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Sample records for glycerol acid phosphatase

  1. 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

  2. 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.

  3. Purification of acidic phosphatase from mustard seedlings

    OpenAIRE

    sprotocols

    2014-01-01

    ### INTRODUCTION Phosphate esters are widely distributed in any organism. Nucleic acids, metabolic intermediates like glucose-6-phosphate, energy-rich substrates (AMP, creatine phosphate) are some obvious examples. While many metabolic intermediates are activated through the transfer of phosphate groups (e.g., by kinases) it is equally important that phosphate esters can also be rapidly broken down. The hydrolytic removal of phosphate groups from phosphoesters is catalyzed by phosphatases...

  4. Phosphatase activity of Poa pratensis seeds. I. Preliminary studies on acid phosphatase II

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    I. Lorenc-Kubis

    2015-01-01

    Full Text Available Acid phosphatase (EC 3.1.3.2 was extracted with 0.1 M sodium acetate buffer pH 5.1 from Poa pratensis seeds, and separated into three fractions by chromatography on DEAE cellulose. The highest activity was found in fraction Il-b (acid phosphatase II. The activity of the enzyme was optimal at pH 4.9. It hydrolyzed p-nitrophenyl phosphate most readily among the various phosphomonoesters examined. Acid phosphatase II showed also a high activity toward β-naphtyl phosphate and phenyl phosphate, very low activity towards β-glycero phosphate, 5'-GMP and no activity with glucose-1 phosphate. The enzyme was inhibited by Ca2+ and fluoride, but activated by Mg2+. EDTA had no influence on the activity of the enzyme.

  5. Phosphatase activity of Poa pratensis seeds. l. Preliminary studies on acid phosphatase II

    Energy Technology Data Exchange (ETDEWEB)

    Lorenc-Kubis, I.; Morawiecka, B.

    1973-01-01

    Acid phosphatase (EC 3.1.3.2) was extracted from 0.1 M sodium acetate buffer, pH 5.1 from Poa pratensis seeds, and separated into three fractions by chromatography on DEAE cellulose. The highest activity was found in fraction II-b (acid phosphatase II). The activity of the enzyme was optimal at pH 4.9. It hydrolyzed p-nitrophenyl phosphate most readily among the various phosphomonoesters examined. Acid phosphatase II showed also a high activity toward ..beta..-naphtyl phosphate and phenyl phosphate, very low activity towards ..beta..-glycero phosphate, 5'-GMP and no activity with glucose-1 phosphate. The enzyme was inhibited by Ca/sup 2 +/ and fluoride, but activated by Mg/sup 2 +/. EDTA had no influence on the activity of the enzyme. 12 references, 3 figures, 4 tables.

  6. Acid phosphatase and lipid peroxidation in human cataractous lens epithelium

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    Vasavada Abhay

    1993-01-01

    Full Text Available The anterior lens epithelial cells undergo a variety of degenerative and proliferative changes during cataract formation. Acid phosphatase is primarily responsible for tissue regeneration and tissue repair. The lipid hydroperoxides that are obtained by lipid peroxidation of polysaturated or unsaturated fatty acids bring about deterioration of biological membranes at cellular and tissue levels. Acid phosphatase and lipid peroxidation activities were studied on the lens epithelial cells of nuclear cataract, posterior subcapsular cataract, mature cataract, and mixed cataract. Of these, mature cataractous lens epithelium showed maximum activity for acid phosphatase (516.83 moles of p-nitrophenol released/g lens epithelium and maximum levels of lipid peroxidation (86.29 O.D./min/g lens epithelium. In contrast, mixed cataractous lens epithelium showed minimum activity of acid phosphatase (222.61 moles of p-nitrophenol released/g lens epithelium and minimum levels of lipid peroxidation (54.23 O.D./min/g lens epithelium. From our study, we correlated the maximum activity of acid phosphatase in mature cataractous lens epithelium with the increased areas of superimposed cells associated with the formation of mature cataract. Likewise, the maximum levels of lipid peroxidation in mature cataractous lens epithelium was correlated with increased permeability of the plasma membrane. Conversely, the minimum levels of lipid peroxidation in mixed cataractous lens epithelium makes us presume that factors other than lipid peroxidation may also account for the formation of mixed type of cataract.

  7. Effect of vanadium compounds on acid phosphatase activity

    OpenAIRE

    Vescina, Cecilia M.; Sálice, Viviana C.; Cortizo, Ana María; Etcheverry, Susana B.

    1996-01-01

    The direct effect of different vanadium compounds on acid phosphatase (ACP) activity was investigated. Vanadate and vanadyl but not pervanadate inhibited the wheat germ ACP activity. These vanadium derivatives did not alter the fibroblast Swiss 3T3 soluble fraction ACP activity. Using inhibitors of tyrosine phosphatases (PTPases), the wheat germ ACP was partially characterized as a PTPase. This study suggests that the inhibitory ability of different vanadium derivatives to modulate ACP activi...

  8. Biocatalysis with Sol-Gel Encapsulated Acid Phosphatase

    Science.gov (United States)

    Kulkarni, Suhasini; Tran, Vu; Ho, Maggie K.-M.; Phan, Chieu; Chin, Elizabeth; Wemmer, Zeke; Sommerhalter, Monika

    2010-01-01

    This experiment was performed in an upper-level undergraduate biochemistry laboratory course. Students learned how to immobilize an enzyme in a sol-gel matrix and how to perform and evaluate enzyme-activity measurements. The enzyme acid phosphatase (APase) from wheat germ was encapsulated in sol-gel beads that were prepared from the precursor…

  9. Yeast Acid Phosphatases and Phytases: Production, Characterization and Commercial Prospects

    Science.gov (United States)

    Kaur, Parvinder; Satyanarayana, T.

