro inhibitors while screening for untoward effects. PMID:11171526

  6. Simple, specific analysis of organophosphorus and carbamate pesticides in sediments using column extraction and gas chromatography

    Science.gov (United States)

    Belisle, A.A.; Swineford, D.M.

    1988-01-01

    A simple, specific procedure was developed for the analysis of organophosphorus and carbamate pesticides in sediment. The wet soil was mixed with anhydrous sodium sulfate to bind water and the residues were column extracted in acetone:methylene chloride (1:l,v/v). Coextracted water was removed by additional sodium sulfate packed below the sample mixture. The eluate was concentrated and analyzed directly by capillary gas chromatography using phosphorus and nitrogen specific detectors. Recoveries averaged 93 % for sediments extracted shortly after spiking, but decreased significantly as the samples aged.

  7. Pralidoxime in acute organophosphorus insecticide poisoning--a randomised controlled trial.

    Directory of Open Access Journals (Sweden)

    Michael Eddleston

    2009-06-01

    Full Text Available Poisoning with organophosphorus (OP insecticides is a major global public health problem, causing an estimated 200,000 deaths each year. Although the World Health Organization recommends use of pralidoxime, this antidote's effectiveness remains unclear. We aimed to determine whether the addition of pralidoxime chloride to atropine and supportive care offers benefit.We performed a double-blind randomised placebo-controlled trial of pralidoxime chloride (2 g loading dose over 20 min, followed by a constant infusion of 0.5 g/h for up to 7 d versus saline in patients with organophosphorus insecticide self-poisoning. Mortality was the primary outcome; secondary outcomes included intubation, duration of intubation, and time to death. We measured baseline markers of exposure and pharmacodynamic markers of response to aid interpretation of clinical outcomes. Two hundred thirty-five patients were randomised to receive pralidoxime (121 or saline placebo (114. Pralidoxime produced substantial and moderate red cell acetylcholinesterase reactivation in patients poisoned by diethyl and dimethyl compounds, respectively. Mortality was nonsignificantly higher in patients receiving pralidoxime: 30/121 (24.8% receiving pralidoxime died, compared with 18/114 (15.8% receiving placebo (adjusted hazard ratio [HR] 1.69, 95% confidence interval [CI] 0.88-3.26, p = 0.12. Incorporating the baseline amount of acetylcholinesterase already aged and plasma OP concentration into the analysis increased the HR for patients receiving pralidoxime compared to placebo, further decreasing the likelihood that pralidoxime is beneficial. The need for intubation was similar in both groups (pralidoxime 26/121 [21.5%], placebo 24/114 [21.1%], adjusted HR 1.27 [95% CI 0.71-2.29]. To reduce confounding due to ingestion of different insecticides, we further analysed patients with confirmed chlorpyrifos or dimethoate poisoning alone, finding no evidence of benefit.Despite clear reactivation of

  8. Glycoside hydrolase gene transcription by Alicyclobacillus acidocaldarius during growth on wheat arabinoxylan and monosaccharides: a proposed xylan hydrolysis mechanism

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Brady D.; Apel, William A.; Sheridan, Peter P.; DeVeaux, Linda C.

    2018-04-16

    Background Metabolism of carbon bound in wheat arabinoxylan (WAX) polysaccharides by bacteria requires a number of glycoside hydrolases active toward different bonds between sugars and other molecules. Alicyclobacillus acidocaldarius is a Gram-positive thermoacidophilic bacterium capable of growth on a variety of mono-, di-, oligo-, and polysaccharides. Nineteen proposed glycoside hydrolases have been annotated in the A. acidocaldarius Type Strain ATCC27009/DSM 446 genome. Results Molecular analysis using high-density oligonucleotide microarrays was performed on A. acidocaldarius strain ATCC27009 when growing on WAX. When a culture growing exponentially at the expense of arabinoxylan saccharides was challenged with glucose or xylose, most glycoside hydrolases were down-regulated. Interestingly, regulation was more intense when xylose was added to the culture than when glucose was added, a clear departure from classical carbon catabolite repression demonstrated by many Gram-positive bacteria. In silico analyses of the regulated glycoside hydrolases, along with the results from the microarray analyses, yielded a potential mechanism for arabinoxylan metabolism by A. acidocaldarius. Glycoside hydrolases expressed by this strain may have broad substrate specificity, and initial hydrolysis is catalyzed by an extracellular xylanase, while subsequent steps are likely performed inside the growing cell. Conclusions Glycoside hydrolases, for the most part, appear to be found in clusters, throughout the A. acidocaldarius genome. Not all of the glycoside hydrolase genes found at loci within these clusters were regulated during the experiment, indicating that a specific subset of the 19 glycoside hydrolase genes found in A. acidocaldarius were used during metabolism of WAX. While specific functions of the glycoside hydrolases was not tested as part of the research discussed, many of the glycoside hydrolases found in the A. acidocaldarius Type Strain appear to have a broader

  9. Properties of immobilized papain by radiation polymerization

    International Nuclear Information System (INIS)

    Kumakura, Minoru; Kaetsu, Isao

    1984-01-01

    Papain was immobilized by the radiation polymerization of various monomers at low temperatures and the effects of the polymer matrix on the enzyme activity and thermal stability of the immobilized enzymes were studied. The activity of the immobilized enzymes prepared from monofunctional (acrylate and methacrylate) monomers was higher than that from bifunctional (bismethacrylate) monomers and that from polyoxyethylene dimethacrylate monomers increased with an increase in the number of oxyethylene units. The thermal stability of the immobilized enzymes prepared from hydrophilic monomers was higher than that from hydrophobic monomers and increased markedly with increasing monomer concentration. (author)

  10. Peptidoglycan Hydrolases of Local Lactic Acid Bacteria from Kazakh Traditional Food

    Directory of Open Access Journals (Sweden)

    Serik Shaikhin

    2014-01-01

    Full Text Available Introduction: Peptidoglycan (PG is a major component of the cell wall of Gram-positive bacteria and is essential for maintaining the integrity of the bacterial cell and its shape. The bacteria synthesize PG hydrolases, which are capable of cleaving the covalent bonds of PG. They also play an important role in modeling PG, which is required for bacterial growth and division. In an era of increasing antibiotic-resistant pathogens, PG hydrolases that destroy these important structures of the cell wall act as a potential source of new antimicrobials. The aim of this study is to identify the main PG hydrolases of local lactic acid bacteria isolated from traditional foods that enhance probiotic activity of a biological preparation. Methods. Lactococcus lactis 17А and Lactococcus garvieae 19А were isolated from the traditional sausage-like meat product called kazy. They were isolated according to standards methods of microbiology. Genetic identification of the isolates were tested by determining the nucleotide sequences of 16S rDNA. The Republican collection of microorganisms took strains of Lactobacillus casei subsp. Rhamnosus 13-P, L. delbrueckii subsp. lactis CG-1 B-RKM 0044 from cheese, Lactobacillus casei subsp. casei B-RKM 0202 from homemade butter. They used the standard technique of renaturating polyacrylamide gel electrophoresis to detect PG hydrolases activity. Results. According to the profiles of PG hydrolase activity on zymograms, the enzymes of Lactococci 17A and 19A in kazy are similar in electrophoretic mobility to major autolysin AcmA, while the lactobacilli of industrial and home-made dairy products have enzymes similar to extracellular proteins p40 and p75, which have probiotic activity. Conclusions. Use of peptidoglycan hydrolases seems to be an interesting approach in the fight against multi-drug resistant strains of bacteria and could be a valuable tool for the treatment of diseases caused by these microorganisms in Kazakhstan.

  11. DEVELOPMENT OF A RISK ASSESSMENT MODEL FOR THE EFFECTS OF ORGANOPHOSPHORUS PESTICIDES ON INFECTIOUS DISEASE SUSCEPTIBILITY AND THE IMMUNE SYSTEM

    Science.gov (United States)

    There is increased concern about the sublethal effects of organophosphorus (OP) pesticides on human and animal health. This class of chemicals has been shown to affect the immune function of macrophages and lymphocytes. Malathion, an OP compound, is one of the most widely used ...

  12. Structural Analysis and Bioengineering of Thermostable Pyrococcus furiosus Prolidase for the Optimization of Organophosphorus Nerve Agent Detoxification

    Science.gov (United States)

    2012-04-26

    organophosphorus acid anhydrase from a halophilic bacterial isolate. J Bacteriol, 173, 1938-1943. Du, X., Tove, S., Kast -Hutcheson, K. & Grunden, A. M...1938-1943. Du, X., Tove, S., Kast -Hutcheson, K. & Grunden, A. M. 2005. Characterization of the dinuclear metal center of Pyrococcus furiosus

  13. Confirmed organophosphorus and carbamate pesticide poisonings in South African wildlife (2009–2014

    Directory of Open Access Journals (Sweden)

    Christo J. Botha

    2015-12-01

    Full Text Available During a six-year period (from January 2009 to December 2014, specimens collected from 344 cases of suspected organophosphorus and carbamate pesticide poisonings in wildlife, including birds, were submitted to the Toxicology Laboratory (ARC-OVI for analysis. A positive diagnosis was made in 135 (39% of these cases. The majority of cases were from birds, which included Cape vultures (Gyps coprotheres and African white-backed vultures (Gyps africanus and bateleur eagles (Terathopius ecaudatus. In one incident 49 vultures were killed when a farmer intentionally laced carcasses with carbofuran in an attempt to control jackal predation. There were 22 incidents of poisoning in helmeted guineafowl (Numida meleagris. On nine different occasions blue cranes (Anthropoides paradiseus were poisoned, in one incident 14 birds were reported to have been killed. Over the period of investigation, there were 20 cases of poisoning involving mammalian species, the majority being vervet monkeys (Chlorocebus pygerythrus. The carbamate pesticides were responsible for 57 incidents of poisoning. Aldicarb, carbofuran and methomyl were detected in 26, 18 and 12 cases respectively. The majority of organophosphorus pesticide poisonings were caused by diazinon (n = 19, monocrotophos (n = 13 and methamidophos (n = 10.

  14. In vivo tracing of organophosphorus pesticides in cabbage (Brassica parachinensis) and aloe (Barbadensis)

    Energy Technology Data Exchange (ETDEWEB)

    Qiu, Junlang; Chen, Guosheng; Zhou, Hong; Xu, Jianqiao; Wang, Fuxin; Zhu, Fang, E-mail: ceszf@mail.sysu.edu.cn; Ouyang, Gangfeng, E-mail: cesoygf@mail.sysu.edu.cn

    2016-04-15

    In vivo solid-phase microextraction (SPME) sampling method coupled with gas chromatography–mass spectrometry (GC–MS) analysis was employed to trace the uptake and elimination of organophosphorus pesticides (OPPs) in two kinds of edible plants, cabbage (Brassica parachinensis) and aloe (Barbadensis). The metabolism of fenthion in aloe was also investigated by the liquid chromatography tandem mass spectrometry analysis (LC–MS/MS) to understand the fate of OPPs in living plants better. Transpiration stream concentration factor (TSCF) and depuration rate constants of the OPPs in living plants were obtained therein. The health risk of the OPPs treated aloe was estimated by the maximum residue limit (MRL) approach, and it revealed that the OPPs were rather safe for their fast degradable property. However, peak concentration of fenthion-sulfoxide was found to exceed the MRL and was higher than that of the parent fenthion, which indicated the potential risk of pesticide metabolites. This study highlighted the application of in vivo SPME for contaminant tracing in different living edible plants. The in vivo tracing method is very convenient and can provide more data to evaluate the risk of different pesticides, which are very important for the safety of agriculture production. - Highlights: • In vivo SPME was employed to sample organophosphorus pesticides in vegetables. • Uptake and elimination of OPPs were traced in cabbage and aloe. • In vivo tracing of fenthion demonstrated its metabolites could be rather dangerous. • The risks of OPPs were assessed based on the in vivo tracing data.

  15. Metagenomic Functional Potential Predicts Degradation Rates of a Model Organophosphorus Xenobiotic in Pesticide Contaminated Soils

    Directory of Open Access Journals (Sweden)

    Thomas C. Jeffries

    2018-02-01

    Full Text Available Chemical contamination of natural and agricultural habitats is an increasing global problem and a major threat to sustainability and human health. Organophosphorus (OP compounds are one major class of contaminant and can undergo microbial degradation, however, no studies have applied system-wide ecogenomic tools to investigate OP degradation or use metagenomics to understand the underlying mechanisms of biodegradation in situ and predict degradation potential. Thus, there is a lack of knowledge regarding the functional genes and genomic potential underpinning degradation and community responses to contamination. Here we address this knowledge gap by performing shotgun sequencing of community DNA from agricultural soils with a history of pesticide usage and profiling shifts in functional genes and microbial taxa abundance. Our results showed two distinct groups of soils defined by differing functional and taxonomic profiles. Degradation assays suggested that these groups corresponded to the organophosphorus degradation potential of soils, with the fastest degrading community being defined by increases in transport and nutrient cycling pathways and enzymes potentially involved in phosphorus metabolism. This was against a backdrop of taxonomic community shifts potentially related to contamination adaptation and reflecting the legacy of exposure. Overall our results highlight the value of using holistic system-wide metagenomic approaches as a tool to predict microbial degradation in the context of the ecology of contaminated habitats.

  16. Separating esterase targets of organophosphorus compounds in the brain by preparative chromatography.

    Science.gov (United States)

    Mangas, I; Vilanova, E; Benabent, M; Estévez, J

    2014-02-10

    Low level exposure to organophosphorus esters (OPs) may cause long-term neurological effects and affect specific cognition domains in experimental animals and humans. Action on known targets cannot explain most of these effects by. Soluble carboxylesterases (EC 3.1.1.1) of chicken brain have been kinetically discriminated using paraoxon, mipafox and phenylmethyl sulfonylfluoride as inhibitors and phenyl valerate as a substrate. Three different enzymatic components were discriminated and called Eα, Eβ and Eγ. In this work, a fractionation procedure with various steps was developed using protein native separation methods by preparative HPLC. Gel permeation chromatography followed by ion exchange chromatography allowed enriched fractions with different kinetic behaviors. The soluble chicken brain fraction was fractionated, while total esterase activity, proteins and enzymatic components Eα, Eβ and Eγ were monitored in each subfraction. After the analysis, 13 fractions were pooled and conserved. Preincubation of the soluble chicken brain fraction of with the organophosphorus mipafox gave rise to a major change in the ion exchange chromatography profile, but not in the molecular exchanged chromatography profile, which suggest that mipafox permanently modifies the ionic properties of numerous proteins. Copyright © 2013 Elsevier Ireland Ltd. All rights reserved.

  17. Osmoregulatory function in ducks following ingestion of the organophosphorus insecticide fenthion

    Science.gov (United States)

    Rattner, B.A.; Fleming, W.J.; Murray, H.C.

    1983-01-01

    Salt gland function and osmoregulation in aquatic birds drinking hyperosmotic water has been suggested to be impaired by organophosphorus insecticides. To test this hypothesis, adult black ducks (Anas rubripes) were provided various regimens of fresh or salt (1.5% NaCl) water before, during, and after ingestion of mash containing 21 ppm fenthion. Ducks were bled by jugular venipuncture after I, 7. and 12 days of treatment, and were then killed. Brain and salt gland acetylcholinesterase activities were substantially inhibited (44-61% and 14-36%) by fenthion. However, salt gland weight and Na + -K + -ATPase activity, and plasma Na + , CI- , and osmolality, were uniformly elevated in all groups receiving salt water including those ingesting fenthion. In a second study, salt gland Na + -K + -ATPase activity in mallards (A. platyrhynchos) was not affected after in vitro incubation with either fenthion or fenthion oxon at concentrations ranging from 0.04 to 400 ?M, but was reduced in the presence of 40 and 400 ?M DDE (positive control). These findings suggest that environmentally realistic concentrations of organophosphorus insecticides do not markedly affect osmoregulatory function in adult black ducks.

  18. Organophosphorus and Organochlorine Pesticides Bioaccumulation by Eichhornia crassipes in Irrigation Canals in an Urban Agricultural System.

    Science.gov (United States)

    Mercado-Borrayo, B M; Cram Heydrich, Silke; Pérez, Irma Rosas; Hernández Quiroz, Manuel; De León Hill, Claudia Ponce

    2015-01-01

    A natural wetland in Mexico City Metropolitan Area is one of the main suppliers of crops and flowers, and in consequence its canals hold a high concentration of organochlorine (OC) and organophosphorus (OP) pesticides. There is also an extensive population of water hyacinth (Eichhornia crassipes), which is considered a plague; but literature suggests water hyacinth may be used as a phytoremediator. This study demonstrates bioaccumulation difference for the OC in vivo suggesting their bioaccumulation is ruled by their log K(ow), while all the OP showed bioaccumulation regardless of their log K(ow). The higher bioaccumulation factors (BAF) of the accumulated OC pesticides cannot be explained by their log K(ow), suggesting that the OC pesticides may also be transported passively into the plant. Translocation ratios showed that water hyacinth is an accumulating plant with phytoremediation potential for all organophosphorus pesticides studied and some organochlorine pesticides. An equation for free water surface wetlands with floating macrophytes, commonly used for the construction of water-cleaning wetlands, showed removal of the pesticides by the wetland with room for improvement with appropriate management.

  19. The analysis of common metabolites of organophosphorus pesticides in urine by gas chromatography/mass spectrometry

    International Nuclear Information System (INIS)

    Park, Seong Soo; Pyo, Hee Soo; Lee, Kang Jin; Park, Song Ja; Park, Taek Kyu

    1998-01-01

    Most organophosphorus pesticides may be metabolized to yield some common phosphates in human or in animals, and these metabolites may be used as the exposure biomarkers to pesticides. In this study, we developed the extraction method of four phosphate metabolites from the spiked human urine in high recovery by the solid phase extraction with a reverse-phase cartridge (cyclohexyl silica) followed by the elution with methanol. The extracted urinary metabolites were derivatized with hexamethyldisilazane/trimethyl-chlorosilane/pyridine (2:1:10, v/v/v) and identified by gas chromatography/mass spectrometry. Calibration curve obtained from each metabolite standard using by GC/MS/SIM has shown good linearity and detection limits of metabolites were the range of 0.05-0.1 μg/ml in urine. Phenthoate, one of the organophosphorus pesticides, was orally administrated to rats. Four metabolites were detected in the rat urine. The results of this study may be applied to development of exposure biomarkers for monitoring of environmental pollutants

  20. Organochlorine and organophosphorus pesticide residues in fodder and milk samples along Musi river belt, India

    Directory of Open Access Journals (Sweden)

    Korrapati Kotinagu

    2015-04-01

    Full Text Available Aim: The present study was conducted to find the organochlorine pesticide (OCP and organophosphorus pesticide (OPP residues in fodder and milk samples along Musi river belt, India. Materials and Methods: Fodder and milk samples collected from the six zones of Musi river belt, Hyderabad India were analyzed by gas chromatography with electron capture detector for OCP residues and pulsated flame photometric detector for the presence of OPP residues. Results: The gas chromatographic analysis of fodder samples of Zone 5 of Musi river showed the residues of dicofol at concentration of 0.07±0.0007 (0.071-0.077. Among organophosphorus compounds, dimetheoate was present in milk samples collected from Zone 6 at a level of 0.13±0.006 (0.111-0.167. The residues of OCPs, OPPs and cyclodies were below the detection limit in the remaining fodder and milk samples collected from Musi river belt in the present study. Conclusion: The results indicate that the pesticide residues in fodder and milk samples were well below the maximum residue level (MRL values, whereas dicofol in fodder and dimethoate in milk were slightly above the MRL values specified by EU and CODEX.

  1. Organochlorine and organophosphorus pesticide residues in fodder and milk samples along Musi river belt, India.

    Science.gov (United States)

    Kotinagu, Korrapati; Krishnaiah, Nelapati

    2015-04-01

    The present study was conducted to find the organochlorine pesticide (OCP) and organophosphorus pesticide (OPP) residues in fodder and milk samples along Musi river belt, India. Fodder and milk samples collected from the six zones of Musi river belt, Hyderabad India were analyzed by gas chromatography with electron capture detector for OCP residues and pulsated flame photometric detector for the presence of OPP residues. The gas chromatographic analysis of fodder samples of Zone 5 of Musi river showed the residues of dicofol at concentration of 0.07±0.0007 (0.071-0.077). Among organophosphorus compounds, dimetheoate was present in milk samples collected from Zone 6 at a level of 0.13±0.006 (0.111-0.167). The residues of OCPs, OPPs and cyclodies were below the detection limit in the remaining fodder and milk samples collected from Musi river belt in the present study. The results indicate that the pesticide residues in fodder and milk samples were well below the maximum residue level (MRL) values, whereas dicofol in fodder and dimethoate in milk were slightly above the MRL values specified by EU and CODEX.

  2. ACUTE EXOGENOUS INTOXICATIONS WITH ORGANOPHOSPHORUS PESTICIDES: DURATION OF THE HOSPITAL TREATMENT AND CLINICAL CRITERIA FOR PROGNOSIS

    Directory of Open Access Journals (Sweden)

    Petko Marinov

    2017-05-01

    Full Text Available Purpose: Several criteria have been suggested to estimate the intoxication severity, yet so far no system of clinical criteria has been developed to determine the duration of hospitalisation. The forecast is linked to the influence of the extended corrected QT interval and GCS (Glasgow Coma Scale on the frequency of the developing acute pulmonary insufficiency and lethality. The average duration of hospital treatment is also crucial. First of all, it is determined by the intoxication severity and lasts from 3 to 26 days. The aim of this study is to develop an individual forecast about the duration of hospitalisation for patients suffering from acute exogenous intoxication with organophosphorus pesticides (OPP. Materials/Methods: The subjects are 160 patients. We use statistical regression analysis to study the significance of 5 of the most typical clinical indicators of organophosphorus intoxication on the duration of hospitalisation: type of conscience, presence of spasms, pulmonary oedema, shock and multi-organ insufficiency syndrome (MOIS. To forecast the treatment length, we obtain simplified mathematical expressions in the form of score estimates. Results: The significance of the clinical indicators “MOIS”, “conscience” and “spasm” has been confirmed. A forecast matrix that gives the opportunity to forecast the personal duration of hospital treatment for each patient has been built.

  3. In vivo tracing of organophosphorus pesticides in cabbage (Brassica parachinensis) and aloe (Barbadensis)

    International Nuclear Information System (INIS)

    Qiu, Junlang; Chen, Guosheng; Zhou, Hong; Xu, Jianqiao; Wang, Fuxin; Zhu, Fang; Ouyang, Gangfeng

    2016-01-01

    In vivo solid-phase microextraction (SPME) sampling method coupled with gas chromatography–mass spectrometry (GC–MS) analysis was employed to trace the uptake and elimination of organophosphorus pesticides (OPPs) in two kinds of edible plants, cabbage (Brassica parachinensis) and aloe (Barbadensis). The metabolism of fenthion in aloe was also investigated by the liquid chromatography tandem mass spectrometry analysis (LC–MS/MS) to understand the fate of OPPs in living plants better. Transpiration stream concentration factor (TSCF) and depuration rate constants of the OPPs in living plants were obtained therein. The health risk of the OPPs treated aloe was estimated by the maximum residue limit (MRL) approach, and it revealed that the OPPs were rather safe for their fast degradable property. However, peak concentration of fenthion-sulfoxide was found to exceed the MRL and was higher than that of the parent fenthion, which indicated the potential risk of pesticide metabolites. This study highlighted the application of in vivo SPME for contaminant tracing in different living edible plants. The in vivo tracing method is very convenient and can provide more data to evaluate the risk of different pesticides, which are very important for the safety of agriculture production. - Highlights: • In vivo SPME was employed to sample organophosphorus pesticides in vegetables. • Uptake and elimination of OPPs were traced in cabbage and aloe. • In vivo tracing of fenthion demonstrated its metabolites could be rather dangerous. • The risks of OPPs were assessed based on the in vivo tracing data.

  4. Radiolytic investigations of solutions of organophosphorus compounds in cyclohexane and benzene

    International Nuclear Information System (INIS)

    Otrebski, W.

    1981-01-01

    Organphosphorus compounds are used in various branches of the chemical industry, but in many cases the reaction mechanisms are not well elucidated and less is known about the intermediates of organophosphines. In order to learn more about these rather complicated processes several organophosphorus compounds were used as model substrates in cyclohexane or benzene solution. The systems have been investigated applying the pulse radiolysis technique and steady-state irradiation methods. As representative solutes were chosen diphenylphosphinous chloride, diphenylmethylphosphine, and triphenylphosphine. By means of the pulse radiolysis it was possible to obtain spectroscopic and kinetic data for characterization of the various transients. The final radiolytic products have been analyzed following steady-state and multipulse radiolysis. Since some of the rate constants were not directly accessible by the applied kinetic method, they have been determined by simulation computation. Thereby the experimental data obtained by pulse radiolysis were used. Based on the kinetic, spectroscopic and computed data as well as on the identification of final products, it was possible to elucidate the reaction mechanism of the diphenylphosphinous chloride/cyclohexane system. As a main primary specie was identified the diphenylphoshorus radical. Its spectral and kinetic data have been determined. The reactions of diphenylmethylphosphine involve the same radical, but only to a lesser extent. The reactions of the primary radiolysis products with triphenylphosphine yield mainly adducts. The results represent a contribution in the field of reaction kinetics of organophosphorus compounds. (author)

  5. Epoxide hydrolase-lasalocid a structure provides mechanistic insight into polyether natural product biosynthesis.

    Science.gov (United States)

    Wong, Fong T; Hotta, Kinya; Chen, Xi; Fang, Minyi; Watanabe, Kenji; Kim, Chu-Young

    2015-01-14

    Biosynthesis of some polyether natural products involves a kinetically disfavored epoxide-opening cyclic ether formation, a reaction termed anti-Baldwin cyclization. One such example is the biosynthesis of lasalocid A, an ionophore antibiotic polyether. During lasalocid A biosynthesis, an epoxide hydrolase, Lsd19, converts the bisepoxy polyketide intermediate into the tetrahydrofuranyl-tetrahydropyran product. We report the crystal structure of Lsd19 in complex with lasalocid A. The structure unambiguously shows that the C-terminal domain of Lsd19 catalyzes the intriguing anti-Baldwin cyclization. We propose a general mechanism for epoxide selection by ionophore polyether epoxide hydrolases.

  6. High-throughput analysis of endogenous fruit glycosyl hydrolases using a novel chromogenic hydrogel substrate assay

    DEFF Research Database (Denmark)

    Schückel, Julia; Kracun, Stjepan Kresimir; Lausen, Thomas Frederik

    2017-01-01

    A broad range of enzyme activities can be found in a wide range of different fruits and fruiting bodies but there is a lack of methods where many samples can be handled in a high-throughput and efficient manner. In particular, plant polysaccharide degrading enzymes – glycosyl hydrolases (GHs) play...... led to a more profound understanding of the importance of GH activity and regulation, current methods for determining glycosyl hydrolase activity are lacking in throughput and fail to keep up with data output from transcriptome research. Here we present the use of a versatile, easy...

  7. Production of Biodiesel Using Immobilized Lipase and the Characterization of Different Co-Immobilizing Agents and Immobilization Methods

    Directory of Open Access Journals (Sweden)

    Kang Zhao

    2016-08-01

    Full Text Available Lipase from Candida sp. 99–125 is widely employed to catalyzed transesterification and can be used for biodiesel production. In this study, the lipase was immobilized by combined adsorption and entrapment to catalyze biodiesel production from waste cooking oil (WCO via transesterification, and investigating co-immobilizing agents as additives according to the enzyme activity. The addition of the mixed co-immobilizing agents has positive effects on the activities of the immobilized lipase. Three different immobilizing methods were compared by the conversion ratio of biodiesel and structured by Atom Force Microscopy (AFM and Scanning Electron Microscopy (SEM, respectively. It was found that entrapment followed by adsorption was the best method. The effect of the co-immobilizing agent amount, lipase dosage, water content, and reuse ability of the immobilized lipase was investigated. By comparison with previous research, this immobilized lipase showed good reuse ability: the conversion ratio excesses 70% after 10 subsequent reactions, in particular, was better than Novozym435 and TLIM on waste cooking oil for one unit of lipase.

  8. Technetium Immobilization Forms Literature Survey

    Energy Technology Data Exchange (ETDEWEB)

    Westsik, Joseph H.; Cantrell, Kirk J.; Serne, R. Jeffrey; Qafoku, Nikolla

    2014-05-01

    Of the many radionuclides and contaminants in the tank wastes stored at the Hanford site, technetium-99 (99Tc) is one of the most challenging to effectively immobilize in a waste form for ultimate disposal. Within the Hanford Tank Waste Treatment and Immobilization Plant (WTP), the Tc will partition between both the high-level waste (HLW) and low-activity waste (LAW) fractions of the tank waste. The HLW fraction will be converted to a glass waste form in the HLW vitrification facility and the LAW fraction will be converted to another glass waste form in the LAW vitrification facility. In both vitrification facilities, the Tc is incorporated into the glass waste form but a significant fraction of the Tc volatilizes at the high glass-melting temperatures and is captured in the off-gas treatment systems at both facilities. The aqueous off-gas condensate solution containing the volatilized Tc is recycled and is added to the LAW glass melter feed. This recycle process is effective in increasing the loading of Tc in the LAW glass but it also disproportionally increases the sulfur and halides in the LAW melter feed which increases both the amount of LAW glass and either the duration of the LAW vitrification mission or the required supplemental LAW treatment capacity.

  9. Optimization of Adsorptive Immobilization of Alcohol Dehydrogenases

    NARCIS (Netherlands)

    Trivedi, Archana; Heinemann, Matthias; Spiess, Antje C.; Daussmann, Thomas; Büchs, Jochen

    2005-01-01

    In this work, a systematic examination of various parameters of adsorptive immobilization of alcohol dehydrogenases (ADHs) on solid support is performed and the impact of these parameters on immobilization efficiency is studied. Depending on the source of the enzymes, these parameters differently

  10. Plutonium Immobilization Can Loading Equipment Review

    International Nuclear Information System (INIS)

    Kriikku, E.; Ward, C.; Stokes, M.; Randall, B.; Steed, J.; Jones, R.; Hamilton, L.

    1998-05-01

    This report lists the operations required to complete the Can Loading steps on the Pu Immobilization Plant Flow Sheets and evaluates the equipment options to complete each operation. This report recommends the most appropriate equipment to support Plutonium Immobilization Can Loading operations

  11. Strong and Reversible Monovalent Supramolecular Protein Immobilization

    NARCIS (Netherlands)

    Young, Jacqui F.; Nguyen, Hoang D.; Yang, Lanti; Huskens, Jurriaan; Jonkheijm, Pascal; Brunsveld, Luc

    2010-01-01

    Proteins with an iron clasp: Site-selective incorporation of a ferrocene molecule into a protein allows for easy, strong, and reversible supramolecular protein immobilization through a selective monovalent interaction of the ferrocene with a cucurbit[7]uril immobilized on a gold surface. The

  12. Drug immobilization of walrus (Odobenus rosmarus)

    Science.gov (United States)

    DeMaster, D.P.; Faro, J.B.; Estes, J.A.; Taggart, James; Zabel, C.

    1981-01-01

    Five out of nine walrus (Odobenus rosmarus) were successfully immobilized at Round Island, Alaska, in May of 1978 by combinations of phencyclidine hydrochloride and acepromazine hydrochloride. A crossbow was an effective delivery technique. Walruses that had recently hauled out were more suitable for immobilization than well-rested animals. Care was taken to prevent walruses from overheating or suffocating.

  13. How to find soluble proteins: a comprehensive analysis of alpha/beta hydrolases for recombinant expression in E. coli

    Directory of Open Access Journals (Sweden)

    Barth Sandra

    2005-04-01

    Full Text Available Abstract Background In screening of libraries derived by expression cloning, expression of active proteins in E. coli can be limited by formation of inclusion bodies. In these cases it would be desirable to enrich gene libraries for coding sequences with soluble gene products in E. coli and thus to improve the efficiency of screening. Previously Wilkinson and Harrison showed that solubility can be predicted from amino acid composition (Biotechnology 1991, 9(5:443–448. We have applied this analysis to members of the alpha/beta hydrolase fold family to predict their solubility in E. coli. alpha/beta hydrolases are a highly diverse family with more than 1800 proteins which have been grouped into homologous families and superfamilies. Results The predicted solubility in E. coli depends on hydrolase size, phylogenetic origin of the host organism, the homologous family and the superfamily, to which the hydrolase belongs. In general small hydrolases are predicted to be more soluble than large hydrolases, and eukaryotic hydrolases are predicted to be less soluble in E. coli than prokaryotic ones. However, combining phylogenetic origin and size leads to more complex conclusions. Hydrolases from prokaryotic, fungal and metazoan origin are predicted to be most soluble if they are of small, medium and large size, respectively. We observed large variations of predicted solubility between hydrolases from different homologous families and from different taxa. Conclusion A comprehensive analysis of all alpha/beta hydrolase sequences allows more efficient screenings for new soluble alpha/beta hydrolases by the use of libraries which contain more soluble gene products. Screening of hydrolases from families whose members are hard to express as soluble proteins in E. coli should first be done in coding sequences of organisms from phylogenetic groups with the highest average of predicted solubility for proteins of this family. The tools developed here can be used

  14. Immobilized fluid membranes for gas separation

    Science.gov (United States)

    Liu, Wei; Canfield, Nathan L; Zhang, Jian; Li, Xiaohong Shari; Zhang, Jiguang

    2014-03-18

    Provided herein are immobilized liquid membranes for gas separation, methods of preparing such membranes and uses thereof. In one example, the immobilized membrane includes a porous metallic host matrix and an immobilized liquid fluid (such as a silicone oil) that is immobilized within one or more pores included within the porous metallic host matrix. The immobilized liquid membrane is capable of selective permeation of one type of molecule (such as oxygen) over another type of molecule (such as water). In some examples, the selective membrane is incorporated into a device to supply oxygen from ambient air to the device for electrochemical reactions, and at the same time, to block water penetration and electrolyte loss from the device.

  15. Soluble epoxide hydrolase in the generation and maintenance of high blood pressure in spontaneously hypertensive rats

    NARCIS (Netherlands)

    Koeners, Maarten P.; Wesseling, Sebastiaan; Ulu, Arzu; Lopez Sepulveda, Rocio; Morisseau, Christophe; Braam, Branko; Hammock, Bruce D.; Joles, Jaap A.

    Koeners MP, Wesseling S, Ulu A, Sepulveda RL, Morisseau C, Braam B, Hammock BD, Joles JA. Soluble epoxide hydrolase in the generation and maintenance of high blood pressure in spontaneously hypertensive rats. Am J Physiol Endocrinol Metab 300: E691-E698, 2011. First published January 25, 2011; doi:

  16. Regulatory regions in the rat lactase-phlorizin hydrolase gene that control cell-specific expression

    NARCIS (Netherlands)

    Verhave, Menno; Krasinski, Stephen D.; Christian, Sara I.; van Schaik, Sandrijn; van den Brink, Gijs R.; Doting, Edwina M. H.; Maas, Saskia M.; Wolthers, Katja C.; Grand, Richard J.; Montgomery, Robert K.

    2004-01-01

    OBJECTIVES: Lactase-phlorizin hydrolase (LPH) is an enterocyte-specific gene whose expression has been well-characterized, not only developmentally but also along the crypt-villus axis and along the length of the small bowel. Previous studies from the authors' laboratory have demonstrated that 2 kb

  17. High-throughput screening for gene libraries expressing carbohydrate hydrolase activity

    NARCIS (Netherlands)

    Leemhuis, Hans; Euverink, Gert-Jan W.; Dijkhuizen, Lubbert

    2003-01-01

    A simple and fast method is described allowing screening of large number of Escherichia coli clones (4000 per day) for the presence of functional or improved carbohydrate hydrolase enzymes. The procedure is relatively cheap and has the advantage that carbohydrate degrading activity can be directly

  18. Steady state kinetic analysis of substrate specificity of glycoside hydrolases from families 13 and 38

    DEFF Research Database (Denmark)

    Nielsen, Jonas Willum

    Glycosidases are widespread in nature, where they perform a diverse range of functions. The glycoside hydrolase (GH) family 38, α-mannosidase II enzymes play a crucial role in mammalian cells, in the maturation of N-glycosylated proteins in the Golgi apparatus and in catabolism in cytosol...

  19. Cloning and characterization of an epoxide hydrolase-encoding gene from Rhodotorula glutinis

    NARCIS (Netherlands)

    Visser, H.; Vreugdenhil, S.; Bont, de J.A.M.; Verdoes, J.C.

    2000-01-01

    We cloned and characterized the epoxide hydrolase gene, EPH1, from Rhodotorula glutinis. The EPH1 open reading frame of 1230 bp was interrupted by nine introns and encoded a polypeptide of 409 amino acids with a calculated molecular mass of 46.3 kDa. The amino acid sequence was similar to that of

  20. In Silico Investigation of Flavonoids as Potential Trypanosomal Nucleoside Hydrolase Inhibitors

    Directory of Open Access Journals (Sweden)

    Christina Hung Hung Ha

    2015-01-01

    Full Text Available Human African Trypanosomiasis is endemic to 37 countries of sub-Saharan Africa. It is caused by two related species of Trypanosoma brucei. Current therapies suffer from resistance and public accessibility of expensive medicines. Finding safer and effective therapies of natural origin is being extensively explored worldwide. Pentamidine is the only available therapy for inhibiting the P2 adenosine transporter involved in the purine salvage pathway of the trypanosomatids. The objective of the present study is to use computational studies for the investigation of the probable trypanocidal mechanism of flavonoids. Docking experiments were carried out on eight flavonoids of varying level of hydroxylation, namely, flavone, 5-hydroxyflavone, 7-hydroxyflavone, chrysin, apigenin, kaempferol, fisetin, and quercetin. Using AutoDock 4.2, these compounds were tested for their affinity towards inosine-adenosine-guanosine nucleoside hydrolase and the inosine-guanosine nucleoside hydrolase, the major enzymes of the purine salvage pathway. Our results showed that all of the eight tested flavonoids showed high affinities for both hydrolases (lowest free binding energy ranging from −10.23 to −7.14 kcal/mol. These compounds, especially the hydroxylated derivatives, could be further studied as potential inhibitors of the nucleoside hydrolases.

  1. Mode of action of xylogalacturonan hydrolase towards xylogalacturonan and xylogalacturonan oligosaccharides

    NARCIS (Netherlands)

    Zandleven, J.S.; Beldman, G.; Bosveld, M.; Benen, J.A.E.; Voragen, A.G.J.

    2005-01-01

    XGH (xylogalacturonan hydrolase; GH 28) is an enzyme that is capable of degrading XGA (xylogalacturonan), which is a polymer of ¿-D-galacturonic acid, highly substituted with ß-D-xylose. XGA is present in cell walls of various plants and exudates, such as gum tragacanth. XGA oligosaccharides were

  2. Enzymatic degradation studies of xylogalacturonans from apple and potato, using xylogalacturonan hydrolase

    NARCIS (Netherlands)

    Zandleven, J.S.; Beldman, G.; Bosveld, M.; Schols, H.A.; Voragen, A.G.J.

    2006-01-01

    Action of xylogalacturonan hydrolase (XGH) towards xylogalacturonan (XGA) present in the alkali saponified ¿modified hairy regions¿ from potato and apple pectin was studied. Analysis of enzymatic degradation products from XGA in these complex pectins demonstrated that the degradable

  3. The role of epoxide hydrolase Y113H gene variant in pancreatic diseases.

    NARCIS (Netherlands)

    Ockenga, J.; Strunck, S.; Post, C.; Schulz, H.U.; Halangk, J.; Pfutzer, R.H.; Lohr, M.; Oettle, H.; Kage, A.; Rosendahl, J.; Keim, V.; Drenth, J.P.H.; Jansen, J.B.M.J.; Lochs, H.; Witt, H.

    2009-01-01

    OBJECTIVES: Chronic pancreatitis (CP) and pancreatic adenocarcinoma (pCA) are associated with risk factors such as alcohol intake and tobacco smoking. Microsomal epoxide hydrolase (EPHX1) is a phase II detoxifying enzyme capable of tobacco-borne toxicant inactivation. We studied the role of the

  4. Oxidoreductive Cellulose Depolymerization by the Enzymes Cellobiose Dehydrogenase and Glycoside Hydrolase 61▿†

    Science.gov (United States)

    Langston, James A.; Shaghasi, Tarana; Abbate, Eric; Xu, Feng; Vlasenko, Elena; Sweeney, Matt D.

    2011-01-01

    Several members of the glycoside hydrolase 61 (GH61) family of proteins have recently been shown to dramatically increase the breakdown of lignocellulosic biomass by microbial hydrolytic cellulases. However, purified GH61 proteins have neither demonstrable direct hydrolase activity on various polysaccharide or lignacious components of biomass nor an apparent hydrolase active site. Cellobiose dehydrogenase (CDH) is a secreted flavocytochrome produced by many cellulose-degrading fungi with no well-understood biological function. Here we demonstrate that the binary combination of Thermoascus aurantiacus GH61A (TaGH61A) and Humicola insolens CDH (HiCDH) cleaves cellulose into soluble, oxidized oligosaccharides. TaGH61A-HiCDH activity on cellulose is shown to be nonredundant with the activities of canonical endocellulase and exocellulase enzymes in microcrystalline cellulose cleavage, and while the combination of TaGH61A and HiCDH cleaves highly crystalline bacterial cellulose, it does not cleave soluble cellodextrins. GH61 and CDH proteins are coexpressed and secreted by the thermophilic ascomycete Thielavia terrestris in response to environmental cellulose, and the combined activities of T. terrestris GH61 and T. terrestris CDH are shown to synergize with T. terrestris cellulose hydrolases in the breakdown of cellulose. The action of GH61 and CDH on cellulose may constitute an important, but overlooked, biological oxidoreductive system that functions in microbial lignocellulose degradation and has applications in industrial biomass utilization. PMID:21821740

  5. Fungal lytic polysaccharide monooxygenases bind starch and β-cyclodextrin similarly to amylolytic hydrolases

    DEFF Research Database (Denmark)

    Nekiunaite, Laura; Isaksen, Trine; Vaaje-Kolstad, Gustav

    2016-01-01

    , the clustering of CBM20s from starch-targeting LPMOs and hydrolases was in accord with taxonomy and did not correlate to appended catalytic activity. Altogether, these results demonstrate that the CBM20-binding scaffold is retained in the evolution of hydrolytic and oxidative starch-degrading activities....