    The element phosphorus is critical to all life forms as it forms the basic component of nucleic acids and ATP and has a number of indispensable biochemical roles. Unlike C or N, the biogeochemical cycling of phosphorus is very slow, and thus making it the growth-limiting element in most soils and aquatic systems. Phosphohydrolases (e.g. acid phosphatases and phytases) are enzymes that break the C-O-P ester bonds and provide available inorganic phosphorus from various inassimilable organic forms of phosphorus like phytates. These enzymes are of significant value in effectively combating phosphorus pollution. Although phytases and acid phosphatases are produced by various plants, animals and micro organisms, microbial sources are more promising for the production on a commercial scale. Yeasts being the simplest eukaryotes are ideal candidates for phytase and phos-phatase research due to their mostly non-pathogenic and GRAS status. They have not, however, been utilized to their full potential. This chapter focuses attention on the present state of knowledge on the production, characterization and potential commercial prospects of yeast phytases and acid phosphatases.

  10. Effect of vanadium compounds on acid phosphatase activity.

    Science.gov (United States)

    Vescina, C M; Sálice, V C; Cortizo, A M; Etcheverry, S B

    1996-01-01

    The direct effect of different vanadium compounds on acid phosphatase (ACP) activity was investigated. Vanadate and vanadyl but not pervanadate inhibited the wheat germ ACP activity. These vanadium derivatives did not alter the fibroblast Swiss 3T3 soluble fraction ACP activity. Using inhibitors of tyrosine phosphatases (PTPases), the wheat germ ACP was partially characterized as a PTPase. This study suggests that the inhibitory ability of different vanadium derivatives to modulate ACP activity seems to depend on the geometry around the vanadium atom more than on the oxidation state. Our results indicate a correlation between the PTPase activity and the sensitivity to vanadate and vanadyl cation.

  11. Phosphotyrosine as a substrate of acid and alkaline phosphatases.

    Science.gov (United States)

    Apostoł, I; Kuciel, R; Wasylewska, E; Ostrowski, W S

    1985-01-01

    A new spectrophotometric method for following dephosphorylation of phosphotyrosine has been described. The absorption spectra of phosphotyrosine and tyrosine were plotted over the pH range from 3 to 9. The change in absorbance accompanying the conversion of phosphotyrosine to tyrosine was the greatest at 286 nm. The difference absorption coefficients were calculated for several pH values. Dephosphorylation of phosphotyrosine by acid phosphatases from human prostate gland, from wheat germ and potatoes obeys the Michaelis-Menten equation, whereas alkaline phosphatases calf intestine and E. coli are inhibited by excess of substrate.

  12. Human skeletal muscle fatty acid and glycerol metabolism during rest, exercise and recovery

    DEFF Research Database (Denmark)

    Van Hall, Gerrit; Sacchetti, M; Rådegran, G

    2002-01-01

    glycerol uptake was observed, which was substantially higher during exercise. Total body skeletal muscle FA and glycerol uptake/release was estimated to account for 18-25 % of whole body R(d) or R(a). In conclusion: (1) skeletal muscle FA and glycerol metabolism, using the leg arterial-venous difference......This study was conducted to investigate skeletal muscle fatty acid (FA) and glycerol kinetics and to determine the contribution of skeletal muscle to whole body FA and glycerol turnover during rest, 2 h of one-leg knee-extensor exercise at 65 % of maximal leg power output, and 3 h of recovery....... To this aim, the leg femoral arterial-venous difference technique was used in combination with a continuous infusion of [U-(13)C]palmitate and [(2)H(5)]glycerol in five post-absorptive healthy volunteers (22 +/- 3 years). The influence of contamination from non-skeletal muscle tissues, skin and subcutaneous...

  13. Acid phosphatases in seeds and developing of squash (Cucurbita ficifolia

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    Irena Lorenc-Kubis

    2014-01-01

    Full Text Available Changes in protein content and acid phosphatase activity were followed during germination (imbition through seedlings development in extracts from cotyledons of squash (Cucurbita ficifolia. It has been shown that the activity of acid phosphatase was initially low and than increased to a maximum after 6 days of imbition. Acid phosphates were isolated from cotyledons of seeds and from 6-, 10- and 22-days old seedlings by extraction the proteins with 0.1 M acetate buffer pH 5.1, precipitation with ethanol and by affinity chromatography on con A-Sepharose. Two glycoprotein enzymes AcPase Ba and AcPase Bb which differ in their affinity to immobilized con A were obtained. Both acid phosphatates retained the enzyme activity after binding to free con A. Rocket affinity electrophoresis of AcPase Ba and AcPase Bb, isolated from cotyledons of seeds and seedlings, revealed differences in their ability to bind to con A during seeds germination and seedling develop-ment indicating changes in their sugar component. Con A was found to activate both enzymes. The enzymes cross-reacted with monospecific antibodies raised against grass seed acid phosphatate Ba indicating an antigenic relationship between squash and grass acid phosphatases.

  14. Decryptification of Acid Phosphatase in Arthrospores of Geotrichum Species Treated with Dimethyl Sulfoxide and Acetone

    Science.gov (United States)

    Cotter, David A.; Martel, Anita J.; MacDonald, Paul

    1975-01-01

    Decryptification of acid phosphatase in Geotrichum sp. arthrospores was accomplished using acetone or dimethyl sulfoxide treatment. Both dimethyl sulfoxide and acetone irreversibly destroyed the integrity of the spore membranes without solubilizing acid phosphatase. PMID:1167386

  15. An acid phosphatase in the plasma membranes of human astrocytoma showing marked specificity toward phosphotyrosine protein.

    OpenAIRE

    Leis, J F; Kaplan, N O

    1982-01-01

    The plasma membrane from the human tumor astrocytoma contains an active acid phosphatase activity based on hydrolysis of p-nitrophenyl phosphate. Other acid phosphatase substrates--beta-glycerophosphate, O-phosphorylcholine, and 5'-AMP--are not hydrolyzed significantly. The phosphatase activity is tartrate insensitive and is stimulated by Triton X-100 and EDTA. Of the three known phosphoamino acids, only free O-phosphotyrosine is hydrolyzed by the membrane phosphatase activity. Other acid pho...

  16. Synthesis and characterization of polyesters derived from glycerol and phthalic acid

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    Danilo Hansen Guimarães

    2007-09-01

    Full Text Available The production of polyester via polycondensation between glycerol and phthalic acid using dibutyltin dilaurate is reported. Three glycerol:phthalic acid molar ratio used for the bulk polymerization were: 2:2; 2:3 and 2:4. FTIR confirmed the esterification of glycerol by the acid for all the polymers. DSC indicated no crystallinity, although the XRD plots indicate a very incipient crystallinity for the polymers containing higher amounts of phthalic anhydride. Scanning electron microscopy results indicates high homogeneity for all the polymers prepared.

  17. A histochemical study of rat salivary gland acid phosphatase.

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    Isacsson, G

    1986-01-01

    Male Sprague-Dawley rats received 4 mg pilocarpine/100 g body wt intraperitoneally or physiological saline as control and were killed at various intervals. Acid phosphatase was reacted on frozen sections from soft palate, parotid and submandibular glands using sodium-alpha-naphthyl acid phosphate as substrate. Various inhibitors were added to the incubation medium. The strongest acid phosphatase activity was in the parotid gland acinar and proximal secretory duct cells; the mucous minor glands of the palate were completely negative. Activity was found in the acinar cells, proximal secretory duct cells, granular and striated duct and excretory duct cells. Pilocarpine injection slightly reduced the activity up to 6 h after injection. Cupric chloride added to the incubation medium lowered the overall activity. Fluoride and molybdate inhibited the acid phosphatase reaction in all structures. Tartrate inhibited the reaction in all structures except the submandibular striated duct cells. The tartrate-resistant activity may be a Na+K+-dependent ATPase involved in re-absorbing water and electrolytes from the primary saliva.

  18. Fermentative utilization of glycerol residue for the production of acetic acid

    Science.gov (United States)

    Irvan; Trisakti, B.; Hasibuan, R.; Joli, M.

    2018-02-01

    Glycerol residue, frequently known as pitch, is a waste produced from the downstream product of crude glycerine distillation. With the increasing need of pure glycerine in the world, the glycerol residue produced is also increasing. Glycerol residue is a solid waste at room temperature, highly alkaline (pH > 13), corrosive, and categorized as hazardous and poisonous waste. In this research, acetic acid was produced from glycerol residue through the anaerobic fermentation process by using purple non-sulphur photosynthetic bacteria. The purpose of this study was to find out the influence of concentration change of glycerol residue on time and to find out the possibility of glycerol residue to be utilized as acetic acid. In this research, at first 400 g of glycerol residue was diluted with 200 ml of distilled water to change the glycerine phase, from solid to liquid at room temperature, acidified by using hydrochloric acid until pH 2. The top layer formed was fatty acid and triglycerides that should be removed. Meanwhile, the bottom layer was diluted glycerol residue which was then neutralized with caustic soda. To produce acetic acid, glycerol residue with various concentrations, salt, and purple non-sulphur photosynthetic bacteria were put together into a 100 ml bottle which had been previously sterilized, then incubated for four weeks under the light of 40-watt bulb. The result showed that on the 28th day of fermentation, the produced acetic acid were 0.28, 1.85, and 0.2% (w/w) by using glycerine with the concentration of 0.5, 1.0, and 1.5% (w/w), respectively.

  19. Malic acid production by chemically induced Aspergillus niger MTCC 281 mutant from crude glycerol.

    Science.gov (United States)

    Iyyappan, J; Bharathiraja, B; Baskar, G; Jayamuthunagai, J; Barathkumar, S; Anna Shiny, R

    2018-03-01

    In the present investigation, crude glycerol derived from transesterification process was utilized to produce the commercially-valuable malic acid. A combined resistant on methanol and malic acid strain of Aspergillus niger MTCC 281 mutant was generated in solid medium containing methanol (1-5%) and malic acid (40-80 g/L) by the adaptation process for 22 weeks. The ability of induced Aspergillus niger MTCC 281 mutant to utilize crude glycerol and pure glycerol to produce malic acid was studied. The yield of malic acid was increased with 4.45 folds compared with that of parent strain from crude glycerol. The highest concentration of malic acid from crude glycerol by using beneficial mutant was found to be 77.38 ± 0.51 g/L after 192 h at 25 °C. This present study specified that crude glycerol by-product from biodiesel production could be used for producing high amount of malic acid without any pretreatment. Copyright © 2017 Elsevier Ltd. All rights reserved.