  6. Recent Developments in Organophosphorus Flame Retardants Containing P-C Bond and Their Applications

    Directory of Open Access Journals (Sweden)

    Sophie Wendels

    2017-07-01

    Full Text Available Organophosphorus compounds containing P-C bonds are increasingly developed as flame retardant additives due to their excellent thermal and hydrolytic stability and ease of synthesis. The latest development (since 2010 in organophosphorus flame retardants containing P-C bonds summarized in this review. In this review, we have broadly classified such phosphorus compounds based on the carbon unit linked to the phosphorus atom i.e., could be a part of either an aliphatic or an aromatic unit. We have only considered those published literature where a P-C bond was created as a part of synthetic strategy to make either an intermediate or a final organophosphorus compound with an aim to use it as a flame retardant. General synthetic strategies to create P-C bonds are briefly discussed. Most popular synthetic strategies used for developing P-C containing phosphorus based flame retardants include Michael addition, Michaelis–Arbuzov, Friedels–Crafts and Grignard reactions. In general, most flame retardant derivatives discussed in this review have been prepared via a one- to two-step synthetic strategy with relatively high yields greater than 80%. Specific examples of P-C containing flame retardants synthesized via suitable synthetic strategy and their applications on various polymer systems are described in detail. Aliphatic phosphorus compounds being liquids or low melting solids are generally applied in polymers via coatings (cellulose or are incorporated in the bulk of the polymers (epoxy, polyurethanes during their polymerization as reactive or non-reactive additives. Substituents on the P atoms and the chemistry of the polymer matrix greatly influence the flame retardant behavior of these compounds (condensed phase vs. the gas phase. Recently, aromatic DOPO based phosphinate flame retardants have been developed with relatively higher thermal stabilities (>250 °C. Such compounds have potential as flame retardants for high temperature processable

  7. Trace Detection of Organophosphorus Chemical Warfare Agents in Wastewater and Plants by Luminescent UIO-67(Hf) and Evaluating the Bioaccumulation of Organophosphorus Chemical Warfare Agents.

    Science.gov (United States)

    Lian, Xiao; Yan, Bing

    2018-05-02

    Organophosphorus chemical warfare agents (OPCWAs) are a group of organic pollutants characterized by high toxicity and chemical stability, and they are very difficult to be degraded. The trace quality of OPCWAs in water and food will cause great harm to the human body. Therefore, the detection of OPCWAs is a difficult challenge, which has become the research hotspot over the world. In this work, a Hf-based luminescent metal-organic framework (Eu@1) is prepared, and the reactivity of Hf 12 results in a methanephosphonic acid (MPA)-induced luminescence quenching and the charge transfer from MPA to Hf(IV) and generated exciplexes which are responsible for this quenching effect. The excellent performance of Eu@1 in the detection of MPA, with its finer selectivity, high sensitivity (LOD = 0.4 ppm), and large linear range (10 -7 to 10 -3 M), is encouraging for application in wastewater detection. Importantly, MPA is a pollutant that can be absorbed by plants and causes the bioaccumulation effect, and thus, the detection of MPA in real plant samples is a purposeful topic. Eu@1 also achieved satisfactory results in actual plant sample testing, and the bioaccumulation of MPA in onions, turnips, and cabbages is determined via our sensor. This fabricated detector provides a feasible path for the detection of ppm-level OPCWAs in a complex environment, which will help humans to avoid OPCWA-contaminated foods.

  8. Supplementing with non-glycoside hydrolase proteins enhances enzymatic deconstruction of plant biomass.

    Science.gov (United States)

    Su, Xiaoyun; Zhang, Jing; Mackie, Roderick I; Cann, Isaac K O

    2012-01-01

    The glycoside hydrolases (GH) of Caldicellulosiruptor bescii are thermophilic enzymes, and therefore they can hydrolyze plant cell wall polysaccharides at high temperatures. Analyses of two C. bescii glycoside hydrolases, CbCelA-TM1 and CbXyn10A with cellulase and endoxylanase activity, respectively, demonstrated that each enzyme is highly thermostable under static incubation at 70°C. Both enzymes, however, rapidly lost their enzymatic activities when incubated at 70°C with end-over-end shaking. Since crowding conditions, even at low protein concentrations, seem to influence enzymatic properties, three non-glycoside hydrolase proteins were tested for their capacity to stabilize the thermophilic proteins at high temperatures. The three proteins investigated were a small heat shock protein CbHsp18 from C. bescii, a histone MkHistone1 from Methanopyrus kandleri, and bovine RNase A, from a commercial source. Fascinatingly, each of these proteins increased the thermostability of the glycoside hydrolases at 70°C during end-over-end shaking incubation, and this property translated into increases in hydrolysis of several substrates including the bioenergy feedstock Miscanthus. Furthermore, MkHistone1 and RNase A also altered the initial products released from the cello-oligosaccharide cellopentaose during hydrolysis with the cellodextrinase CbCdx1A, which further demonstrated the capacity of the three non-GH proteins to influence hydrolysis of substrates by the thermophilic glycoside hydrolases. The non-GH proteins used in the present report were small proteins derived from each of the three lineages of life, and therefore expand the space from which different polypeptides can be tested for their influence on plant cell wall hydrolysis, a critical step in the emerging biofuel industry.

  9. Supplementing with non-glycoside hydrolase proteins enhances enzymatic deconstruction of plant biomass.

    Directory of Open Access Journals (Sweden)

    Xiaoyun Su

    Full Text Available The glycoside hydrolases (GH of Caldicellulosiruptor bescii are thermophilic enzymes, and therefore they can hydrolyze plant cell wall polysaccharides at high temperatures. Analyses of two C. bescii glycoside hydrolases, CbCelA-TM1 and CbXyn10A with cellulase and endoxylanase activity, respectively, demonstrated that each enzyme is highly thermostable under static incubation at 70°C. Both enzymes, however, rapidly lost their enzymatic activities when incubated at 70°C with end-over-end shaking. Since crowding conditions, even at low protein concentrations, seem to influence enzymatic properties, three non-glycoside hydrolase proteins were tested for their capacity to stabilize the thermophilic proteins at high temperatures. The three proteins investigated were a small heat shock protein CbHsp18 from C. bescii, a histone MkHistone1 from Methanopyrus kandleri, and bovine RNase A, from a commercial source. Fascinatingly, each of these proteins increased the thermostability of the glycoside hydrolases at 70°C during end-over-end shaking incubation, and this property translated into increases in hydrolysis of several substrates including the bioenergy feedstock Miscanthus. Furthermore, MkHistone1 and RNase A also altered the initial products released from the cello-oligosaccharide cellopentaose during hydrolysis with the cellodextrinase CbCdx1A, which further demonstrated the capacity of the three non-GH proteins to influence hydrolysis of substrates by the thermophilic glycoside hydrolases. The non-GH proteins used in the present report were small proteins derived from each of the three lineages of life, and therefore expand the space from which different polypeptides can be tested for their influence on plant cell wall hydrolysis, a critical step in the emerging biofuel industry.

  10. Plutonium Immobilization Can Loading Concepts

    International Nuclear Information System (INIS)

    Kriikku, E.; Ward, C.; Stokes, M.; Randall, B.; Steed, J.; Jones, R.; Hamilton, L.; Rogers, L.; Fiscus, J.; Dyches, G.

    1998-05-01

    The Plutonium Immobilization Facility will encapsulate plutonium in ceramic pucks and seal the pucks inside welded cans. Remote equipment will place these cans in magazines and the magazines in a Defense Waste Processing Facility (DWPF) canister. The DWPF will fill the canister with glass for permanent storage. This report discusses five can loading conceptual designs and the lists the advantages and disadvantages for each concept. This report identifies loading pucks into cans and backfilling cans with helium as the top priority can loading development areas. The can loading welder and cutter are very similar to the existing Savannah River Site (SRS) FB-Line bagless transfer welder and cutter and thus they are a low priority development item

  11. Immobilization of organic liquid wastes

    International Nuclear Information System (INIS)

    Greenhalgh, W.O.

    1985-01-01

    This report describes a portland cement immobilization process for the disposal treatment of radioactive organic liquid wastes which would be generated in a a FFTF fuels reprocessing line. An incineration system already on-hand was determined to be too costly to operate for the 100 to 400 gallons per year organic liquid. Organic test liquids were dispersed into an aqueous phosphate liquid using an emulsifier. A total of 109 gallons of potential and radioactive aqueous immiscible organic liquid wastes from Hanford 300 Area operations were solidified with portland cement and disposed of as solid waste during a 3-month test program with in-drum mixers. Waste packing efficiencies varied from 32 to 40% and included pump oils, mineral spirits, and TBP-NPH type solvents

  12. Uranium Immobilization in Wetland Soils

    Science.gov (United States)

    Jaffe, Peter R.; Koster van Groos, Paul G.; Li, Dien; Chang, Hyun-Shik; Seaman, John C.; Kaplan, Daniel I.; Peacock, Aaron D.; Scheckel, Kirk

    2014-05-01

    stronger for the mesocosms with the higher Fe(II) load. Analysis via XANES showed that a fraction (up to ~1/3) of uranium was reduced to U(IV), for mesocosms operated under low iron loading, indicating that iron cycling in the rhizosphere also results in uranium reduction and immobilization. For mesocosms operating under the higher iron loading, the fraction of uranium immobilized as U(IV) was much lower, indicating that uranium co-precipitation with iron might have been the dominant immobilization process. In parallel to these mesocosm experiments, dialysis samplers have been deployed at the Savannah River National Laboratory near a creek with uranium contamination, to determine dissolved species, including Fe(II) and U(VI) in these wetland soils and their seasonal variability. The results show that there is a strong seasonal variability in dissolved iron and uranium, indicating a strong immobilization during the growing season, which is consistent with the mesocosm experimental results that the rhizosphere iron and uranium cycling are closely linked.

  13. Estimation of solubility of organo-phosphorus extractants by P determination using molybdovanadophosphoric acid method

    International Nuclear Information System (INIS)

    Gill, J.S.; Kotekar, M.K.; Singh, H.

    2005-01-01

    Solvent extraction processes have been found to be suitable for uranium recovery from phosphoric acid. Various extractants like di-2-ethyl hexylphosphoric acid (D2EHPA), di-nonylphenyl phosphoric acid (DNPPA) and synergistic agents like tri-butyl phosphate (TBP), tri-octyl phosphine oxide (TOPO) have been used in liquid-liquid extraction of uranium from phosphoric acid. Contents of these organo-phosphorus compounds in aqueous raffinates need estimation for process requirements. Solubility of Tri-butyl phosphate (TBP) and Di-2-ethylhexyl phosphoric acid (D2EHPA) extractants have been determined in different media of water, oxalic acid (0.6M) and sulphuric acid (3.75M) solutions. These compounds were estimated by determining their phosphorus (P) contents employing molybdovanadophosphoric acid method, after digesting and solubalizing them in nitric and perchloric acid. (author)

  14. Concentration of Organochlorine and Organophosphorus Pesticides in Different Molluscs from Tighra Reservoir, Gwalior, India.

    Science.gov (United States)

    Mamta; Rao, R J; Wani, Khursheed Ahmad

    2015-09-01

    Concentration of organochlorine and organophosphorus pesticides and their metabolites were determined in whole body homogenate of L. acuminata, I. exustus, V. dissimilis, V. bengalensis, from Tighra Reservoir during summer and post monsoon season using GC-MS technique. The different types of pesticides viz., HCB, heptachlor, aldrin, endosulfan, dieldrin, p,p-DDT, choloropyrifos, methyl parathion, dicholorovos, ethion, malathion, parathion were found in resident molluscs studied. Concentration of these pesticides varied independently during the summer and the post monsoon season at monitored sites. The study concluded that presence of pesticides in Tighra Reservoir is a major concern on public and ecosystem health and use of biopesticides in the adjacent area of Reservoir is highly recommended.

  15. Electrochemical process for the treatment of water contaminated with organophosphorus pesticides

    International Nuclear Information System (INIS)

    Samet, Youssef; Agengui, Lamia; Abdelhedi, Ridha

    2009-01-01

    The aim of this work is the use of electrochemical process for the total mineralization of water contaminated with organophosphorus pesticides like chloropyrifos. This pesticide is widely used both for agricultural pest control and in households as a termiticide. The process was studied under galvanostatic polarization mode using Ta/PbO 2 anodes and graphite carbon bar as cathode. The kinetic of organic matter decay and the mineralization efficiency were evaluated by means of the chemical oxygen demand (COD) measurement. The influence of the experimental parameters such as the initial concentration of chloropyrifos, temperature, and current density, on the electrochemical process performance was investigated. The experimental results showed that COD removal always follows a pseudo-first-order kinetics. The degradation rate increased drastically with increasing current density and temperature. However, it decreased with the increase of the initial pollutant concentrations. Very high organic matter degradation, approximately 90 pour cent in 10 h experiments, was obtained.

  16. Degradation kinetics of seven organophosphorus pesticides in milk during yoghurt processing

    Directory of Open Access Journals (Sweden)

    LI-YING BO

    2011-03-01

    Full Text Available Bovine milk spiked with seven organophosphorus pesticides, i.e., dimethoate, fenthion, malathion, methyl parathion, monocrotophos, phorate and trichlorphon, was fermented at 42 °C with commercial directed vat set (DVS starters to investigate the degradation kinetics of the pesticides during yoghurt processing. The spiked pesticides were extracted from the prepared samples with an organic solvent and analyzed by gas chromatography after purification. Based on published results that the degradation kinetics of pesticides is first order, the rate constant of degradation and the half live period of the pesticides were calculated. The results indicated that degradation of the pesticides in milk during yoghurt processing were enhanced by one or both starters, except for malathion, and the two commercial DVS starters had different influences on the degradation kinetics of the pesticides.

  17. Assessment of some biochemical and hematological parameters in treated with the organophosphorus insecticide cyanox

    International Nuclear Information System (INIS)

    ElMahdy, A.A.; Fayz, V.; Hassanin, M.M.

    2002-01-01

    The effect of single acute oral doses of 29 and 58 mg/kg of cyanox (an organophosphorus pesticide) on selected biochemical and hematological parameters in male rats were investigated. This compound inhibited blood acetylcholine esterase (AChE) significantly, over 72 hours post-treatment with the higher dose level. Serum alkaline phosphatase (ALP) was significantly depressed, 48 hr after treatment with 58 mg/kg. Serum bilirubin was elevated significantly after 48 and 24 hr of treatment with 29 and 58 mg/kg, respectively. Serum cholesterol increased significantly over 48 hr post-treatment with both dose levels.Hypertriglyceridemia was noticed only in the higher dose group. Serum total lipids were increased significantly at both dose levels. A slight treatment-related effect was observed in serum creatinine level. The hematological investigations revealed the occurrence of macrocytic normochromic anemia that was more evident in the lower dose group

  18. Is the stoichiometry of the europium nitrate complexes with neutral organophosphorus extractants be anticipated?

    International Nuclear Information System (INIS)

    Beudaert, Ph.; Lamare, V.; Wipff, G.

    2001-01-01

    Molecular dynamics simulations have been performed in water on europium nitrate complexes with three neutral organophosphorus extractants (TBP, TPPO and CMPO) in order to determine on what criteria it is possible to obtain by simulations the experimental 1:3 stoichiometry in organic solution. This stoichiometry was investigated by progressive saturation of the cation coordination sphere. When the nitrate counter-ions are bidentate, the 1:3 stoichiometry corresponds to the degree of saturation where the interaction energy between europium and water becomes repulsive. Beyond this stoichiometry, complexes with TPPO and CMPO are unstable, although a 1:4 complex with TBP may exist but its formation appears to be energetically unfavored. (author)

  19. Influence of modifiers on the separation of dysprosium from neodymium using organophosphorus acid derivates

    Energy Technology Data Exchange (ETDEWEB)

    Elwert, Tobias; Schwarz, Sabrina; Goldmann, Daniel [TU Clausthal, Clausthal-Zellerfeld (Germany). Lehrstuhl fuer Rohstoffaufbereitung und Recycling

    2016-01-15

    The aim of this study was to investigate the applicability of three organophosphorus acid derivates (D2EHPA, EHEHPA and Cyanex 572) for the separation of terbium and dysprosium from praseodymium and neodymium from NdFeB magnets in chloride solution. A special focus was put on the effect of phase modifiers. The investigations revealed that all extractants show in general a similar extraction behavior but the extraction is shifted to higher pH values in the order D2EHPA < EHEHPA < Cyanex 572. Therefore, and due to higher realizable loadings, EHEHPA and Cyanex 572 are more suitable for the investigated separation problem than D2EHPA. Whereas EHEHPA requires 1-decanol as phase modifier, Cyanex 572 can be employed without modifier addition.

  20. Nicotine And The Risk Of Exposure To The Organophosphorus Insecticide Cyolane

    International Nuclear Information System (INIS)

    Hassanin M, M.; Bahig Mervat, E.

    1999-01-01

    The present investigation was undertaken to show the effect of repeated oral doses of nicotine (0.5 mg/kg) on rats pretreated or during treatment with cyolane (0.5 mg/kg 1/20 LD 5 0). The results revealed that exposure of smokers to organophosphorus pesticides exerted slight changes in GOT and GPT. Alkaline phosphatase was significantly increased to reach maximal (228.54 and 148.64%) after nicotine + cyolane and/or nicotine were given for a week to rats pretreated with cyolane for 2 weeks. Total protein, albumin and Albumin/Globulin (A/G) ratio were also affected. Administration of nicotine along with cyolane to rats showed a significant increase in cholesterol content compared to that of cyolane treated rats. Values of thyroxine (T 4 ) and triiodothyronine (T 3 ) also fluctuated

  1. Multipathway organophosphorus pesticide exposures of preschool children living in agricultural and nonagricultural communities

    International Nuclear Information System (INIS)

    Lu Chensheng; Kedan, Golan; Fisker-Andersen, Jennifer; Kissel, J.C.; Fenske, R.A.

    2004-01-01

    Environmental measurements of organophosphorus (OP) pesticides were conducted in the homes of 13 children, who lived either in the Seattle metropolitan area or in the agricultural region of Washington State, to ascertain exposure through multiple pathways. Each home was sampled for two 24-h periods during two seasons, summer and fall. Samples included 24-h indoor air, drinking water, soil, house dust, and hand and toy wipes and 24-h duplicate diets. At least one OP pesticide was found in each of the matrices sampled except for drinking water. Half of the indoor air samples contained detectable levels of chlorpyrifos or diazinon. Detectable levels of diazinon and azinphosmethyl in house dust were found in most of the agricultural homes, whereas only diazinon was found in the Seattle homes in the summer. Quantifiable chlorpyrifos and azinphosmethyl were found on either agricultural children's hands or their toys. These findings suggest different exposure pathways for children living in agricultural and nonagricultural regions

  2. Radioactive seed immobilization techniques for interstitial brachytherapy

    International Nuclear Information System (INIS)

    Yan, K.; Podder, T.; Buzurovic, I.; Hu, Y.; Dicker, A.; Valicenti, R.; Yu, Y.; Messing, E.; Rubens, D.; Sarkar, N.; Ng, W.

    2008-01-01

    In prostate brachytherapy, seeds can detach from their deposited sites and move locally in the pelvis or migrate to distant sites including the pulmonary and cardiac regions. Undesirable consequences of seed migration include inadequate dose coverage of the prostate and tissue irradiation effects at the site of migration. Thus, it is clinically important to develop seed immobilization techniques. We first analyze the possible causes for seed movement, and propose three potential techniques for seed immobilization: (1) surgical glue, (2) laser coagulation and (3) diathermy coagulation. The feasibility of each method is explored. Experiments were carried out using fresh bovine livers to investigate the efficacy of seed immobilization using surgical glue. Results have shown that the surgical glue can effectively immobilize the seeds. Evaluation of the radiation dose distribution revealed that the non-immobilized seed movement would change the planned isodose distribution considerably; while by using surgical glue method to immobilize the seeds, the changes were negligible. Prostate brachytherapy seed immobilization is necessary and three alternative mechanisms are promising for addressing this issue. Experiments for exploring the efficacy of the other two proposed methods are ongoing. Devices compatible with the brachytherapy procedure will be designed in future. (orig.)

  3. The solvent extraction of zinc, iron, and indium from chloride solutions by neutral organophosphorus compounds

    International Nuclear Information System (INIS)

    Preston, J.S.; Du Preez, A.C.

    1985-01-01

    The preparation of several neutral organophosphorus compounds and their evaluation as selective extractants for zinc in chloride media are described. The compounds belong to the series trialkyl phosphates (RO) 3 PO, dialkyl alkylphosphonates R'PO(OR) 2 , alkyl dialkylphosphinates R 2 'PO(OR), and trialkyl-phosphine oxides R 3 'PO. They were characterized by measurement of their physical properties (melting and boiling points, refractive indices, and densities), and their purities were confirmed by osmometric determination of their molecular masses; by carbon and hydrogen microanalysis; by the titrimetric determination of acidic impurities; and, for liquid products, by comparison of their experimental molar refractivities with empirical values. Metal-distribution equilibria were determined for solutions of the extractants in xylene and aqueous phase containing 0,5 to 5,0 M sodium chloride. Moderately good selectivities were shown for zinc(II) over iron(III), and excellent selectivities were shown for zinc(II) over iron(II), copper(II), lead(II), and cadmium(II). The extraction of indium(III) was similar to that of zinc(II). The extraction of zinc(III), iron(III), and indium(III) increased markedly through the series. (RO) 3 PO 2 2 'PO(OR) 3 'PO. The incorporation of phenyl groups into the compounds led to weaker extraction. The extracted complexes of zinc(II), iron(III), and indium(III) have the stoichiometries ZnCl 2 L 2 ,FeCl 3 L 2 (H 2 O), and InCl 3 L 2 (H 2 O) respectively, where L represents the neutral organophosphorus compound

  4. Surface cell immobilization within perfluoroalkoxy microchannels

    Energy Technology Data Exchange (ETDEWEB)

    Stojkovič, Gorazd; Krivec, Matic [Faculty of Chemistry and Chemical Technology, University of Ljubljana, Aškerčeva 5, SI-1000 Ljubljana (Slovenia); Vesel, Alenka [Jožef Stefan Institute, Jamova cesta 39, 1000 Ljubljana (Slovenia); Marinšek, Marjan [Faculty of Chemistry and Chemical Technology, University of Ljubljana, Aškerčeva 5, SI-1000 Ljubljana (Slovenia); Žnidaršič-Plazl, Polona, E-mail: polona.znidarsic@fkkt.uni-lj.si [Faculty of Chemistry and Chemical Technology, University of Ljubljana, Aškerčeva 5, SI-1000 Ljubljana (Slovenia)

    2014-11-30

    Graphical abstract: - Highlights: • A very efficient approach for immobilization of cells into microreactors is presented. • It is applicable to various materials, including PFA and cyclic olefin (co)polymers. • It was used to immobilize different prokaryotic and eukaryotic microbes. • Cells were immobilized on the surface in high density and showed good stability. • Mechanisms of APTES interactions with target materials are proposed. - Abstract: Perfluoroalkoxy (PFA) is one of the most promising materials for the fabrication of cheap, solvent resistant and reusable microfluidic chips, which have been recently recognized as effective tools for biocatalytic process development. The application of biocatalysts significantly depends on efficient immobilization of enzymes or cells within the reactor enabling long-term biocatalyst use. Functionalization of PFA microchannels by 3-aminopropyltriethoxysilane (ATPES) and glutaraldehyde was used for rapid preparation of microbioreactors with surface-immobilized cells. X-ray photoelectron spectroscopy and scanning electron microscopy were used to accurately monitor individual treatment steps and to select conditions for cell immobilization. The optimized protocol for Saccharomyces cerevisiae immobilization on PFA microchannel walls comprised ethanol surface pretreatment, 4 h contacting with 10% APTES aqueous solution, 10 min treatment with 1% glutaraldehyde and 20 min contacting with cells in deionized water. The same protocol enabled also immobilization of Escherichia coli, Pseudomonas putida and Bacillus subtilis cells on PFA surface in high densities. Furthermore, the developed procedure has been proved to be very efficient also for surface immobilization of tested cells on other materials that are used for microreactor fabrication, including glass, polystyrene, poly (methyl methacrylate), polycarbonate, and two olefin-based polymers, namely Zeonor{sup ®} and Topas{sup ®}.

  5. Immobilization of cellulase using porous polymer matrix

    International Nuclear Information System (INIS)

    Kumakura, M.; Kaetsu, I.

    1984-01-01

    A new method is discussed for the immobilization of cellulase using porous polymer matrices, which were obtained by radiation polymerization of hydrophilic monomers. In this method, the immobilized enzyme matrix was prepared by enzyme absorbtion in the porous polymer matrix and drying treatment. The enzyme activity of the immobilized enzyme matrix varied with monomer concentration, cooling rate of the monomer solution, and hydrophilicity of the polymer matrix, takinn the change of the nature of the porous structure in the polymer matrix. The leakage of the enzymes from the polymer matrix was not observed in the repeated batch enzyme reactions

  6. Immobilization of Peroxidase onto Magnetite Modified Polyaniline

    Directory of Open Access Journals (Sweden)

    Eduardo Fernandes Barbosa

    2012-01-01

    Full Text Available The present study describes the immobilization of horseradish peroxidase (HRP on magnetite-modified polyaniline (PANImG activated with glutaraldehyde. After the optimization of the methodology, the immobilization of HRP on PANImG produced the same yield (25% obtained for PANIG with an efficiency of 100% (active protein. The optimum pH for immobilization was displaced by the effect of the partition of protons produced in the microenvironment by the magnetite. The tests of repeated use have shown that PANImG-HRP can be used for 13 cycles with maintenance of 50% of the initial activity.

  7. Preparation and characterization of immobilized lipase on magnetic hydrophobic microspheres

    DEFF Research Database (Denmark)

    Guo, Zheng; Bai, Shu; Sun, Yan

    2003-01-01

    H for the immobilized CCL were determined. Activity amelioration of the immobilized CCL for the hydrolysis of olive oil was observed, indicating an interfacial activation of the enzyme after immobilization. Moreover, the immobilized CCL showed enhanced thermal stability and good durability in the repeated use after...

  8. Divergent effects of postmortem ambient temperature on organophosphorus- and carbamate-inhibited brain cholinesterase activity in birds

    Science.gov (United States)

    Hill, E.F.

    1989-01-01

    Time- and temperature-dependent postmortem changes in inhibited brain cholinesterase (ChE) activity may confound diagnosis of field poisoning of wildlife by anticholinesterase pesticide. Carbamate-inhibited ChE activity may return to normal within 1 to 2 days of exposure of intact carcass to moderate ambient temperature (18-32C). Organophosphorus-inhibited ChE activity becomes more depressed over the same time. Uninhibited ChE activity was resilient to above freezing temperature to 32C for 1 day and 25C for 3 days. Carbamate- and organophosphorus-inhibited ChE can be separated by incubation of homogenate for 1 hour at physiological temperatures; carbamylated ChE can be readily reactivated while phosphorylated ChE cannot.

  9. Increased fetal endocardial echogenicity mimicking endocardial fibroelastosis following maternal organophosphorus poisoning and its complete regression in utero

    International Nuclear Information System (INIS)

    Balakumar, Karippaliyil; Misha, Kannan; Milind, Karippaliyil

    2013-01-01

    Fetal endocardial fibroelastosis (EFE) has been diagnosed by antenatal ultrasonography in the past few years. A typical case of isolated endocardial fibroelastosis is illustrated here, in a fetus of 22 weeks of gestational age exposed to maternal organophosphorus poisoning at 20 weeks. No other structural cardiac or other systemic anomalies were detected in this fetus. The abnormal fetal echocardiographic features mimicking endocardial fibroelastosis completely regressed after 14 weeks and a normal full-term baby was delivered. Postnatal echocardiogram showed normal cardiac parameters. The diagnostic features mimicking EFE following maternal organophosphorus poisoning at 20 weeks of gestational age and the subsequent complete reversal of these changes after 14 weeks of diagnosis are reported for the first time in the literature

  10. Synergistic Extraction of Copper from Nitrate Solutions Using β-Hydroxy-Naphthaldoxime and Organophosphorus Compounds into Carbon-Tetrachloride

    Science.gov (United States)

    Dey, Pulak; Basu, Sukalyan

    2011-12-01

    The extraction behavior of Cu(II) from an aqueous nitrate medium employing β-hydroxy-naphthaldoxime in carbon tetrachloride has been investigated in the presence of several organophosphorus donors like tri-octyl phosphine oxide, tri-butyl phosphine oxide, and tri-butyl phosphate at pH 1.5. The concentration of the metal was measured by atomic absorption spectrophotometry. Synergism was observed when neutral donor was added because of the formation of the adduct [Cu(L)2.(S)] in CCl4 (S denotes neutral donor). The equilibrium constants of the binary system using β-hydroxy-naphthaldoxime and the ternary system involving another addition of an organophosphorus compound were calculated from the extraction date obtained. Furthermore, the temperature dependence of the equilibrium constants was also investigated to evaluate standard enthalpy (Δ H°), entropy (Δ S°), and free energy (Δ G°) of the reactions proposed.

  11. Structural analysis of Clostridium acetobutylicum ATCC 824 glycoside hydrolase from CAZy family GH105

    International Nuclear Information System (INIS)

    Germane, Katherine L.; Servinsky, Matthew D.; Gerlach, Elliot S.; Sund, Christian J.; Hurley, Margaret M.

    2015-01-01

    The crystal structure of the protein product of the C. acetobutylicum ATCC 824 gene CA-C0359 is structurally similar to YteR, an unsaturated rhamnogalacturonyl hydrolase from B. subtilis strain 168. Substrate modeling and electrostatic studies of the active site of the structure of CA-C0359 suggests that the protein can now be considered to be part of CAZy glycoside hydrolase family 105. Clostridium acetobutylicum ATCC 824 gene CA-C0359 encodes a putative unsaturated rhamnogalacturonyl hydrolase (URH) with distant amino-acid sequence homology to YteR of Bacillus subtilis strain 168. YteR, like other URHs, has core structural homology to unsaturated glucuronyl hydrolases, but hydrolyzes the unsaturated disaccharide derivative of rhamnogalacturonan I. The crystal structure of the recombinant CA-C0359 protein was solved to 1.6 Å resolution by molecular replacement using the phase information of the previously reported structure of YteR (PDB entry (http://scripts.iucr.org/cgi-bin/cr.cgi?rm)) from Bacillus subtilis strain 168. The YteR-like protein is a six-α-hairpin barrel with two β-sheet strands and a small helix overlaying the end of the hairpins next to the active site. The protein has low primary protein sequence identity to YteR but is structurally similar. The two tertiary structures align with a root-mean-square deviation of 1.4 Å and contain a highly conserved active pocket. There is a conserved aspartic acid residue in both structures, which has been shown to be important for hydration of the C=C bond during the release of unsaturated galacturonic acid by YteR. A surface electrostatic potential comparison of CA-C0359 and proteins from CAZy families GH88 and GH105 reveals the make-up of the active site to be a combination of the unsaturated rhamnogalacturonyl hydrolase and the unsaturated glucuronyl hydrolase from Bacillus subtilis strain 168. Structural and electrostatic comparisons suggests that the protein may have a slightly different substrate

  12. Structural analysis of Clostridium acetobutylicum ATCC 824 glycoside hydrolase from CAZy family GH105

    Energy Technology Data Exchange (ETDEWEB)

    Germane, Katherine L., E-mail: katherine.germane.civ@mail.mil [Oak Ridge Associated Universities, 4692 Millennium Drive, Suite 101, Belcamp, MD 21017 (United States); Servinsky, Matthew D. [US Army Research Laboratory, 2800 Powder Mill Road, Adelphi, MD 20783 (United States); Gerlach, Elliot S. [Federal Staffing Resources, 2200 Somerville Road, Annapolis, MD 21401 (United States); Sund, Christian J. [US Army Research Laboratory, 2800 Powder Mill Road, Adelphi, MD 20783 (United States); Hurley, Margaret M., E-mail: katherine.germane.civ@mail.mil [US Army Research Laboratory, 4600 Deer Creek Loop, Aberdeen Proving Ground, MD 21005 (United States); Oak Ridge Associated Universities, 4692 Millennium Drive, Suite 101, Belcamp, MD 21017 (United States)

    2015-07-29

    The crystal structure of the protein product of the C. acetobutylicum ATCC 824 gene CA-C0359 is structurally similar to YteR, an unsaturated rhamnogalacturonyl hydrolase from B. subtilis strain 168. Substrate modeling and electrostatic studies of the active site of the structure of CA-C0359 suggests that the protein can now be considered to be part of CAZy glycoside hydrolase family 105. Clostridium acetobutylicum ATCC 824 gene CA-C0359 encodes a putative unsaturated rhamnogalacturonyl hydrolase (URH) with distant amino-acid sequence homology to YteR of Bacillus subtilis strain 168. YteR, like other URHs, has core structural homology to unsaturated glucuronyl hydrolases, but hydrolyzes the unsaturated disaccharide derivative of rhamnogalacturonan I. The crystal structure of the recombinant CA-C0359 protein was solved to 1.6 Å resolution by molecular replacement using the phase information of the previously reported structure of YteR (PDB entry (http://scripts.iucr.org/cgi-bin/cr.cgi?rm)) from Bacillus subtilis strain 168. The YteR-like protein is a six-α-hairpin barrel with two β-sheet strands and a small helix overlaying the end of the hairpins next to the active site. The protein has low primary protein sequence identity to YteR but is structurally similar. The two tertiary structures align with a root-mean-square deviation of 1.4 Å and contain a highly conserved active pocket. There is a conserved aspartic acid residue in both structures, which has been shown to be important for hydration of the C=C bond during the release of unsaturated galacturonic acid by YteR. A surface electrostatic potential comparison of CA-C0359 and proteins from CAZy families GH88 and GH105 reveals the make-up of the active site to be a combination of the unsaturated rhamnogalacturonyl hydrolase and the unsaturated glucuronyl hydrolase from Bacillus subtilis strain 168. Structural and electrostatic comparisons suggests that the protein may have a slightly different substrate

  13. Expression of organophosphorus-degradation gene ( opd) in aggregating and non-aggregating filamentous nitrogen-fixing cyanobacteria

    Science.gov (United States)

    Li, Qiong; Tang, Qing; Xu, Xudong; Gao, Hong

    2010-11-01

    Genetic engineering in filamentous N2-fixing cyanobacteria usually involves Anabaena sp. PCC 7120 and several other non-aggregating species. Mass culture and harvest of such species are more energy consuming relative to aggregating species. To establish a gene transfer system for aggregating species, we tested many species of Anabaena and Nostoc, and identified Nostoc muscorum FACHB244 as a species that can be genetically manipulated using the conjugative gene transfer system. To promote biodegradation of organophosphorus pollutants in aquatic environments, we introduced a plasmid containing the organophosphorus-degradation gene ( opd) into Anabaena sp. PCC 7120 and Nostoc muscorum FACHB244 by conjugation. The opd gene was driven by a strong promoter, P psbA . From both species, we obtained transgenic strains having organophosphorus-degradation activities. At 25°C, the whole-cell activities of the transgenic Anabaena and Nostoc strains were 0.163±0.001 and 0.289±0.042 unit/μg Chl a, respectively. However, most colonies resulting from the gene transfer showed no activity. PCR and DNA sequencing revealed deletions or rearrangements in the plasmid in some of the colonies. Expression of the green fluorescent protein gene from the same promoter in Anabaena sp. PCC 7120 showed similar results. These results suggest that there is the potential to promote the degradation of organophosphorus pollutants with transgenic cyanobacteria and that selection of high-expression transgenic colonies is important for genetic engineering of Anabaena and Nostoc species. For the first time, we established a gene transfer and expression system in an aggregating filamentous N2-fixing cyanobacterium. The genetic manipulation system of Nostoc muscorum FACHB244 could be utilized in the elimination of pollutants and large-scale production of valuable proteins or metabolites.

  14. Antimicrobial activity of immobilized lactoferrin and lactoferricin.

    Science.gov (United States)

    Chen, Renxun; Cole, Nerida; Dutta, Debarun; Kumar, Naresh; Willcox, Mark D P

    2017-11-01

    Lactoferrin and lactoferricin were immobilized on glass surfaces via two linkers, 4-azidobenzoic acid (ABA) or 4-fluoro-3-nitrophenyl azide (FNA). The resulting surfaces were characterized by X-ray photoelectron spectroscopy (XPS) and contact angle measurements. The antimicrobial activity of the surfaces was determined using Pseudomonas aeruginosa and Staphylococcus aureus strains by fluorescence microscopy. Lactoferrin and lactoferricin immobilization was confirmed by XPS showing significant increases (p lactoferricin immobilized on glass significantly (p lactoferricin were successfully immobilized on glass surfaces and showed promising antimicrobial activity against pathogenic bacteria. © 2016 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 105B: 2612-2617, 2017. © 2016 Wiley Periodicals, Inc.

  15. Immobilization of Rocky Flats Graphite Fines Residue

    International Nuclear Information System (INIS)

    Rudisill, T.S.

    1999-01-01

    The development of the immobilization process for graphite fines has proceeded through a series of experimental programs. The experimental procedures and results from each series of experiments are discussed in this report

  16. Immobilization and characterization of inulinase from Ulocladium ...

    Indian Academy of Sciences (India)

    2014-10-20

    Oct 20, 2014 ... The enzyme had optimum pH at 5.6 for free and immobilized U. atrum inulinase on polyester ... ceutical industry because of their beneficial effects in ..... Hanover LWJ 1993 Manufacturing, composing and applications of.

  17. Plutonium Immobilization Bagless Transfer Can Size Evaluation

    International Nuclear Information System (INIS)

    Kriikku, E.; Stokes, M.; Rogers, L.; Ward, C.

    1998-02-01

    This report identifies and documents the most appropriate bagless transfer can size to support Plutonium Immobilization Can Loading operations. Also, this report considers can diameter, can wall thickness, and can length

  18. Modeling intrinsic kinetics in immobilized photocatalytic microreactors

    NARCIS (Netherlands)

    Visan, Aura; Rafieian Boroujeni, Damon; Ogieglo, Wojciech; Lammertink, Rob G.H.

    2014-01-01

    The article presents a simple model for immobilized photocatalytic microreactors following a first order reaction rate with either light independency or light dependency described by photon absorption carrier generation semiconductor physics. Experimental data obtained for various residence times,

  19. A simplified technique for nasoendotracheal tube immobilization.

    OpenAIRE

    Berardo, N.; Leban, S. G.; Williams, F. A.

    1989-01-01

    A simplified technique for immobilization of a nasoendotracheal tube is described in which a wide strap of open cell, hypoallergenic, foam-backed fabric is secured to the patient's head with a Velcro fastener.

  20. Variation in bleomycin hydrolase gene is associated with reduced survival after chemotherapy for testicular germ cell cancer

    NARCIS (Netherlands)

    de Haas, Esther C.; Zwart, Nynke; Meijer, Coby; Nuver, Janine; Boezen, H. Marike; Suurmeijer, Albert J. H.; Hoekstra, Harald J.; van der Steege, Gerrit; Sleijfer, Dirk Th.; Gietema, Jourik A.

    2008-01-01

    Purpose Response to chemotherapy may be determined by gene polymorphisms involved in metabolism of cytotoxic drugs. A plausible candidate is the gene for bleomycin hydrolase (BLMH), an enzyme that inactivates bleomycin, an essential component of chemotherapy regimens for disseminated testicular

  1. Immobilization technology for krypton in amorphous zeolite

    International Nuclear Information System (INIS)

    Takusagawa, Atsushi; Ishiyama, Keiichi

    1989-01-01

    Radioactive krypton recovered from the offgas of a reprocessing plant requires long-term storage on the order of 100 years. Immobilization technology for krypton into amorphous zeolite 5A is considered one of the best methods for long-term storage. In this report, conditions for immobilization treatment and stability of amorphous zeolite 5A loaded krypton against heat, radiation and water are discussed, and a treatment system using this technology is described. (author)

  2. Immobilization Technologies in Probiotic Food Production

    Directory of Open Access Journals (Sweden)

    Gregoria Mitropoulou

    2013-01-01

    Full Text Available Various supports and immobilization/encapsulation techniques have been proposed and tested for application in functional food production. In the present review, the use of probiotic microorganisms for the production of novel foods is discussed, while the benefits and criteria of using probiotic cultures are analyzed. Subsequently, immobilization/encapsulation applications in the food industry aiming at the prolongation of cell viability are described together with an evaluation of their potential future impact, which is also highlighted and assessed.

  3. [Determination of 44 organophosphorus pesticides in food by SPE disk extraction-capillary gas chromatography with pulsed flame photometric detection].

    Science.gov (United States)

    Luo, Xiao-Fei; Yang, Yuan; Sun, Cheng-Jun

    2012-01-01

    To develop a method for the simultaneous determination of 44 organophosphorus pesticides in food by SPE disk extraction-capillary gas chromatography with pulsed flame photometric detection. Organophosphorus pesticides in food were extracted ultrasonically with water. Then the extract was cleaned-up with SPE disk and eluted with ethyl acetate. Finally the eluent was condensed to 1mL under N2 at 55 degrees C. Gas chromatography was applied for quantitative detection of the organophosphorus pesticides in the sample. The linear range of the method for all the pesticides were in the range of 0.01-0.5 mg/kg with correlation coefficients of 0.992-1.000. The detection limits of the method were in the range of 0.0005-0.01 mg/kg. The recoveries for most pesticides were 60%-120% with relative standard deviations of less than 15%. The method is simple, sensitive, environmentally friendly and suitable for the determination of organophosphorous pesticides in food.

  4. Identification and isolation of bacteria containing OPH enzyme for biodegradation of organophosphorus pesticide diazinon from contaminated agricultural soil

    Directory of Open Access Journals (Sweden)

    Sara Mobarakpoor

    2015-04-01

    Full Text Available Background: Organophosphorus insecticide diazinon has been widely used in agriculture and has the ability to transfer and accumulate in soil, water and animal tissues, and to induce toxicity in plants, animals and humans. In humans, diazinon inhibits nerve transmission by inactivating acetylcholinesterase enzyme. The present study was carried out to identify bacteria containing OPH enzyme for biodegradation of diazinon from contaminated agricultural soil. Methods: In this study, 8 contaminated agricultural soil samples that were exposed to pesticides, especially diazinon in the last two decades, were collected from the farms of Hamedan province. After preparing the media, for isolation of several bacterial strains containing OPH enzyme that are capable of biodegrading organophosphorus pesticides by diazinon enzymatic hydrolysis, bacterial genomic DNA extraction, plasmid product sequencing, phylogenetic sequence processing and phylogenetic tree drawing were carried out. Results: Eight bacterial strains, capable of secreting OPH enzyme, were isolated from soil samples, one of which named BS-1 with 86% similarity to Bacillus safensis displayed the highest organophosphate-hydrolyzing capability and can be used as a source of carbon and phosphorus. Conclusion: It can be concluded that the isolated bacterial strain identified in this study with OPH enzyme secretion has the potential for biodegradation of organophosphorus pesticides, especially diazinon in invitro conditions. Also, further studies such as the environmental stability and interaction, production strategies, safety, cost-benefit, environmental destructive parameters, and, toxicological, genetic and biochemical aspects are recommended prior to the application of bacterial strains in the field-scale bioremediation.

  5. Ceramification: A plutonium immobilization process

    Energy Technology Data Exchange (ETDEWEB)

    Rask, W.C. [Dept. of Energy, Golden, CO (United States); Phillips, A.G. [Rocky Flats Environmental Technology Site, Golden, CO (United States)

    1996-05-01

    This paper describes a low temperature technique for stabilizing and immobilizing actinide compounds using a combination process/storage vessel of stainless steel, in which measured amounts of actinide nitrate solutions and actinide oxides (and/or residues) are systematically treated to yield a solid article. The chemical ceramic process is based on a coating technology that produces rare earth oxide coatings for defense applications involving plutonium. The final product of this application is a solid, coherent actinide oxide with process-generated encapsulation that has long-term environmental stability. Actinide compounds can be stabilized as pure materials for ease of re-use or as intimate mixtures with additives such as rare earth oxides to increase their degree of proliferation resistance. Starting materials for the process can include nitrate solutions, powders, aggregates, sludges, incinerator ashes, and others. Agents such as cerium oxide or zirconium oxide may be added as powders or precursors to enhance the properties of the resulting solid product. Additives may be included to produce a final product suitable for use in nuclear fuel pellet production. The process is simple and reduces the time and expense for stabilizing plutonium compounds. It requires a very low equipment expenditure and can be readily implemented into existing gloveboxes. The process is easily conducted with less associated risk than proposed alternative technologies.

  6. Biotechnological production of vanillin using immobilized enzymes.

    Science.gov (United States)

    Furuya, Toshiki; Kuroiwa, Mari; Kino, Kuniki

    2017-02-10

    Vanillin is an important and popular plant flavor, but the amount of this compound available from plant sources is very limited. Biotechnological methods have high potential for vanillin production as an alternative to extraction from plant sources. Here, we report a new approach using immobilized enzymes for the production of vanillin. The recently discovered oxygenase Cso2 has coenzyme-independent catalytic activity for the conversion of isoeugenol and 4-vinylguaiacol to vanillin. Immobilization of Cso2 on Sepabeads EC-EA anion-exchange carrier conferred enhanced operational stability enabling repetitive use. This immobilized Cso2 catalyst allowed 6.8mg yield of vanillin from isoeugenol through ten reaction cycles at a 1mL scale. The coenzyme-independent decarboxylase Fdc, which has catalytic activity for the conversion of ferulic acid to 4-vinylguaiacol, was also immobilized on Sepabeads EC-EA. We demonstrated that the immobilized Fdc and Cso2 enabled the cascade synthesis of vanillin from ferulic acid via 4-vinylguaiacol with repetitive use of the catalysts. This study is the first example of biotechnological production of vanillin using immobilized enzymes, a process that provides new possibilities for vanillin production. Copyright © 2016 Elsevier B.V. All rights reserved.

  7. Radiation technology for immobilization of bioactive materials

    International Nuclear Information System (INIS)

    1988-12-01

    Within the framework of the Agency's coordinated research programme on ''Application of Radiation Technology in Immobilization of Bioactive Materials'', the third and final research coordination meeting was held at Beijing University, Beijing, People's Republic of China, 15-18 June 1987. The present publication compiles all presentations made at the meeting. Fundamental processes for the immobilization of enzymes, antibodies, cells and drugs were developed and established using gamma radiation, electron beams and plasma discharge. Applications of various biofunctional components, immobilized by radiation techniques in different processes, were studied. A range of backbone polymers has been examined together with various monomers. Coupling procedures have been developed which are relevant to our particular requirements. Enzymes of various types and characteristics have been immobilized with considerable efficiency. The immobilized biocatalysts have been shown to possess significant activity and retention of activity on storage. There appears to be a high degree of specificity associated with the properties of the immobilised biocatalysts, their activity and the ease of their preparation. Novel additives which lower the total radiation dose in grafting have been discovered and their value in immobilization processes assessed. Potential applications include: medical (diagnostic, therapeutic), and industrial processes (fermentation, bioseparation, etc.). Refs, figs and tabs

  8. Biosynthesis of intestinal microvillar proteins. Dimerization of aminopeptidase N and lactase-phlorizin hydrolase

    DEFF Research Database (Denmark)

    Danielsen, E M

    1990-01-01

    of dimers of this enzyme therefore occurs prior to the Golgi-associated processing, and the slow rate of dimerization may be the rate-limiting step in the transport from the endoplasmic reticulum to the Golgi complex. For lactase-phlorizin hydrolase, the posttranslational processing includes a proteolytic......The pig intestinal brush border enzymes aminopeptidase N (EC 3.4.11.2) and lactase-phlorizin hydrolase (EC 3.2.1.23-62) are present in the microvillar membrane as homodimers. Dimethyl adipimidate was used to cross-link the two [35S]methionine-labeled brush border enzymes from cultured mucosal...... explants. For aminopeptidase N, dimerization did not begin until 5-10 min after synthesis, and maximal dimerization by cross-linking of the transient form of the enzyme required 1 h, whereas the mature form of aminopeptidase N cross-linked with unchanged efficiency from 45 min to 3 h of labeling. Formation...

  9. A new insight into the physiological role of bile salt hydrolase among intestinal bacteria from the genus Bifidobacterium.

    Science.gov (United States)

    Jarocki, Piotr; Podleśny, Marcin; Glibowski, Paweł; Targoński, Zdzisław

    2014-01-01

    This study analyzes the occurrence of bile salt hydrolase in fourteen strains belonging to the genus Bifidobacterium. Deconjugation activity was detected using a plate test, two-step enzymatic reaction and activity staining on a native polyacrylamide gel. Subsequently, bile salt hydrolases from B. pseudocatenulatum and B. longum subsp. suis were purified using a two-step chromatographic procedure. Biochemical characterization of the bile salt hydrolases showed that the purified enzymes hydrolyzed all of the six major human bile salts under the pH and temperature conditions commonly found in the human gastrointestinal tract. Next, the dynamic rheometry was applied to monitor the gelation process of deoxycholic acid under different conditions. The results showed that bile acids displayed aqueous media gelating properties. Finally, gel-forming abilities of bifidobacteria exhibiting bile salt hydrolase activity were analyzed. Our investigations have demonstrated that the release of deconjugated bile acids led to the gelation phenomenon of the enzymatic reaction solution containing purified BSH. The presented results suggest that bile salt hydrolase activity commonly found among intestinal microbiota increases hydrogel-forming abilities of certain bile salts. To our knowledge, this is the first report showing that bile salt hydrolase activity among Bifidobacterium is directly connected with the gelation process of bile salts. In our opinion, if such a phenomenon occurs in physiological conditions of human gut, it may improve bacterial ability to colonize the gastrointestinal tract and their survival in this specific ecological niche.

  10. Preparation, crystallization and preliminary X-ray crystallographic studies of diadenosine tetraphosphate hydrolase from Shigella flexneri 2a

    Energy Technology Data Exchange (ETDEWEB)

    Hu, Wenxin; Wang, Qihai; Bi, Ruchang, E-mail: rcbi@sun5.ibp.ac.cn [Institute of Biophysics, Chinese Academy of Sciences, 15 Datun Road, Chaoyang District, Beijing 100101 (China)

    2005-12-01

    The 31.3 kDa Ap{sub 4}A hydrolase from Shigella flexneri 2a has been cloned, expressed and purified using an Escherichia coli expression system. Crystals of Ap{sub 4}A hydrolase have been obtained by the hanging-drop technique at 291 K using PEG 550 MME as precipitant. Diadenosine tetraphosphate (Ap{sub 4}A) hydrolase (EC 3.6.1.41) hydrolyzes Ap{sub 4}A symmetrically in prokaryotes. It plays a potential role in organisms by regulating the concentration of Ap{sub 4}A in vivo. To date, no three-dimensional structures of proteins with significant sequence homology to this protein have been determined. The 31.3 kDa Ap{sub 4}A hydrolase from Shigella flexneri 2a has been cloned, expressed and purified using an Escherichia coli expression system. Crystals of Ap{sub 4}A hydrolase have been obtained by the hanging-drop technique at 291 K using PEG 550 MME as precipitant. Ap{sub 4}A hydrolase crystals diffract X-rays to 3.26 Å and belong to space group P2{sub 1}, with unit-cell parameters a = 118.9, b = 54.6, c = 128.5 Å, β = 95.7°.

  11. Screening brazilian macrophomina phaseolina isolates for alkaline lipases and other extracellular hydrolases

    OpenAIRE

    Schinke, Cláudia; Germani, Jose Carlos

    2012-01-01

    Macrophomina phaseolina, phylum Ascomycota, is a phytopathogenic fungus distributed worldwide in hot dry areas. There are few studies on its secreted lipases and none on its colony radial growth rate, an indicator of fungal ability to use nutrients for growth, on media other than potato-dextrose agar. In this study, 13 M. phaseolina isolates collected in different Brazilian regions were screened for fast-growth and the production of hydrolases of industrial interest, especially alkaline lipas...

  12. Murein Hydrolase Activity in the Surface Layer of Lactobacillus acidophilus ATCC 4356▿

    OpenAIRE

    Prado Acosta, Mariano; Palomino, María Mercedes; Allievi, Mariana C.; Rivas, Carmen Sanchez; Ruzal, Sandra M.

    2008-01-01

    We describe a new enzymatic functionality for the surface layer (S-layer) of Lactobacillus acidophilus ATCC 4356, namely, an endopeptidase activity against the cell wall of Salmonella enterica serovar Newport, assayed via zymograms and identified by Western blotting. Based on amino acid sequence comparisons, the hydrolase activity was predicted to be located at the C terminus. Subsequent cloning and expression of the C-terminal domain in Bacillus subtilis resulted in the functional verificati...

  13. Functional analysis of the Escherichia coli genome for members of the alpha/beta hydrolase family.

    Science.gov (United States)

    Zhang, L; Godzik, A; Skolnick, J; Fetrow, J S

    1998-01-01

    Database-searching methods based on sequence similarity have become the most commonly used tools for characterizing newly sequenced proteins. Due to the often underestimated functional diversity in protein families and superfamilies, however, it is difficult to make the characterization specific and accurate. In this work, we have extended a method for active-site identification from predicted protein structures. The structural conservation and variation of the active sites of the alpha/beta hydrolases with known structures were studied. The similarities were incorporated into a three-dimensional motif that specifies essential requirements for the enzymatic functions. A threading algorithm was used to align 651 Escherichia coli open reading frames (ORFs) to one of the members of the alpha/beta hydrolase fold family. These ORFs were then screened according to our three-dimensional motif and with an extra requirement that demands conservation of the key active-site residues among the proteins that bear significant sequence similarity to the ORFs. 17 ORFs from E. coli were predicted to have hydrolase activity and their putative active-site residues were identified. Most were in agreement with the experiments and results of other database-searching methods. The study further suggests that YHET_ECOLI, a hypothetical protein classified as a member of the UPF0017 family (an uncharacterized protein family), bears all the hallmarks of the alpha/beta hydrolase family. The novel feature of our method is that it uses three-dimensional structural information for function prediction. The results demonstrate the importance and necessity of such a method to fill the gap between sequence alignment and function prediction; furthermore, the method provides a way to verify the structure predictions, which enables an expansion of the applicable scope of the threading algorithms.

  14. Phenotypic assessment of THC discriminative stimulus properties in fatty acid amide hydrolase knockout and wildtype mice

    OpenAIRE

    Walentiny, D. Matthew; Vann, Robert E.; Wiley, Jenny L.

    2015-01-01

    A number of studies have examined the ability of the endogenous cannabinoid anandamide to elicit Δ9 -tetrahydrocannabinol (THC)-like subjective effects, as modeled through the THC discrimination paradigm. In the present study, we compared transgenic mice lacking fatty acid amide hydrolase (FAAH), the enzyme primarily responsible for anandamide catabolism, to wildtype counterparts in a THC discrimination procedure. THC (5.6 mg/kg) served as a discriminative stimulus in both genotypes, with sim...

  15. Characterization of an epoxide hydrolase from the Florida red tide dinoflagellate, Karenia brevis.

    Science.gov (United States)

    Sun, Pengfei; Leeson, Cristian; Zhi, Xiaoduo; Leng, Fenfei; Pierce, Richard H; Henry, Michael S; Rein, Kathleen S

    2016-02-01

    Epoxide hydrolases (EH, EC 3.3.2.3) have been proposed to be key enzymes in the biosynthesis of polyether (PE) ladder compounds such as the brevetoxins which are produced by the dinoflagellate Karenia brevis. These enzymes have the potential to catalyze kinetically disfavored endo-tet cyclization reactions. Data mining of K. brevis transcriptome libraries revealed two classes of epoxide hydrolases: microsomal and leukotriene A4 (LTA4) hydrolases. A microsomal EH was cloned and expressed for characterization. The enzyme is a monomeric protein with molecular weight 44kDa. Kinetic parameters were evaluated using a variety of epoxide substrates to assess substrate selectivity and enantioselectivity, as well as its potential to catalyze the critical endo-tet cyclization of epoxy alcohols. Monitoring of EH activity in high and low toxin producing cultures of K. brevis over a three week period showed consistently higher activity in the high toxin producing culture implicating the involvement of one or more EH in brevetoxin biosynthesis. Copyright © 2015 Elsevier Ltd. All rights reserved.

  16. Purification, crystallization and preliminary crystallographic studies of plant S-adenosyl-l-homocysteine hydrolase (Lupinus luteus)

    International Nuclear Information System (INIS)

    Brzezinski, Krzysztof; Bujacz, Grzegorz; Jaskolski, Mariusz

    2008-01-01

    Single crystals of recombinant S-adenosyl-l-homocysteine hydrolase from L. luteus in complex with adenosine diffract X-rays to 1.17 Å resolution at 100 K. The crystals are tetragonal, space group P4 3 2 1 2, and contain one copy of the dimeric enzyme in the asymmetric unit. By degrading S-adenosyl-l-homocysteine, which is a byproduct of S-adenosyl-l-methionine-dependent methylation reactions, S-adenosyl-l-homocysteine hydrolase (SAHase) acts as a regulator of cellular methylation processes. S-Adenosyl-l-homocysteine hydrolase from the leguminose plant yellow lupin (Lupinus luteus), LlSAHase, which is composed of 485 amino acids and has a molecular weight of 55 kDa, has been cloned, expressed in Escherichia coli and purified. Crystals of LlSAHase in complex with adenosine were obtained by the hanging-drop vapour-diffusion method using 20%(w/v) PEG 4000 and 10%(v/v) 2-propanol as precipitants in 0.1 M Tris–HCl buffer pH 8.0. The crystals were tetragonal, space group P4 3 2 1 2, with unit-cell parameters a = 122.4, c = 126.5 Å and contained two protein molecules in the asymmetric unit, corresponding to the functional dimeric form of the enzyme. Atomic resolution (1.17 Å) X-ray diffraction data have been collected using synchrotron radiation

  17. Structure of HsaD, a steroid-degrading hydrolase, from Mycobacterium tuberculosis

    International Nuclear Information System (INIS)

    Lack, Nathan; Lowe, Edward D.; Liu, Jie; Eltis, Lindsay D.; Noble, Martin E. M.; Sim, Edith; Westwood, Isaac M.

    2007-01-01

    The structure of HsaD, a carbon–carbon bond serine hydrolase involved in steroid catabolism that is critical for the survival of M. tuberculosis inside human macrophages, has been solved by X-ray crystallography. Data were collected at the Diamond Light Source in Oxfordshire, England: this paper describes one of the first structures determined at the new synchrotron. Tuberculosis is a major cause of death worldwide. Understanding of the pathogenicity of Mycobacterium tuberculosis has been advanced by gene analysis and has led to the identification of genes that are important for intracellular survival in macrophages. One of these genes encodes HsaD, a meta-cleavage product (MCP) hydrolase that catalyzes the hydrolytic cleavage of a carbon–carbon bond in cholesterol metabolism. This paper describes the production of HsaD as a recombinant protein and, following crystallization, the determination of its three-dimensional structure to 2.35 Å resolution by X-ray crystallography at the Diamond Light Source in Oxfordshire, England. To the authors’ knowledge, this study constitutes the first report of a structure determined at the new synchrotron facility. The volume of the active-site cleft of the HsaD enzyme is more than double the corresponding active-site volumes of related MCP hydrolases involved in the catabolism of aromatic compounds, consistent with the specificity of HsaD for steroids such as cholesterol. Knowledge of the structure of the enzyme facilitates the design of inhibitors

  18. Structure of a Trypanosoma brucei α/β-hydrolase fold protein with unknown function

    International Nuclear Information System (INIS)

    Merritt, Ethan A.; Holmes, Margaret; Buckner, Frederick S.; Van Voorhis, Wesley C.; Quartly, Erin; Phizicky, Eric M.; Lauricella, Angela; Luft, Joseph; DeTitta, George; Neely, Helen; Zucker, Frank; Hol, Wim G. J.

    2008-01-01

    T. brucei gene Tb10.6k15.0140 codes for an α/β-hydrolase fold protein of unknown function. The 2.2 Å crystal structure shows that members of this sequence family retain a conserved Ser residue at the expected site of a catalytic nucleophile, but that trypanosomatid sequences lack structural homologs for the other expected residues of the catalytic triad. The structure of a structural genomics target protein, Tbru020260AAA from Trypanosoma brucei, has been determined to a resolution of 2.2 Å using multiple-wavelength anomalous diffraction at the Se K edge. This protein belongs to Pfam sequence family PF08538 and is only distantly related to previously studied members of the α/β-hydrolase fold family. Structural superposition onto representative α/β-hydrolase fold proteins of known function indicates that a possible catalytic nucleophile, Ser116 in the T. brucei protein, lies at the expected location. However, the present structure and by extension the other trypanosomatid members of this sequence family have neither sequence nor structural similarity at the location of other active-site residues typical for proteins with this fold. Together with the presence of an additional domain between strands β6 and β7 that is conserved in trypanosomatid genomes, this suggests that the function of these homologs has diverged from other members of the fold family

  19. Brucella abortus choloylglycine hydrolase affects cell envelope composition and host cell internalization.

    Directory of Open Access Journals (Sweden)

    María Inés Marchesini

    Full Text Available Choloylglycine hydrolase (CGH, E.C. 3.5.1.24 is a conjugated bile salt hydrolase that catalyses the hydrolysis of the amide bond in conjugated bile acids. Bile salt hydrolases are expressed by gastrointestinal bacteria, and they presumably decrease the toxicity of host's conjugated bile salts. Brucella species are the causative agents of brucellosis, a disease affecting livestock and humans. CGH confers Brucella the ability to deconjugate and resist the antimicrobial action of bile salts, contributing to the establishment of a successful infection through the oral route in mice. Additionally, cgh-deletion mutant was also attenuated in intraperitoneally inoculated mice, which suggests that CGH may play a role during systemic infection other than hydrolyzing conjugated bile acids. To understand the role CGH plays in B. abortus virulence, we infected phagocytic and epithelial cells with a cgh-deletion mutant (Δcgh and found that it is defective in the internalization process. This defect along with the increased resistance of Δcgh to the antimicrobial action of polymyxin B, prompted an analysis of the cell envelope of this mutant. Two-dimensional electrophoretic profiles of Δcgh cell envelope-associated proteins showed an altered expression of Omp2b and different members of the Omp25/31 family. These results were confirmed by Western blot analysis with monoclonal antibodies. Altogether, the results indicate that Brucella CGH not only participates in deconjugation of bile salts but also affects overall membrane composition and host cell internalization.

  20. Purification, crystallization and preliminary crystallographic studies of plant S-adenosyl-l-homocysteine hydrolase (Lupinus luteus)

    Energy Technology Data Exchange (ETDEWEB)

    Brzezinski, Krzysztof [Center for Biocrystallographic Research, Institute of Bioorganic Chemistry, Polish Academy of Sciences, Poznan (Poland); Department of Crystallography, Faculty of Chemistry, A. Mickiewicz University, Poznan (Poland); Bujacz, Grzegorz [Center for Biocrystallographic Research, Institute of Bioorganic Chemistry, Polish Academy of Sciences, Poznan (Poland); Faculty of Food Chemistry and Biotechnology, Technical University of Lodz (Poland); Jaskolski, Mariusz, E-mail: mariuszj@amu.edu.pl [Center for Biocrystallographic Research, Institute of Bioorganic Chemistry, Polish Academy of Sciences, Poznan (Poland); Department of Crystallography, Faculty of Chemistry, A. Mickiewicz University, Poznan (Poland)

    2008-07-01

    Single crystals of recombinant S-adenosyl-l-homocysteine hydrolase from L. luteus in complex with adenosine diffract X-rays to 1.17 Å resolution at 100 K. The crystals are tetragonal, space group P4{sub 3}2{sub 1}2, and contain one copy of the dimeric enzyme in the asymmetric unit. By degrading S-adenosyl-l-homocysteine, which is a byproduct of S-adenosyl-l-methionine-dependent methylation reactions, S-adenosyl-l-homocysteine hydrolase (SAHase) acts as a regulator of cellular methylation processes. S-Adenosyl-l-homocysteine hydrolase from the leguminose plant yellow lupin (Lupinus luteus), LlSAHase, which is composed of 485 amino acids and has a molecular weight of 55 kDa, has been cloned, expressed in Escherichia coli and purified. Crystals of LlSAHase in complex with adenosine were obtained by the hanging-drop vapour-diffusion method using 20%(w/v) PEG 4000 and 10%(v/v) 2-propanol as precipitants in 0.1 M Tris–HCl buffer pH 8.0. The crystals were tetragonal, space group P4{sub 3}2{sub 1}2, with unit-cell parameters a = 122.4, c = 126.5 Å and contained two protein molecules in the asymmetric unit, corresponding to the functional dimeric form of the enzyme. Atomic resolution (1.17 Å) X-ray diffraction data have been collected using synchrotron radiation.

  1. ClbS Is a Cyclopropane Hydrolase That Confers Colibactin Resistance.

    Science.gov (United States)

    Tripathi, Prabhanshu; Shine, Emilee E; Healy, Alan R; Kim, Chung Sub; Herzon, Seth B; Bruner, Steven D; Crawford, Jason M

    2017-12-13

    Certain commensal Escherichia coli contain the clb biosynthetic gene cluster that codes for small molecule prodrugs known as precolibactins. Precolibactins are converted to colibactins by N-deacylation; the latter are postulated to be genotoxic and to contribute to colorectal cancer formation. Though advances toward elucidating (pre)colibactin biosynthesis have been made, the functions and mechanisms of several clb gene products remain poorly understood. Here we report the 2.1 Å X-ray structure and molecular function of ClbS, a gene product that confers resistance to colibactin toxicity in host bacteria and which has been shown to be important for bacterial viability. The structure harbors a potential colibactin binding site and shares similarity to known hydrolases. In vitro studies using a synthetic colibactin analog and ClbS or an active site residue mutant reveal cyclopropane hydrolase activity that converts the electrophilic cyclopropane of the colibactins into an innocuous hydrolysis product. As the cyclopropane has been shown to be essential for genotoxic effects in vitro, this ClbS-catalyzed ring-opening provides a means for the bacteria to circumvent self-induced genotoxicity. Our study provides a molecular-level view of the first reported cyclopropane hydrolase and support for a specific mechanistic role of this enzyme in colibactin resistance.

  2. Regulation of catalytic behaviour of hydrolases through interactions with functionalized carbon-based nanomaterials

    International Nuclear Information System (INIS)

    Pavlidis, Ioannis V.; Vorhaben, Torge; Gournis, Dimitrios; Papadopoulos, George K.; Bornscheuer, Uwe T.; Stamatis, Haralambos

    2012-01-01

    The interaction of enzymes with carbon-based nanomaterials (CBNs) is crucial for the function of biomolecules and therefore for the design and development of effective nanobiocatalytic systems. In this study, the effect of functionalized CBNs, such as graphene oxide (GO) and multi-wall carbon nanotubes (CNTs), on the catalytic behaviour of various hydrolases of biotechnological interest was monitored and the interactions between CBNs and proteins were investigated. The enzyme–nanomaterial interactions significantly affect the catalytic behaviour of enzymes, resulting in an increase up to 60 % of the catalytic efficiency of lipases and a decrease up to 30 % of the esterase. Moreover, the use of CNTs and GO derivatives, especially those that are amine-functionalized, led to increased thermal stability of most the hydrolases tested. Fluorescence and circular dichroism studies indicated that the altered catalytic behaviour of enzymes in the presence of CBNs arises from specific enzyme–nanomaterial interactions, which can lead to significant conformational changes. In the case of lipases, the conformational changes led to a more active and rigid structure, while in the case of esterases this led to destabilization and unfolding. Kinetic and spectroscopic studies indicated that the extent of the interactions between CBNs and hydrolases can be mainly controlled by the functionalization of nanomaterials than by their geometry.

  3. Regulation of catalytic behaviour of hydrolases through interactions with functionalized carbon-based nanomaterials

    Energy Technology Data Exchange (ETDEWEB)

    Pavlidis, Ioannis V. [University of Ioannina, Laboratory of Biotechnology, Department of Biological Applications and Technologies (Greece); Vorhaben, Torge [Institute of Biochemistry, Greifswald University, Department of Biotechnology and Enzyme Catalysis (Germany); Gournis, Dimitrios [University of Ioannina, Department of Materials Science and Engineering (Greece); Papadopoulos, George K. [Epirus Institute of Technology, Laboratory of Biochemistry and Biophysics, Faculty of Agricultural Technology (Greece); Bornscheuer, Uwe T. [Institute of Biochemistry, Greifswald University, Department of Biotechnology and Enzyme Catalysis (Germany); Stamatis, Haralambos, E-mail: hstamati@cc.uoi.gr [University of Ioannina, Laboratory of Biotechnology, Department of Biological Applications and Technologies (Greece)

    2012-05-15

    The interaction of enzymes with carbon-based nanomaterials (CBNs) is crucial for the function of biomolecules and therefore for the design and development of effective nanobiocatalytic systems. In this study, the effect of functionalized CBNs, such as graphene oxide (GO) and multi-wall carbon nanotubes (CNTs), on the catalytic behaviour of various hydrolases of biotechnological interest was monitored and the interactions between CBNs and proteins were investigated. The enzyme-nanomaterial interactions significantly affect the catalytic behaviour of enzymes, resulting in an increase up to 60 % of the catalytic efficiency of lipases and a decrease up to 30 % of the esterase. Moreover, the use of CNTs and GO derivatives, especially those that are amine-functionalized, led to increased thermal stability of most the hydrolases tested. Fluorescence and circular dichroism studies indicated that the altered catalytic behaviour of enzymes in the presence of CBNs arises from specific enzyme-nanomaterial interactions, which can lead to significant conformational changes. In the case of lipases, the conformational changes led to a more active and rigid structure, while in the case of esterases this led to destabilization and unfolding. Kinetic and spectroscopic studies indicated that the extent of the interactions between CBNs and hydrolases can be mainly controlled by the functionalization of nanomaterials than by their geometry.

  4. Lysophosphatidic acids are new substrates for the phosphatase domain of soluble epoxide hydrolase.

    Science.gov (United States)

    Oguro, Ami; Imaoka, Susumu

    2012-03-01

    Soluble epoxide hydrolase (sEH) is a bifunctional enzyme that has a C-terminus epoxide hydrolase domain and an N-terminus phosphatase domain. The endogenous substrates of epoxide hydrolase are known to be epoxyeicosatrienoic acids, but the endogenous substrates of the phosphatase activity are not well understood. In this study, to explore the substrates of sEH, we investigated the inhibition of the phosphatase activity of sEH toward 4-methylumbelliferyl phosphate by using lecithin and its hydrolyzed products. Although lecithin itself did not inhibit the phosphatase activity, the hydrolyzed lecithin significantly inhibited it, suggesting that lysophospholipid or fatty acid can inhibit it. Next, we investigated the inhibition of phosphatase activity by lysophosphatidyl choline, palmitoyl lysophosphatidic acid, monopalmitoyl glycerol, and palmitic acid. Palmitoyl lysophosphatidic acid and fatty acid efficiently inhibited phosphatase activity, suggesting that lysophosphatidic acids (LPAs) are substrates for the phosphatase activity of sEH. As expected, palmitoyl, stearoyl, oleoyl, and arachidonoyl LPAs were efficiently dephosphorylated by sEH (Km, 3-7 μM; Vmax, 150-193 nmol/min/mg). These results suggest that LPAs are substrates of sEH, which may regulate physiological functions of cells via their metabolism.

  5. Structure of the Cyanuric Acid Hydrolase TrzD Reveals Product Exit Channel.

    Science.gov (United States)

    Bera, Asim K; Aukema, Kelly G; Elias, Mikael; Wackett, Lawrence P

    2017-03-27

    Cyanuric acid hydrolases are of industrial importance because of their use in aquatic recreational facilities to remove cyanuric acid, a stabilizer for the chlorine. Degradation of excess cyanuric acid is necessary to maintain chlorine disinfection in the waters. Cyanuric acid hydrolase opens the cyanuric acid ring hydrolytically and subsequent decarboxylation produces carbon dioxide and biuret. In the present study, we report the X-ray structure of TrzD, a cyanuric acid hydrolase from Acidovorax citrulli. The crystal structure at 2.19 Å resolution shows a large displacement of the catalytic lysine (Lys163) in domain 2 away from the active site core, whereas the two other active site lysines from the two other domains are not able to move. The lysine displacement is proposed here to open up a channel for product release. Consistent with that, the structure also showed two molecules of the co-product, carbon dioxide, one in the active site and another trapped in the proposed exit channel. Previous data indicated that the domain 2 lysine residue plays a role in activating an adjacent serine residue carrying out nucleophilic attack, opening the cyanuric acid ring, and the mobile lysine guides products through the exit channel.

  6. Reversible thermal denaturation of immobilized rhodanese

    International Nuclear Information System (INIS)

    Horowitz, P.; Bowman, S.

    1987-01-01

    For the first time, the enzyme rhodanese had been refolded after thermal denaturation. This was previously not possible because of the strong tendency for the soluble enzyme to aggregate at temperatures above 37 degrees C. The present work used rhodanese that was covalently coupled to a solid support under conditions that were found to preserve enzyme activity. Rhodanese was immobilized using an N-hydroxymalonimidyl derivative of Sepharose containing a 6-carbon spacer. The number of immobilized competent active sites was measured by using [ 35 S]SO 3 (2-) to form an active site persulfide that is the obligatory catalytic intermediate. Soluble enzyme was irreversibly inactivated in 10 min at 52 degrees C. The immobilized enzyme regained at least 30% of its original activity even after boiling for 20 min. The immobilized enzyme had a Km and Vmax that were each approximately 3 times higher than the corresponding values for the native enzyme. After preincubation at high temperatures, progress curves for the immobilized enzyme showed induction periods of up to 5 min before attaining apparently linear steady states. The pH dependence of the activity was the same for both the soluble and the immobilized enzyme. These results indicate significant stabilization of rhodanese after immobilization, and instabilities caused by adventitious solution components are not the sole reasons for irreversibility of thermal denaturation seen with the soluble enzyme. The results are consistent with models for rhodanese that invoke protein association as a major cause of inactivation of the enzyme. Furthermore, the induction period in the progress curves is consistent with studies which show that rhodanese refolding proceeds through intermediate states

  7. Characteristics of Immobilized Urease on Grafted Alginate Bead Systems

    Directory of Open Access Journals (Sweden)

    Enas N. Danial

    2015-04-01

    Full Text Available This study evaluated the biological importance of immobilized urease enzyme over the free urease. The support material used for urease immobilization was alginate. Generally, the immobilization of urease in alginate gel showed a marked increase in Km and Vmax. However, the immobilized urease showed higher thermal stability than that of free enzyme. The rate of thermal inactivation of the immobilized enzyme decreased due to entrapment in gel matrix. Also, the activity of the immobilized urease was more stable in retention than that of the free enzyme during the storage in solution, although the activity of the immobilized enzyme was lower in comparison with the free enzyme. A stable immobilized system and long storage life are convenient for applications that would not be feasible with a soluble enzyme system. These results highlighted the technical and biochemical benefits of immobilized urease over the free enzyme.

  8. STUDY OF CLINICAL PROFILE AND OUTCOME OF ORGANOPHOSPHORUS POISONING IN RELATION TO PSEUDOCHOLINESTERASE LEVEL

    Directory of Open Access Journals (Sweden)

    Rajyalakshmi

    2017-11-01

    Full Text Available BACKGROUND The state of Andhra Pradesh, particularly the coastal districts are an area of intensive agricultural production. Pesticide use is high, and the state has one of the highest reported rates of pesticide poisoning in India. The resources for treating this number of cases in government hospitals are limited and likely to have an impact on patient outcome. The present study was carried out in one such hospital of the state. Amongst these pesticides, insecticides constitute an important group, and organophosphorus compounds are possibly the insecticides widely used, all over the world. MATERIALS AND METHODS Hundred patients of pesticide poisoning admitted into the medical ward of Government General Hospital, Kakinada during the period of August 2010 to July 2014 were studied. Detailed history was taken in each case from patient and attendants. A meticulous physical examination was done on each of them at the time of admission. The diagnosis of poisoning was suspected from the characteristic garlic and kerosene like odour, characteristic signs and symptoms of poisoning and corroborative evidence collected in the form of packets or containers obtained from the site by family members or bystanders. RESULTS Out of the 14 patients who died, 11 died due to organophosphate poisoning, 2 patients died due to organochlorine poisoning and 1 patient died due to herbicide poisoning. Out of the 11 patients who expired due to organophosphate poisoning, 10 patients had pseudocholinesterase value ≤1 unit/mL. The remaining one (1 patient who died, had a pseudocholinesterase value of 2.2 units/mL. Of the 11 patients who died due to organophosphate poisoning, Monocrotophos recorded highest number of deaths (6 cases, followed by dimethoate, which was responsible for 2 deaths. Methyl parathion, Profenophos and Chlorpyriphos caused 1 death each. An organochlorine compound, Endosulfan caused 2 deaths. Paraquat, a herbicide was responsible for 1 death

  9. [Research on rapid and quantitative detection method for organophosphorus pesticide residue].

    Science.gov (United States)

    Sun, Yuan-Xin; Chen, Bing-Tai; Yi, Sen; Sun, Ming

    2014-05-01

    The methods of physical-chemical inspection is adopted in the traditional pesticide residue detection, which require a lot of pretreatment processes, are time-consuming and complicated. In the present study, the authors take chlorpyrifos applied widely in the present agricultural field as the research object and propose a rapid and quantitative detection method for organophosphorus pesticide residues. At first, according to the chemical characteristics of chlorpyrifos and comprehensive chromogenic effect of several colorimetric reagents and secondary pollution, the pretreatment of the scheme of chromogenic reaction of chlorpyrifos with resorcin in a weak alkaline environment was determined. Secondly, by analyzing Uv-Vis spectrum data of chlorpyrifos samples whose content were between 0. 5 and 400 mg kg-1, it was confirmed that the characteristic information after the color reaction mainly was concentrated among 360 approximately 400 nm. Thirdly, the full spectrum forecasting model was established based on the partial least squares, whose correlation coefficient of calibration was 0. 999 6, correlation coefficient of prediction reached 0. 995 6, standard deviation of calibration (RMSEC) was 2. 814 7 mg kg-1, and standard deviation of verification (RMSEP) was 8. 012 4 mg kg-1. Fourthly, the wavelengths whose center wavelength is 400 nm was extracted as characteristic region to build a forecasting model, whose correlation coefficient of calibration was 0. 999 6, correlation coefficient of prediction reached 0. 999 3, standard deviation of calibration (RMSEC) was 2. 566 7 mg kg-1 , standard deviation of verification (RMSEP) was 4. 886 6 mg kg-1, respectively. At last, by analyzing the near infrared spectrum data of chlorpyrifos samples with contents between 0. 5 and 16 mg kg-1, the authors found that although the characteristics of the chromogenic functional group are not obvious, the change of absorption peaks of resorcin itself in the neighborhood of 5 200 cm

  10. Generation and characterization of epoxide hydrolase 3 (EPHX3-deficient mice.

    Directory of Open Access Journals (Sweden)

    Samantha L Hoopes

    Full Text Available Cytochrome P450 (CYP epoxygenases metabolize arachidonic acid into epoxyeicosatrienoic acids (EETs, which play an important role in blood pressure regulation, protection against ischemia-reperfusion injury, angiogenesis, and inflammation. Epoxide hydrolases metabolize EETs to their corresponding diols (dihydroxyeicosatrienoic acids; DHETs which are biologically less active. Microsomal epoxide hydrolase (EPHX1, mEH and soluble epoxide hydrolase (EPHX2, sEH were identified >30 years ago and are capable of hydrolyzing EETs to DHETs. A novel epoxide hydrolase, EPHX3, was recently identified by sequence homology and also exhibits epoxide hydrolase activity in vitro with a substrate preference for 9,10-epoxyoctadecamonoenoic acid (EpOME and 11,12-EET. EPHX3 is highly expressed in the skin, lung, stomach, esophagus, and tongue; however, its endogenous function is unknown. Therefore, we investigated the impact of genetic disruption of Ephx3 on fatty acid epoxide hydrolysis and EET-related physiology in mice. Ephx3-/- mice were generated by excising the promoter and first four exons of the Ephx3 gene using Cre-LoxP methodology. LC-MS/MS analysis of Ephx3-/- heart, lung, and skin lysates revealed no differences in endogenous epoxide:diol ratios compared to wild type (WT. Ephx3-/- mice also exhibited no change in plasma levels of fatty acid epoxides and diols relative to WT. Incubations of cytosolic and microsomal fractions prepared from Ephx3-/- and WT stomach, lung, and skin with synthetic 8,9-EET, 11,12-EET, and 9,10-EpOME revealed no significant differences in rates of fatty acid diol formation between the genotypes. Ephx3-/- hearts had similar functional recovery compared to WT hearts following ischemia/reperfusion injury. Following intranasal lipopolysaccharide (LPS exposure, Ephx3-/- mice were not different from WT in terms of lung histology, bronchoalveolar lavage fluid cell counts, or fatty acid epoxide and diol levels. We conclude that genetic

  11. Excess Weapons Plutonium Immobilization in Russia

    International Nuclear Information System (INIS)

    Jardine, L.; Borisov, G.B.

    2000-01-01

    The joint goal of the Russian work is to establish a full-scale plutonium immobilization facility at a Russian industrial site by 2005. To achieve this requires that the necessary engineering and technical basis be developed in these Russian projects and the needed Russian approvals be obtained to conduct industrial-scale immobilization of plutonium-containing materials at a Russian industrial site by the 2005 date. This meeting and future work will provide the basis for joint decisions. Supporting R and D projects are being carried out at Russian Institutes that directly support the technical needs of Russian industrial sites to immobilize plutonium-containing materials. Special R and D on plutonium materials is also being carried out to support excess weapons disposition in Russia and the US, including nonproliferation studies of plutonium recovery from immobilization forms and accelerated radiation damage studies of the US-specified plutonium ceramic for immobilizing plutonium. This intriguing and extraordinary cooperation on certain aspects of the weapons plutonium problem is now progressing well and much work with plutonium has been completed in the past two years. Because much excellent and unique scientific and engineering technical work has now been completed in Russia in many aspects of plutonium immobilization, this meeting in St. Petersburg was both timely and necessary to summarize, review, and discuss these efforts among those who performed the actual work. The results of this meeting will help the US and Russia jointly define the future direction of the Russian plutonium immobilization program, and make it an even stronger and more integrated Russian program. The two objectives for the meeting were to: (1) Bring together the Russian organizations, experts, and managers performing the work into one place for four days to review and discuss their work with each other; and (2) Publish a meeting summary and a proceedings to compile reports of all the

  12. Gastric Lavage in Acute Organophosphorus Pesticide poisoning (GLAOP – a randomised controlled trial of multiple vs. single gastric lavage in unselected acute organophosphorus pesticide poisoning

    Directory of Open Access Journals (Sweden)

    Cao YuPing

    2006-10-01

    Full Text Available Abstract Background Organophosphorus (OP pesticide poisoning is the most common form of pesticide poisoning in many Asian countries. Guidelines in western countries for management of poisoning indicate that gastric lavage should be performed only if two criteria are met: within one hour of poison ingestion and substantial ingested amount. But the evidence on which these guidelines are based is from medicine overdoses in developed countries and may be irrelevant to OP poisoning in Asia. Chinese clinical experience suggests that OP remains in the stomach for several hours or even days after ingestion. Thus, there may be reasons for doing single or multiple gastric lavages for OP poisoning. There have been no randomised controlled trials (RCTs to assess this practice of multiple lavages. Since it is currently standard therapy in China, we cannot perform a RCT of no lavage vs. a single lavage vs. multiple lavages. We will compare a single gastric lavage with three gastric lavages as the first stage to assess the role of gastric lavage in OP poisoning. Methods/Design We have designed an RCT assessing the effectiveness of multiple gastric lavages in adult OP self-poisoning patients admitted to three Chinese hospitals within 12 hrs of ingestion. Patients will be randomised to standard treatment plus either a single gastric lavage on admission or three gastric lavages at four hour intervals. The primary outcome is in-hospital mortality. Analysis will be on an intention-to-treat basis. On the basis of the historical incidence of OP at the study sites, we expect to enroll 908 patients over three years. This projected sample size provides sufficient power to evaluate the death rate; and a variety of other exposure and outcome variables, including particular OPs and ingestion time. Changes of OP level will be analyzed in order to provide some toxic kinetic data. Discussion the GLAOP study is a novel, prospective cohort study that will explore to the toxic

  13. Disposition of surplus fissile materials via immobilization

    International Nuclear Information System (INIS)

    Gray, L.W.; Kan, T.; Sutcliffe, W.G.; McKibben, J.M.; Danker, W.