  20. Phosphatase activity of Poa pratensis seeds. II. Purification and characterization of acid phosphatase Ia2 and Ia3

    Directory of Open Access Journals (Sweden)

    I. Lorenc-Kubis

    2015-01-01

    Full Text Available Two acid phosphatases (Ia2, Ia3 have been isolated from Poa pratensis seeds and partially purified. Both enzymes showed maximal activity at pH 4,9. They exhibited high activity towards p-nitrophenyl phosphate, inorganic pyrophosphate and phenyl phosphate, much less activity towards glucose-6 phosphate, and mononucleotides. Phosphatases a2 and a3 differed in their activity towards ADP. Orthophosphate, fluoride and Zn2+ were effective inhibitors. EDTA, β-mercaptoethanol and Mg2+ activated phophatase a2 but had no effect on phosphatase a3. Zn2+ inhibited the activity of phosphatase a2 noncompetitively, whereas phosphatase a3 showed inhibition of mixed type. Trypsin, chymotrypsin and pronase had no effect on the enzyme activities of both molecular forms.

  1. Radioimmunoassay for prostatic acid phosphatase in human serum. Methodologic aspects

    Energy Technology Data Exchange (ETDEWEB)

    Pradalier, N; Canal, P; Pujol, A; Fregevu, Y [Groupe de Recherches du Centre Claudius-Regaud, Toulouse (France); Soula, G [Faculte des Sciences Pharmaceutiques, Toulouse (France)

    1982-01-01

    We propose a double antibody radioimmunoassay for human prostatic acid phosphatase (PAP) in serum for diagnosis and management of prostatic adenocarcinoma under treatment. The antigen is purified from human prostatic fluid by a gel-filtration on Sephadex G 100 followed by affinity chromatography on Con A Sepharose. A specific antibody is raised in rabbits and purified by immunoadsorption with a female serum. The described technique offers both radioisotopic sensibility and immunologic specificity. Physiological values determined in the serum of 125 healthy males are below 2 ng/ml. No significative differences are observed with age. The proposed technique also shows significant differences between values evaluated for benign prostatic hyperplasia and prostatic adenocarcinoma.

  2. Synthesis and characterization of unsatured polyesters from the reaction of glycerol with fumaric acid

    International Nuclear Information System (INIS)

    Medeiros, Marina A.O.; Brioude, Michel M.; Agrela, Sara P.; Rosa, Leandro O.S.; Jose, Nadia M.; Prado, Luis A.S.A.

    2009-01-01

    The biodiesel production from vegetable oils has been encouraged by the Brazilian Federal Government, since biodiesel is a renewable fuel. The utilization of glycerol (by-product of biodiesel production) has gained importance, since it corresponds to 30 wt-% of the produced biodiesel. In this context, the present work aims at preparing and characterizing polymers based on glycerol, which could have an application. In this way, the production of biodiesel could be further stimulated. Unsaturated polyesters were preparing by esterification of glycerol with fumaric acid. The reaction mixture was heated up to 240 deg C. After the polymerization was complete, the material was cast onto Teflon molds. The materials were characterized by Infrared Spectroscopy, X-ray diffraction. The thermal stability was evaluated by thermogravimetric analysis and differential scanning calorimetry. The materials showed thermal stability comparable to alkyd thermoset derived from maleic anhydride and glycerol. (author)

  3. Glycerol-plasticised silk membranes made using formic acid are ductile, transparent and degradation-resistant.

    Science.gov (United States)

    Allardyce, Benjamin J; Rajkhowa, Rangam; Dilley, Rodney J; Redmond, Sharon L; Atlas, Marcus D; Wang, Xungai

    2017-11-01

    Regenerated silk fibroin membranes tend to be brittle when dry. The use of plasticisers such as glycerol improve membrane ductility, but, when combined with aqueous processing, can lead to a higher degradation rate than solvent-annealed membranes. This study investigated the use of formic acid as the solvent with glycerol to make deformable yet degradation-resistant silk membranes. Here we show that membranes cast using formic acid had low light scattering, with a diffuse transmittance of less than 5% over the visible wavelengths, significantly lower than the 20% transmittance of aqueous derived silk/glycerol membranes. They had 64% β-sheet content and lost just 30% of the initial silk weight over 6h when tested with an accelerated enzymatic degradation assay, in comparison the aqueous membranes completely degraded within this timeframe. The addition of glycerol also improved the maximum elongation of formic acid derived membranes from under 3% to over 100%. They also showed good cytocompatibility and supported the adhesion and migration of human tympanic membrane keratinocytes. Formic acid based, silk/glycerol membranes may be of great use in medical applications such as repair of tympanic membrane perforation or ocular applications where transparency and resistance to enzymatic degradation are important. Copyright © 2017 Elsevier B.V. All rights reserved.

  4. Efficient production of succinic acid in immobilized fermentation with crude glycerol from Escherichia coli

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    Nik Nor Aziati, A.A.

    2017-10-01

    Full Text Available The increase in the price of commercial succinic acid has necessitated the need for its synthesis from waste materials such as glycerol. Glycerol residue is a waste product of Oleochemical production which is cheaply available and a very good source of carbon. The use of immobilized cells can further reduce the overall cost of the production process. This study primarily aims to produce succinic acid from glycerol residue through the use of immobilized Escherichia coli in a batch fermentation process. The parameters which affect bacterial fermentation process such as the mass substrate, temperature, inoculum size and duration of fermentation were screened using One-Factor-At-a-Time (OFAT method. The result of the screening process shows that a substrate (glycerol concentration of 30 g, inoculum size 20% v/v, and time 4 h produced the maximum succinic acid concentration of 117.99 g/L. The immobilized cells were found to be stable as well as retain their fermentative ability up to the 6th cycle of recycling, thereby presenting as an advantage over the free cell system. Therefore, conclude that using immobilized cells can contribute immensely to the cost-effective production of succinic acid from glycerol residue.

  5. Radioimmunoassay for prostatic acid phosphatase in human serum. Methodologic aspects

    International Nuclear Information System (INIS)

    Pradalier, N.; Canal, P.; Pujol, A.; Fregevu, Y.; Soula, G.

    1982-01-01

    We propose a double antibody radioimmunoassay for human prostatic acid phosphatase (PAP) in serum for diagnosis and management of prostatic adenocarcinoma under treatment. The antigen is purified from human prostatic fluid by a gel-filtration on Sephadex G 100 followed by affinity chromatography on Con A Sepharose. A specific antibody is raised in rabbits and purified by immunoadsorption with a female serum. The described technique offers both radioisotopic sensibility and immunologic specificity. Physiological values determined in the serum of 125 healthy males are below 2 ng/ml. No significative differences are observed with age. The proposed technique also shows significant differences between values evaluated for benign prostatic hyperplasia and prostatic adenocarcinoma [fr

  6. Wet oxidation of glycerol into fine organic acids: catalyst selection and kinetic evaluation

    Directory of Open Access Journals (Sweden)

    J. E. N. Brainer

    2014-12-01

    Full Text Available The liquid phase oxidation of glycerol was performed producing fine organic acids. Catalysts based on Pt, Pd and Bi supported on activated carbon were employed to perform the conversion of glycerol into organic acids at 313 K, 323 K and 333 K, under atmospheric pressure (1.0 bar, in a mechanically agitated slurry reactor (MASR. The experimental results indicated glycerol conversions of 98% with production of glyceric, tartronic and glycolic acids, and dihydroxyacetone. A yield of glyceric acid of 69.8%, and a selectivity of this compound of 70.6% were reached after 4 h of operation. Surface mechanisms were proposed and rate equations were formulated to represent the kinetic behavior of the process. Selective formation of glyceric acid was observed, and the kinetic parameter values indicated the lowest activation energy (38.5 kJ/mol for its production reaction step, and the highest value of the adsorption equilibrium constant of the reactant glycerol (10-4 dm³/mol.

  7. Phosphatase activity of Poa pratensis seeds. III. Effect of fluoride, citrate, urea and other substances on the activity of acid phosphatase Ia2 and Ia3

    Directory of Open Access Journals (Sweden)

    Irena Lorenc-Kubis

    2015-01-01

    Full Text Available Effects of fluoride, citrate, urea and other substances on the activity of acid phosphatase a2 and a3 toward p-nitrophenylphosphate and phenylphosphate were investigated. Both enzymes were inhibited by fluoride, p-chloromercuribenzoate and oxalate. Fluoride inhibited acid phosphatase a2 noncorapetitively with p-mitrophenylphosphate, whereas acid phosphatase a3 showed inhibition of mixed type. Hydrolysis of phenylphosphate by both acid phosphatases was activated by citrate. Cytosine and uridine inhibited the activity of phosphatase a2 toward p-nitrophenylphosphate and phenylphosphate, but no effect was observed in case of acid phosphatase a3. After 30 min. incubation with 4 M urea both enzymes lost about 30% of activity.

  8. Poly(glycerol adipate)-fatty acid esters as versatile nanocarriers

    DEFF Research Database (Denmark)

    Weiss, Verena M; Naolou, Toufik; Hause, Gerd

    2012-01-01

    Poly(glycerol adipate) (PGA) is a biodegradable polymer with promising features for nanoparticulate drug carrier systems. By acylation of PGA with fatty acids, composite systems with amphiphilic properties can be obtained. Variation of the fatty acid (laurate, stearate and behenate) and their sub...... and the nanoparticles. With their diverse particle shapes and internal structures as well as their different thermal behavior, aggregate states and polarities, the systems offer promising possibilities as delivery systems for lipophilic, amphiphilic and water soluble drugs.......Poly(glycerol adipate) (PGA) is a biodegradable polymer with promising features for nanoparticulate drug carrier systems. By acylation of PGA with fatty acids, composite systems with amphiphilic properties can be obtained. Variation of the fatty acid (laurate, stearate and behenate...

  9. Vanadate monomers and dimers both inhibit the human prostatic acid phosphatase.

    Science.gov (United States)

    Crans, D C; Simone, C M; Saha, A K; Glew, R H

    1989-11-30

    A combination of enzyme kinetics and 51V NMR spectroscopy was used to identify the species of vanadate that inhibits acid phosphatases. Monomeric vanadate was shown to inhibit wheat germ and potato acid phosphatases. At pH 5.5, the vanadate dimer inhibits the human prostatic acid phosphatase whereas at pH 7.0 it is the vanadate monomer that inhibits this enzyme. The pH-dependent shift in the affinity of the prostatic phosphatase for vanadate is presumably due to deprotonation of an amino acid side chain in or near the binding site resulting in a conformational change in the protein. pH may be a subtle effector of the insulin-like vanadate activity in biological systems and may explain some of the differences in selectivity observed with the protein phosphatases.

  10. 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...