    1995-01-01

    In the Cold War aftermath, the US and Russia have agreed to large reductions in nuclear weapons. To aid in the selection of long-term management options, the USDOE has undertaken a multifaceted study to select options for storage and disposition of surplus plutonium (Pu). One disposition alternative being considered is immobilization. Immobilization is a process in which surplus Pu would be embedded in a suitable material to produce an appropriate form for ultimate disposal. To arrive at an appropriate form, we first reviewed published information on HLW immobilization technologies to identify forms to be prescreened. Surviving forms were screened using multi-attribute utility analysis to determine promising technologies for Pu immobilization. We further evaluated the most promising immobilization families to identify and seek solutions for chemical, chemical engineering, environmental, safety, and health problems; these problems remain to be solved before we can make technical decisions about the viability of using the forms for long-term disposition of Pu. All data, analyses, and reports are being provided to the DOE Office of Fissile Materials Disposition to support the Record of Decision that is anticipated in Summer of 1996

  14. Production of cellulase from immobilized Trichoderma reesei

    International Nuclear Information System (INIS)

    Kasai, Noboru; Tamada, Masao; Kumakura, Minoru

    1989-05-01

    This report completed the results that obtained on the study of the enzyme activity in the culture of immobilized Trichoderma reesei cells in flask scale (100ml) and bench scale (30l). In the flask scale culture, the batch and repeated batch culture were carried out, and in the bench scale culture, the batch, repeated batch and continuous culture were done by using a culture equipment that is an unit process of the bench scale test plant for saccharification of cellulosic wastes. The enzyme activity of the immobilized cells was higher than that of the intact cells in the flask scale culture and it was confirmed that the enzyme activity was not decreased on the repeated batch culture of six times even. In the bench scale culture, it was found that a optimum culture condition of the immobilized cells was not different from that of the free cells and the immobilized cells gave the enzyme solution with a high enzyme activity in the culture condition of 450rpm stirring speed and air supply of 0.1v/v/m above. The technique of the repeated batch and continuous culture for long times in bench scale without contamination was established. The enzyme activity of the immobilized cells in continuous culture became to be 85 % to that in batch culture and it was found that the enzyme solution with high enzyme activity was continuously obtained in the continuous culture for long times. (author)

  15. Haloalkane hydrolysis with an immobilized haloalkane dehalogenase.

    Science.gov (United States)

    Dravis, B C; Swanson, P E; Russell, A J

    2001-11-20

    Haloalkane dehalogenase from Rhodococcus rhodochrous was covalently immobilized onto a polyethyleneimine impregnated gamma-alumina support. The dehalogenating enzyme was found to retain greater than 40% of its original activity after immobilization, displaying an optimal loading (max. activity/supported protein) of 70 to 75 mg/g with an apparent maximum (max. protein/support) of 156 mg/g. The substrate, 1,2,3-trichloropropane, was found to favorably partition (adsorb) onto the inorganic alumina carrier (10 to 20 mg/g), thereby increasing the local reactant concentration with respect to the catalyst's environment, whereas the product, 2,3-dichloropropan-1-ol, demonstrated no affinity. Additionally, the inorganic alumina support exhibited no adverse effects because of solvent/component incompatibilities or deterioration due to pH variance (pH 7.0 to 10.5). As a result of the large surface area to volume ratio of the support matrix and the accessibility of the bound protein, the immobilized biocatalyst was not subject to internal mass transfer limitations. External diffusional restrictions could be eliminated with simple agitation (mixing speed: 50 rpm; flux: 4.22 cm/min). The pH-dependence of the immobilized dehalogenase was essentially the same as that for the native enzyme. Finally, both the thermostability and resistance toward inactivation by organic solvent were improved by more than an order of magnitude after immobilization. Copyright 2001 John Wiley & Sons, Inc.

  16. Organophosphorus flame retardants in mangrove sediments from the Pearl River Estuary, South China.

    Science.gov (United States)

    Hu, Yong-Xia; Sun, Yu-Xin; Li, Xiao; Xu, Wei-Hai; Zhang, Ying; Luo, Xiao-Jun; Dai, Shou-Hui; Xu, Xiang-Rong; Mai, Bi-Xian

    2017-08-01

    Forty-eight surface sediments were collected from three mangrove wetlands in the Pearl River Estuary (PRE) of South China to investigate the distribution of organophosphorus flame retardants (OPFRs) and the relationship between OPFRs and microbial community structure determined by phospholipid fatty acid. Concentrations of ΣOPFRs in mangrove sediments of the PRE ranged from 13.2 to 377.1 ng g -1 dry weight. Levels of ΣOPFRs in mangrove sediments from Shenzhen and Guangzhou were significantly higher than those from Zhuhai, indicating that OPFRs were linked to industrialization and urbanization. Tris(chloropropyl)phosphate was the predominant profile of OPFRs in mangrove sediments from Shenzhen (38.9%) and Guangzhou (35.0%), while the composition profile of OPFRs in mangrove sediments from Zhuhai was dominated by tris(2-chloroethyl) phosphate (25.5%). The mass inventories of OPFRs in the mangrove sediments of Guangzhou, Zhuhai and Shenzhen were 439.5, 133.5 and 662.3 ng cm -2 , respectively. Redundancy analysis revealed that OPFRs induced a shift in the structure of mangrove sediment microbial community and the variations were significantly correlated with tris(1,3-dichloro-2-propyl)phosphate and tris(2-butoxyethyl) phosphate. Copyright © 2017 Elsevier Ltd. All rights reserved.

  17. Sensitive spectrophotometric methods for determination of some organophosphorus pesticides in vegetable samples

    Directory of Open Access Journals (Sweden)

    MAGDA A. AKL

    2010-03-01

    Full Text Available Three rapid, simple, reproducible and sensitive spectrophotometric methods (A, B and C are described for the determination of two organophosphorus pesticides, (malathion and dimethoate in formulations and vegetable samples. The methods A and B involve the addition of an excess of Ce4+ into sulphuric acid medium and the determination of the unreacted oxidant by decreasing the red color of chromotrope 2R (C2R at a suitable lmax = 528 nm for method A, or a decrease in the orange pink color of rhodamine 6G (Rh6G at a suitable lmax = = 525 nm. The method C is based on the oxidation of malathion or dimethoate with the slight excess of N-bromosuccinimide (NBS and the determination of unreacted oxidant by reacting it with amaranth dye (AM in hydrochloric acid medium at a suitable lmax = 520 nm. A regression analysis of Beer-Lambert plots showed a good correlation in the concentration range of 0.1-4.2 μg mL−1. The apparent molar absorptivity, Sandell sensitivity, the detection and quantification limits were calculated. For more accurate analysis, Ringbom optimum concentration ranges are 0.25-4.0 μg mL−1. The developed methods were successfully applied to the determination of malathion, and dimethoate in their formulations and environmental vegetable samples.

  18. Partitioning of organophosphorus pesticides into phosphatidylcholine small unilamellar vesicles studied by second-derivative spectrophotometry.

    Science.gov (United States)

    Takegami, Shigehiko; Kitamura, Keisuke; Ohsugi, Mayuko; Ito, Aya; Kitade, Tatsuya

    2015-06-15

    In order to quantitatively examine the lipophilicity of the widely used organophosphorus pesticides (OPs) chlorfenvinphos (CFVP), chlorpyrifos-methyl (CPFM), diazinon (DZN), fenitrothion (FNT), fenthion (FT), isofenphos (IFP), profenofos (PFF) and pyraclofos (PCF), their partition coefficient (Kp) values between phosphatidylcholine (PC) small unilamellar vesicles (SUVs) and water (liposome-water system) were determined by second-derivative spectrophotometry. The second-derivative spectra of these OPs in the presence of PC SUV showed a bathochromic shift according to the increase in PC concentration and distinct derivative isosbestic points, demonstrating the complete elimination of the residual background signal effects that were observed in the absorption spectra. The Kp values were calculated from the second-derivative intensity change induced by addition of PC SUV and obtained with a good precision of R.S.D. below 10%. The Kp values were in the order of CPFM>FT>PFF>PCF>IFP>CFVP>FNT⩾DZN and did not show a linear correlation relationship with the reported partition coefficients obtained using an n-octanol-water system (R(2)=0.530). Also, the results quantitatively clarified the effect of chemical-group substitution in OPs on their lipophilicity. Since the partition coefficient for the liposome-water system is more effective for modeling the quantitative structure-activity relationship than that for the n-octanol-water system, the obtained results are toxicologically important for estimating the accumulation of these OPs in human cell membranes. Copyright © 2015 Elsevier B.V. All rights reserved.

  19. Susceptibility of nine organophosphorus pesticides in skimmed milk towards inoculated lactic acid bacteria and yogurt starters.

    Science.gov (United States)

    Zhou, Xin-Wei; Zhao, Xin-Huai

    2015-01-01

    Previous research has shown that fresh milk might be polluted by some organophosphorus pesticides (OPPs). In this study the dissipation of nine OPPs, namely chlorpyrifos, chlorpyrifos-methyl, diazinon, dichlorvos, fenthion, malathion, phorate, pirimiphos-methyl and trichlorphon, in skimmed milk was investigated to clarify their susceptibility towards lactic acid bacteria (LAB) and yogurt starters. Skimmed milk was spiked with nine OPPs, inoculated with five strains of LAB and two commercial yogurt starters at 42 °C for 24 and 5 h respectively and subjected to quantitative OPP analysis by gas chromatography. Degradation kinetic constants of these OPPs were calculated based on a first-order reaction model. OPP dissipation in the milk was enhanced by the inoculated strains and starters, resulting in OPP concentrations decreasing by 7.0-64.6 and 7.4-19.2% respectively. Totally, the nine OPPs were more susceptible to Lactobacillus bulgaricus, as it enhanced their degradation rate constants by 18.3-133.3%. Higher phosphatase production of the assayed stains was observed to bring about greater OPP degradation in the milk. Both LAB and yogurt starters could enhance OPP dissipation in skimmed milk, with the nine OPPs studied having different susceptibilities towards them. Phosphatase was a key factor governing OPP dissipation. The LAB of higher phosphatase production have more potential to decrease OPPs in fermented foods. © 2014 Society of Chemical Industry.

  20. A portable liquid crystal-based polarized light system for the detection of organophosphorus nerve gas

    Science.gov (United States)

    He, Feng Jie; Liu, Hui Long; Chen, Long Cong; Xiong, Xing Liang

    2018-03-01

    Liquid crystal (LC)-based sensors have the advantageous properties of being fast, sensitive, and label-free, the results of which can be accessed directly only through the naked eye. However, the inherent disadvantages possessed by LC sensors, such as relying heavily on polarizing microscopes and the difficulty to quantify, have limited the possibility of field applications. Herein, we have addressed these issues by constructing a portable polarized detection system with constant temperature control. This system is mainly composed of four parts: the LC cell, the optics unit, the automatic temperature control unit, and the image processing unit. The LC cell was based on the ordering transitions of LCs in the presence of analytes. The optics unit based on the imaging principle of LCs was designed to substitute the polarizing microscope for the real-time observation. The image processing unit is expected to quantify the concentration of analytes. The results have shown that the presented system can detect dimethyl methyl phosphonate (a stimulant for organophosphorus nerve gas) within 25 s, and the limit of detection is about 10 ppb. In all, our portable system has potential in field applications.

  1. Determination of organophosphorus pesticides using molecularly imprinted polymer solid phase extraction

    International Nuclear Information System (INIS)

    Mohd Marsin Sanagi; Syairah Salleh; Wan Aini Wan Ibrahim

    2011-01-01

    Molecularly imprinted polymer solid phase extraction (MIP-SPE) method has been developed for the determination of organophosphorus pesticides (OPPs) in water samples. The MIP was prepared by thermo-polymerization method using methacrylic acid (MAA) as functional monomer, ethylene glycol dimethacrylate (EGDMA) as crosslinker, acetonitrile as porogenic solvent and quinalphos as the template molecule. The three OPPs (diazinon, quinalphos and chloropyrifos) were selected as target analytes as they are widely used in agriculture sector. Various parameters affecting the extraction efficiency of the imprinted polymers have been evaluated to optimize the selective preconcentration of OPPs from aqueous samples. The characteristics of the MIP-SPE method were validated by high performance liquid chromatography (HPLC). The accuracy and selectivity of the MIP-SPE process developed were verified using non-imprinted polymer solid phase extraction (NIP-SPE) and a commercial C 18 -SPE was used for comparison. The recoveries of the target analytes obtained using the MIPs as the solid phase sorbent ranged from 83% to 98% (RSDs 1.05 - 1.98 %; n=3) for water sample. The developed MIP-SPE method demonstrates that it could be applied for the determination of OPPs in water samples. (author)

  2. Removal of actinides from nuclear fuel reprocessing waste solutions with bidentate organophosphorus extractants

    International Nuclear Information System (INIS)

    Schulz, W.W.; McIsaac, L.D.

    1975-08-01

    The neutral bidentate organophosphorus reagents DBDECMP (dibutyl-N,N-diethylcarbamylmethylenephosphonate) and its dihexyl analogue DHDECMP are candidate extractants for removal of actinides from certain acidic waste streams produced at the U. S. ERDA Hanford and Idaho Falls sites. Various chemical and physical properties including availability, cost, purification, alpha radiolysis, and aqueous phase solubility of DBDECMP and DHDECMP are reviewed. A conceptual flowsheet employing a 15 percent DBDECMP (or DHDECMP)--CCl 4 extractant for removal (and recovery) of Am and Pu from Hanford's Plutonium Reclamation Facility acid waste stream (CAW solution) was successfully demonstrated in laboratory-scale mixer-settler tests; this extraction scheme can be used to produce an actinide-free waste. A 30 percent DBDECMP-xylene flowsheet is being tested at the Idaho Falls site for removal of U, Np, Pu, and Am from Idaho Chemical Processing Plant first-cycle high-level raffinate to produce an actinide-free (less than 10 nCi alpha activity/gram) waste. (auth)

  3. Improvement of Some Biochemical Activities of Rats Treated with The Organophosphorus Insecticide Cytrolane Using Soyabean

    International Nuclear Information System (INIS)

    Abdel-Fattah, A.M.; Elmahdy, A.A.

    2005-01-01

    This Study aims to evaluate the role of soyabean diet in improvement of some biochemical activities of female rats received daily oral dose 0.89 mg/kg (1/10 LD 50 )of cytrolane as organophosphorus insecticide on some biochemical activities in female rats for ten consecutive days. Prior pesticide administration, female rats received soyabean at dose 58 g/kg body weight for 2 and 4 weeks. Under the effect of cytrolane administration, the results showed significant increase in serum triglycerides, total cholesterol, HDL-cholesterol and CPK mean levels. Total serum protein and progesterone levels were significantly decreased compared to the control. On the other hand, by the administration of soyabean prior cytrolane, it reduced considerably the changes produced by cytrolane on levels of serum cholesterol, triglyceride, HDL-cholesterol which decreased more or less compared to control, total protein level was within normal value. Also, serum progesterone concentration increased. Therefore, soyabean administration accelerated the normalization and improvement processes of the altered lipid profiles, protein and progesterone hormone

  4. A ratiometric fluorescent quantum dots based biosensor for organophosphorus pesticides detection by inner-filter effect.

    Science.gov (United States)

    Yan, Xu; Li, Hongxia; Han, Xiaosong; Su, Xingguang

    2015-12-15

    In this work, we develop a novel and sensitive sensor for the detection of organophosphorus pesticides based on the inner-filter effect (IFE) between gold nanoparticles (AuNPs) and ratiometric fluorescent quantum dots (RF-QDs). The RF-QDs has been designed by hybridizing two differently colored CdTe QDs, in which the red emissive QDs entrapped in the silica sphere acting as the reference signal, and the green emissive QDs covalently attached on the silica surface serving as the response signal.The fluorescence of RF-QDs could be quenched by AuNPs based on IFE. Protamine could effectively turn on the fluorescence due to the electrostatic attraction between protamine and AuNPs. Trypsin can easily hydrolyze protamine, leading to the quench of the fluorescence. Then, the fluorescence could be recovered again by the addition of parathion-methyl (PM) which could inhibit the activity of trypsin. By measuring the fluorescence of RF-QDs, the inhibition efficiency of PM to trypsin activity was evaluated. Under the optimized conditions, the inhibition efficiency was proportional to the logarithm of PM concentration in the range of 0.04-400 ng mL(-1), with a detection limit of 0.018 ng mL(-1). Furthermore, the simple and convenient method had been used for PM detection in environmental and agricultural samples with satisfactory results. Copyright © 2015 Elsevier B.V. All rights reserved.

  5. Organophosphorus pesticides effect on early stages of the axolotl Ambystoma mexicanum (Amphibia: Caudata).

    Science.gov (United States)

    Robles-Mendoza, C; García-Basilio, C; Cram-Heydrich, S; Hernández-Quiroz, M; Vanegas-Pérez, C

    2009-02-01

    Ambystoma mexicanum is an endemic salamander of Xochimilco, a wetland of the basin of Mexico valley. Nowadays, axolotl populations are decreasing due environmental stressors. Particularly, studies about organophosphorus pesticides (OPPs; i.e. chlorpyrifos and malathion) toxicity are of great importance due to their intensive use in agricultural activities in Xochimilco. Thus, the aim of this study was to evaluate under controlled conditions the toxicity of chlorpyrifos (CPF) and malathion (MLT) on embryos and larvae (stage 44 and 54) of A. mexicanum. Embryos and larvae were exposure 96h from 0.5 to 3mg CPFL(-1) and from 10 to 30mg MLTL(-1) in independent tests. Embryos at the end of this period were maintained 9d without pesticide in order to identify possible recuperation. Differences obtained in mortality, hatching success, development, morphological abnormalities, behaviour and activity, suggest that toxicity of CPF and MLT differs in embryos and larval stages. Embryos were less sensitive to OPPs acute exposure than axolotl larvae; additionally, toxicity of CPF in larval stages was greater than MLT. On the other hand, data obtained in axolotl embryos during the period of recuperation to CPF in particular as delay and inhibition of development, malformations and success of hatching, indicated that these responses turned out more sensitive than mortality. This study allowed to identify the toxicological potential of OPPs on early developmental stages of A. mexicanum and it is a valuable contribution for the future management of the axolotl wild population.

  6. Biosensors and their applications in detection of organophosphorus pesticides in the environment.

    Science.gov (United States)

    Hassani, Shokoufeh; Momtaz, Saeideh; Vakhshiteh, Faezeh; Maghsoudi, Armin Salek; Ganjali, Mohammad Reza; Norouzi, Parviz; Abdollahi, Mohammad

    2017-01-01

    This review discusses the past and recent advancements of biosensors focusing on detection of organophosphorus pesticides (OPs) due to their exceptional use during the last decades. Apart from agricultural benefits, OPs also impose adverse toxicological effects on animal and human population. Conventional approaches such as chromatographic techniques used for pesticide detection are associated with several limitations. A biosensor technology is unique due to the detection sensitivity, selectivity, remarkable performance capabilities, simplicity and on-site operation, fabrication and incorporation with nanomaterials. This study also provided specifications of the most OPs biosensors reported until today based on their transducer system. In addition, we highlighted the application of advanced complementary materials and analysis techniques in OPs detection systems. The availability of these new materials associated with new sensing techniques has led to introduction of easy-to-use analytical tools of high sensitivity and specificity in the design and construction of OPs biosensors. In this review, we elaborated the achievements in sensing systems concerning innovative nanomaterials and analytical techniques with emphasis on OPs.

  7. New Cinchona Oximes Evaluated as Reactivators of Acetylcholinesterase and Butyrylcholinesterase Inhibited by Organophosphorus Compounds

    Directory of Open Access Journals (Sweden)

    Maja Katalinić

    2017-07-01

    Full Text Available For the last six decades, researchers have been focused on finding efficient reactivators of organophosphorus compound (OP-inhibited acetylcholinesterase (AChE and butyrylcholinesterase (BChE. In this study, we have focused our research on a new oxime scaffold based on the Cinchona structure since it was proven to fit the cholinesterases active site and reversibly inhibit their activity. Three Cinchona oximes (C1, C2, and C3, derivatives of the 9-oxocinchonidine, were synthesized and investigated in reactivation of various OP-inhibited AChE and BChE. As the results showed, the tested oximes were more efficient in the reactivation of BChE and they reactivated enzyme activity to up to 70% with reactivation rates similar to known pyridinium oximes used as antidotes in medical practice today. Furthermore, the oximes showed selectivity towards binding to the BChE active site and the determined enzyme-oxime dissociation constants supported work on the future development of inhibitors in other targeted studies (e.g., in treatment of neurodegenerative disease. Also, we monitored the cytotoxic effect of Cinchona oximes on two cell lines Hep G2 and SH-SY5Y to determine the possible limits for in vivo application. The cytotoxicity results support future studies of these compounds as long as their biological activity is targeted in the lower micromolar range.

  8. Degradation of Organophosphorus and Pyrethroid Insecticides in Beverages: Implications for Risk Assessment

    Directory of Open Access Journals (Sweden)

    Samantha A. Radford

    2018-02-01

    Full Text Available Since urinary insecticide metabolites are commonly used as biomarkers of exposure, it is important that we quantify whether insecticides degrade in food and beverages in order to better perform risk assessment. This study was designed to quantify degradation of organophosphorus and pyrethroid insecticides in beverages. Purified water, white grape juice, orange juice, and red wine were fortified with 500 ng/mL diazinon, malathion, chlorpyrifos, permethrin, cyfluthrin, cypermethrin, and deltamethrin, and aliquots were extracted several times over a 15-day storage period at 2.5 °C. Overall, statistically significant loss of at least one insecticide was observed in each matrix, and at least five out of seven insecticides demonstrated a statistically significant loss in all matrices except orange juice. An investigation of an alternative mechanism of insecticide loss—adsorption onto the glass surface of the storage jars—was carried out, which indicated that this mechanism of loss is insignificant. Results of this work suggest that insecticides degrade in these beverages, and this degradation may lead to pre-existing insecticide degradates in the beverages, suggesting that caution should be exercised when using urinary insecticide metabolites to assess exposure and risk.

  9. Gas chromatography with flame photometric detection of 31 organophosphorus pesticide residues in Alpinia oxyphylla dried fruits.

    Science.gov (United States)

    Zhao, Xiangsheng; Kong, Weijun; Wei, Jianhe; Yang, Meihua

    2014-11-01

    A simple, rapid and effective gas chromatography-flame photometric detection method was established for simultaneous multi-component determination of 31 organophosphorus pesticides (OPPs) residues in Alpinia oxyphylla, which is widely consumed as a traditional medicine and food in China. Sample preparation was completed in a single step without any clean-up procedure. All pesticides expressed good linear relationships between 0.004 and 1.0 μg/mL with correlation coefficients higher than 0.9973. The method gave satisfactory recoveries for most pesticides. The limits of detection varied from 1 to 10 ng/mL, and the limits of quantification (LOQs) were between 4 and 30 ng/mL. The proposed method was successfully applied to 55 commercial samples purchased from five different areas. Five pesticide residues were detected in four (7.27%) samples. The positive samples were confirmed by gas chromatography with tandem mass spectrometry (GC-MS/MS). Copyright © 2014 Elsevier Ltd. All rights reserved.

  10. Theoretical and experimental study of actinide complexes with monoamides and organophosphorus ligands in solution

    International Nuclear Information System (INIS)

    Ribokaite, Kristina

    2013-01-01

    Monoamides and organophosphate are of great interest for the nuclear fuel cycle. Such ligands can selectively extract actinides in liquid-liquid extraction processes. The structure of the extractant (its functional group and its alkyl substituents) has a predominant role in the selective separation of actinides. This thesis concerns the theoretical and experimental studies of model systems in the aim of better understanding of the effect on molecular structures of the complexes. Structures of actinides complexes formed with model ligands in simple media (water or methanol in the presence of nitrate ions) have been characterized. At first, the complexation of uranyl by monoamide and phosphine oxide was studied in water and methanol. Molecular Dynamics simulations and DFT calculations were used to quantify the stability of uranyl complexes with those ligands, and to determine their structural properties. The theoretical results were then compared with experimental results obtained by UV-visible, infrared, Raman and EXAFS on the same chemical systems. The results were used to highlight the greater stability of uranyl complexes with phosphine oxide and monoamides. Further spectroscopic measurements combined with molecular modeling were used to gain a better understanding of the coordination mode of nitrate ion around the uranyl in both water and methanol. Finally, DFT calculations were used to study the influence of the structure of the monoamide or organophosphorus ligand and their interaction with the actinides (IV, VI) including steric effects in the first coordination sphere. (author) [fr

  11. Pharmacological treatment of organophosphorus insecticide poisoning: the old and the (possible) new.

    Science.gov (United States)

    Eddleston, Michael; Chowdhury, Fazle Rabbi

    2016-03-01

    Despite being a major clinical and public health problem across the developing world, responsible for at least 5 million deaths over the last three decades, the clinical care of patients with organophosphorus (OP) insecticide poisoning has little improved over the last six decades. We are still using the same two antidotes - atropine and oximes - that first came into clinical use in the late 1950s. Clinical research in South Asia has shown how improved regimens of atropine can prevent deaths. However, we are still unsure about which patients are most likely to benefit from the use of oximes. Supplemental antidotes, such as magnesium, clonidine and sodium bicarbonate, have all been proposed and studied in small trials without production of definitive answers. Novel antidotes such as nicotinic receptor antagonists, beta-adrenergic agonists and lipid emulsions are being studied in large animal models and in pilot clinical trials. Hopefully, one or more of these affordable and already licensed antidotes will find their place in routine clinical care. However, the large number of chemically diverse OP insecticides, the varied poisoning they produce and their varied response to treatment might ultimately make it difficult to determine definitively whether these antidotes are truly effective. In addition, the toxicity of the varied solvents and surfactants formulated with the OP active ingredients complicates both treatment and studies. It is possible that the only effective way to reduce deaths from OP insecticide poisoning will be a steady reduction in their agricultural use worldwide. © 2015 The British Pharmacological Society.

  12. Cholinesterase reactivators and bioscavengers for pre- and post-exposure treatments of organophosphorus poisoning.

    Science.gov (United States)

    Masson, Patrick; Nachon, Florian

    2017-08-01

    Organophosphorus agents (OPs) irreversibly inhibit acetylcholinesterase (AChE) causing a major cholinergic syndrome. The medical counter-measures of OP poisoning have not evolved for the last 30 years with carbamates for pretreatment, pyridinium oximes-based AChE reactivators, antimuscarinic drugs and neuroprotective benzodiazepines for post-exposure treatment. These drugs ensure protection of peripheral nervous system and mitigate acute effects of OP lethal doses. However, they have significant limitations. Pyridostigmine and oximes do not protect/reactivate central AChE. Oximes poorly reactivate AChE inhibited by phosphoramidates. In addition, current neuroprotectants do not protect the central nervous system shortly after the onset of seizures when brain damage becomes irreversible. New therapeutic approaches for pre- and post-exposure treatments involve detoxification of OP molecules before they reach their molecular targets by administrating catalytic bioscavengers, among them phosphotriesterases are the most promising. Novel generation of broad spectrum reactivators are designed for crossing the blood-brain barrier and reactivate central AChE. This is an article for the special issue XVth International Symposium on Cholinergic Mechanisms. © 2017 International Society for Neurochemistry.

  13. Effects of organophosphorus flame retardant TDCPP on normal human corneal epithelial cells: Implications for human health.

    Science.gov (United States)

    Xiang, Ping; Liu, Rong-Yan; Li, Chao; Gao, Peng; Cui, Xin-Yi; Ma, Lena Q

    2017-11-01

    Tris(1,3-dichloro-2-propyl) phosphate (TDCPP) is one of the most detected organophosphorus flame retardants (OPFRs) in the environment, especially in indoor dust. Continuous daily exposure to TDCPP-containing dust may adversely impact human cornea. However, its detrimental effects on human corneal epithelium are largely unknown. In this study, we investigated the cell apoptosis in normal human corneal epithelial cells (HCECs) after TDCPP exposure and elucidated the underlying molecular mechanisms. Our data indicated a dose-dependent decrease of cell viability after TDCPP exposure with LC 50 at 202 μg/mL. A concentration-dependent apoptotic sign was observed in HCECs after exposing to ≥2 μg/mL TDCPP. Endoplasmic reticulum stress induction was evidenced by up-regulation of its biomarker genes (ATF-4, CHOP, BiP, and XBP1). Furthermore, alternation of Bcl-2/Bax expression, mitochondrial membrane potential loss, cellular ATP content decrease, and caspase-3 and -9 activity increase were observed after exposing to 2 or 20 μg/mL TDCPP. Taken together, the data implicated the involvement of endoplasmic reticulum stress in TDCPP-induced HCEC apoptosis, probably mediated by mitochondrial apoptotic pathway. Our findings showed TDCPP exposure induced toxicity to human cornea. Due to TDCPP's presence at high levels in indoor dust, further study is warranted to evaluate its health risk on human corneas. Published by Elsevier Ltd.

  14. Suicidal Death due to Organophosphorus Compound Poisoning ─ an Experience of 67 Cases

    Directory of Open Access Journals (Sweden)

    Nashid Tabassum Khan

    2016-05-01

    Full Text Available Background: Bangladesh is an agro-based country. Suicide by agrochemical compounds are increasing day by day in this country. Organophosphorus compounds (OPC are commonly used for suicide. Mostly these are used for suicidal purpose in rural areas in our country due to low cost, toxicity and availability. Objective: To find out the relationship of age and sex variation along with the causes that influenced different income group people to ingest OPC for committing suicide. Materials and Methods: This study was conducted in the Department of Forensic Medicine, Dhaka Medical College during January to December 2010. Data were collected at the time of autopsy and from postmortem examination report of viscera. Viscera were preserved and sent to the Chief Chemical Examiner’s Office, Dhaka for toxicological analysis. Results: In this study, middle aged subjects (20–30 years were found to commit suicide using OPC in comparison to other age groups. Among the cases male were 57% and female 43%. Poverty was found as the most common cause (20% of OPC poisoning. Conclusion: Poverty is the leading cause of death of OPC poisoning followed by failure in love and adultery. Business failure, unhappiness in conjugal life, demand for dowry and violence against women are other causes to commit suicide by OPC.

  15. Organophosphorus pesticide exposure in agriculture: effects of temperature, ultraviolet light and abrasion on PVC gloves

    Science.gov (United States)

    ISMAIL, Ismaniza; GASKIN, Sharyn; PISANIELLO, Dino; EDWARDS, John W.

    2017-01-01

    Elbow length PVC gloves are often recommended for protection against organophosphorus pesticide (OP) exposure in agriculture. However, performance may be reduced due to high temperature, UV exposure and abrasion. We sought to assess these impacts for two OPs under normal use and reasonable worst-case scenarios. Glove permeation tests were conducted using ASTM cells with two PVC glove brands at 23°C and 45°C for up to 8 h. Technical grade dichlorvos and formulated diazinon were used undiluted and at application strength. Breakthough of undiluted dichlorvos occurred at both 23°C and 45°C, but only at 45°C for application strength. Breakthrough of diazinon was not achieved, except when undiluted at 45°C. UV-exposed and abraded gloves showed reduced performance, with the effect being approximately two-fold for dichlorvos. Only small differences were noted between glove brands. Extra precautions should be taken when handling concentrated OPs at high temperature, or when using abraded or sunlight-exposed gloves. PMID:29199264

  16. Effect of diluents on the extraction of actinides and nitric acid by bidentate organophosphorus compounds

    International Nuclear Information System (INIS)

    Rozen, A.M.

    1986-01-01

    The effect of dilutents on extraction by bidentate organophosphorus compounds (diphosphine dioxides, carbamoyl phosphonates, and phosphine oxides) was studied. Figures show the effect of dilutents on the extraction of americium by TOPO and by carbamoylmethylene phosphonate, and the effect of dilutents on the extraction of nitric acid and americium by carbamoylphosphine oxide. Also shown is the effect of dilutents on the extraction of americium by diphenyldioctyl methylenediphosphine dioxide, and the effect of dilutents on the extraction of americium by tetraphenylmethylenediphosphine dioxide. It was concluded that when TBP is added the distribution coefficient of Am increases but the effect of TBP may not be represented by the usual power relationship between the distribution coefficient and the TBP concentration, which would be expected if TBP was found to be very strong but for dilution by DCE it was relatively weak. The observed facts can be explained if it is assumed that TBP reacts with the bridging protons in the complex, which are free for dilution by benzene and are partially occupied when dichlorethane is used

  17. Organophosphorus esters in the oceans and possible relation with ocean gyres

    International Nuclear Information System (INIS)

    Cheng, Wenhan; Xie, Zhouqing; Blais, Jules M.; Zhang, Pengfei; Li, Ming; Yang, Chengyun; Huang, Wen; Ding, Rui; Sun, Liguang

    2013-01-01

    Four organophosphorus esters (OPEs) were detected in aerosol samples collected in the West Pacific, the Indian Ocean and the Southern Ocean from 2009 to 2010, suggesting their circumpolar and global distribution. In general, the highest concentrations were detected near populated regions in China, Australia and New Zealand. OPE concentrations in the Southern Ocean were about two orders of magnitude lower than those near major continents. Additionally, relatively high OPE concentrations were detected at the Antarctic Peninsula, where several scientific survey stations are located. The four OPEs investigated here are significantly correlated with each other, suggesting they may derive from the same source. In the circumpolar transect, OPE concentrations were associated with ocean gyres in the open ocean. Their concentrations were positively related with average vorticity in the sampling area suggesting that a major source of OPEs may be found in ocean gyres where plastic debris is known to accumulate. -- Highlights: •We provide OPE concentrations in aerosols in a circumpolar expedition. •We find strong anthropogenic source of OPE pollution. •We suggest potential relationship between ocean gyres and OPE pollution. -- Our work provides a circumpolar investigation on OPEs in the Southern Ocean and we suggest a possibility that ocean currents and gyres may act as important roles in global transport of OPEs

  18. Computational Enzymology and Organophosphorus Degrading Enzymes: Promising Approaches Toward Remediation Technologies of Warfare Agents and Pesticides.

    Science.gov (United States)

    Ramalho, Teodorico C; de Castro, Alexandre A; Silva, Daniela R; Silva, Maria Cristina; Franca, Tanos C C; Bennion, Brian J; Kuca, Kamil

    2016-01-01

    The re-emergence of chemical weapons as a global threat in hands of terrorist groups, together with an increasing number of pesticides intoxications and environmental contaminations worldwide, has called the attention of the scientific community for the need of improvement in the technologies for detoxification of organophosphorus (OP) compounds. A compelling strategy is the use of bioremediation by enzymes that are able to hydrolyze these molecules to harmless chemical species. Several enzymes have been studied and engineered for this purpose. However, their mechanisms of action are not well understood. Theoretical investigations may help elucidate important aspects of these mechanisms and help in the development of more efficient bio-remediators. In this review, we point out the major contributions of computational methodologies applied to enzyme based detoxification of OPs. Furthermore, we highlight the use of PTE, PON, DFP, and BuChE as enzymes used in OP detoxification process and how computational tools such as molecular docking, molecular dynamics simulations and combined quantum mechanical/molecular mechanics have and will continue to contribute to this very important area of research.

  19. Toxicology of organophosphorus compounds in view of an increasing terrorist threat.

    Science.gov (United States)

    Worek, Franz; Wille, Timo; Koller, Marianne; Thiermann, Horst

    2016-09-01

    The implementation of the Chemical Weapon Convention (CWC), prohibiting the development, production, storage and use of chemical weapons by 192 nations and the ban of highly toxic OP pesticides, especially class I pesticides according to the WHO classification, by many countries constitutes a great success of the international community. However, the increased interest of terrorist groups in toxic chemicals and chemical warfare agents presents new challenges to our societies. Almost seven decades of research on organophosphorus compound (OP) toxicology was mainly focused on a small number of OP nerve agents despite the fact that a huge number of OP analogues, many of these agents having comparable toxicity to classical nerve agents, were synthesized and published. Only limited physicochemical, toxicological and medical information on nerve agent analogues is available in the open literature. This implies potential gaps of our capabilities to detect, to decontaminate and to treat patients if nerve agent analogues are disseminated and may result in inadequate effectiveness of newly developed countermeasures. In summary, our societies may face new, up to now disregarded, threats by toxic OP which calls for increased awareness and appropriate preparedness of military and civilian CBRN defense, a broader approach for new physical and medical countermeasures and an integrated system of effective detection, decontamination, physical protection and treatment.

  20. Determinants of Organophosphorus Pesticide Urinary Metabolite Levels in Young Children Living in an Agricultural Community

    Directory of Open Access Journals (Sweden)

    Brenda Eskenazi

    2011-04-01

    Full Text Available Organophosphorus (OP pesticides are used in agriculture and several are registered for home use. As young children age they may experience different pesticide exposures due to varying diet, behavior, and other factors. We measured six OP dialkylphosphate (DAP metabolites (three dimethyl alkylphosphates (DMAP and three diethyl alkylphosphates (DEAP in urine samples collected from ~400 children living in an agricultural community when they were 6, 12, and 24 months old. We examined bivariate associations between DAP metabolite levels and determinants such as age, diet, season, and parent occupation. To evaluate independent impacts, we then used generalized linear mixed multivariable models including interaction terms with age. The final models indicated that DMAP metabolite levels increased with age. DMAP levels were also positively associated with daily servings of produce at 6- and 24-months. Among the 6-month olds, DMAP metabolite levels were higher when samples were collected during the summer/spring versus the winter/fall months. Among the 12-month olds, DMAP and DEAP metabolites were higher when children lived ≤60 meters from an agricultural field. Among the 24-month-olds, DEAP metabolite levels were higher during the summer/spring months. Our findings suggest that there are multiple determinants of OP pesticide exposures, notably dietary intake and temporal and spatial proximity to agricultural use. The impact of these determinants varied by age and class of DAP metabolite.

  1. Specificity of carboxylesterase protection against the toxicity of organophosphorus compounds. (Reannouncement with new availability information)

    Energy Technology Data Exchange (ETDEWEB)

    Maxwell, D.M.

    1992-12-31

    The ability of endogenous carboxylesterase (CaE) to protect against the lethal effects of a variety of organophosphorus (OP) compounds was examined in rats. The in vivo protection provided by endogenous CaE was measured by the difference in the LD50 values of OP compounds in controlrats and rats whose CaE activity had been inhibited by sc injection with2 mg/kg of 2-(O cresyl)-4H-1,3,2-benzodi oxaphosphorin-2-oxide. Endogenous CaE provided significant protection against the in vivo toxicity of soman, sarin, tabun, and paraoxon, but not against dichlorvos, diisopropyl fluorophosphate, or ethoxymethyl-S-2- (DIISOPROPYLAMINO)ETHYL THIOPHOSPHONATE (VX). The relationship between the in vivo CaE protection against OP compounds and their relative reactivities with CaE and acetylcholinesterase (AChE) was evaluated by measuring the in vitro bimolecular rate constants (ki) for inhibition of plasma CaE and brain AChE. Except for VX, ki values for CaE inhibition varied <10-fold while ki values for AChE inhibition varied 105-fold. Chemical warfare agents, Nerve agents, Organophosphoruscompound soman, VX, Carboxylesterase, Protection, Pretreatment.

  2. An overview of technologies for immobilization of enzymes and surface analysis techniques for immobilized enzymes

    Science.gov (United States)

    Mohamad, Nur Royhaila; Marzuki, Nur Haziqah Che; Buang, Nor Aziah; Huyop, Fahrul; Wahab, Roswanira Abdul

    2015-01-01

    The current demands of sustainable green methodologies have increased the use of enzymatic technology in industrial processes. Employment of enzyme as biocatalysts offers the benefits of mild reaction conditions, biodegradability and catalytic efficiency. The harsh conditions of industrial processes, however, increase propensity of enzyme destabilization, shortening their industrial lifespan. Consequently, the technology of enzyme immobilization provides an effective means to circumvent these concerns by enhancing enzyme catalytic properties and also simplify downstream processing and improve operational stability. There are several techniques used to immobilize the enzymes onto supports which range from reversible physical adsorption and ionic linkages, to the irreversible stable covalent bonds. Such techniques produce immobilized enzymes of varying stability due to changes in the surface microenvironment and degree of multipoint attachment. Hence, it is mandatory to obtain information about the structure of the enzyme protein following interaction with the support surface as well as interactions of the enzymes with other proteins. Characterization technologies at the nanoscale level to study enzymes immobilized on surfaces are crucial to obtain valuable qualitative and quantitative information, including morphological visualization of the immobilized enzymes. These technologies are pertinent to assess efficacy of an immobilization technique and development of future enzyme immobilization strategies. PMID:26019635

  3. A disposal centre for immobilized nuclear waste

    International Nuclear Information System (INIS)

    1980-02-01

    This report describes a conceptual design of a disposal centre for immobilized nuclear waste. The surface facilities consist of plants for the preparation of steel cylinders containing nuclear waste immobilized in glass, shaft headframe buildings and all necessary support facilities. The underground disposal vault is located on one level at a depth of 1000 m. The waste cylinders are emplaced into boreholes in the tunnel floors. All surface and subsurface facilities are described, operations and schedules are summarized, and cost estimates and manpower requirements are given. (auth)

  4. Radiation Synthesis of Nanogel for Bioactives Immobilization

    Energy Technology Data Exchange (ETDEWEB)

    Hamzah, M. Y. [Polymer Modification Group, Malaysian Nuclear Agency, Bangi (Malaysia)

    2009-07-01

    Both hydrophilic and hydrophobic core nanogel are currently being developed for immobilization and delivery purposes in Malaysian Nuclear Agency. Hydrophilic nanogel is produced by using inverse micelles irradiation of polyethelyne glycol diacrylate (PEGDA). The hydrophobic nanogel is produced via irradiation of acrylated form of palm oil. These nanogels will be used to immobilize bio actives such as curcumin, tyhmoquinone, oryzanol and chitosan. Preliminary investigation of the nanogel size using dynamic light scattering (DLS) shows that nanogel with sizes below 100nm can be obtained. (author)

  5. Plutonium Immobilization Can Loading Conceptual Design

    International Nuclear Information System (INIS)

    Kriikku, E.

    1999-01-01

    'The Plutonium Immobilization Facility will encapsulate plutonium in ceramic pucks and seal the pucks inside welded cans. Remote equipment will place these cans in magazines and the magazines in a Defense Waste Processing Facility (DWPF) canister. The DWPF will fill the canister with glass for permanent storage. This report discusses the Plutonium Immobilization can loading conceptual design and includes a process block diagram, process description, preliminary equipment specifications, and several can loading issues. This report identifies loading pucks into cans and backfilling cans with helium as the top priority can loading development areas.'

  6. Radiation Synthesis of Nanogel for Bioactives Immobilization

    International Nuclear Information System (INIS)

    Hamzah, M.Y.

    2009-01-01

    Both hydrophilic and hydrophobic core nanogel are currently being developed for immobilization and delivery purposes in Malaysian Nuclear Agency. Hydrophilic nanogel is produced by using inverse micelles irradiation of polyethelyne glycol diacrylate (PEGDA). The hydrophobic nanogel is produced via irradiation of acrylated form of palm oil. These nanogels will be used to immobilize bio actives such as curcumin, tyhmoquinone, oryzanol and chitosan. Preliminary investigation of the nanogel size using dynamic light scattering (DLS) shows that nanogel with sizes below 100nm can be obtained. (author)

  7. Plutonium Immobilization Can Loading Conceptual Design

    Energy Technology Data Exchange (ETDEWEB)

    Kriikku, E.