  11. Zinc-ion-dependent acid phosphatase exhibits magnesium-ion-dependent myo-inositol-1-phosphatase activity.

    Science.gov (United States)

    Fujimoto, S; Okano, I; Tanaka, Y; Sumida, Y; Tsuda, J; Kawakami, N; Shimohama, S

    1996-06-01

    We have purified bovine brain Zn(2+)-dependent acid phosphatase (Zn(2+)-APase), which requires Zn2+ ions to hydrolyze the substrate p-nitrophenyl phosphate (pNPP) in an acidic environment. The substrate specificity and metal requirement of Zn(2+)-APase at a physiological pH was also studied. The enzyme exhibited hydrolytic activity on myo-inositol-1- and -2-monophosphates, 2'-adenosine monophosphate, 2'-guanosine monophosphate, and the alpha- and beta-glycerophosphates, glucose-1-phosphate, and fructose-6-phosphate in 50 mM Tris-HCl buffer (pH 7.4) in the presence of Mg2+ ions, but not on pNPP and phosphotyrosine. Zn2+, Mn2+ and Co2+ ions were less effective for activation. Among the above substrates, myo-inositol-1-phosphate was the most susceptible to hydrolysis by the enzyme in the presence of 3 mM Mg2+ ions. The enzyme exhibited an optimum pH at around 8 for myo-inositol-1-phosphate in the presence of 3 mM Mg2+ ions. The Mg(2+)-dependent myo-inositol-1-phosphatase activity of the enzyme was significantly inhibited by Li+ ions. The Zn(2+)-dependent p-nitrophenyl phosphatase activity and Mg(2+)-dependent myo-inositol-1-phosphatase activity of the purified enzyme fraction exhibited similar behavior on Sephadex G-100 and Mono Q colomns. These findings suggest that Zn(2+)-APase also exhibits Mg(2+)-dependent myo-inositol-1-phosphatase activity under physiological conditions.

  12. Oxidative dehydration of glycerol to acrylic acid over vanadium-impregnated zeolite beta

    Energy Technology Data Exchange (ETDEWEB)

    Pestana, Carolina F.M.; Guerra, Antonio C.O.; Turci, Cassia C. [Universidade Federal do Rio de Janeiro, RJ (Brazil). Inst. de Quimica; Ferreira, Glaucio B. [Universidade Federal Fluminense, Niteroi, RJ (Brazil). Inst. de Quimica; Mota, Claudio J.A., E-mail: cmota@iq.ufrj.br [INCT Energia e Ambiente, Universidade Federal do Rio de Janeiro, RJ (Brazil)

    2013-01-15

    The oxidative dehydration of glycerol to acrylic acid was studied over vanadium-impregnated zeolite Beta. Catalysts were prepared by wet impregnation of ammonium metavanadate over ammonium-exchanged zeolite Beta, followed by air calcination at 823 K. Impregnation reduced the specific surface area, but did not significantly affected the acidity (Bronsted and Lewis) of the zeolites. The catalytic evaluation was carried out in a fixed bed flow reactor using air as the carrier and injecting glycerol by means of a syringe pump. Acrolein was the main product, with acetaldehyde and hydroxy-acetone (acetol) being also formed. Acrylic acid was formed with approximately 25% selectivity at 548 K over the impregnated zeolites. The result can be explained by XPS (X-ray photoelectron spectroscopy) measurements, which indicated a good dispersion of the vanadium inside the pores. (author)

  13. Oxidative dehydration of glycerol to acrylic acid over vanadium-impregnated zeolite beta

    International Nuclear Information System (INIS)

    Pestana, Carolina F.M.; Guerra, Antonio C.O.; Turci, Cassia C.

    2013-01-01

    The oxidative dehydration of glycerol to acrylic acid was studied over vanadium-impregnated zeolite Beta. Catalysts were prepared by wet impregnation of ammonium metavanadate over ammonium-exchanged zeolite Beta, followed by air calcination at 823 K. Impregnation reduced the specific surface area, but did not significantly affected the acidity (Bronsted and Lewis) of the zeolites. The catalytic evaluation was carried out in a fixed bed flow reactor using air as the carrier and injecting glycerol by means of a syringe pump. Acrolein was the main product, with acetaldehyde and hydroxy-acetone (acetol) being also formed. Acrylic acid was formed with approximately 25% selectivity at 548 K over the impregnated zeolites. The result can be explained by XPS (X-ray photoelectron spectroscopy) measurements, which indicated a good dispersion of the vanadium inside the pores. (author)

  14. A comparative study on glycerol metabolism to erythritol and citric acid in Yarrowia lipolytica yeast cells.

    Science.gov (United States)

    Tomaszewska, Ludwika; Rakicka, Magdalena; Rymowicz, Waldemar; Rywińska, Anita

    2014-09-01

    Citric acid and erythritol biosynthesis from pure and crude glycerol by three acetate-negative mutants of Yarrowia lipolytica yeast was investigated in batch cultures in a wide pH range (3.0-6.5). Citric acid biosynthesis was the most effective at pH 5.0-5.5 in the case of Wratislavia 1.31 and Wratislavia AWG7. With a decreasing pH value, the direction of biosynthesis changed into erythritol synthesis accompanied by low production of citric acid. Pathways of glycerol conversion into erythritol and citric acid were investigated in Wratislavia K1 cells. Enzymatic activity was compared in cultures run at pH 3.0 and 4.5, that is, under conditions promoting the production of erythritol and citric acid, respectively. The effect of pH value (3.0 and 4.5) and NaCl presence on the extracellular production and intracellular accumulation of citric acid and erythritol was compared as well. Low pH and NaCl resulted in diminished activity of glycerol kinase, whereas such conditions stimulated the activity of glycerol-3-phosphate dehydrogenase. The presence of NaCl strongly influenced enzymes activity - the effective erythritol production was correlated with a high activity of transketolase and erythrose reductase. Therefore, presented results confirmed that transketolase and erythrose reductase are involved in the overproduction of erythritol in the cells of Y. lipolytica yeast. © 2014 Federation of European Microbiological Societies. Published by John Wiley & Sons Ltd. All rights reserved.