    1999-05-13

    'The Plutonium Immobilization Facility will encapsulate plutonium in ceramic pucks and seal the pucks inside welded cans. Remote equipment will place these cans in magazines and the magazines in a Defense Waste Processing Facility (DWPF) canister. The DWPF will fill the canister with glass for permanent storage. This report discusses the Plutonium Immobilization can loading conceptual design and includes a process block diagram, process description, preliminary equipment specifications, and several can loading issues. This report identifies loading pucks into cans and backfilling cans with helium as the top priority can loading development areas.'

  8. Immobilization of spent resin with epoxy resin

    International Nuclear Information System (INIS)

    Gultom, O.; Suryanto; Sayogo; Ramdan

    1997-01-01

    immobilization of spent resin using epoxy resin has been conducted. The spent resin was mixtured with epoxy resin in variation of concentration, i.e., 30, 40, 50, 60, 70 weight percent of spent resin. The mixture were pour into the plastic tube, with a diameter of 40 mm and height of 40 mm. The density, compressive strength and leaching rate were respectively measured by quanta chrome, paul weber apparatus and gamma spectrometer. The results showed that the increasing of waste concentration would be decreased the compressive strength, and increased density by immobilized waste. The leaching rate of 137 Cs from waste product was not detected in experiment (author)

  9. [ACTIVITY OF Ca2+,Mg(2+)-ATPase OF SARCOPLASMIC RETICULUM AND CONTRACTION STRENGTH OF THE FROG SKELETAL MUSCLES UNDER THE EFFECT OF ORGANOPHOSPHORUS INSECTICIDES].

    Science.gov (United States)

    Nozdrenko, D M; Korchinska, L V; Soroca, V M

    2015-01-01

    The results of an experimental study of organophosphorus insecticides, including pirimiphosmethyl, diazinon and chlorpyrifos caused a decline of the contraction properties in m. tibialis anterior fiber bundles of Rana temporaria, as well as sarcoplasmic reticulum Ca2+, Mg(2+)-ATPase enzymatic activity reduction are outlined in this paper. Concentration-dependent strengths response diminishing in isolated skeletal muscle fiber bundles as a result of non-cholinergic influence of organophosphorus insecticides were found. A decrease of Ca2+, Mg(2+)-ATPase enzymatic activity in sarcoplasmic reticulum was observed after administration of each insecticide. The most significant inhibition of this enzyme was observed when using chlorpyrifos.

  10. Preparation of Laccase Immobilized Cryogels and Usage for Decolorization

    Directory of Open Access Journals (Sweden)

    Murat Uygun

    2013-01-01

    Full Text Available Poly(methyl methacrylate-co-glycidyl methacrylate (poly(MMA-co-GMA cryogels were synthesized by radical cryopolymerization technique. Then, laccase enzyme was covalently attached to the cryogel and characterized by using swelling studies and SEM and EDX analyses. Kinetic properties and optimum conditions of the immobilized and free laccase were studied and it was found that of the immobilized laccase was lower than that of free laccase. of the immobilized laccase was increased upon immobilization. Optimum pH was found to be 4.0 for each type of laccase, while optimum temperature was shifted to the warmer region after the immobilization. It was also found that thermal stability of the immobilized laccase was higher than that of free laccase. Immobilized laccase could be used for 10 times successive reuse with no significant decrease in its activity. Also, these laccase immobilized cryogels were successfully used for the decolorization of seven different dyes.

  11. Immobilized cells of Candida rugosa possessing fumarase activity

    Energy Technology Data Exchange (ETDEWEB)

    Yang, L.; Zhone, L.

    1980-01-01

    Immobilized cells of C. rugosa that possessed fumarase activity were prepared by different methods; the most active immobilized cells were entrapped in polyacrylamide gels. The effects of pH temperature, and divalent cations on the fumarase activity of both immobilized and native cells were the same. Mn/sup 2 +/, Mg/sup 2 +/, Ca/sup 2 +/, and Fe/sup 2 +/ did not protect the immobilized enzyme against thermal inactivation. The activity of immobilized fumarase remained constant during 91 days of storage of 4-6 degrees. The immobilized cell column was used for the continuous production of L-malic acid from 1M fumarate at 30 degrees and pH 8.5. The immobilized column operated steadily for 2 months. Half life of the immobilized fumarase at 30 degrees was 95 days.

  12. Bed Rest and Immobilization: Risk Factors for Bone Loss

    Science.gov (United States)

    ... Risk Factors for Bone Loss Bed Rest and Immobilization: Risk Factors for Bone Loss Like muscle, bone ... complications of pregnancy; and those who are experiencing immobilization of some part of the body because of ...

  13. Preparation and characterization of two types of covalently immobilized amyloglucosidase

    Directory of Open Access Journals (Sweden)

    ZORAN VUJCIC

    2005-05-01

    Full Text Available Amyloglucosidase from A. niger was covalently immobilized onto poly (GMA-co-EGDMA by the glutaraldehyde and periodate method. The immobilization of amyloglucosidase after periodate oxidation gave a preparate with the highest specific activity reported so far on similar polymers. The obtained immobilized preparates show the same pH optimum, but a higher temperature optimum compared with the soluble enzyme. The kinetic parameters for the hydrolysis of soluble starch by free and both immobilized enzymes were determined.

  14. Immobilization of Isolated Lipase From Moldy Copra (Aspergillus Oryzae)

    OpenAIRE

    Dali, Seniwati; Patong, A. B. D. Rauf; Jalaluddin, M. Noor; Pirman; Hamzah, Baharuddin

    2011-01-01

    Enzyme immobilization is a recovery technique that has been studied in several years, using support as a media to help enzyme dissolutions to the reaction substrate. Immobilization method used in this study was adsorption method, using specific lipase from Aspergillus oryzae. Lipase was partially purified from the culture supernatant of Aspergillus oryzae. Enzyme was immobilized by adsorbed on silica gel. Studies on free and immobilized lipase systems for determination of optimum pH, optimum ...

  15. Mitochondrial NUDIX hydrolases: A metabolic link between NAD catabolism, GTP and mitochondrial dynamics.

    Science.gov (United States)

    Long, Aaron; Klimova, Nina; Kristian, Tibor

    2017-10-01

    NAD + catabolism and mitochondrial dynamics are important parts of normal mitochondrial function and are both reported to be disrupted in aging, neurodegenerative diseases, and acute brain injury. While both processes have been extensively studied there has been little reported on how the mechanisms of these two processes are linked. This review focuses on how downstream NAD + catabolism via NUDIX hydrolases affects mitochondrial dynamics under pathologic conditions. Additionally, several potential targets in mitochondrial dysfunction and fragmentation are discussed, including the roles of mitochondrial poly(ADP-ribose) polymerase 1(mtPARP1), AMPK, AMP, and intra-mitochondrial GTP metabolism. Mitochondrial and cytosolic NUDIX hydrolases (NUDT9α and NUDT9β) can affect mitochondrial and cellular AMP levels by hydrolyzing ADP- ribose (ADPr) and subsequently altering the levels of GTP and ATP. Poly (ADP-ribose) polymerase 1 (PARP1) is activated after DNA damage, which depletes NAD + pools and results in the PARylation of nuclear and mitochondrial proteins. In the mitochondria, ADP-ribosyl hydrolase-3 (ARH3) hydrolyzes PAR to ADPr, while NUDT9α metabolizes ADPr to AMP. Elevated AMP levels have been reported to reduce mitochondrial ATP production by inhibiting the adenine nucleotide translocase (ANT), allosterically activating AMPK by altering the cellular AMP: ATP ratio, and by depleting mitochondrial GTP pools by being phosphorylated by adenylate kinase 3 (AK3), which uses GTP as a phosphate donor. Recently, activated AMPK was reported to phosphorylate mitochondria fission factor (MFF), which increases Drp1 localization to the mitochondria and promotes mitochondrial fission. Moreover, the increased AK3 activity could deplete mitochondrial GTP pools and possibly inhibit normal activity of GTP-dependent fusion enzymes, thus altering mitochondrial dynamics. Published by Elsevier Ltd.

  16. Effects of the organophosphorus pesticide Folisuper 600 (methyl parathion on the heart function of bullfrog tadpoles, Lithobates catesbeianus (Shaw, 1802

    Directory of Open Access Journals (Sweden)

    M. J. Costa

    Full Text Available Abstract The aim of this work was to evaluate whether the heart function of bullfrog tadpoles (25 Gosner stage is affected by their acute exposure (48 h to a sub-lethal concentration (10 µg.L–1 of the active principle of the organophosphorus pesticide Folisuper 600R (methyl parathion - MP. Our results demonstrated that MP causes not only a reduction in tadpoles’ cardiac ventricular mass, resulting in a marked reduction in their cardiac twitch force, but also impairs their swimming performance, irrespective of increasing their heart rate. Together, these findings indicate that low and realistic concentration of MP have a negative impact on tadpoles’ performance, jeopardizing their survival.

  17. Computer-aided design of bromelain and papain covalent immobilization

    OpenAIRE

    Cutiño-Avila, Bessy; Gil Pradas, Dayrom; Aragón Abreu, Carlos; Fernández Marrero, Yuniel; Hernández de la Torre, Martha; Salas Sarduy, Emir; Chávez Planes, María de los Ángeles; Guisán Seijas, José Manuel; Díaz Brito, Joaquín; del Monte-Martínez, Alberto

    2014-01-01

    Enzymes as immobilized derivatives have been widely used in Food, Agrochemical, Pharmaceutical and Biotechnological industries. Protein immobilization is probably the most used technology to improve the operational stability of these molecules. Bromelain (Ananas comosus) and papain (Carica papaya) are cystein proteases extensively used as immobilized biocatalyst with several applications in therapeutics, racemic mixtures resolution, affinity chromatography and others industrial scenarios. The...

  18. Short-Term Limb Immobilization Affects Cognitive Motor Processes

    Science.gov (United States)

    Toussaint, Lucette; Meugnot, Aurore

    2013-01-01

    We examined the effects of a brief period of limb immobilization on the cognitive level of action control. A splint placed on the participants' left hand was used as a means of immobilization. We used a hand mental rotation task to investigate the immobilization-induced effects on motor imagery performance (Experiments 1 and 2) and a number mental…

  19. Immobilization of microbial cells: A promising tool for treatment of ...

    African Journals Online (AJOL)

    The review articles on cell immobilization have been published since 1980 and reflect the general interest in this topic. Immobilized microbial cells create opportunities in a wide range of sectors including environmental pollution control. Compared with suspended microorganism technology, cell immobilization shows many ...

  20. Characterization of immobilized post-carbohydrate meal salivary α ...

    African Journals Online (AJOL)

    The effect of experimental parameters like pH, temperature and substrate concentration on the activity of the immobilized post-carbohydrate meal salivary ... of immobilized post-carbohydrate meal salivary α-amylase in this study show that immobilization had no significant effect on the enzyme and compared to kinetic ...

  1. Characteristics of immobilized aminoacylase from Aspergillus oryzae on macroporous copolymers.

    Science.gov (United States)

    He, B L; Jiang, P; Qiu, Y B

    1990-01-01

    Aminoacylase from Aspergillus oryzae was adsorbed on functionallized macroporous copolymers where the enzyme showed excellent catalyzing activity and operation stability. Various factors which effect the activity of the immobilized aminoacylase such as temperature, pH and ionic strength were investigated. The continuous operation of the enzyme immobilized on macroporous copolymers was compared with that of the enzyme immobilized on DEAE-Sephadex.

  2. Some hydrolase activities from the tick Hyalomma lusitanicum Koch, 1844 (Ixodoidea: Ixodida

    Directory of Open Access Journals (Sweden)

    Giménez-Pardo C.

    2008-12-01

    Full Text Available In this work has been made a detection and preliminary characterization of some hydrolases in whole extracts from unfed adult males and females of Hyalomma lusitanicum, one of the vectors for Theileria annulata that causes Mediterranean theileriosis in cattle. We have elected as targets, proteases as enzymes implicated in the nutritional processes of ticks, esterases that are usually implicated in resistance to organophosphates and phosphatises often implicated in protein phosphorilation and control of ticks salivary gland. The biological role and physiological significance are discussed in terms of the possibility of use these enzymes as possible in future anti-tick vaccination or acaricide resistance.

  3. Studies on whole cell fluorescence-based screening for epoxide hydrolases and Baeyer-Villiger monooxygenases

    International Nuclear Information System (INIS)

    Bicalho, Beatriz; Chen, Lu S.; Marsaioli, Anita J.; Grognux, Johann; Reymond, Jean-Louis

    2004-01-01

    Biocatalysis reactions were performed on microtiter plates (200 μL) aiming at the utilization of fluorogenic substrates (100 μmol L -1 ) for rapid whole cell screening for epoxide hydrolases (EHs) and Baeyer-Villiger monooxygenases (BVMOs). A final protocol was achieved for EHs, with 3 new enzymatic sources being detected (Agrobacterium tumefaciens, Pichia stipitis, Trichosporom cutaneum). The fluorogenic assay for BVMO did not work as expected. However, an approach to possible variables involved (aeration; pH) provided the first detection of a BVMO activity in T. cutaneum. (author)

  4. Protein features as determinants of wild-type glycoside hydrolase thermostability

    DEFF Research Database (Denmark)

    Geertz-Hansen, Henrik Marcus; Kiemer, Lars; Nielsen, Morten

    2017-01-01

    -silico methods guiding the discovery process would be of high value. To develop such an in-silico method and provide the data foundation of it, we determined the melting temperatures of 602 fungal glycoside hydrolases from the families GH5, 6, 7, 10, 11, 43 and AA9 (formerly GH61). We, then used sequence...... and homology modeled structure information of these enzymes to develop the ThermoP melting temperature prediction method. Futhermore, in the context of thermostability, we determined the relative importance of 160 molecular features, such as amino acid frequencies and spatial interactions, and exemplified...

  5. A proton wire and water channel revealed in the crystal structure of isatin hydrolase

    DEFF Research Database (Denmark)

    Bjerregaard-Andersen, Kaare; Sommer, Theis; Jensen, Jan Kristian

    2014-01-01

    to a novel family of metalloenzymes that include the bacterial kynurenine formamidase. The product state, mimicked by bound thioisatinate, reveals a water molecule that bridges the thioisatinate to a proton wire in an adjacent water channel and thus allows the proton released by the reaction to escape only...... when the product is formed. The functional proton wire present in IH-b represents a unique catalytic feature common to all hydrolases is here trapped and visualized for the first time. The local molecular environment required to coordinate thioisatinate allows stronger and more confident identification...

  6. Immobilization: A Revolution in Traditional Brewing

    Science.gov (United States)

    Virkajärvi, Ilkka; Linko, Matti

    In nature many micro-organisms tend to bind to solid surfaces. This tendency has long been utilized in a number of processes, for example in producing vinegar and acetic acid in bioreactors filled with wood shavings. Acetobacteria are attached to the surface of these shavings. In modern technical language: they are immobilized. Also yeast cells can be immobilized. In the brewing industry this has been the basis for maintaining efficient, continuous fermentation in bioreactors with very high yeast concentrations. The most dramatic change in brewing over recent years has been the replacement of traditional lagering of several weeks by a continuous process in which the residence time is only about 2h. Continuous primary fermentation is used on a commercial scale in New Zealand. In this process, instead of a carrier, yeast is retained in reactors by returning it partly after separation. In many pilot scale experiments the primary fermentation is shortened from about 1week to 1-2days using immobilized yeast reactors. When using certain genetically modified yeast strains no secondary fermentation is needed, and the total fermentation time in immobilized yeast reactors can therefore be shortened to only 2days.

  7. Silica gel matrix immobilized Chlorophyta hydrodictyon africanum ...

    African Journals Online (AJOL)

    Chlorophyta hydrodictyon africanum was immobilized on a silica gel matrix to improve its mechanical properties. The algae-silica gel adsorbent was used for batch sorption studies of a cationic dye, methylene blue (MB). Optimum adsorption was obtained with a dosage of 0.8 g bio sorbent. Results from sorption studies ...

  8. Isomaltulose production using free and immobilized Serratia ...

    African Journals Online (AJOL)

    André

    2016-05-18

    May 18, 2016 ... After 2 h of reaction time in shake flasks, a high production of ... immobilized cells in calcium alginate was studied in a packed bed bioreactor during seven days in a .... cell biomass was obtained from fermentation in a 6.6 L bioreactor .... carbohydrates were analyzed comparing their retention times with.

  9. Immobilization and packaging of recovered tritium

    International Nuclear Information System (INIS)

    Holtslander, W.J.; Miller, J.M.

    1982-09-01

    The evaluation of metal hydrides as a medium for immobilization of tritium is reviewed. The work demonstrated methods of preparation and examined the properties of titanium and zirconium hydride for this application. Methods of packaging the metal hydrides for transportation and recoverable storage of tritium were also examined

  10. Halloysite Clay Nanotubes for Enzyme Immobilization.

    Science.gov (United States)

    Tully, Joshua; Yendluri, Raghuvara; Lvov, Yuri

    2016-02-08

    Halloysite clay is an aluminosilicate nanotube formed by rolling flat sheets of kaolinite clay. They have a 15 nm lumen, 50-70 nm external diameter, length of 0.5-1 μm, and different inside/outside chemistry. Due to these nanoscale properties, they are used for loading, storage, and controlled release of active chemical agents, including anticorrosions, biocides, and drugs. We studied the immobilization in halloysite of laccase, glucose oxidase, and lipase. Overall, negatively charged proteins taken above their isoelectric points were mostly loaded into the positively charged tube's lumen. Typical tube loading with proteins was 6-7 wt % from which one-third was released in 5-10 h and the other two-thirds remained, providing enhanced biocatalysis in nanoconfined conditions. Immobilized lipase showed enhanced stability at acidic pH, and the optimum pH shifted to more alkaline pH. Immobilized laccase was more stable with respect to time, and immobilized glucose oxidase showed retention of enzymatic activity up to 70 °C, whereas the native sample was inactive.

  11. Immobilizing Biomolecules Near the Diffraction Limit

    DEFF Research Database (Denmark)

    Skovsen, Esben; Petersen, Maria Teresa Neves; Gennaro, Ane Kold Di

    2009-01-01

    Our group has previously shown that biomolecules containing disulfide bridges in close proximity to aromatic residues can be immobilized, through covalent bonds, onto thiol derivatized surfaces upon UV excitation of the aromatic residue(s). We have also previously shown that our new technology ca...

  12. Enzyme Engineering for In Situ Immobilization.

    Science.gov (United States)

    Rehm, Fabian B H; Chen, Shuxiong; Rehm, Bernd H A

    2016-10-14

    Enzymes are used as biocatalysts in a vast range of industrial applications. Immobilization of enzymes to solid supports or their self-assembly into insoluble particles enhances their applicability by strongly improving properties such as stability in changing environments, re-usability and applicability in continuous biocatalytic processes. The possibility of co-immobilizing various functionally related enzymes involved in multistep synthesis, conversion or degradation reactions enables the design of multifunctional biocatalyst with enhanced performance compared to their soluble counterparts. This review provides a brief overview of up-to-date in vitro immobilization strategies while focusing on recent advances in enzyme engineering towards in situ self-assembly into insoluble particles. In situ self-assembly approaches include the bioengineering of bacteria to abundantly form enzymatically active inclusion bodies such as enzyme inclusions or enzyme-coated polyhydroxyalkanoate granules. These one-step production strategies for immobilized enzymes avoid prefabrication of the carrier as well as chemical cross-linking or attachment to a support material while the controlled oriented display strongly enhances the fraction of accessible catalytic sites and hence functional enzymes.

  13. Metal immobilization in soils using synthetic zeolites

    NARCIS (Netherlands)

    Osté, L.A.; Lexmond, T.M.; Riemsdijk, van W.H.

    2002-01-01

    In situ immobilization of heavy metals in contaminated soils is a technique to improve soil quality. Synthetic zeolites are potentially useful additives to bind heavy metals. This study selected the most effective zeolite in cadmium and zinc binding out of six synthetic zeolites (mordenite-type,

  14. Adsorption of metals by immobilized tannins

    Energy Technology Data Exchange (ETDEWEB)

    Santana, J L; Olivares, S; De La Rosa, D; Martinez, F; Vargas, L M [Centro de Estudios Aplicados al Desarrollo Nuclear (CEADEN), La Habana (Cuba)

    1996-05-01

    Simultaneous adsorption of thorium, europium, cerium, and neodymium by immobilized tannic was studied at different ph values. Tannic materials have excellent ability to adsorb selectively thorium at pH 5. The rest of the elements could be isolated in group at pH 7.

  15. Immobilization of Trichoderma reesei by radiation polymerization

    International Nuclear Information System (INIS)

    Zhou Ruimin; Ma Zueteh; Kaetus, Isao; Kumakura, Minoro

    1993-01-01

    Immobilization of Trichoderma reesei was carried out by radiation polymerization. It was found that the activity of fixed cells increased with increasing surface area of the carrier and was affected by the concentration of monomer tetraethylenglycol dimethacrylate and the shape of the substrate composition and structure of cotton textile fabrics. (author)

  16. Application of radiopolymerization for immobilization of enzymes

    International Nuclear Information System (INIS)

    Higa, O.Z.; Mastro, N.L. del; Castagnet, A.C.G.

    1986-01-01

    Hydrophilic glass-forming monomers were used in an application of irradiation technology for the immobilization of cellulase and cellobiase. Experiments to observe the effect of additives such as silicates and polyethylene glycol in the enzyme entrapment are reported on. In all cases, enzymatic activity was maintained for more than fifteen batch enzyme reactions. (Author) [pt

  17. Plutonium Immobilization Can Loading Preliminary Specifications

    Energy Technology Data Exchange (ETDEWEB)

    Kriikku, E.

    1998-11-25

    This report discusses the Plutonium Immobilization can loading preliminary equipment specifications and includes a process block diagram, process description, equipment list, preliminary equipment specifications, plan and elevation sketches, and some commercial catalogs. This report identifies loading pucks into cans and backfilling cans with helium as the top priority can loading development areas.

  18. Immobilization of Enzymes in Polymer Supports.

    Science.gov (United States)

    Conlon, Hugh D.; Walt, David R.

    1986-01-01

    Two experiments in which an enzyme is immobilized onto a polymeric support are described. The experiments (which also demonstrate two different polymer preparations) involve: (1) entrapping an enzyme in an acrylamide polymer; and (2) reacting the amino groups on the enzyme's (esterase) lysine residues with an activated polymer. (JN)

  19. IN SITU LEAD IMMOBILIZATION BY APATITE

    Science.gov (United States)

    Lead contamination is of environmental concern due to its effect on human health. The purpose of this study was to develop a technology to immobilize Pb in situ in contaminated soils and wastes using apatite. Hydroxyapatite [Ca10(PO4)6(O...

  20. Isomaltulose production using free and immobilized Serratia ...

    African Journals Online (AJOL)

    Isomaltulose is a low cariogenic sweetener used as a substitute for sucrose in the food industry. In this study, isomaltulose production by Serratia plymuthica ATCC 15928 was performed using free and immobilized cells. Response Surface Methodology was employed to evaluate the influence of temperature, wet cell mass ...

  1. Physico-chemical characteristics of immobilized polygalacturonase ...

    African Journals Online (AJOL)

    Polygalacturonase (PG) was isolated from Aspergillus niger (A. niger) (SA6), partially purified, characterized and immobilized by entrapment using calcium alginate. The polygalacturonase showed two bands on sodium dodecyl sulfate polyacryamide gel electrophoresis (SDS-PAGE) suggesting an “endo and exo” ...

  2. Adsorption of metals by immobilized tannins

    International Nuclear Information System (INIS)

    Santana, J.L.; Olivares, S.; De La Rosa, D.; Martinez, F.; Vargas, L.M.

    1996-01-01

    Simultaneous adsorption of thorium, europium, cerium, and neodymium by immobilized tannic was studied at different ph values. Tannic materials have excellent ability to adsorb selectively thorium at pH 5. The rest of the elements could be isolated in group at pH 7

  3. Enzyme Immobilization: An Overview on Methods, Support Material, and Applications of Immobilized Enzymes.

    Science.gov (United States)

    Sirisha, V L; Jain, Ankita; Jain, Amita

    Immobilized enzymes can be used in a wide range of processes. In recent years, a variety of new approaches have emerged for the immobilization of enzymes that have greater efficiency and wider usage. During the course of the last two decades, this area has rapidly expanded into a multidisciplinary field. This current study is a comprehensive review of a variety of literature produced on the different enzymes that have been immobilized on various supporting materials. These immobilized enzymes have a wide range of applications. These include applications in the sugar, fish, and wine industries, where they are used for removing organic compounds from waste water. This study also reviews their use in sophisticated biosensors for metabolite control and in situ measurements of environmental pollutants. Immobilized enzymes also find significant application in drug metabolism, biodiesel and antibiotic production, bioremediation, and the food industry. The widespread usage of immobilized enzymes is largely due to the fact that they are cheaper, environment friendly, and much easier to use when compared to equivalent technologies. © 2016 Elsevier Inc. All rights reserved.

  4. Purification and characterization of RihC, a xanthosine-inosine-uridine-adenosine-preferring hydrolase from Salmonella enterica serovar Typhimurium

    DEFF Research Database (Denmark)

    Hansen, Michael Riis; Dandanell, Gert

    2005-01-01

    as the sole carbon and energy source. By functional complementation, we have isolated a nucleoside hydrolase (rihC) that can complement a xapA deletion in E. coli and we have overexpressed, purified and characterized this hydrolase. RihC is a heat stable homotetrameric enzyme with a molecular weight of 135 k...... the neutral form of xanthosine....

  5. Characterization of two novel bacterial type A exo-chitobiose hydrolases having C-terminal 5/12-type carbohydrate-binding modules

    DEFF Research Database (Denmark)

    Binti Jamek, Shariza; Nyffenegger, Christian; Muschiol, Jan

    2017-01-01

    "exo-chitobiose hydrolases." In this study, the chitinase type A from Serratia marcescens (SmaChiA) was used as a template for identifying two novel exo-chitobiose hydrolase type A enzymes, FbalChi18A and MvarChi18A, originating from the marine organisms Ferrimonas balearica and Microbulbifer...

  6. Cellular localization of peptide hydrolases in chicken embryo tissues and influence of gamma irradiation on their activity

    Energy Technology Data Exchange (ETDEWEB)

    Khristov, D; Marinopolski, G

    1975-01-01

    Studied was the influence of chicken embryo irradiation at 600 R and 1000 R gamma rays on the activity of tissue peptide hydrolases in mitochondrial-lysosomal, microsomal and supernatant (cell hyaloplasm) cell fractions. The investigation was performed 50 to 168 hours post irradiation. The wole tissue (of the whole embryo) was examined following irradiation of 4-day-old embryos whose liver, muscle and brain tissues were post irradiation examined on day 12 and 16 of incubation. Prior to treatment, the tissues were threfold rinsed with sucrose solution to eliminate proeinase inhibitors. Lysosome membranes were destroyed by adding 0.5 % desoxycholate. It was found that: Peptide hydrolase activity of mitochondrial-lysosomal cell fractions of tissues of whole 6-day chicken embryos is 4-5 times as high as that of cell hyaloplasm. Peptide hydrolase activity of mitochondrial-lysosomal fractions of liver tissues decreases on day 18 and 19 post incubation, while the same fraction of muscle and brain tissues shows high activity. Peptide hydrolase activity of microsomal fraction and of cell hyaloplasm rises during embryonal development and exceeds the activity of liver tissue mitochondrial fraction. Peptide hydrolase activity of mitochondrial-lysosomal fraction of tissue of whole 6-day-old embryos 50 hours post irradiation is higher than the activity of non-irradiated embryos. Later the activity of this fraction diminishes and on the 168 hr post irradiation it drops below the normal. Microsomal fraction and cell hyaloplasm activity likewise show deviation from the norm. Peptide hydrolase activity of mitochondrial-lysosomal fraction of liver, muscle and brain tissue of 14 and 18-day-old embryos is higher than the control 50 hours post irradiation and then declines. The activity of mitochondrial-lysosomal fraction of embryo brain tissue changes most strikingly on irradiation, while other brain cell fractions change less compared with liver and muscle fractions.

  7. Cellular localization of peptide hydrolases in chicken embryo tissues and influence of gamma irradiation on their activity

    International Nuclear Information System (INIS)

    Khristov, D.; Marinopolski, G.

    1975-01-01

    Studied was the influence of chicken embryo irradiation at 600 R and 1000 R gamma rays on the activity of tissue peptide hydrolases in mitochondrial-lysosomal, microsomal and supernatant (cell hyaloplasm) cell fractions. The investigation was performed 50 to 168 hours post irradiation. The wole tissue (of the whole embryo) was examined following irradiation of 4-day-old embryos whose liver, muscle and brain tissues were post irradiation examined on day 12 and 16 of incubation. Prior to treatment, the tissues were threfold rinsed with sucrose solution to eliminate proeinase inhibitors. Lysosome membranes were destroyed by adding 0.5 % desoxycholate. It was found that: Peptide hydrolase activity of mitochondrial-lysosomal cell fractions of tissues of whole 6-day chicken embryos is 4-5 times as high as that of cell hyaloplasm. Peptide hydrolase activity of mitochondrial-lysosomal fractions of liver tissues decreases on day 18 and 19 post incubation, while the same fraction of muscle and brain tissues shows high activity. Peptide hydrolase activity of microsomal fraction and of cell hyaloplasm rises during embryonal development and exceeds the activity of liver tissue mitochondrial fraction. Peptide hydrolase activity of mitochondrial-lysosomal fraction of tissue of whole 6-day-old embryos 50 hours post irradiation is higher than the activity of non-irradiated embryos. Later the activity of this fraction diminishes and on the 168 hr post irradiation it drops below the normal. Microsomal fraction and cell hyaloplasm activity likewise show deviation from the norm. Peptide hydrolase activity of mitochondrial-lysosomal fraction of liver, muscle and brain tissue of 14 and 18-day-old embryos is higher than the control 50 hours post irradiation and then declines. The activity of mitochondrial-lysosomal fraction of embryo brain tissue changes most strikingly on irradiation, while other brain cell fractions change less compared with liver and muscle fractions

  8. Phytase production by Aspergillus niger NCIM 563 for a novel application to degrade organophosphorus pesticides.

    Science.gov (United States)

    Shah, Parin C; Kumar, V Ravi; Dastager, Syed G; Khire, Jayant M

    2017-12-01

    The production of phytase using Aspergillus niger NCIM 563 under submerged fermentation conditions was studied using protein rich chickpea flour as substrate. Employing a hybrid statistical media optimization strategy of Plackett-Burman and Box-Behnken experimental designs in shake-flasks gave an increased phytase activity from an initial 66 IU/mL in 216 h to 160 IU/mL in a reduced time of 132 h. Productivity, thus increased by 3.97 times from 7.3 to 29 IU/mL/day. Using the optimized media, the production was successfully scaled-up further and improved up to 164 IU/mL in 96 h by studies carried out employing 2 and 10-L fermenters. The enzyme supernatant was recovered using centrifugal separation of biomass and the stability of the produced phytase was tested for animal feed applications under gastric conditions. In vitro degradation studies of water soluble monocrotophos, methyl parathion and water insoluble chlorpyrifos, pesticides used extensively in agriculture was carried out. It was observed by HPLC analysis that phytase could degrade 72% of chlorpyrifos at pH 7.0, 35 °C. Comparable results were obtained with monocrotophos and methyl parathion. With chlorpyrifos at higher temperature 50 °C as much as 91% degradation could be obtained. The degradation of chlorpyrifos was further validated by spraying phytase on harvested green chilli (Capsicum annuum L) under normal conditions of pH 7.0, 35 °C and the degradation products obtained analyzed by LCMS. Thus, the present study brings out a potentially novel application of phytase for biodegradation of organophosphorus pesticides.

  9. Determination of Organophosphorus Pesticides in Soil by Dispersive Liquid–Liquid Microextraction and Gas Chromatography

    Science.gov (United States)

    Yang, Zhonghua; Liu, Yu; Liu, Donghui; Zhou, Zhiqiang

    2012-01-01

    In this article, a rapid and sensitive sample pretreatment technique for the determination of organophosphorus pesticides (OPPs) in soil samples is developed by using dispersive liquid–liquid microextraction (DLLME) combined with gas chromatography–flame photometric detection. Experimental conditions, including the kind of extraction and disperser solvent and their volumes, the extraction time, and the salt addition, are investigated, and the following experiment factors are used: 20 µL chlorobenzene as the extraction solvent; 1.0 mL acetonitrile as the disperser solvent; no addition of salt; and an extraction time of 1 min. Under the optimum conditions, the linearities for the three target OPPs (ethoprophos, chlorpyriphos, and profenofos) are obtained by five points in the concentration range of 2.5–1500 µg/kg, and three replicates are used for each point. Correlation coefficients vary from 0.9987 to 0.9997. The repeatability is tested by spiking soil samples at a concentration level of 5.0 µg/kg. The relative standard deviation (n = 3) varied between 2.0% and 6.6%. The limits of detection, based on a signal-to-noise ratio (S/N) of 3, range from 200 to 500 pg/g. This method is applied to the analysis of the spiked samples S1, S2, and S3, which are collected from the China Agriculture University's orchard, lawn, and garden, respectively. The recoveries for each target analyte are in the range between 87.9% and 108.0%, 87.4% and 108.0%, and 86.7% and 107.2%, respectively. PMID:22291051

  10. Spatial learning impairment in prepubertal guinea pigs prenatally exposed to the organophosphorus pesticide chlorpyrifos: Toxicological implications

    Science.gov (United States)

    Mamczarz, Jacek; Pescrille, Joseph D.; Gavrushenko, Lisa; Burke, Richard D.; Fawcett, William P.; DeTolla, Louis J.; Chen, Hegang; Pereira, Edna F.R.; Albuquerque, Edson X.

    2017-01-01

    Exposure of the developing brain to chlorpyrifos (CPF), an organophosphorus (OP) pesticide used extensively in agriculture worldwide, has been associated with increased prevalence of cognitive deficits in children, particularly boys. The present study was designed to test the hypothesis that cognitive deficits induced by prenatal exposure to sub-acute doses of CPF can be reproduced in precocial small species. To address this hypothesis, pregnant guinea pigs were injected daily with CPF (25 mg/kg, s.c.) or vehicle (peanut oil) for 10 days starting on presumed gestation day (GD) 53–55. Offspring were born around GD 65, weaned on postnatal day (PND) 20, and subjected to behavioral tests starting around PND 30. On the day of birth, butyrylcholinesterase (BuChE), an OP bioscavenger used as a biomarker of OP exposures, and acetylcholinesterase (AChE), a major molecular target of OP compounds, were significantly inhibited in the blood of CPF-exposed offspring. In their brains, BuChE, but not AChE, was significantly inhibited. Prenatal CPF exposure had no significant effect on locomotor activity or on locomotor habituation, a form of non-associative memory assessed in open fields. Spatial navigation in the Morris water maze (MWM) was found to be sexually dimorphic among guinea pigs, with males outperforming females. Prenatal CPF exposure impaired spatial learning more significantly among male than female guinea pigs and, consequently, reduced the sexual dimorphism of the task. The results presented here, which strongly support the test hypothesis, reveal that the guinea pig is a valuable animal model for preclinical assessment of the developmental neurotoxicity of OP pesticides. These findings are far reaching as they lay the groundwork for future studies aimed at identifying therapeutic interventions to treat and/or prevent the neurotoxic effects of CPF in the developing brain. PMID:27296654

  11. Effect of organophosphorus insecticides and their metabolites on astroglial cell proliferation

    International Nuclear Information System (INIS)

    Guizzetti, Marina; Pathak, Shantha; Giordano, Gennaro; Costa, Lucio G.

    2005-01-01

    Though little attention has been given to the possibility that glial cells may represent a target for the developmental neurotoxicity of organophosphorus (OP) insecticides, recent evidence, obtained in particular with chlorpyrifos (CP), suggests that developmental exposure to this compound may indeed target astrocytes. To substantiate and expand these observations, we carried out a series of in vitro studies utilizing fetal rat astrocytes and a human astrocytoma cell line, 1321N1 cells, to investigate the effect of the OPs CP, diazinon (DZ) and parathion (P), their oxygen analogs chlorpyrifos oxon (CPO), diazoxon (DZO) and paraoxon (PO), and their metabolites 3,5,6-trichloro-2-pyridinol (TCP), 2-isopropyl-6-methyl-4-pyrimidol (IMP) and para-nitrophenol (PNP), on cell proliferation. In fetal rat astrocytes and astrocytoma cells maintained in serum, CP, DZ, P, CPO, DZO, and PO induced a concentration-dependent inhibition in [ 3 H]thymidine incorporation with a very similar potency (IC 50 between 45 and 57 μM). Among the other metabolites, PNP was the most potent (IC 50 = 70-80 μM), while TCP and IMP were much less effective (IC 50 > 100 μM). Cytotoxicity appears to account only for a small part of the effect on DNA synthesis. OP insecticides and their oxons were three- to six-fold more potent in inhibiting [ 3 H]thymidine incorporation when cells were synchronized in the G 0 /G 1 phase of the cell cycle and re-stimulated by carbachol or epidermal growth factor. These results suggest that OP insecticides and their oxons affect astroglial cell proliferation and that the transition from the G 0 /G 1 to the S/G 2 phase of the cell cycle may be particularly sensitive to the action of these compounds

  12. Modulatory Effect Of Olive Oil On Toxicity Induced By Organophosphorus Pesticides In Male Rat

    International Nuclear Information System (INIS)

    AFIFI, E.A.A.; ALI, S.E.

    2009-01-01

    The present study was carried out to investigate the modulatory effect of olive oil (5 ml/kg b.wt.) against the toxicological effects of repeated daily oral administration of the organophosphorus pesticides malaphos (137.5 mg/kg), mephosfolan (0.89 mg/kg) and phosfolan (1.0 mg/kg) for one, two and four weeks on certain biochemical parameters such as serum albumin, globulin and A/G ratio, low density lipoprotein-cholesterol (LDL-cholesterol), high density lipoprotein-cholesterol (HDL-cholesterol), total cholesterol, total protein, gamma glutamyl transferase ( GT) and plasma triglycerides. In addition, modulation of blood urea, creatinine and uric acid were observed through all the experimental intervals. Also, the serum concentration of triiodothyronine (T 3 ), thyroxine (T 4 ) and thyroid stimulating hormone (TSH) were determined.The data obtained revealed significant decrease in serum total protein, albumin, globulin and HDL-cholesterol while significant increase in serum albumin to globulin ratio (A/G), triglycerides, creatinine, urea, uric acid, LDL-cholesterol, total cholesterol and GT in all treated groups was observed. On the other hand, the data recorded imbalance in thyroid function as a result of pesticides treatments, which donated that each of the three pesticides increased TSH secretion, while malaphos caused significant decrease in both T 3 and T 4 levels, mephosfolan increased T 4 and decreased T 3 levels, whereas phosfolan pesticide decreased T 4 and increased T 3 levels after one, two and four weeks post-treatment.Administration of olive oil during treatment with malaphos, mephosfolan and phosfolan pesticides attenuates to a great extent the destructive effects of pesticides on the assayed parameters, this effect is attributed to the beneficial properties whom olive oil possess as anti-oxidative potential that may act to protect the body organs against the pesticides toxicity and also due to the amelioration of oxidative stress of free radicals.

  13. Organophosphorus pesticides decrease M2 muscarinic receptor function in guinea pig airway nerves via indirect mechanisms.

    Directory of Open Access Journals (Sweden)

    Becky J Proskocil

    Full Text Available BACKGROUND: Epidemiological studies link organophosphorus pesticide (OP exposures to asthma, and we have shown that the OPs chlorpyrifos, diazinon and parathion cause airway hyperreactivity in guinea pigs 24 hr after a single subcutaneous injection. OP-induced airway hyperreactivity involves M2 muscarinic receptor dysfunction on airway nerves independent of acetylcholinesterase (AChE inhibition, but how OPs inhibit neuronal M2 receptors in airways is not known. In the central nervous system, OPs interact directly with neurons to alter muscarinic receptor function or expression; therefore, in this study we tested whether the OP parathion or its oxon metabolite, paraoxon, might decrease M2 receptor function on peripheral neurons via similar direct mechanisms. METHODOLOGY/PRINCIPAL FINDINGS: Intravenous administration of paraoxon, but not parathion, caused acute frequency-dependent potentiation of vagally-induced bronchoconstriction and increased electrical field stimulation (EFS-induced contractions in isolated trachea independent of AChE inhibition. However, paraoxon had no effect on vagally-induced bradycardia in intact guinea pigs or EFS-induced contractions in isolated ileum, suggesting mechanisms other than pharmacologic antagonism of M2 receptors. Paraoxon did not alter M2 receptor expression in cultured cells at the mRNA or protein level as determined by quantitative RT-PCR and radio-ligand binding assays, respectively. Additionally, a biotin-labeled fluorophosphonate, which was used as a probe to identify molecular targets phosphorylated by OPs, did not phosphorylate proteins in guinea pig cardiac membranes that were recognized by M2 receptor antibodies. CONCLUSIONS/SIGNIFICANCE: These data indicate that neither direct pharmacologic antagonism nor downregulated expression of M2 receptors contributes to OP inhibition of M2 function in airway nerves, adding to the growing evidence of non-cholinergic mechanisms of OP neurotoxicity.

  14. Dialkyl phosphate metabolites of organophosphorus in applicators of agricultural pesticides in Majes – Arequipa (Peru

    Directory of Open Access Journals (Sweden)

    Chung Arturo

    2006-12-01

    Full Text Available Abstract Background Organophosphorus (OPs pesticides are the most commonly used pesticides in Peruvian agriculture. The population at risk for OPs exposure includes formulators, applicators and farmers. Majes Valley is the most important agricultural center of the Southern region of Peru. The present study was aimed to determine the knowledge about using OPs, safety practice and urinary dialkylphosphate metabolites on OP applicators in the Majes Valley, Peru. Methods This study was based on a questionnaire which included socio-demographic characteristics, knowledge of safety practices to handling OPs, characteristics of pesticide application and use of protective measures to avoid pesticide contamination. Exposure was assessed by measuring six urinary OP metabolites (DMP, DMTP, DMDTP, DEP, DETP, and DEDTP by gas chromatography using a single flame photometric detector. The sample consisted of 31 men and 2 women aged 20 – 65 years old. Results 76% of applicators had at least one urinary dialkylphosphate metabolite above the limit of detection. The geometric mean (GM and the geometric standard deviation (GSD of DMP and DEP were 5.73 ug/g cr. (GSD 2.51, and 6.08 ug/g cr. (GSD 3.63, respectively. The percentage of applicators with detectable DMP, DMDTP, and DMTP in urine was 72.72%, 3.03%, and 15.15%, respectively, while the corresponding figures for DEP, DETP, and DEDTP were 48.48%, 36.36% and 15.15%, respectively. There was no significant association between the use of protection practices and the absence of urine OPs metabolites suggesting inadequate protection practices. Conclusion The pesticide applicators in Majes Valley have significant exposure to OP pesticides, probably due to inappropriate protective practices. Future work should evaluate possible health effects.

  15. Organophosphorus pollutants (OPP) in aquatic environment at Damietta Governorate, Egypt: implications for monitoring and biomarker responses.

    Science.gov (United States)

    Abdel-Halim, K Y; Salama, A K; El-Khateeb, E N; Bakry, N M

    2006-06-01

    The study was carried out from spring 1999 to spring 2001 to monitor the residue levels of organophosphorus pollutants (OPP) in aquatic environment of the drainage canal surrounding a pesticide factory at Damietta Governorate. Water, sediment, and fish samples were collected at six different seasonal periods. OPPs were analyzed by GLC and confirmed using GC-MS. Chlorpyrifos, chlorpyrifos-methyl, malathion, diazinon, pirimiphos-methyl and profenofos were detected in most samples. Chlorpyrifos was dominant in all water and sediment samples. It was ranged from 24.5 to 303.8 and 0.9 to 303.8 ppb in water and sediment samples, respectively. Diazinon level was slightly similar to chlorpyrifos in fish samples. Data based on the grand total concentration of OPP showed that the most polluted samples were collected either at spring 1999 or autumn 2000. They were 675.5 and 303.8 ppb in water samples and 43.0 and 52.2 ppb in fish collected at spring 1999 and autumn 2000, respectively. The obtained results are in parallel to that found in case of cholinesterase activity where the activity of both acetylcholinesterase (AChE) and butyrylcholinesterase (BuChE) was declined at these seasonal period. The activity levels of AChE and BuChE were found to be 77.18% and 59.67% of control at spring 1999 and 78.62% and 85.80% of control, at autumn 2000, respectively. Thus, AChE and BuChE could be used as biomarkers for tracing and biomonitoring OPP pollution.

  16. Antioxidant Role of Pomegranates on Liver and Brain Tissues of Rats Exposed to an Organophosphorus Insecticide

    International Nuclear Information System (INIS)

    Abd Elmonem, H.A.

    2014-01-01

    Toxicities of organophosphorus insecticides cause oxidative damage on many organs such as the liver and brain due to generation of reactive oxygen species. Pomegranate is among the richest fruit in poly - phenols. The aim of this study was to compare between the antioxidant strength of pomegranate juice (PJ) and pomegranate molasses (PM) and their effects on alanine transferase (ALT), aspartate aminotransferase (AST), Alkaline phosphatase (ALP) and total protein (TP) in liver and levels of malondialdehyde (MAD), reduced glutathione (GSH) and nitric oxide (NO) in rat liver and brain tissues exposed to 1/10 LD 50 diazinon (DI). Six groups each of 6 male albino rats were used comprising control, DI, PJ, PM, PJ + DI and PM + DI for 15 days. The activities of ALT, AST, and TP concentration in liver have been increased due to treatment of rats with DI. These increases restored to normalcy when rats were supplemented with PJ or PM with DI. The results demonstrate that treatment with DI induced significant increase in MDA and NO concentrations and significant decrease in GSH levels of liver and brain tissues. The administration of PJ or PM along with DI significant decrease in MDA and NO levels and significant increase in GSH level compared to DI-group. The present study suggest that PJ or PM has a potential protective effect as it can elevate antioxidant defense system, lessens induced oxidative dam - ages and protect the brain and liver tissue against DI-induced toxicity. In addition, comaring PJ with PM it was noticed that PJ had higher antioxidant activity as evidenced by increased GSH content and decreased NO level in the liver by greater extend than PM.

  17. Evaluation of medical countermeasures against organophosphorus compounds: the value of experimental data and computer simulations.

    Science.gov (United States)

    Worek, Franz; Aurbek, Nadine; Herkert, Nadja M; John, Harald; Eddleston, Michael; Eyer, Peter; Thiermann, Horst

    2010-09-06

    Despite extensive research for more than six decades on medical countermeasures against poisoning by organophosphorus compounds (OP) the treatment options are meagre. The presently established acetylcholinesterase (AChE) reactivators (oximes), e.g. obidoxime and pralidoxime, are insufficient against a number of nerve agents and there is ongoing debate on the benefit of oxime treatment in human OP pesticide poisoning. Up to now, the therapeutic efficacy of oximes was mostly evaluated in animal models but substantial species differences prevent direct extrapolation of animal data to humans. Hence, it was considered essential to establish relevant experimental in vitro models for the investigation of oximes as antidotes and to develop computer models for the simulation of oxime efficacy in different scenarios of OP poisoning. Kinetic studies on the various interactions between erythrocyte AChE from various species, structurally different OP and different oximes provided a basis for the initial assessment of the ability of oximes to reactivate inhibited AChE. In the present study, in vitro enzyme-kinetic and pharmacokinetic data from a minipig model of dimethoate poisoning and oxime treatment were used to calculate dynamic changes of AChE activities. It could be shown that there is a close agreement between calculated and in vivo AChE activities. Moreover, computer simulations provided insight into the potential and limitations of oxime treatment. In the end, such data may be a versatile tool for the ongoing discussion of the pros and cons of oxime treatment in human OP pesticide poisoning. Copyright (c) 2009 Elsevier Ireland Ltd. All rights reserved.

  18. Developmental neurotoxicity of the organophosphorus insecticide chlorpyrifos: from clinical findings to preclinical models and potential mechanisms.

    Science.gov (United States)

    Burke, Richard D; Todd, Spencer W; Lumsden, Eric; Mullins, Roger J; Mamczarz, Jacek; Fawcett, William P; Gullapalli, Rao P; Randall, William R; Pereira, Edna F R; Albuquerque, Edson X

    2017-08-01

    Organophosphorus (OP) insecticides are pest-control agents heavily used worldwide. Unfortunately, they are also well known for the toxic effects that they can trigger in humans. Clinical manifestations of an acute exposure of humans to OP insecticides include a well-defined cholinergic crisis that develops as a result of the irreversible inhibition of acetylcholinesterase (AChE), the enzyme that hydrolyzes the neurotransmitter acetylcholine (ACh). Prolonged exposures to levels of OP insecticides that are insufficient to trigger signs of acute intoxication, which are hereafter referred to as subacute exposures, have also been associated with neurological deficits. In particular, epidemiological studies have reported statistically significant correlations between prenatal subacute exposures to OP insecticides, including chlorpyrifos, and neurological deficits that range from cognitive impairments to tremors in childhood. The primary objectives of this article are: (i) to address the short- and long-term neurological issues that have been associated with acute and subacute exposures of humans to OP insecticides, especially early in life (ii) to discuss the translational relevance of animal models of developmental exposure to OP insecticides, and (iii) to review mechanisms that are likely to contribute to the developmental neurotoxicity of OP insecticides. Most of the discussion will be focused on chlorpyrifos, the top-selling OP insecticide in the United States and throughout the world. These points are critical for the identification and development of safe and effective interventions to counter and/or prevent the neurotoxic effects of these chemicals in the developing brain. This is an article for the special issue XVth International Symposium on Cholinergic Mechanisms. © 2017 International Society for Neurochemistry.

  19. Immobilization of Mortierella vinacea cells by radiation polymerization

    International Nuclear Information System (INIS)

    Kumakura, M.; Kaetsu, I.

    1983-01-01

    Immobilization of Mortierella vinacea cells, which contain active α-galactosidase, by radiation polymerization at low temperatures was studied. The durability of the enzymatic activity of the immobilized cells obtained with hydrophilic monomers was affected by the concentrations of the cells and monomer in which optimum conditions were observed. The enzymatic activity of the immobilized cells obtained with hydrophilic monomers was compared to that of hydrophobic monomers. Michaelis constants of the immobilized cells varied with monomer concentration. The effect of addition of porous solid substances on the immobilization of the cells was studied

  20. Identification of the chain-dispersing peptidoglycan hydrolase LytB of Streptococcus gordonii.

    Directory of Open Access Journals (Sweden)

    Riccardo Arrigucci

    Full Text Available Bacterial cell division ends with the separation of the daughter cells, a process that requires peptidoglycan hydrolases (PGHs. Bacteria lacking cell separating PGHs are impaired in cell separation with the formation of long chains or clusters. We identified a gene in Streptococcus gordonii encoding for a putative glucosaminidase (lytB. The lytB isogenic mutant grew in long bacterial chains and resulted in impaired biofilm formation. Purified recombinant LytB showed a murolytic activity on Micrococcus lysodeikticus cell suspension and was able to disperse the long chains of the mutant, restoring the wild type diplococci/short chain phenotype. LytB protein was localized only in culture supernatant cell fraction of S. gordonii, and co-cultures of wild type and lytB mutant showed a significant reduction of bacterial chain length, indicating that LytB is a secreted enzyme. Our results demonstrate that LytB is a secreted peptidoglycan hydrolase required for S. gordonii cell separation.

  1. Screening Brazilian Macrophomina phaseolina isolates for alkaline lipases and other extracellular hydrolases.

    Science.gov (United States)

    Schinke, Claudia; Germani, José C

    2012-03-01

    Macrophomina phaseolina, phylum Ascomycota, is a phytopathogenic fungus distributed worldwide in hot dry areas. There are few studies on its secreted lipases and none on its colony radial growth rate, an indicator of fungal ability to use nutrients for growth, on media other than potato-dextrose agar. In this study, 13 M. phaseolina isolates collected in different Brazilian regions were screened for fast-growth and the production of hydrolases of industrial interest, especially alkaline lipases. Hydrolase detection and growth rate determination were done on citric pectin, gelatin, casein, soluble starch, and olive oil as substrates. Ten isolates were found to be active on all substrates tested. The most commonly detected enzymes were pectinases, amylases, and lipases. The growth rate on pectin was significantly higher (P media identified CMM 2105, CMM 1091, and PEL as the fastest-growing isolates. The lipase activity of four isolates grown on olive oil was followed for 4 days by measuring the activity in the cultivation broth. The specific lipolytic activity of isolate PEL was significantly higher at 96 h (130 mU mg protein(-1)). The broth was active at 37 °C, pH 8, indicating the potential utility of the lipases of this isolate in mild alkaline detergents. There was a strong and positive correlation (0.86) between radial growth rate and specific lipolytic activity.

  2. Targeted discovery of glycoside hydrolases from a switchgrass-adapted compost community

    Energy Technology Data Exchange (ETDEWEB)

    Allgaier, M.; Reddy, A.; Park, J. I.; Ivanova, N.; D' haeseleer, P.; Lowry, S.; Sapra, R.; Hazen, T.C.; Simmons, B.A.; VanderGheynst, J. S.; Hugenholtz, P.

    2009-11-15

    Development of cellulosic biofuels from non-food crops is currently an area of intense research interest. Tailoring depolymerizing enzymes to particular feedstocks and pretreatment conditions is one promising avenue of research in this area. Here we added a green-waste compost inoculum to switchgrass (Panicum virgatum) and simulated thermophilic composting in a bioreactor to select for a switchgrass-adapted community and to facilitate targeted discovery of glycoside hydrolases. Small-subunit (SSU) rRNA-based community profiles revealed that the microbial community changed dramatically between the initial and switchgrass-adapted compost (SAC) with some bacterial populations being enriched over 20-fold. We obtained 225 Mbp of 454-titanium pyrosequence data from the SAC community and conservatively identified 800 genes encoding glycoside hydrolase domains that were biased toward depolymerizing grass cell wall components. Of these, {approx}10% were putative cellulases mostly belonging to families GH5 and GH9. We synthesized two SAC GH9 genes with codon optimization for heterologous expression in Escherichia coli and observed activity for one on carboxymethyl cellulose. The active GH9 enzyme has a temperature optimum of 50 C and pH range of 5.5 to 8 consistent with the composting conditions applied. We demonstrate that microbial communities adapt to switchgrass decomposition using simulated composting condition and that full-length genes can be identified from complex metagenomic sequence data, synthesized and expressed resulting in active enzyme.

  3. Targeted discovery of glycoside hydrolases from a switchgrass-adapted compost community.

    Directory of Open Access Journals (Sweden)

    Martin Allgaier

    Full Text Available Development of cellulosic biofuels from non-food crops is currently an area of intense research interest. Tailoring depolymerizing enzymes to particular feedstocks and pretreatment conditions is one promising avenue of research in this area. Here we added a green-waste compost inoculum to switchgrass (Panicum virgatum and simulated thermophilic composting in a bioreactor to select for a switchgrass-adapted community and to facilitate targeted discovery of glycoside hydrolases. Small-subunit (SSU rRNA-based community profiles revealed that the microbial community changed dramatically between the initial and switchgrass-adapted compost (SAC with some bacterial populations being enriched over 20-fold. We obtained 225 Mbp of 454-titanium pyrosequence data from the SAC community and conservatively identified 800 genes encoding glycoside hydrolase domains that were biased toward depolymerizing grass cell wall components. Of these, approximately 10% were putative cellulases mostly belonging to families GH5 and GH9. We synthesized two SAC GH9 genes with codon optimization for heterologous expression in Escherichia coli and observed activity for one on carboxymethyl cellulose. The active GH9 enzyme has a temperature optimum of 50 degrees C and pH range of 5.5 to 8 consistent with the composting conditions applied. We demonstrate that microbial communities adapt to switchgrass decomposition using simulated composting condition and that full-length genes can be identified from complex metagenomic sequence data, synthesized and expressed resulting in active enzyme.

  4. Extracellular Xylanolytic and Pectinolytic Hydrolase Production by Aspergillus flavus Isolates Contributes to Crop Invasion

    Directory of Open Access Journals (Sweden)

    Jay E. Mellon

    2015-08-01

    Full Text Available Several atoxigenic Aspergillus flavus isolates, including some being used as biocontrol agents, and one toxigenic isolate were surveyed for the ability to produce extracellular xylanolytic and pectinolytic hydrolases. All of the tested isolates displayed good production of endoxylanases when grown on a medium utilizing larch xylan as a sole carbon substrate. Four of the tested isolates produced reasonably high levels of esterase activity, while the atoxigenic biocontrol agent NRRL 21882 isolate esterase level was significantly lower than the others. Atoxigenic A. flavus isolates 19, 22, K49, AF36 (the latter two are biocontrol agents and toxigenic AF13 produced copious levels of pectinolytic activity when grown on a pectin medium. The pectinolytic activity levels of the atoxigenic A. flavus 17 and NRRL 21882 isolates were significantly lower than the other tested isolates. In addition, A. flavus isolates that displayed high levels of pectinolytic activity in the plate assay produced high levels of endopolygalacturonase (pectinase P2c, as ascertained by isoelectric focusing electrophoresis. Isolate NRRL 21882 displayed low levels of both pectinase P2c and pectin methyl esterase. A. flavus appears capable of producing these hydrolytic enzymes irrespective of aflatoxin production. This ability of atoxigenic isolates to produce xylanolytic and pectinolytic hydrolases mimics that of toxigenic isolates and, therefore, contributes to the ability of atoxigenic isolates to occupy the same niche as A. flavus toxigenic isolates.

  5. Differential recognition and hydrolysis of host carbohydrate antigens by Streptococcus pneumoniae family 98 glycoside hydrolases.

    Science.gov (United States)

    Higgins, Melanie A; Whitworth, Garrett E; El Warry, Nahida; Randriantsoa, Mialy; Samain, Eric; Burke, Robert D; Vocadlo, David J; Boraston, Alisdair B

    2009-09-18

    The presence of a fucose utilization operon in the Streptococcus pneumoniae genome and its established importance in virulence indicates a reliance of this bacterium on the harvesting of host fucose-containing glycans. The identities of these glycans, however, and how they are harvested is presently unknown. The biochemical and high resolution x-ray crystallographic analysis of two family 98 glycoside hydrolases (GH98s) from distinctive forms of the fucose utilization operon that originate from different S. pneumoniae strains reveal that one enzyme, the predominant type among pneumococcal isolates, has a unique endo-beta-galactosidase activity on the LewisY antigen. Altered active site topography in the other species of GH98 enzyme tune its endo-beta-galactosidase activity to the blood group A and B antigens. Despite their different specificities, these enzymes, and by extension all family 98 glycoside hydrolases, use an inverting catalytic mechanism. Many bacterial and viral pathogens exploit host carbohydrate antigens for adherence as a precursor to colonization or infection. However, this is the first evidence of bacterial endoglycosidase enzymes that are known to play a role in virulence and are specific for distinct host carbohydrate antigens. The strain-specific distribution of two distinct types of GH98 enzymes further suggests that S. pneumoniae strains may specialize to exploit host-specific antigens that vary from host to host, a factor that may feature in whether a strain is capable of colonizing a host or establishing an invasive infection.

  6. α/β-Hydrolase Domain 6 in the Ventromedial Hypothalamus Controls Energy Metabolism Flexibility

    Directory of Open Access Journals (Sweden)

    Alexandre Fisette

    2016-10-01

    Full Text Available α/β-Hydrolase domain 6 (ABHD6 is a monoacylglycerol hydrolase that degrades the endocannabinoid 2-arachidonoylglycerol (2-AG. Although complete or peripheral ABHD6 loss of function is protective against diet-induced obesity and insulin resistance, the role of ABHD6 in the central control of energy balance is unknown. Using a viral-mediated knockout approach, targeted endocannabinoid measures, and pharmacology, we discovered that mice lacking ABHD6 from neurons of the ventromedial hypothalamus (VMHKO have higher VMH 2-AG levels in conditions of endocannabinoid recruitment and fail to physiologically adapt to key metabolic challenges. VMHKO mice exhibited blunted fasting-induced feeding and reduced food intake, energy expenditure, and adaptive thermogenesis in response to cold exposure, high-fat feeding, and dieting (transition to a low-fat diet. Our findings identify ABHD6 as a regulator of the counter-regulatory responses to major metabolic shifts, including fasting, nutrient excess, cold, and dieting, thereby highlighting the importance of ABHD6 in the VMH in mediating energy metabolism flexibility.

  7. The Serine Hydrolase ABHD6 Is a Critical Regulator of the Metabolic Syndrome

    Directory of Open Access Journals (Sweden)

    Gwynneth Thomas

    2013-10-01

    Full Text Available The serine hydrolase α/β hydrolase domain 6 (ABHD6 has recently been implicated as a key lipase for the endocannabinoid 2-arachidonylglycerol (2-AG in the brain. However, the biochemical and physiological function for ABHD6 outside of the central nervous system has not been established. To address this, we utilized targeted antisense oligonucleotides (ASOs to selectively knock down ABHD6 in peripheral tissues in order to identify in vivo substrates and understand ABHD6’s role in energy metabolism. Here, we show that selective knockdown of ABHD6 in metabolic tissues protects mice from high-fat-diet-induced obesity, hepatic steatosis, and systemic insulin resistance. Using combined in vivo lipidomic identification and in vitro enzymology approaches, we show that ABHD6 can hydrolyze several lipid substrates, positioning ABHD6 at the interface of glycerophospholipid metabolism and lipid signal transduction. Collectively, these data suggest that ABHD6 inhibitors may serve as therapeutics for obesity, nonalcoholic fatty liver disease, and type II diabetes.

  8. Screening and evaluation of the glucoside hydrolase activity in Saccharomyces and Brettanomyces brewing yeasts.

    Science.gov (United States)

    Daenen, L; Saison, D; Sterckx, F; Delvaux, F R; Verachtert, H; Derdelinckx, G

    2008-02-01

    The aim of this study was to select and examine Saccharomyces and Brettanomyces brewing yeasts for hydrolase activity towards glycosidically bound volatile compounds. A screening for glucoside hydrolase activity of 58 brewing yeasts belonging to the genera Saccharomyces and Brettanomyces was performed. The studied Saccharomyces brewing yeasts did not show 1,4-beta-glucosidase activity, but a strain dependent beta-glucanase activity was observed. Some Brettanomyces species did show 1,4-beta-glucosidase activity. The highest constitutive activity was found in Brettanomyces custersii. For the most interesting strains the substrate specificity was studied and their activity was evaluated in fermentation experiments with added hop glycosides. Fermentations with Br. custersii led to the highest release of aglycones. Pronounced exo-beta-glucanase activity in Saccharomyces brewing yeasts leads to a higher release of certain aglycones. Certain Brettanomyces brewing yeasts, however, are more interesting for hydrolysis of glycosidically bound volatiles of hops. The release of flavour active compounds from hop glycosides opens perspectives for the bioflavouring and product diversification of beverages like beer. The release can be enhanced by using Saccharomyces strains with high exo-beta-glucanase activity. Higher activities can be found in Brettanomyces species with beta-glucosidase activity.

  9. Malbranchea cinnamomea: A thermophilic fungal source of catalytically efficient lignocellulolytic glycosyl hydrolases and metal dependent enzymes.

    Science.gov (United States)

    Mahajan, Chhavi; Basotra, Neha; Singh, Surender; Di Falco, Marcos; Tsang, Adrian; Chadha, B S

    2016-01-01

    This study reports thermophilic fungus Malbranchea cinnamomea as an important source of lignocellulolytic enzymes. The secretome analysis using LC-MS/MS orbitrap showed that fungus produced a spectrum of glycosyl hydrolases (cellulase/hemicellulase), polysaccharide lyases (PL) and carbohydrate esterases (CE) in addition to cellobiose dehydrogenase (CDH) indicating the presence of functional classical and oxidative cellulolytic mechanisms. The protein fractions in the secretome resolved by ion exchange chromatography were analyzed for ability to hydrolyze alkali treated carrot grass (ATCG) in the presence of Mn(2+)/Cu(2+). This strategy in tandem with peptide mass fingerprinting led to identification of metal dependent protein hydrolases with no apparent hydrolytic activity, however, showed 5.7 folds higher saccharification in presence of Mn(2+). Furthermore, adding different protein fractions to commercial cellulase (Novozymes: Cellic CTec2) resulted in enhanced hydrolysis of ATCG ranging between 1.57 and 3.43 folds indicating the enzymes from M. cinnamomea as catalytically efficient. Copyright © 2015 Elsevier Ltd. All rights reserved.

  10. Novel Strategies for Upstream and Downstream Processing of Tannin Acyl Hydrolase

    Directory of Open Access Journals (Sweden)

    Luis V. Rodríguez-Durán

    2011-01-01

    Full Text Available Tannin acyl hydrolase also referred as tannase is an enzyme with important applications in several science and technology fields. Due to its hydrolytic and synthetic properties, tannase could be used to reduce the negative effects of tannins in beverages, food, feed, and tannery effluents, for the production of gallic acid from tannin-rich materials, the elucidation of tannin structure, and the synthesis of gallic acid esters in nonaqueous media. However, industrial applications of tannase are still very limited due to its high production cost. Thus, there is a growing interest in the production, recovery, and purification of this enzyme. Recently, there have been published a number of papers on the improvement of upstream and downstream processing of the enzyme. These papers dealt with the search for new tannase producing microorganisms, the application of novel fermentation systems, optimization of culture conditions, the production of the enzyme by recombinant microorganism, and the design of efficient protocols for tannase recovery and purification. The present work reviews the state of the art of basic and biotechnological aspects of tannin acyl hydrolase, focusing on the recent advances in the upstream and downstream processing of the enzyme.

  11. Novel strategies for upstream and downstream processing of tannin acyl hydrolase.

    Science.gov (United States)

    Rodríguez-Durán, Luis V; Valdivia-Urdiales, Blanca; Contreras-Esquivel, Juan C; Rodríguez-Herrera, Raúl; Aguilar, Cristóbal N

    2011-01-01

    Tannin acyl hydrolase also referred as tannase is an enzyme with important applications in several science and technology fields. Due to its hydrolytic and synthetic properties, tannase could be used to reduce the negative effects of tannins in beverages, food, feed, and tannery effluents, for the production of gallic acid from tannin-rich materials, the elucidation of tannin structure, and the synthesis of gallic acid esters in nonaqueous media. However, industrial applications of tannase are still very limited due to its high production cost. Thus, there is a growing interest in the production, recovery, and purification of this enzyme. Recently, there have been published a number of papers on the improvement of upstream and downstream processing of the enzyme. These papers dealt with the search for new tannase producing microorganisms, the application of novel fermentation systems, optimization of culture conditions, the production of the enzyme by recombinant microorganism, and the design of efficient protocols for tannase recovery and purification. The present work reviews the state of the art of basic and biotechnological aspects of tannin acyl hydrolase, focusing on the recent advances in the upstream and downstream processing of the enzyme.

  12. Microbial biodegradation of biuret: defining biuret hydrolases within the isochorismatase superfamily.

    Science.gov (United States)

    Robinson, Serina L; Badalamenti, Jonathan P; Dodge, Anthony G; Tassoulas, Lambros J; Wackett, Lawrence P

    2018-03-12

    Biuret is a minor component of urea fertilizer and an intermediate in s-triazine herbicide biodegradation. The microbial metabolism of biuret has never been comprehensively studied. Here, we enriched and isolated bacteria from a potato field that grew on biuret as a sole nitrogen source. We sequenced the genome of the fastest-growing isolate, Herbaspirillum sp. BH-1 and identified genes encoding putative biuret hydrolases (BHs). We purified and characterized a functional BH enzyme from Herbaspirillum sp. BH-1 and two other bacteria from divergent phyla. The BH enzymes reacted exclusively with biuret in the range of 2-11 µmol min -1 mg -1 protein. We then constructed a global protein superfamily network to map structure-function relationships in the BH subfamily and used this to mine > 7000 genomes. High-confidence BH sequences were detected in Actinobacteria, Alpha- and Beta-proteobacteria, and some fungi, archaea and green algae, but not animals or land plants. Unexpectedly, no cyanuric acid hydrolase homologs were detected in > 90% of genomes with BH homologs, suggesting BHs may have arisen independently of s-triazine ring metabolism. This work links genotype to phenotype by enabling accurate genome-mining to predict microbial utilization of biuret. Importantly, it advances understanding of the microbial capacity for biuret biodegradation in agricultural systems. © 2018 Society for Applied Microbiology and John Wiley & Sons Ltd.

  13. COMPARATIVE MODELLING AND LIGAND BINDING SITE PREDICTION OF A FAMILY 43 GLYCOSIDE HYDROLASE FROM Clostridium thermocellum

    Directory of Open Access Journals (Sweden)

    Shadab Ahmed

    2012-06-01

    Full Text Available The phylogenetic analysis of Clostridium thermocellum family 43 glycoside hydrolase (CtGH43 showed close evolutionary relation with carbohydrate binding family 6 proteins from C. cellulolyticum, C. papyrosolvens, C. cellulyticum, and A. cellulyticum. Comparative modeling of CtGH43 was performed based on crystal structures with PDB IDs 3C7F, 1YIF, 1YRZ, 2EXH and 1WL7. The structure having lowest MODELLER objective function was selected. The three-dimensional structure revealed typical 5-fold beta–propeller architecture. Energy minimization and validation of predicted model with VERIFY 3D indicated acceptability of the proposed atomic structure. The Ramachandran plot analysis by RAMPAGE confirmed that family 43 glycoside hydrolase (CtGH43 contains little or negligible segments of helices. It also showed that out of 301 residues, 267 (89.3% were in most favoured region, 23 (7.7% were in allowed region and 9 (3.0% were in outlier region. IUPred analysis of CtGH43 showed no disordered region. Active site analysis showed presence of two Asp and one Glu, assumed to form a catalytic triad. This study gives us information about three-dimensional structure and reaffirms the fact that it has the similar core 5-fold beta–propeller architecture and so probably has the same inverting mechanism of action with the formation of above mentioned catalytic triad for catalysis of polysaccharides.

  14. Molecular Basis of Prodrug Activation by Human Valacyclovirase, an [alpha]-Amino Acid Ester Hydrolase

    Energy Technology Data Exchange (ETDEWEB)

    Lai, Longsheng; Xu, Zhaohui; Zhou, Jiahai; Lee, Kyung-Dall; Amidon, Gordon L. (Michigan)

    2008-07-08

    Chemical modification to improve biopharmaceutical properties, especially oral absorption and bioavailability, is a common strategy employed by pharmaceutical chemists. The approach often employs a simple structural modification and utilizes ubiquitous endogenous esterases as activation enzymes, although such enzymes are often unidentified. This report describes the crystal structure and specificity of a novel activating enzyme for valacyclovir and valganciclovir. Our structural insights show that human valacyclovirase has a unique binding mode and specificity for amino acid esters. Biochemical data demonstrate that the enzyme hydrolyzes esters of {alpha}-amino acids exclusively and displays a broad specificity spectrum for the aminoacyl moiety similar to tricorn-interacting aminopeptidase F1. Crystal structures of the enzyme, two mechanistic mutants, and a complex with a product analogue, when combined with biochemical analysis, reveal the key determinants for substrate recognition; that is, a flexible and mostly hydrophobic acyl pocket, a localized negative electrostatic potential, a large open leaving group-accommodating groove, and a pivotal acidic residue, Asp-123, after the nucleophile Ser-122. This is the first time that a residue immediately after the nucleophile has been found to have its side chain directed into the substrate binding pocket and play an essential role in substrate discrimination in serine hydrolases. These results as well as a phylogenetic analysis establish that the enzyme functions as a specific {alpha}-amino acid ester hydrolase. Valacyclovirase is a valuable target for amino acid ester prodrug-based oral drug delivery enhancement strategies.

  15. Cloning, expression and mutation of a triazophos hydrolase gene from Burkholderia sp. SZL-1.

    Science.gov (United States)

    Zhang, Hao; Li, Qiang; Guo, Su-Hui; Cheng, Ming-Gen; Zhao, Meng-Jun; Hong, Qing; Huang, Xing

    2016-06-01

    Triazophos is a broad-spectrum and highly effective insecticide, and the residues of triazophos have been frequently detected in the environment. A triazophos-degrading bacterium, Burkholderia sp. SZL-1, was isolated from a long-term triazophos-polluted soil. Strain SZL-1 could hydrolyze triazophos to 1-phenyl-3-hydroxy-1,2,4-triazole, which was further utilized as the carbon sources for growth. The triazophos hydrolase gene trhA, cloned from strain SZL-1, was expressed and homogenously purified using Ni-nitrilotriacetic acid affinity chromatography. TrhA is 55 kDa and displays maximum activity at 25°C, pH 8.0. This enzyme still has nearly 60% activity at the range of 15°C-50°C for 30 min. TrhA was mutated by sequential error prone PCR and screened for improved activity for triazophos degradation. One purified variant protein (Val89-Gly89) named TrhA-M1 showed up to 3-fold improvement in specific activity against triazophos, and the specificity constants of Kcat and Kcat/Km for TrhA-M1 were improved up to 2.3- and 8.28-fold, respectively, compared to the wild-type enzyme. The results in this paper provided potential material for the contaminated soil remediation and hydrolase genetic structure research. © FEMS 2016. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  16. Identification of the Gene Encoding Isoprimeverose-producing Oligoxyloglucan Hydrolase in Aspergillus oryzae*

    Science.gov (United States)

    Matsuzawa, Tomohiko; Mitsuishi, Yasushi; Kameyama, Akihiko

    2016-01-01

    Aspergillus oryzae produces a unique β-glucosidase, isoprimeverose-producing oligoxyloglucan hydrolase (IPase), that recognizes and releases isoprimeverose (α-d-xylopyranose-(1→6)-d-glucopyranose) units from the non-reducing ends of oligoxyloglucans. A gene encoding A. oryzae IPase, termed ipeA, was identified and expressed in Pichia pastoris. With the exception of cellobiose, IpeA hydrolyzes a variety of oligoxyloglucans and is a member of the glycoside hydrolase family 3. Xylopyranosyl branching at the non-reducing ends was vital for IPase activity, and galactosylation at a α-1,6-linked xylopyranosyl side chain completely abolished IpeA activity. Hepta-oligoxyloglucan saccharide (Xyl3Glc4) substrate was preferred over tri- (Xyl1Glc2) and tetra- (Xyl2Glc2) oligoxyloglucan saccharides substrates. IpeA transferred isoprimeverose units to other saccharides, indicating transglycosylation activity. The ipeA gene was expressed in xylose and xyloglucan media and was strongly induced in the presence of xyloglucan endo-xyloglucanase-hydrolyzed products. This is the first study to report the identification of a gene encoding IPase in eukaryotes. PMID:26755723

  17. Systematic Survey of Serine Hydrolase Activity in Mycobacterium tuberculosis Defines Changes Associated with Persistence

    Energy Technology Data Exchange (ETDEWEB)

    Ortega, Corrie; Anderson, Lindsey N.; Frando, Andrew; Sadler, Natalie C.; Brown, Robert W.; Smith, Richard D.; Wright, Aaron T.; Grundner, Christoph

    2016-02-01

    The transition between replication and non-replication underlies much of Mycobacterium tuberculosis (Mtb) pathogenicity, as non- or slowly replicating Mtb are responsible for persistence and poor treatment outcomes. Therapeutic targeting of non-replicating, persistent populations is a priority for tuberculosis treatment, but only few drug targets in non-replicating Mtb are currently known. Here, we directly measure the activity of the highly diverse and druggable serine hydrolases (SHs) during active replication and non-replication by activity-based proteomics. We predict serine hydrolase activity for 78 proteins, including 27 proteins with previously unknown function, and identify 37 SHs that remain active even in the absence of replication, providing a set of candidate persistence targets. Non-replication was associated with large shifts in the activity of the majority of SHs. These activity changes were largely independent of SH abundance, indicating extensive post-translational regulation. By probing a large cross-section of druggable Mtb enzyme space during replication and non-replication, we identify new SHs and suggest new persistence targets.

  18. Targeted Discovery of Glycoside Hydrolases from a Switchgrass-Adapted Compost Community

    Energy Technology Data Exchange (ETDEWEB)

    Reddy, Amitha; Allgaier, Martin; Park, Joshua I.; Ivanoval, Natalia; Dhaeseleer, Patrik; Lowry, Steve; Sapra, Rajat; Hazen, Terry C.; Simmons, Blake A.; VanderGheynst, Jean S.; Hugenholtz, Philip

    2011-05-11

    Development of cellulosic biofuels from non-food crops is currently an area of intense research interest. Tailoring depolymerizing enzymes to particular feedstocks and pretreatment conditions is one promising avenue of research in this area. Here we added a green-waste compost inoculum to switchgrass (Panicum virgatum) and simulated thermophilic composting in a bioreactor to select for a switchgrass-adapted community and to facilitate targeted discovery of glycoside hydrolases. Smallsubunit (SSU) rRNA-based community profiles revealed that the microbial community changed dramatically between the initial and switchgrass-adapted compost (SAC) with some bacterial populations being enriched over 20-fold. We obtained 225 Mbp of 454-titanium pyrosequence data from the SAC community and conservatively identified 800 genes encoding glycoside hydrolase domains that were biased toward depolymerizing grass cell wall components. Of these, ,10percent were putative cellulasesmostly belonging to families GH5 and GH9. We synthesized two SAC GH9 genes with codon optimization for heterologous expression in Escherichia coli and observed activity for one on carboxymethyl cellulose. The active GH9 enzyme has a temperature optimum of 50uC and pH range of 5.5 to 8 consistent with the composting conditions applied. We demonstrate that microbial communities adapt to switchgrass decomposition using simulated composting condition and that full-length genes can be identified from complex metagenomic sequence data, synthesized and expressed resulting in active enzyme.

  19. Dust Measurement of Two Organophosphorus Flame Retardants, Resorcinol Bis(diphenylphosphate) (RBDPP) and Bisphenol A Bis(diphenylphosphate) (BPA-BDPP), Used as Alternatives for BDE-209

    NARCIS (Netherlands)

    Brandsma, S.H.; Sellström, U.; de Wit, C.A.; de Boer, J.; Leonards, P.E.G.

    2013-01-01

    Resorcinol bis(diphenylphosphate) (RBDPP) and bisphenol A bis(diphenylphosphate) (BPA-BDPP) are two halogen-free organophosphorus flame retardant (PFRs) that are used as an alternative for the decabromodiphenyl ether (Deca-BDE) technical mixture in TV/flatscreen housing and other electronic consumer

  20. Monitoring of organochlorine and organophosphorus pesticide residues in water during different seasons of Tighra reservoir Gwalior, Madhya Pradesh, India.

    Science.gov (United States)

    Mamta; Rao, R J; Wani, Khursheed Ahmad

    2015-11-01

    Analysis of pesticides during different seasons for pesticidal contamination in water samples of Tighra reservoir was carried out on gas chromatograph-electron capture detector with capillary columns following multiresidual analytical technique. Organochlorine pesticides, viz., hexachlorobenzene (HCB), alpha-benzene hexachloride (BHC), beta-BHC, γ-BHC, heptachlor, aldrin, alpha-endosulfan, beta-endosulfan, p,p-DDE, dieldrin, o,p-dichlorodiphenyldichloroethane (DDD), p,p-DDD, p,p-dichlorodiphenyltrichloroethane (DDT), and endrin, and organophosphorus pesticides, viz., choloropyrifos, methyl parathion, diazion, dicholorovos, ethion, malathion, and parathion, were detected in water samples during different seasons. However, the pesticide concentration varied during different seasons at different sites. The prominent reason of contamination is the use of pesticides (both organochlorine and organophosphorus) in the agricultural fields near Tighra reservoir. On the basis of our observations, more extensive monitoring studies need to be carried out, covering all wetlands of Madhya Pradesh to enforce the policies for the restricted application of pesticides in agricultural fields adjacent to wetlands.

  1. Pharmacokinetics and effects on serum cholinesterase activities of organophosphorus pesticides acephate and chlorpyrifos in chimeric mice transplanted with human hepatocytes.

    Science.gov (United States)

    Suemizu, Hiroshi; Sota, Shigeto; Kuronuma, Miyuki; Shimizu, Makiko; Yamazaki, Hiroshi

    2014-11-01

    Organophosphorus pesticides acephate and chlorpyrifos in foods have potential to impact human health. The aim of the current study was to investigate the pharmacokinetics of acephate and chlorpyrifos orally administered at lowest-observed-adverse-effect-level doses in chimeric mice transplanted with human hepatocytes. Absorbed acephate and its metabolite methamidophos were detected in serum from wild type mice and chimeric mice orally administered 150mg/kg. Approximately 70% inhibition of cholinesterase was evident in plasma of chimeric mice with humanized liver (which have higher serum cholinesterase activities than wild type mice) 1day after oral administrations of acephate. Adjusted animal biomonitoring equivalents from chimeric mice studies were scaled to human biomonitoring equivalents using known species allometric scaling factors and in vitro metabolic clearance data with a simple physiologically based pharmacokinetic (PBPK) model. Estimated plasma concentrations of acephate and chlorpyrifos in humans were consistent with reported concentrations. Acephate cleared similarly in humans and chimeric mice but accidental/incidental overdose levels of chlorpyrifos cleared (dependent on liver metabolism) more slowly from plasma in humans than it did in mice. The data presented here illustrate how chimeric mice transplanted with human hepatocytes in combination with a simple PBPK model can assist evaluations of toxicological potential of organophosphorus pesticides. Copyright © 2014 Elsevier Inc. All rights reserved.

  2. Novel organophosphorus scaffolds of urease inhibitors obtained by substitution of Morita-Baylis-Hillman adducts with phosphorus nucleophiles.

    Science.gov (United States)

    Ntatsopoulos, Vassilis; Vassiliou, Stamatia; Macegoniuk, Katarzyna; Berlicki, Łukasz; Mucha, Artur

    2017-06-16

    The reactivity of Morita-Baylis-Hillman allyl acetates was employed to introduce phosphorus-containing functionalities to the side chain of the cinnamic acid conjugated system by nucleophilic displacement. The proximity of two acidic groups, the carboxylate and phosphonate/phosphinate groups, was necessary to form interactions in the active site of urease by recently described inhibitor frameworks. Several organophosphorus scaffolds were obtained and screened for inhibition of the bacterial urease, an enzyme that is essential for survival of urinary and gastrointestinal tract pathogens. α-Substituted phosphonomethyl- and 2-phosphonoethyl-cinnamate appeared to be the most potent and were further optimized. As a result, one of the most potent organophosphorus inhibitors of urease, α-phosphonomethyl-p-methylcinnamic acid, was identified, with K i  = 0.6 μM for Sporosarcina pasteurii urease. High complementarity to the enzyme active site was achieved with this structure, as any further modifications significantly decreased its affinity. Finally, this work describes the challenges faced in developing ligands for urease. Copyright © 2017 Elsevier Masson SAS. All rights reserved.

  3. Synthesis of organophosphorus modified nanoparticles and their reinforcements on the fire safety and mechanical properties of polyurea

    Energy Technology Data Exchange (ETDEWEB)

    Qian, Xiaodong [State Key Laboratory of Fire Science, University of Science and Technology of China, 96 Jinzhai Road, Hefei, Anhui 230026 (China); USTC-CityU Joint Advanced Research Centre, Suzhou Key Laboratory of Urban Public Safety, Suzhou Institute for Advanced Study, University of Science and Technology of China, 166 Ren’ai Road Suzhou, Jiangsu 215123 (China); Song, Lei, E-mail: leisong@ustc.edu.cn [State Key Laboratory of Fire Science, University of Science and Technology of China, 96 Jinzhai Road, Hefei, Anhui 230026 (China); Wang, Bibo [State Key Laboratory of Fire Science, University of Science and Technology of China, 96 Jinzhai Road, Hefei, Anhui 230026 (China); Hu, Yuan, E-mail: yuanhu@ustc.edu.cn [State Key Laboratory of Fire Science, University of Science and Technology of China, 96 Jinzhai Road, Hefei, Anhui 230026 (China); USTC-CityU Joint Advanced Research Centre, Suzhou Key Laboratory of Urban Public Safety, Suzhou Institute for Advanced Study, University of Science and Technology of China, 166 Ren’ai Road Suzhou, Jiangsu 215123 (China); Yuen, Richard K.K., E-mail: Richard.Yuen@cityu.edu.hk [USTC-CityU Joint Advanced Research Centre, Suzhou Key Laboratory of Urban Public Safety, Suzhou Institute for Advanced Study, University of Science and Technology of China, 166 Ren’ai Road Suzhou, Jiangsu 215123 (China); Department of Building and Construction, City University of Hong Kong, Tat Chee Avenue Kowloon (Hong Kong)

    2013-05-15

    Novel organophosphorus modified nanoparticles (FRs-nanoparticles) were synthesized by the hydrolysis and condensation of both 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide modified vinyl trimethoxy silane (DOPO-VTS) and 3-triethoxysilylpropylamine. FRs-nanoparticles were incorporated into the polyurea matrix in different ratios via in situ polymerization, resulting in the formation of organic/inorganic nanocomposites. The nanocomposites were characterized by thermogravimetric analysis (TGA), real-time fourier transform infrared spectra (RTIR), microscale combustion calorimeter (MCC) and tensile testing machine. The TGA results revealed that FRs-nanoparticles could slightly catalyze the thermal degradation of the nanocomposites in nitrogen atmosphere, but significantly improve the thermal stability of the nanocomposites in air atmosphere. The T{sub 0.5} (50wt.% weight loss) of the nanocomposites was delayed by 32 °C in air atmosphere. Moreover, the char yield increased from 2.3wt.% to 8.9 wt.% at 550 °C when the loadings of FRs-nanoparticles was 10wt.%, indicating the catalyzing charring effect of FRs-nanoparticles. The MCC results revealed that all the nanocomposites exhibited much lower flammability compared with virgin polyurea. Furthermore, the tensile test indicated that the FRs-nanoparticles could also improve the mechanical properties of polyurea. - Highlights: ► Novel organophosphorus modified nanoparticles (FRs-nanoparticles) were synthesized. ► FRs-nanoparticles were incorporated into the polyurea. ► Both the thermal stability and mechanical properties of polyurea were improved.