  15. Effect of succinic acid concentration in poly(glycerol citrate/succinate) properties

    International Nuclear Information System (INIS)

    Brioude, Michel M.; Guimaraes, Danilo H.; Fiuza, Raigenis P.; Jose, Nadia M.

    2011-01-01

    In this work were prepared and characterized polymer based on glycerol, citric and succinic acid, in three different ratios to evaluate the effect of succinic acid concentration in materials properties. The polymers were obtained by polycondensation reaction between polyol and poly acids, and were characterized by X-ray diffraction (XRD), infrared spectroscopy (FTIR), thermogravimetric analysis (TGA), scanning differential calorimetry (DSC), scanning electron microscopy (SEM). The materials are amorphous polyesters and its thermal and morphological properties change depending on the succinic acid concentration. (author)

  16. Monomeric tartrate resistant acid phosphatase induces insulin sensitive obesity.

    Directory of Open Access Journals (Sweden)

    Pernilla Lång

    2008-03-01

    Full Text Available Obesity is associated with macrophage infiltration of adipose tissue, which may link adipose inflammation to insulin resistance. However, the impact of inflammatory cells in the pathophysiology of obesity remains unclear. Tartrate resistant acid phosphatase (TRAP is an enzyme expressed by subsets of macrophages and osteoclasts that exists either as an enzymatically inactive monomer or as an active, proteolytically processed dimer.Using mice over expressing TRAP, we show that over-expression of monomeric, but not the dimeric form in adipose tissue leads to early onset spontaneous hyperplastic obesity i.e. many small fat cells. In vitro, recombinant monomeric, but not proteolytically processed TRAP induced proliferation and differentiation of mouse and human adipocyte precursor cells. In humans, monomeric TRAP was highly expressed in the adipose tissue of obese individuals. In both the mouse model and in the obese humans the source of TRAP in adipose tissue was macrophages. In addition, the obese TRAP over expressing mice exhibited signs of a low-grade inflammatory reaction in adipose tissue without evidence of abnormal adipocyte lipolysis, lipogenesis or insulin sensitivity.Monomeric TRAP, most likely secreted from adipose tissue macrophages, induces hyperplastic obesity with normal adipocyte lipid metabolism and insulin sensitivity.

  17. A Biodegradable Thermoset Polymer Made by Esterification of Citric Acid and Glycerol

    Science.gov (United States)

    Halpern, Jeffrey M.; Urbanski, Richard; Weinstock, Allison K.; Iwig, David F.; Mathers, Robert T.; von Recum, Horst

    2014-01-01

    A new biomaterial, a degradable thermoset polymer, was made from simple, economical, biocompatable monomers without the need for a catalyst. Glycerol and citric acid, non-toxic and renewable reagents, were crosslinked by a melt polymerization reaction at temperatures from 90-150°C. Consistent with a condensation reaction, water was determined to be the primary byproduct. The amount of crosslinking was controlled by the reaction conditions, including temperature, reaction time, and ratio between glycerol and citric acid. Also, the amount of crosslinking was inversely proportional to the rate of degradation. As a proof-of-principle for drug delivery applications, gentamicin, an antibiotic, was incorporated into the polymer with preliminary evaluations of antimicrobial activity. The polymers incorporating gentamicin had significantly better bacteria clearing of Staphylococcus aureus compared to non-gentamicin gels for up to nine days. PMID:23737239

  18. Electrochemical method for producing a biodiesel mixture comprising fatty acid alkyl esters and glycerol

    Science.gov (United States)

    Lin, YuPo J; St. Martin, Edward J

    2013-08-13

    The present invention relates to an integrated method and system for the simultaneous production of biodiesel from free fatty acids (via esterification) and from triglycerides (via transesterification) within the same reaction chamber. More specifically, one preferred embodiment of the invention relates to a method and system for the production of biodiesel using an electrodeionization stack, wherein an ion exchange resin matrix acts as a heterogeneous catalyst for simultaneous esterification and transesterification reactions between a feedstock and a lower alcohol to produce biodiesel, wherein the feedstock contains significant levels of free fatty acid. In addition, because of the use of a heterogeneous catalyst, the glycerol and biodiesel have much lower salt concentrations than raw biodiesel produced by conventional transesterification processes. The present invention makes it much easier to purify glycerol and biodiesel.

  19. An acid phosphatase in the plasma membranes of human astrocytoma showing marked specificity toward phosphotyrosine protein.