  4. Detection of Organophosphorus Pesticides in Wheat by Ionic Liquid-Based Dispersive Liquid-Liquid Microextraction Combined with HPLC

    Directory of Open Access Journals (Sweden)

    Wei Liu

    2018-01-01

    Full Text Available Food safety issues closely related to human health have always received widespread attention from the world society. As a basic food source, wheat is the fundamental support of human survival; therefore, the detection of pesticide residues in wheat is very necessary. In this work, the ultrasonic-assisted ionic liquid-dispersive liquid-liquid microextraction (DLLME method was firstly proposed, and the extraction and analysis of three organophosphorus pesticides were carried out by combining high-performance liquid chromatography (HPLC. The extraction efficiencies of three ionic liquids with bis(trifluoromethylsulfonylimide (Tf2N anion were compared by extracting organophosphorus in wheat samples. It was found that the use of 1-octyl-3-methylimidazolium bis(trifluoromethylsulfonylimide ([OMIM][Tf2N] had both high enrichment efficiency and appropriate extraction recovery. Finally, the method was used for the determination of three wheat samples, and the recoveries of them were 74.8–112.5%, 71.8–104.5%, and 83.8–115.5%, respectively. The results show that the method proposed is simple, fast, and efficient, which can be applied to the extraction of organic matters in wheat samples.

  5. Synthesis of organophosphorus modified nanoparticles and their reinforcements on the fire safety and mechanical properties of polyurea

    International Nuclear Information System (INIS)

    Qian, Xiaodong; Song, Lei; Wang, Bibo; Hu, Yuan; Yuen, Richard K.K.

    2013-01-01

    Novel organophosphorus modified nanoparticles (FRs-nanoparticles) were synthesized by the hydrolysis and condensation of both 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide modified vinyl trimethoxy silane (DOPO-VTS) and 3-triethoxysilylpropylamine. FRs-nanoparticles were incorporated into the polyurea matrix in different ratios via in situ polymerization, resulting in the formation of organic/inorganic nanocomposites. The nanocomposites were characterized by thermogravimetric analysis (TGA), real-time fourier transform infrared spectra (RTIR), microscale combustion calorimeter (MCC) and tensile testing machine. The TGA results revealed that FRs-nanoparticles could slightly catalyze the thermal degradation of the nanocomposites in nitrogen atmosphere, but significantly improve the thermal stability of the nanocomposites in air atmosphere. The T 0.5 (50wt.% weight loss) of the nanocomposites was delayed by 32 °C in air atmosphere. Moreover, the char yield increased from 2.3wt.% to 8.9 wt.% at 550 °C when the loadings of FRs-nanoparticles was 10wt.%, indicating the catalyzing charring effect of FRs-nanoparticles. The MCC results revealed that all the nanocomposites exhibited much lower flammability compared with virgin polyurea. Furthermore, the tensile test indicated that the FRs-nanoparticles could also improve the mechanical properties of polyurea. - Highlights: ► Novel organophosphorus modified nanoparticles (FRs-nanoparticles) were synthesized. ► FRs-nanoparticles were incorporated into the polyurea. ► Both the thermal stability and mechanical properties of polyurea were improved

  6. Screening of supports for immobilization of commercial porcine pancreatic lipase

    Directory of Open Access Journals (Sweden)

    Robison Scherer

    2011-12-01

    Full Text Available The aim of this work is to report the performance of different supports for the immobilization of commercial porcine pancreatic lipase. The immobilization tests were carried out in several types of Accurel, activated alumina, kaolin, montmorillonite, ion exchange resins and zeolites. The characterization of the supports showed differences in terms of specific area and morphology. The characteristics of the supports influenced the amount of enzyme adsorbed, yield of immobilization and esterification activity of the resulting immobilized catalyst. The clays KSF and natural and pillared montmorillonites presented potential for use as support for lipase immobilization in terms of yield and esterification activity. Yields of immobilization of 76.32 and 52.01% were achieved for clays KSF and natural montmorillonite, respectively. Esterification activities of 754.03, 595.51, 591.88 and 515.71 U.g-1 were obtained for lipases immobilized in Accurel MP-100, Amberlite XAD-2, mordenite and pillared montmorillonite, respectively.

  7. Immobilization of Isolated Lipase From Moldy Copra (Aspergillus Oryzae

    Directory of Open Access Journals (Sweden)

    Seniwati Dali

    2011-01-01

    Full Text Available Enzyme immobilization is a recovery technique that has been studied in several years, using support as a media to help enzyme dissolutions to the reaction substrate. Immobilization method used in this study was adsorption method, using specific lipase from Aspergillus oryzae. Lipase was partially purified from the culture supernatant of Aspergillus oryzae. Enzyme was immobilized by adsorbed on silica gel. Studies on free and immobilized lipase systems for determination of optimum pH, optimum temperature, thermal stability and reusability were carried out. The results showed that free lipase had optimum pH 8,2 and optimum temperature 35 °C while the immobilized lipase had optimum 8,2 and optimum temperature 45 °C. The thermal stability of the immobilized lipase, relative to that of the free lipase, was markedly increased. The immobilized lipase can be reused for at least six times.

  8. Technologies for immobilization and disposal of tritium

    International Nuclear Information System (INIS)

    Coppari, N.R.

    1996-01-01

    This study was done within a program one of whose objectives was to know the state of the technology development for tritium separation in the moderator circuit at HWR and to define the possible technologies to be applied to the Argentine nuclear power plants. Within this framework the strategies adopted by each country and the available technologies for a safe disposal of tritium, not only in its gaseous state tritium but also as tritiated water were analyzed. It is considered that if the selected separation method is such that the tritium is in its gaseous state, the hydride formation for long periods of immobilization should be studied. whereas if it were triated water immobilization should be studied to choose the technology between cementation and drying agents, in both cases the final disposal site will have to be selected. (author). 8 refs

  9. Fluctuation correlation models for receptor immobilization

    Science.gov (United States)

    Fourcade, B.

    2017-12-01

    Nanoscale dynamics with cycles of receptor diffusion and immobilization by cell-external-or-internal factors is a key process in living cell adhesion phenomena at the origin of a plethora of signal transduction pathways. Motivated by modern correlation microscopy approaches, the receptor correlation functions in physical models based on diffusion-influenced reaction is studied. Using analytical and stochastic modeling, this paper focuses on the hybrid regime where diffusion and reaction are not truly separable. The time receptor autocorrelation functions are shown to be indexed by different time scales and their asymptotic expansions are given. Stochastic simulations show that this analysis can be extended to situations with a small number of molecules. It is also demonstrated that this analysis applies when receptor immobilization is coupled to environmental noise.

  10. Immobilization of IFR salt wastes in mortar

    International Nuclear Information System (INIS)

    Fisher, D.F.; Johnson, T.R.

    1988-01-01

    Portland cement-base mortars are being considered for immobilizing chloride salt wastes from the fuel cycle of an integral fast reactor (IFR). The IFR is a sodium-cooled fast reactor with metal fuel. It has a close-coupled fuel cycle in which fission products are separated from the actinides in an electrochemical cell operating at 500 degrees C. This cell has a cadmium anode and a liquid salt electrolyte. The salt will be a low-melting mixture of alkaline and alkaline earth chlorides. This paper discusses one method being considered for immobilizing this treated salt, to disperse it in a portland cement-base motar, which would then be sealed in corrosion-resistant containers. For this application, the grout must be sufficiently fluid that it can be pumped into canisters where it will solidify into a strong, leach-resistant material

  11. Capture and immobilization of krypton-85

    International Nuclear Information System (INIS)

    Whitmell, D.S.; Geens, L.; Penzhorn, R.D.; Smith, M.J.S.

    1985-01-01

    It may become necessary to contain the krypton-85 released from nuclear fuel during reprocessing in order to reduce the exposure to the local population and the radioactive background throughout the world. A brief description is given of studies being carried out in the Indirect Action Programme. The separation of krypton from other off-gases by cryogenic distillation in the presence of oxygen is being studied at SCK/CEN Mol, together with the behavior of ozone in the distillation column. Two processes for the immobilization of krypton in solid forms have been successfully developed and demonstrated. At KfK Karlsruhe, krypton is encapsulated in vitrified zeolites; at AERE Harwell, krypton is immobilized within a metallic matrix. These processes offer excellent gas retention and either could be adopted for a reprocessing plant

  12. Weight and height prediction of immobilized patients

    OpenAIRE

    Rabito,Estela Iraci; Vannucchi,Gabriela Bergamini; Suen,Vivian Marques Miguel; Castilho Neto,Laércio Lopes; Marchini,Júlio Sérgio

    2006-01-01

    OBJECTIVE: To confirm the adequacy of the formula suggested in the literature and/or to develop appropriate equations for the Brazilian population of immobilized patients based on simple anthropometric measurements. METHODS: Hospitalized patients were submitted to anthropometry and methods to estimate weight and height of bedridden patients were developed by multiple linear regression. RESULTS: Three hundred sixty eight persons were evaluated at two hospital centers and five weight-predicting...

  13. Immobilized yeast in bioreactor for alcohol fermentation

    International Nuclear Information System (INIS)

    Handy, M.K.; Kim, K.

    1986-01-01

    Mutant of Saccharomyces cerevisiae was developed using a Co-60 source. Cells were immobilized onto sterile, channeled alumina beads and packed into bioreactor column under controlled temperature. Feedstocks containing substrate and nutrients were fed into the bioreactor at specific rates. Beads with greatest porosity and surface area produced the most ethanol. Factors affecting ethanol productivity included: temperature, pH, flow rate, nutrients and substrate in the feedstock

  14. Immobilization of radioactive waste in glass matrices

    International Nuclear Information System (INIS)

    Wicks, G.G.

    1978-01-01

    A promising process for long-term management of high-level radioactive waste is to immobilize the waste in a borosilicate glass matrix. Among the most important criteria characterizing the integrity of the large-scale glass-waste forms are that they possess good chemical stability (including low leachability), thermal stability, mechanical integrity, and high radiation stability. Fulfillment of these criteria ensures the maximum margin of safety of glass-waste products, following solidification, handling, transportation, and long-term storage

  15. Optimization of Immobilization of Nanodiamonds on Graphene

    International Nuclear Information System (INIS)

    Pille, A; Lange, S; Utt, K; Eltermann, M

    2015-01-01

    We report using simple dip-coating method to cover the surface of graphene with nanodiamonds for future optical detection of defects on graphene. Most important part of the immobilization process is the pre-functionalization of both, nanodiamond and graphene surfaces to obtain the selectiveness of the method. This work focuses on an example of using electrostatic attraction to confine nanodiamonds to graphene. Raman spectroscopy, microluminescence imaging and scanning electron microscopy were applied to characterize obtained samples. (paper)

  16. Process arrangement options for Defense waste immobilization

    International Nuclear Information System (INIS)

    1980-02-01

    Current plans are to immobilize the SRP high-level liquid wastes in a high integrity form. Borosilicate glass was selected in 1977 as the reference waste form and a mjaor effort is currently underway to develop the required technology. A large new facility, referred to as the Defense Waste Processing Facility (DWPF) is being designed to carry out this mission, with project authorization targeted for 1982 and plant startup in 1989. However, a number of other process arrangements or manufacturing strategies, including staging the major elements of the project or using existing SRP facilities for some functions, have been suggested in lieu of building the reference DWPF. This study assesses these various options and compares them on a technical and cost basis with the DWPF. Eleven different manufacturing options for SRP defense waste solidification were examined in detail. These cases are: (1) vitrification of acid waste at current generation rate; (2) vitrification of current rate acid waste and caustic sludge; (3 and 4) vitrification of the sludge portion of neutralized waste; (5) decontamination of salt cake and storage of concentrated cesium and strontium for later immobilization; (6) processing waste in a facility with lower capacity than the DWPF; (7) processing waste in a combination of existing and new facilities; (8) waste immobilization in H Canyon; (9) vitrification of both sludge and salt; (10) DWPF with onsite storage; (11) deferred authorization of DWPF

  17. Immobilization of Chloroperoxidase on Aminopropyl-Glass

    Science.gov (United States)

    Kadima, Tenshuk A.; Pickard, Michael A.

    1990-01-01

    Chloroperoxidase (CPO) purified from Caldariomyces fumago CMI 89362 was covalently bound to aminopropyl-glass by using a modification of an established method. Acid-washed glass was derivatized by using aminopropyltriethoxysilane, and the enzyme was ionically bound at low ionic strength. Further treatment with glutaraldehyde covalently linked the enzyme to the glass beads in an active form. No elution of bound activity from glass beads could be detected with a variety of washings. The loading of enzyme protein to the glass beads was highest, 100 mg of CPO per g of glass, at high reaction ratios of CPO to glass, but the specific activity of the immobilized enzyme was highest, 36% of theoretical, at low enzyme-to-carrier ratios. No differences in the properties of the soluble and immobilized enzymes could be detected by a number of criteria: their pH-activity and pH-stability profiles were similar, as were their thermal stabilities. After five uses, the immobilized enzyme retained full activity between pH 6.0 and 6.7. PMID:16348352

  18. Compound immobilization and drug-affinity chromatography.

    Science.gov (United States)

    Rix, Uwe; Gridling, Manuela; Superti-Furga, Giulio

    2012-01-01

    Bioactive small molecules act through modulating a yet unpredictable number of targets. It is therefore of critical importance to define the cellular target proteins of a compound as an entry point to understanding its mechanism of action. Often, this can be achieved in a direct fashion by chemical proteomics. As with any affinity chromatography, immobilization of the bait to a solid support is one of the earliest and most crucial steps in the process. Interfering with structural features that are important for identification of a target protein will be detrimental to binding affinity. Also, many molecules are sensitive to heat or to certain chemicals, such as acid or base, and might be destroyed during the process of immobilization, which therefore needs to be not only efficient, but also mild. The subsequent affinity chromatography step needs to preserve molecular and conformational integrity of both bait compound and proteins in order to result in the desired specific enrichment while ensuring a high level of compatibility with downstream analysis by mass spectrometry. Thus, the right choice of detergent, buffer, and protease inhibitors is also essential. This chapter describes a widely applicable procedure for the immobilization of small molecule drugs and for drug-affinity chromatography with subsequent protein identification by mass spectrometry.

  19. Oxidoreductases provide a more generic response to metallic stressors (Cu and Cd) than hydrolases in soil fungi: new ecotoxicological insights.

    Science.gov (United States)

    Lebrun, Jérémie D; Demont-Caulet, Nathalie; Cheviron, Nathalie; Laval, Karine; Trinsoutrot-Gattin, Isabelle; Mougin, Christian

    2016-02-01

    The present study investigates the effect of metals on the secretion of enzymes from 12 fungal strains maintained in liquid cultures. Hydrolases (acid phosphatase, β-glucosidase, β-galactosidase, and N-acetyl-β-glucosaminidase) and ligninolytic oxidoreductases (laccase, Mn, and lignin peroxidases) activities, as well as biomass production, were measured in culture fluids from fungi exposed to Cu or Cd. Our results showed that all fungi secreted most of the selected hydrolases and that about 50% of them produced a partial oxidative system in the absence of metals. Then, exposure of fungi to metals led to the decrease in biomass production. At the enzymatic level, Cu and Cd modified the secretion profiles of soil fungi. The response of hydrolases to metals was contrasted and complex and depended on metal, enzyme, and fungal strain considered. By contrast, the metals always stimulated the activity of ligninolytic oxidoreductases in fungal strains. In some of them, oxidoreductases were specifically produced following metal exposure. Fungal oxidoreductases provide a more generic response than hydrolases, constituting thus a physiological basis for their use as biomarkers of metal exposure in soils.

  20. Crystal Structure of α-1,4-Glucan Lyase, a Unique Glycoside Hydrolase Family Member with a Novel Catalytic Mechanism

    NARCIS (Netherlands)

    Rozeboom, Henriëtte J.; Yu, Shukun; Madrid, Susan; Kalk, Kor H.; Zhang, Ran; Dijkstra, Bauke W.

    2013-01-01

    α-1,4-Glucan lyase (EC 4.2.2.13) from the red seaweed Gracilariopsis lemaneiformis cleaves α-1,4-glucosidic linkages in glycogen, starch, and malto-oligosaccharides, yielding the keto-monosaccharide 1,5-anhydro-D-fructose. The enzyme belongs to glycoside hydrolase family 31 (GH31) but degrades

  1. Construction and characterisation of a genetically engineered Escherichia coli strain for the epoxide hydrolase-catalysed kinetic resolution of epoxides

    NARCIS (Netherlands)

    Visser, H.; Oliveira Vil Filho, de M.; Liese, A.; Weijers, C.A.G.M.; Verdoes, J.C.

    2003-01-01

    The Rhodotorula glutinis epoxide hydrolase, Eph1, was produced in the heterologous host Escherichia coli BL21(DE3) in order to develop a highly effective epoxide hydrolysis system. A 138-fold increase in Eph1 activity was found in cell extracts of the recombinant E. coli when compared to cell

  2. Cocaine Hydrolase Gene Transfer Demonstrates Cardiac Safety and Efficacy against Cocaine-Induced QT Prolongation in Mice

    OpenAIRE

    Murthy, Vishakantha; Reyes, Santiago; Geng, Liyi; Gao, Yang; Brimijoin, Stephen

    2016-01-01

    Cocaine addiction is associated with devastating medical consequences, including cardiotoxicity and risk-conferring prolongation of the QT interval. Viral gene transfer of cocaine hydrolase engineered from butyrylcholinesterase offers therapeutic promise for treatment-seeking drug users. Although previous preclinical studies have demonstrated benefits of this strategy without signs of toxicity, the specific cardiac safety and efficacy of engineered butyrylcholinesterase viral delivery remains...

  3. Mice lacking lipid droplet-associated hydrolase, a gene linked to human prostate cancer, have normal cholesterol ester metabolism

    DEFF Research Database (Denmark)

    Kory, Nora; Grond, Susanne; Kamat, Siddhesh S

    2017-01-01

    Variations in the gene LDAH (C2ORF43), which encodes lipid droplet-associated hydrolase (LDAH), are among few loci associated with human prostate cancer. Homologs of LDAH have been identified as proteins of lipid droplets (LDs). LDs are cellular organelles that store neutral lipids...

  4. Genetic and biochemical characterization of a novel monoterpene epsilon-lactone hydrolase from Rhodococcus erythropolis DCL14

    NARCIS (Netherlands)

    Vlugt-Bergmans, van der C.J.B.; Werf, van der M.J.

    2001-01-01

    A monoterpene ε-lactone hydrolase (MLH) from Rhodococcus erythropolis DCL14, catalyzing the ring opening of lactones which are formed during degradation of several monocyclic monoterpenes, including carvone and menthol, was purified to apparent homogeneity. It is a monomeric enzyme of 31 kDa that is

  5. Genetic and biochemical characterization of a novel monoterpene e-lactone hydrolase from Rhodococcus erythropolis DCL14

    NARCIS (Netherlands)

    Vlugt-Bergmans, C.J.B. van der; Werf, M.J. van der

    2001-01-01

    A monoterpene ε-lactone hydrolase (MLH) from Rhodococcus erythropolis DCL14, catalyzing the ring opening of lactones which are formed during degradation of several monocyclic monoterpenes, including carvone and menthol, was purified to apparent homogeneity. It is a monomeric enzyme of 31 kDa that is

  6. Biotechnological potential of novel glycoside hydrolase family 70 enzymes synthesizing α-glucans from starch and sucrose

    NARCIS (Netherlands)

    Gangoiti, Joana; Pijning, Tjaard; Dijkhuizen, Lubbert

    Transglucosidases belonging to the glycoside hydrolase (GH) family 70 are promising enzymatic tools for the synthesis of α-glucans with defined structures from renewable sucrose and starch substrates. Depending on the GH70 enzyme specificity, α-glucans with different structures and physicochemical

  7. Acetobacter turbidans α-Amino Acid Ester Hydrolase. How a Single Mutation Improves an Antibiotic-Producing Enzyme

    NARCIS (Netherlands)

    Barends, Thomas R.M.; Polderman-Tijmes, Jolanda J.; Jekel, Peter A.; Williams, Christopher; Wybenga, Gjalt; Janssen, Dick B.; Dijkstra, Bauke W.

    2006-01-01

    The α-amino acid ester hydrolase (AEH) from Acetobacter turbidans is a bacterial enzyme catalyzing the hydrolysis and synthesis of β-lactam antibiotics. The crystal structures of the native enzyme, both unliganded and in complex with the hydrolysis product D-phenylglycine are reported, as well as

  8. Discovery of α-L-arabinopyranosidases from human gut microbiome expands the diversity within glycoside hydrolase family 42

    DEFF Research Database (Denmark)

    Viborg, Alexander Holm; Katayama, Takane; Arakawa, Takatoshi

    2017-01-01

    Enzymes of the glycoside hydrolase family 42 (GH42) are widespread in bacteria of the human gut microbiome and play fundamental roles in the decomposition of both milk and plant oligosaccharides. All GH42 enzymes characterized so far have β-galactosidase activity. Here, we report the existence...

  9. Genetic variation in the bleomycin hydrolase gene and bleomycin-induced pulmonary toxicity in germ cell cancer patients

    NARCIS (Netherlands)

    Nuver, J; Lutke-Holzik, MF; van Zweeden, M; Hoekstra, HJ; Meijer, C; Suurmeijer, AJH; Hofstra, RM; Sluiter, WJ; Sleijfer, D; Gietema, JA; Groen, Hendricus; Groen, Herman

    Objective Use of bleomycin as a cytotoxic agent is limited by its pulmonary toxicity. Bleomycin is mainly excreted by the kidneys, but can also be inactivated by bleomycin hydrolase (BMH). An 1450A > G polymorphic site in the BMH gene results in an amino acid substitution in the C-terminal domain of

  10. Fatty Acid Amide Hydrolase (FAAH) Inhibition Enhances Memory Acquisition through Activation of PPAR-alpha Nuclear Receptors

    Science.gov (United States)

    Mazzola, Carmen; Medalie, Julie; Scherma, Maria; Panlilio, Leigh V.; Solinas, Marcello; Tanda, Gianluigi; Drago, Filippo; Cadet, Jean Lud; Goldberg, Steven R.; Yasar, Sevil

    2009-01-01

    Inhibitors of fatty acid amide hydrolase (FAAH) increase endogenous levels of anandamide (a cannabinoid CB[subscript 1]-receptor ligand) and oleoylethanolamide and palmitoylethanolamide (OEA and PEA, ligands for alpha-type peroxisome proliferator-activated nuclear receptors, PPAR-alpha) when and where they are naturally released in the brain.…

  11. Organophosphorus flame retardants and heavy metals in municipal landfill leachate treatment system in Guangzhou, China.

    Science.gov (United States)

    Deng, Mingjun; Kuo, Dave T F; Wu, Qihang; Zhang, Ying; Liu, Xinyu; Liu, Shengyu; Hu, Xiaodong; Mai, Bixian; Liu, Zhineng; Zhang, Haozhi

    2018-05-01

    The occurrence, distribution and removal efficiencies of organophosphorus flame retardants (OPFRs) and metals were examined in a municipal landfill leachate treatment system in Guangzhou, China. Five OPFRs and thirty-five metals were detected in wastewater samples collected at different treatment stages. ∑OPFRs was reduced from 4807.02 ng L -1 to 103.91 ng L -1 through the treatment system, with close to 98% removed from the dissolved phase. Tris(clorisopropyl) phosphates (TCPPs) dominated through the treatment process and accounted for over 80% and 50% of ∑OPFRs at the influent and the effluent, respectively. TCPPs were most efficiently removed (98.6%) followed by tris(2-chloroethyl) phosphate (TCEP) (96.6%) and triphenyl phosphate (TPP) (88.5%). For metals, Fe, Cr, and Rb were dominant in the raw leachate, detected at 7.55, 2.82, and 4.50 mg L -1 , respectively. Thirteen regulated heavy metals - including eight major pollutants (i.e., As. Cd, Cr, Cu, Hg, Ni, Pb, and Zn) - have been detected in all wastewater samples at sub-mg L -1 levels. Over 99.5% removal was achieved for Cr, Ni, and Fe, and close to 95% removal efficiency was observed for Rb. For the eight major heavy metals, over 99% removal was observed; the only exception was Cu, which was removed at 89%. It was found that microfiltration/reverse osmosis was critical for the removal of OPFRs and heavy metals while the core biological treatment played a minor role towards their removal. Remobilization of Co, Cu, Fe, Hg, Mn, Ni, Sb, and Sr from the returned sludge occurred during the second denitrification, indicating the need for additional post-biological process for effective removal of both contaminants. This study highlights the critical need to develop cheap, effective treatment technologies for contaminants-laden leachate generated from open dumps and under-designed landfills. Copyright © 2018 Elsevier Ltd. All rights reserved.

  12. Distinct patterns of gene and protein expression elicited by organophosphorus pesticides in Caenorhabditis elegans

    Directory of Open Access Journals (Sweden)

    Dennis William E

    2009-04-01

    Full Text Available Abstract Background The wide use of organophosphorus (OP pesticides makes them an important public health concern. Persistent effects of exposure and the mechanism of neuronal degeneration are continuing issues in OP toxicology. To elucidate early steps in the mechanisms of OP toxicity, we studied alterations in global gene and protein expression in Caenorhabditis elegans exposed to OPs using microarrays and mass spectrometry. We tested two structurally distinct OPs (dichlorvos and fenamiphos and employed a mechanistically different third neurotoxicant, mefloquine, as an out-group for analysis. Treatment levels used concentrations of chemical sufficient to prevent the development of 10%, 50% or 90% of mid-vulval L4 larvae into early gravid adults (EGA at 24 h after exposure in a defined, bacteria-free medium. Results After 8 h of exposure, the expression of 87 genes responded specifically to OP treatment. The abundance of 34 proteins also changed in OP-exposed worms. Many of the genes and proteins affected by the OPs are expressed in neuronal and muscle tissues and are involved in lipid metabolism, cell adhesion, apoptosis/cell death, and detoxification. Twenty-two genes were differentially affected by the two OPs; a large proportion of these genes encode cytochrome P450s, UDP-glucuronosyl/UDP-glucosyltransferases, or P-glycoproteins. The abundance of transcripts and the proteins they encode were well correlated. Conclusion Exposure to OPs elicits a pattern of changes in gene expression in exposed worms distinct from that of the unrelated neurotoxicant, mefloquine. The functional roles and the tissue location of the genes and proteins whose expression is modulated in response to exposure is consistent with the known effects of OPs, including damage to muscle due to persistent hypercontraction, neuronal cell death, and phase I and phase II detoxification. Further, the two different OPs evoked distinguishable changes in gene expression; about half

  13. Tracing organophosphorus and brominated flame retardants and plasticizers in an estuarine food web.

    Science.gov (United States)

    Brandsma, Sicco H; Leonards, Pim E G; Leslie, Heather A; de Boer, Jacob

    2015-02-01

    Nine organophosphorus flame retardants (PFRs) were detected in a pelagic and benthic food web of the Western Scheldt estuary, The Netherlands. Concentrations of several PFRs were an order of magnitude higher than those of the brominated flame retardants (BFRs). However, the detection frequency of the PFRs (6-56%) was lower than that of the BFRs (50-97%). Tris(2-butoxyethyl) phosphate (TBOEP), tris(isobutyl) phosphate (TIBP) and tris(2-chloroisopropyl) phosphate (TCIPP) were the dominant PFRs in sediment with median concentrations of 7.0, 8.1 and 1.8 ng/g dry weight (dw), respectively. PFR levels in the suspended particular matter (SPM) were 2-12 times higher than that in sediment. TBOEP, TCIPP, TIBP, tris(2-chloroethyl) phosphate (TCEP) and tris(phenyl) phosphate (TPHP) were found in organisms higher in the estuarine food web. The highest PFR concentrations in the benthic food web were found in sculpin, goby and lugworm with median concentrations of 17, 7.4, 4.6 and 2.0 ng/g wet weight (ww) for TBOEP, TIBP, TCIPP and TPHP, respectively. Comparable levels were observed in the pelagic food web, BDE209 was the predominant PBDE in sediment and SPM with median concentrations up to 9.7 and 385 ng/g dw, respectively. BDE47 was predominant in the biotic compartment of the food web with highest median levels observed in sculpin and common tern eggs of 79 ng/g lipid weight (lw) (2.5 ng/g ww) and 80 ng/g lw (11 ng/g ww), respectively. Trophic magnification was observed for all PBDEs with the exception of BDE209. Indications of trophic magnification of PFRs were observed in the benthic food web for TBOEP, TCIPP and TCEP with tentative trophic magnification factors of 3.5, 2.2 and 2.6, respectively (pwebs. The relative high PFR levels in several fish species suggest high emissions and substantial exposure of organisms to PFRs in the Western Scheldt. Copyright © 2014 Elsevier B.V. All rights reserved.

  14. Bacterial Cell Enlargement Requires Control of Cell Wall Stiffness Mediated by Peptidoglycan Hydrolases.

    Science.gov (United States)

    Wheeler, Richard; Turner, Robert D; Bailey, Richard G; Salamaga, Bartłomiej; Mesnage, Stéphane; Mohamad, Sharifah A S; Hayhurst, Emma J; Horsburgh, Malcolm; Hobbs, Jamie K; Foster, Simon J

    2015-07-28

    Most bacterial cells are enclosed in a single macromolecule of the cell wall polymer, peptidoglycan, which is required for shape determination and maintenance of viability, while peptidoglycan biosynthesis is an important antibiotic target. It is hypothesized that cellular enlargement requires regional expansion of the cell wall through coordinated insertion and hydrolysis of peptidoglycan. Here, a group of (apparent glucosaminidase) peptidoglycan hydrolases are identified that are together required for cell enlargement and correct cellular morphology of Staphylococcus aureus, demonstrating the overall importance of this enzyme activity. These are Atl, SagA, ScaH, and SagB. The major advance here is the explanation of the observed morphological defects in terms of the mechanical and biochemical properties of peptidoglycan. It was shown that cells lacking groups of these hydrolases have increased surface stiffness and, in the absence of SagB, substantially increased glycan chain length. This indicates that, beyond their established roles (for example in cell separation), some hydrolases enable cellular enlargement by making peptidoglycan easier to stretch, providing the first direct evidence demonstrating that cellular enlargement occurs via modulation of the mechanical properties of peptidoglycan. Understanding bacterial growth and division is a fundamental problem, and knowledge in this area underlies the treatment of many infectious diseases. Almost all bacteria are surrounded by a macromolecule of peptidoglycan that encloses the cell and maintains shape, and bacterial cells must increase the size of this molecule in order to enlarge themselves. This requires not only the insertion of new peptidoglycan monomers, a process targeted by antibiotics, including penicillin, but also breakage of existing bonds, a potentially hazardous activity for the cell. Using Staphylococcus aureus, we have identified a set of enzymes that are critical for cellular enlargement. We

  15. Enzymatic Analysis of G- and V-Agents and Their Degradation Products

    National Research Council Canada - National Science Library

    Elashvili, Ilya

    2003-01-01

    .... The nerve agents can be hydrolyzed to their respective methylphosphonate alkyl ester (h-agent) products by alkali treatment or by specific hydrolytic enzymes, such as organophosphorus hydrolase...

  16. The effectiveness of immobilization during prostate irradiation

    International Nuclear Information System (INIS)

    Bentel, Gunilla C.; Marks, Lawrence B.; Sherouse, George W.; Spencer, David P.; Anscher, Mitchell S.

    1995-01-01

    Purpose: To evaluate the effect of a hemibody foam cradle on the reproducibility of patient setup during external beam radiation treatment of prostate cancer. Methods and Materials: Between January 1992 and April 1993, 74 patients received external beam radiation treatment to the prostate ± nodes, generally with a four-field box technique. Forty-four of the 74 patients had a custom-made hemibody foam cast used in an attempt to improve setup accuracy. A review of the routine weekly port films was performed following the completion of therapy to determine the reproducibility of patient setup in all 74 patients. The physician's request of an isocenter shift was used as an indicator of reproducibility. Neither the treating technologists nor the physicians knew at the time the films were taken that the port films would be reviewed for setup reproducibility at a later date. The results were compared between the patients treated with (44) and without (30) an immobilization device. Results: In the 44 immobilized patients, 213 routine checks of the isocenter were performed during the 7-week course of radiation therapy. In 17.4% of these instances (37 out of 213), an isocenter shift was requested. This rate is compared to 23.1% (30 out of 130) in the 30 patients who did not have the immobilization device (p < 0.2). There was a statistically significant reduction in isocenter shifts requested in the anterior to posterior direction in the patients who were immobilized, 5.1% (9 out of 175) vs. 12.6% (13 out of 103) (p < 0.05, two tailed chi-square test). There was no significant improvement in the reproducibility of isocenter placement in the cephalad to caudal or right to left directions. Conclusions: This custom-made hemibody foam cradle appears to improve the reproducibility of patient setup during the 7-week course of fractionated external beam irradiation for patients with adenocarcinoma of the prostate. This type of immobilization device is now routinely used in our

  17. Analysis of monomeric and oligomeric organophosphorus flame retardants in fish muscle tissues using liquid chromatography–electrospray ionization tandem mass spectrometry: Application to Nile tilapia (Oreochromis niloticus) from an e-waste processing area in northern Vietnam

    OpenAIRE

    Matsukami, Hidenori; Suzuki, Go; Tue, Nguyen Minh; Tuyen, Le Huu; Viet, Pham Hung; Takahashi, Shin; Tanabe, Shinsuke; Takigami, Hidetaka

    2016-01-01

    Using electrospray ionization tandem mass spectrometry combined with liquid chromatography (LC), a novel analytical method was developed to quantify eight monomeric organophosphorus flame retardants (m-PFRs) and three oligomeric organophosphorus flame retardants (o-PFRs) in fish muscle samples. The optimization and validation experiments indicate that the developed method can determine accurately the concentrations of analytes in fish muscle samples. The recoveries of analytes in fish muscle ...

  18. Enzyme immobilization and biocatalysis of polysiloxanes

    Science.gov (United States)

    Poojari, Yadagiri

    Lipases have been proven to be versatile and efficient biocatalysts which can be used in a broad variety of esterification, transesterification, and ester hydrolysis reactions. Due to the high chemo-, regio-, and stereo-selectivity and the mild conditions of lipase-catalyzed reactions, the vast potential of these biocatalysts for use in industrial applications has been increasingly recognized. Polysiloxanes (silicones) are well known for their unique physico-chemical properties and can be prepared in the form of fluids, elastomers, gels and resins for a wide variety of applications. However, the enzymatic synthesis of silicone polyesters and copolymers is largely unexplored. In the present investigations, an immobilized Candida antarctica lipase B (CALB) on macroporous acrylic resin beads (Novozym-435 RTM) has been successfully employed as a catalyst to synthesize silicone polyesters and copolymers under mild reaction conditions. The silicone aliphatic polyesters and the poly(dimethylsiloxane)--poly(ethylene glycol) (PDMS-PEG) copolymers were synthesized in the bulk (without using a solvent), while the silicone aromatic polyesters, the silicone aromatic polyamides and the poly(epsilon-caprolactone)--poly(dimethylsiloxane)--poly(epsilon-caprolactone) (PCL-PDMS-PCL) triblock copolymers were synthesized in toluene. The synthesized silicone polyesters and copolymers were characterized by Gel Permeation Chromatography (GPC), Fourier Transform Infrared Spectroscopy (FTIR), Thermogravimetric Analysis (TGA), Differential Scanning Calorimetry (DSC) and Wide Angle X-ray Diffraction (WAXD). This dissertation also describes a methodology for physical immobilization of the enzyme pepsin from Porcine stomach mucosa in silicone elastomers utilizing condensation-cure room temperature vulcanization (RTV) of silanol-terminated poly(dimethylsiloxane) (PDMS). The activity and the stability of free pepsin and pepsin immobilized in silicone elastomers were studied with respect to p

  19. Lipase immobilization and production of fatty acid methyl esters from canola oil using immobilized lipase

    International Nuclear Information System (INIS)

    Yuecel, Yasin; Demir, Cevdet; Dizge, Nadir; Keskinler, Buelent

    2011-01-01

    Lipase enzyme from Aspergillus oryzae (EC 3.1.1.3) was immobilized onto a micro porous polymeric matrix which contains aldehyde functional groups and methyl esters of long chain fatty acids (biodiesel) were synthesized by transesterification of crude canola oil using immobilized lipase. Micro porous polymeric matrix was synthesized from styrene-divinylbenzene (STY-DVB) copolymers by using high internal phase emulsion technique and two different lipases, Lipozyme TL-100L ® and Novozym 388 ® , were used for immobilization by both physical adsorption and covalent attachment. Biodiesel production was carried out with semi-continuous operation. Methanol was added into the reactor by three successive additions of 1:4 M equivalent of methanol to avoid enzyme inhibition. The transesterification reaction conditions were as follows: oil/alcohol molar ratio 1:4; temperature 40 o C and total reaction time 6 h. Lipozyme TL-100L ® lipase provided the highest yield of fatty acid methyl esters as 92%. Operational stability was determined with immobilized lipase and it indicated that a small enzyme deactivation occurred after used repeatedly for 10 consecutive batches with each of 24 h. Since the process is yet effective and enzyme does not leak out from the polymer, the method can be proposed for industrial applications. -- Research highlights: → Lipozyme TL-100L and Novozym 388 were immobilized onto micro porous polymeric matrix by both physical adsorption and covalent linking. → Immobilized enzymes were used for synthesis of fatty acid methyl esters by transesterification of canola oil and methanol using semi-continuous operation system. → According to chromatographic analysis, Lipase Lipozyme TL-100L resulted in the highest yield of methyl ester as 92%.

  20. Identification and characterization of carprofen as a multitarget fatty acid amide hydrolase/cyclooxygenase inhibitor.

    Science.gov (United States)

    Favia, Angelo D; Habrant, Damien; Scarpelli, Rita; Migliore, Marco; Albani, Clara; Bertozzi, Sine Mandrup; Dionisi, Mauro; Tarozzo, Glauco; Piomelli, Daniele; Cavalli, Andrea; De Vivo, Marco

    2012-10-25

    Pain and inflammation are major therapeutic areas for drug discovery. Current drugs for these pathologies have limited efficacy, however, and often cause a number of unwanted side effects. In the present study, we identify the nonsteroidal anti-inflammatory drug carprofen as a multitarget-directed ligand that simultaneously inhibits cyclooxygenase-1 (COX-1), COX-2, and fatty acid amide hydrolase (FAAH). Additionally, we synthesized and tested several derivatives of carprofen, sharing this multitarget activity. This may result in improved analgesic efficacy and reduced side effects (Naidu et al. J. Pharmacol. Exp. Ther.2009, 329, 48-56; Fowler, C. J.; et al. J. Enzyme Inhib. Med. Chem.2012, in press; Sasso et al. Pharmacol. Res.2012, 65, 553). The new compounds are among the most potent multitarget FAAH/COX inhibitors reported so far in the literature and thus may represent promising starting points for the discovery of new analgesic and anti-inflammatory drugs.

  1. Soluble Epoxide Hydrolase Inhibitory Activity of Selaginellin Derivatives from Selaginella tamariscina

    Directory of Open Access Journals (Sweden)

    Jang Hoon Kim

    2015-12-01

    Full Text Available Selaginellin derivatives 1–3 isolated from Selaginella tamariscina were evaluated for their inhibition of soluble epoxide hydrolase (sEH to demonstrate their potential for the treatment of cardiovascular disease. All selaginellin derivatives (1–3 inhibited sEH enzymatic activity and PHOME hydrolysis, in a dose-dependent manner, with IC50 values of 3.1 ± 0.1, 8.2 ± 2.2, and 4.2 ± 0.2 μM, respectively. We further determined that the derivatives function as non-competitive inhibitors. Moreover, the predicted that binding sites and interaction between 1–3 and sEH were solved by docking simulations. According to quantitative analysis, 1–3 were confirmed to have high content in the roots of S. tamariscina; among them, selaginellin 3 exhibited the highest content of 189.3 ± 0.0 μg/g.

  2. N (6-substituted AMPs inhibit mammalian deoxynucleotide N-hydrolase DNPH1.

    Directory of Open Access Journals (Sweden)

    Claire Amiable

    Full Text Available The gene dnph1 (or rcl encodes a hydrolase that cleaves the 2'-deoxyribonucleoside 5'-monophosphate (dNMP N-glycosidic bond to yield a free nucleobase and 2-deoxyribose 5-phosphate. Recently, the crystal structure of rat DNPH1, a potential target for anti-cancer therapies, suggested that various analogs of AMP may inhibit this enzyme. From this result, we asked whether N (6-substituted AMPs, and among them, cytotoxic cytokinin riboside 5'-monophosphates, may inhibit DNPH1. Here, we characterized the structural and thermodynamic aspects of the interactions of these various analogs with DNPH1. Our results indicate that DNPH1 is inhibited by cytotoxic cytokinins at concentrations that inhibit cell growth.

  3. Development and Properties of a Wax Ester Hydrolase in the Cotyledons of Jojoba Seedlings 1

    Science.gov (United States)

    Huang, Anthony H. C.; Moreau, Robert A.; Liu, Kitty D. F.

    1978-01-01

    The activity of a wax ester hydrolase in the cotyledons of jojoba (Simmondsia chinensis) seedlings increased drastically during germination, parallel to the development of the gluconeogenic process. The enzyme at its peak of development was obtained in association with the wax body membrane, and its properties were studied. It had an optimal activity at alkaline pH (8.5-9). The apparent Km value for N-methylindoxylmyristate was 93 μM. It was stable at 40 C for 30 min but was inactivated at higher temperature. Various divalent cations and ethylenediaminetetraacetate had little effect on the activity. p-Chloromercuribenzoate was a strong inhibitor of the enzyme activity, and its effect was reversed by subsequent addition of dithiothreitol. It had a broad substrate specificity with highest activities on monoglycerides, wax esters, and the native substrate (jojoba wax). PMID:16660288

  4. Development and properties of a wax ester hydrolase in the cotyledons of jojoba seedlings.

    Science.gov (United States)

    Huang, A H; Moreau, R A; Liu, K D

    1978-03-01

    The activity of a wax ester hydrolase in the cotyledons of jojoba (Simmondsia chinensis) seedlings increased drastically during germination, parallel to the development of the gluconeogenic process. The enzyme at its peak of development was obtained in association with the wax body membrane, and its properties were studied. It had an optimal activity at alkaline pH (8.5-9). The apparent K(m) value for N-methylindoxylmyristate was 93 muM. It was stable at 40 C for 30 min but was inactivated at higher temperature. Various divalent cations and ethylenediaminetetraacetate had little effect on the activity. p-Chloromercuribenzoate was a strong inhibitor of the enzyme activity, and its effect was reversed by subsequent addition of dithiothreitol. It had a broad substrate specificity with highest activities on monoglycerides, wax esters, and the native substrate (jojoba wax).

  5. Use of nanostructure initiator mass spectrometry (NIMS to deduce selectivity of reaction in glycoside hydrolases

    Directory of Open Access Journals (Sweden)

    Kai eDeng

    2015-10-01

    Full Text Available Chemically synthesized nanostructure-initiator mass spectrometry (NIMS probes derivatized with tetrasaccharides were used to study the reactivity of representative Clostridium thermocellum β-glucosidase, endoglucanases and cellobiohydrolase. Diagnostic patterns for reactions of these different classes of enzymes were observed. Results show sequential removal of glucose by the β-glucosidase and a progressive increase in specificity of reaction from endoglucanases to cellobiohydrolase. Time-dependent reactions of these polysaccharide-selective enzymes were modeled by numerical integration, which provides a quantitative basis to make functional distinctions among a continuum of naturally evolved catalytic properties. Consequently, our method, which combines automated protein translation with high-sensitivity and time-dependent detection of multiple products, provides a new approach to annotate glycoside hydrolase phylogenetic trees with functional measurements.

  6. Chitosanases from Family 46 of Glycoside Hydrolases: From Proteins to Phenotypes

    Directory of Open Access Journals (Sweden)

    Pascal Viens

    2015-10-01

    Full Text Available Chitosanases, enzymes that catalyze the endo-hydrolysis of glycolytic links in chitosan, are the subject of numerous studies as biotechnological tools to generate low molecular weight chitosan (LMWC or chitosan oligosaccharides (CHOS from native, high molecular weight chitosan. Glycoside hydrolases belonging to family GH46 are among the best-studied chitosanases, with four crystallography-derived structures available and more than forty enzymes studied at the biochemical level. They were also subjected to numerous site-directed mutagenesis studies, unraveling the molecular mechanisms of hydrolysis. This review is focused on the taxonomic distribution of GH46 proteins, their multi-modular character, the structure-function relationships and their biological functions in the host organisms.

  7. Selective inhibition of plant serine hydrolases by agrochemicals revealed by competitive ABPP.

    Science.gov (United States)

    Kaschani, Farnusch; Nickel, Sabrina; Pandey, Bikram; Cravatt, Benjamin F; Kaiser, Markus; van der Hoorn, Renier A L

    2012-01-15

    Organophosphate and -phosphonates and their thio derivatives are often used in agroindustry as herbicides and insecticides, but their potential off-targets in the plant are poorly investigated. Here, we use competitive activity-based protein profiling (ABPP) of serine hydrolases (SHs) to detect targets of these agrochemicals and other compounds in Arabidopsis thaliana. Using broad-range and specific probes, and by overexpression of various SHs in planta, we are able to confirm eight SH-compound interactions, including selective inhibition of carboxylesterase CXE12, prolyloligopeptidase, methylesterase MES2 and tripeptidyl peptidase TPP2. These observations can be used for the design of novel probes and selective inhibitors and may help to assess physiological effects of agrochemicals on crop plants. Copyright © 2011 Elsevier Ltd. All rights reserved.

  8. ETHANOL PRECIPITATION OF GLYCOSYL HYDROLASES PRODUCED BY Trichoderma harzianum P49P11

    Directory of Open Access Journals (Sweden)

    M. A. Mariño

    2015-06-01

    Full Text Available AbstractThis study aimed to concentrate glycosyl hydrolases produced by Trichoderma harzianum P49P11 by ethanol precipitation. The variables tested besides ethanol concentration were temperature and pH. The precipitation with 90% (v/v ethanol at pH 5.0 recovered more than 98% of the xylanase activity, regard less of the temperature (5.0, 15.0, or 25.0 °C. The maximum recovery of cellulase activity as FPase was 77% by precipitation carried out at this same pH and ethanol concentration but at 5.0 °C. Therefore, ethanol precipitation can be considered to be an efficient technique for xylanase concentration and, to a certain extent, also for the cellulase complex.

  9. Discovery and characterization of thermophilic limonene-1,2-epoxide hydrolases from hot spring metagenomic libraries

    DEFF Research Database (Denmark)

    Ferrandi, Erica Elisa; Sayer, Christopher; Isupov, Michail N.

    2015-01-01

    thermophilic sources, have higher optimal temperatures and apparent melting temperatures than Re-LEH. The new LEH enzymes have been crystallized and their structures solved to high resolution in the native form and in complex with the inhibitor valpromide for Tomsk-LEH and poly(ethylene glycol) for CH55-LEH......,2-epoxide hydrolase (LEH) family of enzymes. These two LEHs (Tomsk-LEH and CH55-LEH) show EH activities towards different epoxide substrates, differing in most cases from those previously identified for Rhodococcus erythropolis (Re-LEH) in terms of stereoselectivity. Tomsk-LEH and CH55-LEH, both from....... The structural analysis has provided insights into the LEH mechanism, substrate specificity and stereoselectivity of these new LEH enzymes, which has been supported by mutagenesis studies....

  10. Synthesis of novel bioactive lactose-derived oligosaccharides by microbial glycoside hydrolases

    Science.gov (United States)

    Díez-Municio, Marina; Herrero, Miguel; Olano, Agustín; Moreno, F Javier

    2014-01-01

    Prebiotic oligosaccharides are increasingly demanded within the Food Science domain because of the interesting healthy properties that these compounds may induce to the organism, thanks to their beneficial intestinal microbiota growth promotion ability. In this regard, the development of new efficient, convenient and affordable methods to obtain this class of compounds might expand even further their use as functional ingredients. This review presents an overview on the most recent interesting approaches to synthesize lactose-derived oligosaccharides with potential prebiotic activity paying special focus on the microbial glycoside hydrolases that can be effectively employed to obtain these prebiotic compounds. The most notable advantages of using lactose-derived carbohydrates such as lactosucrose, galactooligosaccharides from lactulose, lactulosucrose and 2-α-glucosyl-lactose are also described and commented. PMID:24690139

  11. The use of neutron scattering to determine the functional structure of glycoside hydrolase.

    Science.gov (United States)

    Nakamura, Akihiko; Ishida, Takuya; Samejima, Masahiro; Igarashi, Kiyohiko

    2016-10-01

    Neutron diffraction provides different information from X-ray diffraction, because neutrons are scattered by atomic nuclei, whereas X-rays are scattered by electrons. One of the key advantages of neutron crystallography is the ability to visualize hydrogen and deuterium atoms, making it possible to observe the protonation state of amino acid residues, hydrogen bonds, networks of water molecules and proton relay pathways in enzymes. But, because of technical difficulties, less than 100 enzyme structures have been evaluated by neutron crystallography to date. In this review, we discuss the advantages and disadvantages of neutron crystallography as a tool to investigate the functional structure of glycoside hydrolases, with some examples. Copyright © 2016 Elsevier Ltd. All rights reserved.

  12. Studies on sterol-ester hydrolase from Fusarium oxysporum. I. Partial purification and properties.

    Science.gov (United States)

    Okawa, Y; Yamaguchi, T

    1977-05-01

    1. A search for a long chain fatty acyl sterol-ester hydrolase in microorganisms led to the isolation from soil of five strains belonging to Fusarium sp. which produced strong activity in the culture medium. 2. The cholesterol esterase from Fusarium oxysporum IGH-2 was purified about 270-fold by means of CaCl2 precipitation and Sephadex G-75 column chromatography. 3. The cholesterol esterase was activated by adekatol and Triton X-100. It was inhibited by lecithin and lysolecithin, and completely inactivated by heat treatment (60 degrees C for 30 min, at pH 7.0). 4. The optimum pH of the enzyme was found to be around 7.0. 5. Among various cholesterol esters tested, cholesterol linoleate was the most suitable substrate. 6. Cholesterol esters in serum were also hydrolyzed by this enzyme.

  13. Alternative strategy for converting an inverting glycoside hydrolase into a glycosynthase.

    Science.gov (United States)

    Honda, Yuji; Fushinobu, Shinya; Hidaka, Masafumi; Wakagi, Takayoshi; Shoun, Hirofumi; Taniguchi, Hajime; Kitaoka, Motomitsu

    2008-04-01

    The tyrosine residue Y198 is known to support a nucleophilic water molecule with the general base residue, D263, in the reducing-end xylose-releasing exo-oligoxylanase (Rex). A mutation in the tyrosine residue changing it into phenylalanine caused a drastic decrease in the hydrolytic activity and a small increase in the F(-) releasing activity from alpha-xylobiosyl fluoride in the presence of xylose. In contrast, mutations at D263 resulted in the decreased F(-) releasing activity. As a result of the high F(-) releasing activity and low hydrolytic activity, Y198F of Rex accumulates a large amount of product during the glycosynthase reaction. We propose a novel method for producing a glycosynthase from an inverting glycoside hydrolase by mutating a residue that holds the nucleophilic water molecule with the general base residue while keeping the general base residue intact.

  14. Luciferin Amides Enable in Vivo Bioluminescence Detection of Endogenous Fatty Acid Amide Hydrolase Activity.

    Science.gov (United States)

    Mofford, David M; Adams, Spencer T; Reddy, G S Kiran Kumar; Reddy, Gadarla Randheer; Miller, Stephen C

    2015-07-15

    Firefly luciferase is homologous to fatty acyl-CoA synthetases. We hypothesized that the firefly luciferase substrate d-luciferin and its analogs are fatty acid mimics that are ideally suited to probe the chemistry of enzymes that release fatty acid products. Here, we synthesized luciferin amides and found that these molecules are hydrolyzed to substrates for firefly luciferase by the enzyme fatty acid amide hydrolase (FAAH). In the presence of luciferase, these molecules enable highly sensitive and selective bioluminescent detection of FAAH activity in vitro, in live cells, and in vivo. The potency and tissue distribution of FAAH inhibitors can be imaged in live mice, and luciferin amides serve as exemplary reagents for greatly improved bioluminescence imaging in FAAH-expressing tissues such as the brain.

  15. Preparation of immobilized growing cells and enzymatic hydrolysis of sawdust

    International Nuclear Information System (INIS)

    Kumakura, M.; Kaetsu, I.

    1984-01-01

    Trichoderma reesei cells were immobilized by radiation polymerization using porous materials such as non-woven material and sawdust, and the enzymatic hydrolysis of sawdust with the enzyme solution from the immobilized growing cells was studied. The filter paper activity, which shows the magnitude of cellulase production in the immobilized cells, was comparable with that in the intact cells. The filter paper activity was affected by addition concentration of monomer and porous materials. The cells in the immobilized cells grew to be adhered on the surface of the fibrous polymers. Sawdust, which was pretreated by irradiation technique, was effectively hydrolyzed with the enzyme solution resulting from the culture of the immobilized cells, in which the glucose yield increased increasing the culture time of the immobilized cells. (author)

  16. Ceramic membrane microfilter as an immobilized enzyme reactor.

    Science.gov (United States)

    Harrington, T J; Gainer, J L; Kirwan, D J

    1992-10-01

    This study investigated the use of a ceramic microfilter as an immobilized enzyme reactor. In this type of reactor, the substrate solution permeates the ceramic membrane and reacts with an enzyme that has been immobilized within its porous interior. The objective of this study was to examine the effect of permeation rate on the observed kinetic parameters for the immobilized enzyme in order to assess possible mass transfer influences or shear effects. Kinetic parameters were found to be independent of flow rate for immobilized penicillinase and lactate dehydrogenase. Therefore, neither mass transfer nor shear effects were observed for enzymes immobilized within the ceramic membrane. Both the residence time and the conversion in the microfilter reactor could be controlled simply by regulating the transmembrane pressure drop. This study suggests that a ceramic microfilter reactor can be a desirable alternative to a packed bed of porous particles, especially when an immobilized enzyme has high activity and a low Michaelis constant.

  17. Treatment and immobilization of intermediate level radioactive wastes

    International Nuclear Information System (INIS)

    Lerch, R.E.; Greenhalgh, W.O.; Partridge, J.A.; Richardson, G.L.

    1977-01-01

    This paper discusses a new program underway to develop and demonstrate treatment and immobilization technologies for intermediate level wastes (ILW) generated in the nuclear fuel cycle. Initial work has defined the sources, quantities and types of wastes which comprise ILW. Laboratory studies are underway to define treatment technologies for liquid ILW which contains volatile contaminants and to define immobilization parameters for the residues resulting from treatment of ILW. Immobilization agents initially being evaluated for the various residues include cement, urea-formaldehyde, and bitumen although other immobilization agents will be studied. The program also includes development of acceptable test procedures for the final immobilized products as well as development of proposed criteria for storage, transportation, and disposal of the immobilized ILW. 20 figures, 10 tables

  18. Insulin action in human thighs after one-legged immobilization

    DEFF Research Database (Denmark)

    Richter, Erik; Kiens, Bente; Mizuno, M.

    1989-01-01

    Insulin action was assessed in thighs of five healthy young males who had one knee immobilized for 7 days by a splint. The splint was not worn in bed. Subjects also used crutches to prevent weight bearing of the immobilized leg. Immobilization decreased the activity of citrate synthase and 3-OH......-acyl-CoA-dehydrogenase in the vastus lateralis muscle by 9 and 14%, respectively, and thigh volume by 5%. After 7 days of immobilization, a two-step euglycemic hyperinsulinemic clamp procedure combined with arterial and bilateral femoral venous catheterization was performed. Insulin action on glucose uptake and tyrosine release...... of the thighs at mean plasma insulin concentrations of 67 (clamp step I) and 447 microU/ml (clamp step II) was decreased by immobilization, whereas immobilization did not affect insulin action on thigh exchange of free fatty acids, glycerol, O2, or potassium. Before and during the clamp step I, lactate release...

  19. Tissue Expressions of Soluble Human Epoxide Hydrolase-2 Enzyme in Patients with Temporal Lobe Epilepsy.

    Science.gov (United States)

    Ahmedov, Merdin Lyutviev; Kemerdere, Rahsan; Baran, Oguz; Inal, Berrin Bercik; Gumus, Alper; Coskun, Cihan; Yeni, Seher Naz; Eren, Bulent; Uzan, Mustafa; Tanriverdi, Taner

    2017-10-01

    We sought to simply demonstrate how levels of soluble human epoxide hydrolase-2 show changes in both temporal the cortex and hippocampal complex in patients with temporal lobe epilepsy. A total of 20 patients underwent anterior temporal lobe resection due to temporal lobe epilepsy. The control group comprised 15 people who died in traffic accidents or by falling from a height, and their autopsy findings were included. Adequately sized temporal cortex and hippocampal samples were removed from each patient during surgery, and the same anatomic structures were removed from the control subjects during the autopsy procedures. Each sample was stored at -80°C as rapidly as possible until the enzyme assay. The temporal cortex in the epilepsy patients had a significantly higher enzyme level than did the temporal cortex of the control group (P = 0.03). Correlation analysis showed that as the enzyme level increases in the temporal cortex, it also increases in the hippocampal complex (r 2  = 0.06, P = 0.00001). More important, enzyme tissue levels showed positive correlations with seizure frequency in both the temporal cortex and hippocampal complex in patients (r 2  = 0.7, P = 0.00001 and r 2  = 0.4, P = 0.003, respectively). The duration of epilepsy was also positively correlated with the hippocampal enzyme level (r 2  = 0.06, P = 0.00001). Soluble human epoxy hydrolase enzyme-2 is increased in both lateral and medial temporal tissues in temporal lobe epilepsy. Further studies should be conducted as inhibition of this enzyme has resulted in a significant decrease in or stopping of seizures and attenuated neuroinflammation in experimental epilepsy models in the current literature. Copyright © 2017 Elsevier Inc. All rights reserved.

  20. Crystal structure of glycoside hydrolase family 127 β-L-arabinofuranosidase from Bifidobacterium longum

    Energy Technology Data Exchange (ETDEWEB)

    Ito, Tasuku; Saikawa, Kyo [Department of Biotechnology, The University of Tokyo, Tokyo (Japan); Kim, Seonah [National Bioenergy Center, National Renewable Energy Laboratory, Golden, CO (United States); Fujita, Kiyotaka [Faculty of Agriculture, Kagoshima University, Korimoto, Kagoshima (Japan); Ishiwata, Akihiro [Synthetic Cellular Chemistry Laboratory, RIKEN (Japan); Kaeothip, Sophon [ERATO Glycotrilogy Project, JST, Wako, Saitama (Japan); Arakawa, Takatoshi; Wakagi, Takayoshi [Department of Biotechnology, The University of Tokyo, Tokyo (Japan); Beckham, Gregg T., E-mail: Gregg.Beckham@nrel.gov [National Bioenergy Center, National Renewable Energy Laboratory, Golden, CO (United States); Ito, Yukishige [Synthetic Cellular Chemistry Laboratory, RIKEN (Japan); ERATO Glycotrilogy Project, JST, Wako, Saitama (Japan); Fushinobu, Shinya, E-mail: asfushi@mail.ecc.u-tokyo.ac.jp [Department of Biotechnology, The University of Tokyo, Tokyo (Japan)

    2014-04-25

    Graphical abstract: - Highlights: • HypBA1 β-L-arabinofuranosidase belongs to glycoside hydrolase family 127. • Crystal structure of HypBA1 was determined. • HypBA1 consists of a catalytic barrel and two additional β-sandwich domains. • The active site contains a Zn{sup 2+} coordinated by glutamate and three cysteines. • A possible reaction mechanism involving cysteine as the nucleophile is proposed. - Abstract: Enzymes acting on β-linked arabinofuranosides have been unknown until recently, in spite of wide distribution of β-L-arabinofuranosyl oligosaccharides in plant cells. Recently, a β-L-arabinofuranosidase from the glycoside hydrolase family 127 (HypBA1) was discovered in the newly characterized degradation system of hydroxyproline-linked β-L-arabinooligosaccharides in the bacterium Bifidobacterium longum. Here, we report the crystal structure of HypBA1 in the ligand-free and β-L-arabinofuranose complex forms. The structure of HypBA1 consists of a catalytic barrel domain and two additional β-sandwich domains, with one β-sandwich domain involved in the formation of a dimer. Interestingly, there is an unprecedented metal-binding motif with Zn{sup 2+} coordinated by glutamate and three cysteines in the active site. The glutamate residue is located far from the anomeric carbon of the β-L-arabinofuranose ligand, but one cysteine residue is appropriately located for nucleophilic attack for glycosidic bond cleavage. The residues around the active site are highly conserved among GH127 members. Based on biochemical experiments and quantum mechanical calculations, a possible reaction mechanism involving cysteine as the nucleophile is proposed.

  1. Dysregulation of soluble epoxide hydrolase and lipidomic profiles in anorexia nervosa

    KAUST Repository

    Shih, P. B.

    2015-03-31

    Individuals with anorexia nervosa (AN) restrict eating and become emaciated. They tend to have an aversion to foods rich in fat. Because epoxide hydrolase 2 (EPHX2) was identified as a novel AN susceptibility gene, and because its protein product, soluble epoxide hydrolase (sEH), converts bioactive epoxides of polyunsaturated fatty acid (PUFA) to the corresponding diols, lipidomic and metabolomic targets of EPHX2 were assessed to evaluate the biological functions of EPHX2 and their role in AN. Epoxide substrates of sEH and associated oxylipins were measured in ill AN, recovered AN and gender- and race-matched controls. PUFA and oxylipin markers were tested as potential biomarkers for AN. Oxylipin ratios were calculated as proxy markers of in vivo sEH activity. Several free- and total PUFAs were associated with AN diagnosis and with AN recovery. AN displayed elevated n-3 PUFAs and may differ from controls in PUFA elongation and desaturation processes. Cytochrome P450 pathway oxylipins from arachidonic acid, linoleic acid, alpha-linolenic acid and docosahexaenoic acid PUFAs are associated with AN diagnosis. The diol:epoxide ratios suggest the sEH activity is higher in AN compared with controls. Multivariate analysis illustrates normalization of lipidomic profiles in recovered ANs. EPHX2 influences AN risk through in vivo interaction with dietary PUFAs. PUFA composition and concentrations as well as sEH activity may contribute to the pathogenesis and prognosis of AN. Our data support the involvement of EPHX2-associated lipidomic and oxylipin dysregulations in AN, and reveal their potential as biomarkers to assess responsiveness to future intervention or treatment.

  2. Overexpression of fatty acid amide hydrolase induces early flowering in Arabidopsis thaliana

    Directory of Open Access Journals (Sweden)

    Neal D. Teaster

    2012-02-01

    Full Text Available N-Acylethanolamines (NAEs are bioactive lipids derived from the hydrolysis of the membrane phospholipid N-acylphosphatidylethanolamine (NAPE. In animal systems this reaction is part of the endocannabinoid signaling pathway, which regulates a variety of physiological processes. The signaling function of NAE is terminated by fatty acid amide hydrolase (FAAH, which hydrolyzes NAE to ethanolamine and free fatty acid. Our previous work in Arabidopsis thaliana showed that overexpression of AtFAAH (At5g64440 lowered endogenous levels of NAEs in seeds, consistent with its role in NAE signal termination. Reduced NAE levels were accompanied by an accelerated growth phenotype, increased sensitivity to abscisic acid (ABA, enhanced susceptibility to bacterial pathogens, and early flowering. Here we investigated the nature of the early flowering phenotype of AtFAAH overexpression. AtFAAH overexpressors flowered several days earlier than wild type and AtFAAH knockouts under both non-inductive short day (SD and inductive long day (LD conditions. Microarray analysis revealed that the FLOWERING LOCUS T (FT gene, which plays a major role in regulating flowering time, and one target MADS box transcription factor, SEPATALLA3 (SEP3, were elevated in AtFAAH overexpressors. Furthermore, AtFAAH overexpressors, with the early flowering phenotype had lower endogenous NAE levels in leaves compared to wild type prior to flowering. Exogenous application of NAE 12:0, which was reduced by up to 30% in AtFAAH overexpressors, delayed the onset of flowering in wild type plants. We conclude that the early flowering phenotype of AtFAAH overexpressors is, in part, explained by elevated FT gene expression resulting from the enhanced NAE hydrolase activity of AtFAAH, suggesting that NAE metabolism may participate in floral signaling pathways.

  3. A screening method for β-glucan hydrolase employing Trypan Blue-coupled β-glucan agar plate and β-glucan zymography.

    Science.gov (United States)

    Park, Chang-Su; Yang, Hee-Jong; Kim, Dong-Ho; Kang, Dae-Ook; Kim, Min-Soo; Choi, Nack-Shick

    2012-06-01

    A new screening method for β-(1,3-1,6) glucan hydrolase was developed using a pure β-glucan from Aureobaisidum pullulans by zymography and an LB-agar plate. Paenibacillus sp. was screened as a producer a β-glucan hydrolase on the Trypan Blue-coupled β-glucan LB-agar plate and the activity of the enzyme was analyzed by SDS-β-glucan zymography. The β-glucan was not hydrolyzed by Bacillus spp. strains, which exhibit cellulolytic activity on CMC zymography. The gene, obtaining by shotgun cloning and encoding the β-glucan hydrolase of Paenibacillus sp. was sequenced.

  4. Hierarchically Nanoporous Bioactive Glasses for High Efficiency Immobilization of Enzymes

    DEFF Research Database (Denmark)

    He, W.; Min, D.D.; Zhang, X.D.

    2014-01-01

    Bioactive glasses with hierarchical nanoporosity and structures have been heavily involved in immobilization of enzymes. Because of meticulous design and ingenious hierarchical nanostructuration of porosities from yeast cell biotemplates, hierarchically nanostructured porous bioactive glasses can...... and products of catalytic reactions can freely diffuse through open mesopores (2–40 nm). The formation mechanism of hierarchically structured porous bioactive glasses, the immobilization mechanism of enzyme and the catalysis mechanism of immobilized enzyme are then discussed. The novel nanostructure...

  5. Catalytical Properties of Free and Immobilized Aspergillus niger Tannase

    OpenAIRE

    Abril Flores-Maltos; Luis V. Rodríguez-Durán; Jacqueline Renovato; Juan C. Contreras; Raúl Rodríguez; Cristóbal N. Aguilar

    2011-01-01

    A fungal tannase was produced, recovered, and immobilized by entrapment in calcium alginate beads. Catalytical properties of the immobilized enzyme were compared with those of the free one. Tannase was produced intracellularly by the xerophilic fungus Aspergillus niger GH1 in a submerged fermentation system. Enzyme was recovered by cell disruption and the crude extract was partially purified. The catalytical properties of free and immobilized tannase were evaluated using tannic acid and methy...

  6. Platform for immobilization and observation of subcellular processes

    Science.gov (United States)

    McKnight, Timothy E.; Kalluri, Udaya C.; Melechko, Anatoli V.

    2014-08-26

    A method of immobilizing matter for imaging that includes providing an array of nanofibers and directing matter to the array of the nanofibers. The matter is immobilized when contacting at least three nanofibers of the array of nanofibers simultaneously. Adjacent nanofibers in the array of nanofibers may be separated by a pitch as great as 100 microns. The immobilized matter on the array of nanofibers may then be imaged. In some examples, the matter may be cell matter, such as protoplasts.

  7. The effects of using immobilizer made of the polyurethane foam

    International Nuclear Information System (INIS)

    Kim, Yong Hwan; Chung, Sang Hwa; Kim, Hwa Young; Lim, Shin Taek; Oh, Sae Dong

    1992-01-01

    The immogilzer for control the patient movement during the radiation beam on was made of the polyurethane foam. The time consumption is abut 8 minutes for completely making the immobilizer. In this experimental study, the effects of using the individual immobilizer have shown that the patients have had always a same position with comfortable and high reproducibilities. Furthermore, it has shown the time for patient setup was decreased by using the individual patient immobilizer.

  8. Compostos organofosforados pentavalentes: histórico, métodos sintéticos de preparação e aplicações como inseticidas e agentes antitumorais Organophosphorus pentavalent compounds: history, synthetic methods of preparation and application as insecticides and antitumor agents

    Directory of Open Access Journals (Sweden)

    Viviane Martins Rebello dos Santos

    2007-02-01

    Full Text Available This paper is a review of the history, synthesis and application of organophosphorus compounds, especially of those of pentavalent phosphorus, such as phosphoramidates, phosphorothioates, phosphonates and phosphonic acids with insecticide and anticancer activities. The organophosphorus compounds with agrochemical applications show great structural variety, They include not only insecticides, but also fungicides, herbicides, and others. The large variety of commercially available organophosphorus pesticides is remarkable. Even more interesting is the high efficiency of some organophosphorus compounds as anticancer agents such as cyclophosphamide and its derivatives.

  9. Increase in stability of cellulase immobilized on functionalized magnetic nanospheres

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Wenjuan [Department of Machine Intelligence and Systems Engineering, Faculty of Systems Engineering, Akita Prefectural University, Akita 015-0055 (Japan); Qiu, Jianhui, E-mail: qiu@akita-pu.ac.jp [Department of Machine Intelligence and Systems Engineering, Faculty of Systems Engineering, Akita Prefectural University, Akita 015-0055 (Japan); Feng, Huixia [College of Petrochemical Engineering, Lanzhou University of Technology, Lanzhou 730050 (China); Zang, Limin; Sakai, Eiichi [Department of Machine Intelligence and Systems Engineering, Faculty of Systems Engineering, Akita Prefectural University, Akita 015-0055 (Japan)

    2015-02-01

    Functionalized magnetic nanospheres were prepared by co-condensation of tetraethylorthosilicate with three different amino-silanes: 3-(2-aminoethylamino propyl)-triethoxysilane (AEAPTES), 3-(2-aminoethylamino propyl)-trimethoxysilane (AEAPTMES) and 3-aminopropyltriethoxysilane (APTES). Then three functionalized magnetic nanospheres were used as supports for immobilization of cellulase. The three functionalized magnetic nanospheres with core–shell morphologies exhibited higher capacity for cellulase immobilization than unfunctionalized magnetic nanospheres. The increasing of surface charge of functionalized magnetic nanospheres leads to an enhancement of the capacity of cellulase immobilization. Particularly, AEAPTMES with methoxy groups was favored to be hydrolyzed and grafted on unfunctionalized magnetic nanospheres than the others. AEAPTMES functionalized magnetic nanospheres with the highest zeta potential (29 mV) exhibited 87% activity recovery and the maximum amount of immobilized cellulase was 112 mg/g support at concentration of initial cellulase of 8 mg/mL. Immobilized cellulase on AEAPTMES functionalized magnetic nanospheres had higher temperature stability and broader pH stability than other immobilized cellulases and free cellulase. In particular, it can be used in about 40 °C, demonstrating the potential of biofuel production using this immobilized cellulase. - Highlights: • Three Amino-silane modified magnetic nanospheres were prepared. • Cellulase immobilized AEAPTMES functionalized magnetic nanospheres had higher temperature stability and broader pH stability than free cellulase. • The potential of biofuel production using this immobilized cellulase.

  10. Immobilization of thorium over fibroin by polyacrylonitrile (PAN)

    International Nuclear Information System (INIS)

    Aslani, M.A.A.; Akyil, S.; Eral, M.

    1997-01-01

    This report describes a process for immobilization of thorium over fibroin, which was used as a bio-adsorbant, by polyacrylonitrile. The amounts of thorium in aqueous solutions which may be leached in various aqueous ambients were detected by a spectrophotometer. The results show that polyacrylonitrile processes are feasible to immobilize spent fibroins. The leachability of the materials immobilized with polyacrylonitrile can meet the requirements of storage and final disposal. The leachability of thorium ions from immobilized spent fibroin was rather low for 8 months

  11. Application of magnetic nanoparticles in smart enzyme immobilization.

    Science.gov (United States)

    Vaghari, Hamideh; Jafarizadeh-Malmiri, Hoda; Mohammadlou, Mojgan; Berenjian, Aydin; Anarjan, Navideh; Jafari, Nahideh; Nasiri, Shahin

    2016-02-01

    Immobilization of enzymes enhances their properties for efficient utilization in industrial processes. Magnetic nanoparticles, due to their high surface area, large surface-to-volume ratio and easy separation under external magnetic fields, are highly valued. Significant progress has been made to develop new catalytic systems that are immobilized onto magnetic nanocarriers. This review provides an overview of recent developments in enzyme immobilization and stabilization protocols using this technology. The current applications of immobilized enzymes based on magnetic nanoparticles are summarized and future growth prospects are discussed. Recommendations are also given for areas of future research.

  12. Immobilization of yeast cells by radiation-induced polymerization

    International Nuclear Information System (INIS)

    Fujimura, T.; Kaetsu, I.

    1982-01-01

    Radiation-induced polymerization method was applied to the immobilization of yeast cells. The effects of irradiation, cooling and monomer, which are neccessary for polymerization, were recovered completely by subsequent aerobical incubation of yeast cells. The ethanol productive in immobilized yeast cells increased with the increase of aerobical incubation period. The growth of yeast cells in immobilized yeast cells was indicated. The maximum ethanol productivity in immobilized yeast cell system was around three times as much as that in free yeast cell system. (orig.)

  13. Management of immobilization and its complication for elderly.

    Science.gov (United States)

    Laksmi, Purwita W; Harimurti, Kuntjoro; Setiati, Siti; Soejono, Czeresna H; Aries, Wanarani; Roosheroe, Arya Govinda

    2008-10-01

    Increased life expectancy have an effect on the rising percentage of elderly population in Indonesia and health problem associated with the elderly, particularly immobilization. Immobilization may cause various complications, especially when it has been overlooked without any appropriate and proper medical care in keeping with the procedures. High incidence of immobilization in elderly and the life-threatening complication call for an agreement on management of immobilization and its complication. Management of immobilization needs interdisciplinary team-work cooperation, the patients and their family. The management may be commenced through a complete geriatric review, formulating functional goals and constructing therapeutic plan. Various medical conditions and external factors that may act as risk factors of immobilization as well as drugs intake that may exaggerate the immobilization should be evaluated and optimally managed. Any complication due to immobilization and other concomitant disease/condition should be recognized and managed comprehensively in order to reduce morbidity and mortality. Management of immobilization and its complications include pharmacological and non-pharmacological treatment, i.e. various mobility exercises, utilization of ambulatory device and supporting appliance for assisting patients in stand-up position, as well as the management of urinary voiding and defecation.

  14. Increase in stability of cellulase immobilized on functionalized magnetic nanospheres

    International Nuclear Information System (INIS)

    Zhang, Wenjuan; Qiu, Jianhui; Feng, Huixia; Zang, Limin; Sakai, Eiichi

    2015-01-01

    Functionalized magnetic nanospheres were prepared by co-condensation of tetraethylorthosilicate with three different amino-silanes: 3-(2-aminoethylamino propyl)-triethoxysilane (AEAPTES), 3-(2-aminoethylamino propyl)-trimethoxysilane (AEAPTMES) and 3-aminopropyltriethoxysilane (APTES). Then three functionalized magnetic nanospheres were used as supports for immobilization of cellulase. The three functionalized magnetic nanospheres with core–shell morphologies exhibited higher capacity for cellulase immobilization than unfunctionalized magnetic nanospheres. The increasing of surface charge of functionalized magnetic nanospheres leads to an enhancement of the capacity of cellulase immobilization. Particularly, AEAPTMES with methoxy groups was favored to be hydrolyzed and grafted on unfunctionalized magnetic nanospheres than the others. AEAPTMES functionalized magnetic nanospheres with the highest zeta potential (29 mV) exhibited 87% activity recovery and the maximum amount of immobilized cellulase was 112 mg/g support at concentration of initial cellulase of 8 mg/mL. Immobilized cellulase on AEAPTMES functionalized magnetic nanospheres had higher temperature stability and broader pH stability than other immobilized cellulases and free cellulase. In particular, it can be used in about 40 °C, demonstrating the potential of biofuel production using this immobilized cellulase. - Highlights: • Three Amino-silane modified magnetic nanospheres were prepared. • Cellulase immobilized AEAPTMES functionalized magnetic nanospheres had higher temperature stability and broader pH stability than free cellulase. • The potential of biofuel production using this immobilized cellulase

  15. Degradation of Organophosphorus Pesticides in Water during UV/H2O2 Treatment: Role of Sulphate and Bicarbonate Ions

    Directory of Open Access Journals (Sweden)

    Am Fadaei

    2012-01-01

    Full Text Available The photodegradation of two organophosphorus pesticides, malathian and diazinon, by sulfate radicals and bicarbonate radicals in aqueous solution were studied. The effect of the operational parameters such as pH, salt concentration, water type, H2O2 concentration and initial concentration of pesticides was studied. Gas chromatography mass spectroscopy (GC–MS was used for analyses of pesticides. When salt effect was studied, it was found that sodium bicarbonate was the most powerful inhibitor used, while sodium sulfate was the weakest one. The highest degradation in UV/H2O2 process for malathion was found in alkaline condition and for diazinon in acidic condition. The photodegradation in all waters used in this work exhibited first order kinetics. Photodegradation rate in distilled water was higher than real water. The degradation of pesticides increased with increasing of H2O2 concentration.

  16. Effect of two organophosphorus insecticides on the growth, respiration and (/sup 14/C)-glucose metabolism of Azobacter chroococcum Beij

    Energy Technology Data Exchange (ETDEWEB)

    Balasubramanian, A; Narayanan, R [Tamil Nadu Agricultural Univ., Coimbatore (India)

    1980-01-01

    The two organophosphorus insecticides, commonly applied to soil, viz., disulfoton (0,0-diethyl S-2-ethyl thio ethyl phosphorodithioate) and fensulfothion (0,0-diethyl 0-4-methyl sulphinyl phenyl phosphorothioate) did not affect the in vitro growth of Azotobacter chroococcum Beij., the free-living, nitrogen fixing soil bacterium, at 2 ppm (lower level), while the normal dose (5 ppm) and the higher level (10 ppm) suppressed the growth. Respiration of the organism (glucose oxidation) was adversely affected by the insecticides in the growth medium and the inhibition increased with the concentration of the chemical. Both the insecticides suppressed the assimilation of (/sup 14/C)-glucose in the cold-TCA soluble, hot-TCA soluble fractions and insoluble residue of the cells whereas the /sup 14/C-incorporation in the alcohol soluble and alcohol-ether soluble fractions was enhanced indicating that the insecticides considerably altered the glucose metabolism of the bacterium.

  17. [How aliphatic alcohols and ph affect reactional capability of the horse blood serum cholinesterase at its interaction with organophosphorus inhibitors].

    Science.gov (United States)

    Basova, N E; Kormilitsin, B N; Perchenok, A Iu; Rozengart, E V; Saakov, V S; Suvorov, A A

    2013-01-01

    There was studied action of aliphatic alcohols (ethanol, propanol, isopropanol, n-butanol, isobutanol, secbutanol, tretbetanol) and pH on various kinds of reactional capability the serum cholinesterase. At the alcohols-affected inhibition of the cholinesterase hydrolytic activity, the determining role was played not the total number carbon atoms in the alcohol molecule, but by the "effective length" of the carbohydrate chain. The fact that the presence of alcohols did not affect parameters of the reverse cholinesterase inhibition with onium ions tetramethylammonium and choline allows suggesting the absence of effect solvents on specific acetylcholine sorption in the enzyme active center. With aid of two rows of hydrophobic organophosphorus inhibitors (OPI), we have managed to estimate both the degree and the character itself of the modifying action of alcohols and pH on the process of irreversible inhibition of serum cholinesterase.

  18. [Comparative analysis of sensitivity of proteases (chymotrypsin and trypsin) and cholinesterases of different origin to some organophosphorus inhibitors].

    Science.gov (United States)

    Rozengart, E V

    2009-01-01

    The antichymotrypsin, antitrypsin, and anticholinesterase efficiencies of four homologous series of organophosphorus inhibitors are compared: O-ethyl-S-(n-alkyl)methylthiophosphonates, O-(n-alkyl)-S-(n-butyl)methylthiophosphonates, O-(n-alkyl)-S-beta-(ethylmercaptoethylene)methylthiophosphonates, and their methylsulfomethylates. As sources of a-chymotrypsin and trypsin, commercial compounds of Worthington Biochemical Corporation and Leningrad Myasokombinat were tested. Bimolecular constant of the reaction rate was used as the measure of antienzyme efficiency. In all cases, the antichymotrypsin efficiency was lower, while the antitrypsin--essentially higher than the anticholinesterase activity of the studied inhibitors. These differences were found to much depend both on the inhibitor structure and on nature of the cholinesterase compounds.

  19. Effect of two organophosphorus insecticides on the growth, respiration and (14C)-glucose metabolism of Azobacter chroococcum Beij

    International Nuclear Information System (INIS)

    Balasubramanian, A.; Narayanan, R.

    1980-01-01

    The two organophosphorus insecticides, commonly applied to soil, viz., disulfoton (0,0-diethyl S-2-ethyl thio ethyl phosphorodithioate) and fensulfothion (0,0-diethyl 0-4-methyl sulphinyl phenyl phosphorothioate) did not affect the in vitro growth of Azotobacter chroococcum Beij., the free-living, nitrogen fixing soil bacterium, at 2 ppm (lower level), while the normal dose (5 ppm) and the higher level (10 ppm) suppressed the growth. Respiration of the organism (glucose oxidation) was adversely affected by the insecticides in the growth medium and the inhibition increased with the concentration of the chemical. Both the insecticides suppressed the assimilation of ( 14 C)-glucose in the cold-TCA soluble, hot-TCA soluble fractions and insoluble residue of the cells whereas the 14 C-incorporation in the alcohol soluble and alcohol-ether soluble fractions was enhanced indicating that the insecticides considerably altered the glucose metabolism of the bacterium. (author)

  20. Arsenic mobilization and immobilization in paddy soils

    Science.gov (United States)

    Kappler, A.; Hohmann, C.; Zhu, Y. G.; Morin, G.

    2010-05-01

    Arsenic is oftentimes of geogenic origin and in many cases bound to iron(III) minerals. Iron(III)-reducing bacteria can harvest energy by coupling the oxidation of organic or inorganic electron donors to the reduction of Fe(III). This process leads either to dissolution of Fe(III)-containing minerals and thus to a release of the arsenic into the environment or to secondary Fe-mineral formation and immobilisation of arsenic. Additionally, aerobic and anaerobic iron(II)-oxidizing bacteria have the potential to co-precipitate or sorb arsenic during iron(II) oxidation at neutral pH that is usually followed by iron(III) mineral precipitation. We are currently investigating arsenic immobilization by Fe(III)-reducing bacteria and arsenic co-precipitation and immobilization by anaerobic iron(II)-oxidizing bacteria in batch, microcosm and rice pot experiments. Co-precipitation batch experiments with pure cultures of nitrate-dependent Fe(II)-oxidizing bacteria are used to quantify the amount of arsenic that can be immobilized during microbial iron mineral precipitation, to identify the minerals formed and to analyze the arsenic binding environment in the precipitates. Microcosm and rice pot experiments are set-up with arsenic-contaminated rice paddy soil. The microorganisms (either the native microbial population or the soil amended with the nitrate-dependent iron(II)-oxidizing Acidovorax sp. strain BoFeN1) are stimulated either with iron(II), nitrate, or oxygen. Dissolved and solid-phase arsenic and iron are quantified. Iron and arsenic speciation and redox state in batch and microcosm experiments are determined by LC-ICP-MS and synchrotron-based methods (EXAFS, XANES).