    Science.gov (United States)

    Leis, J F; Kaplan, N O

    1982-11-01

    The plasma membrane from the human tumor astrocytoma contains an active acid phosphatase activity based on hydrolysis of p-nitrophenyl phosphate. Other acid phosphatase substrates--beta-glycerophosphate, O-phosphorylcholine, and 5'-AMP--are not hydrolyzed significantly. The phosphatase activity is tartrate insensitive and is stimulated by Triton X-100 and EDTA. Of the three known phosphoamino acids, only free O-phosphotyrosine is hydrolyzed by the membrane phosphatase activity. Other acid phosphatases tested from potato, wheat germ, milk, and bovine prostate did not show this degree of specificity. The plasma membrane activity also dephosphorylated phosphotyrosine histone at a much greater rate than did the other acid phosphatases. pH profiles for free O-phosphotyrosine and phosphotyrosine histone showed a shift toward physiological pH, indicating possible physiological significance. Phosphotyrosine histone dephosphorylation activity was nearly 10 times greater than that seen for phosphoserine histone dephosphorylation, and Km values were much lower for phosphotyrosine histone dephosphorylation (0.5 microM vs. 10 microM). Fluoride and zinc significantly inhibited phosphoserine histone dephosphorylation. Vanadate, on the other hand, was a potent inhibitor of phosphotyrosine histone dephosphorylation (50% inhibition at 0.5 microM) but not of phosphoserine histone. ATP stimulated phosphotyrosine histone dephosphorylation (160-250%) but inhibited phosphoserine histone dephosphorylation (95%). These results suggest the existence of a highly specific phosphotyrosine protein phosphatase activity associated with the plasma membrane of human astrocytoma.

  20. Influence of triethyl phosphate on phosphatase activity in shooting range soil: Isolation of a zinc-resistant bacterium with an acid phosphatase.

    Science.gov (United States)

    Story, Sandra; Brigmon, Robin L

    2017-03-01

    Phosphatase-mediated hydrolysis of organic phosphate may be a viable means of stabilizing heavy metals via precipitation as a metal phosphate in bioremediation applications. We investigated the effect of triethyl phosphate (TEP) on soil microbial-phosphatase activity in a heavy-metal contaminated soil. Gaseous TEP has been used at subsurface sites for bioremediation of organic contaminants but not applied in heavy-metal contaminated areas. Little is known about how TEP affects microbial activity in soils and it is postulated that TEP can serve as a phosphate source in nutrient-poor groundwater and soil/sediments. Over a 3-week period, TEP amendment to microcosms containing heavy-metal contaminated soil resulted in increased activity of soil acid-phosphatase and repression of alkaline phosphatase, indicating a stimulatory effect on the microbial population. A soil-free enrichment of microorganisms adapted to heavy-metal and acidic conditions was derived from the TEP-amended soil microcosms using TEP as the sole phosphate source and the selected microbial consortium maintained a high acid-phosphatase activity with repression of alkaline phosphatase. Addition of 5mM zinc to soil-free microcosms had little effect on acid phosphatase but inhibited alkaline phosphatase. One bacterial member from the consortium, identified as Burkholderia cepacia sp., expressed an acid-phosphatase activity uninhibited by high concentrations of zinc and produced a soluble, indigo pigment under phosphate limitation. The pigment was produced in a phosphate-free medium and was not produced in the presence of TEP or phosphate ion, indicative of purple acid-phosphatase types that are pressed by bioavailable phosphate. These results demonstrate that TEP amendment was bioavailable and increased overall phosphatase activity in both soil and soil-free microcosms supporting the possibility of positive outcomes in bioremediation applications. Copyright © 2016. Published by Elsevier Inc.

  1. Glycerol oxidehydration into acrolein and acrylic acid over W/V/Nb bronzes with hexagonal structure

    Energy Technology Data Exchange (ETDEWEB)

    Basile, F.; Cavani, F.; Chieregato, A. [Bologna Univ. (Italy). Dipt. di Chimica Industriale e dei Materiali; CIRI Energia e Ambiente, Bologna (Italy); Concepcion, P.; Lopez Nieto, J.M.; Soriano, M.D. [Univ. Politecnica de Valencia (Spain). Inst. de Tecnologia Quimica; Liosi, G.; Trevisanut, C. [Bologna Univ. (Italy). Dipt. di Chimica Industriale e dei Materiali

    2012-07-01

    This paper deals with an investigation of hexagonal W-V-Nb-O and W-V-Mo-O bronzes as catalysts for the one-pot oxidehydration of glycerol into acrylic acid. In a previous work, we reported a study on a bi-component bronze W-V-O that allowed us to obtain a 25% acrylic acid selectivity; in the current work, the incorporation of either Nb or Mo in a tri-component bronze structure allowed us to tune the acid and redox properties of the catalyst, so as to study their influence on the overall reaction scheme. (orig.)

  2. Preliminary Evaluation of Glyceric Acid-producing Ability of Acidomonas methanolica NBRC104435 from Glycerol Containing Methanol.

    Science.gov (United States)

    Sato, Shun; Kitamoto, Dai; Habe, Hiroshi

    2017-06-01

    Some acetic acid bacteria produce large amounts of glyceric acid (GA) from glycerol in culture broth. However, methanol, which is a major contaminant of raw glycerol derived from the biodiesel fuel industry, sharply decreases cell growth and GA production [AMB Express, 3, 20, 2013]. Thus, we evaluated the methylotrophic acetic acid bacterium Acidomonas methanolica NBRC104435 for its ability to produce GA from glycerol containing methanol. This strain accumulated GA in its culture broth when 1-3 wt% glycerol was available as a carbon source. We observed improved cell growth and GA accumulation when 1 vol% methanol was added to the 3-5 wt% glycerol medium. The maximum concentration of GA was 12.8 g/L in medium containing 3 wt% glycerol plus 1 vol% methanol. In addition, the enantiomeric excess (ee) of the GA produced was revealed to be 44%, indicating that this strain converted glycerol to d-GA with a lower enantioselectivity than other acetic acid bacteria, which had 70-99% ee.

  3. Expression of Prostatic Acid Phosphatase in Rat Circumvallate Papillae.

    Directory of Open Access Journals (Sweden)

    Kentaro Nishida

    Full Text Available ATP and its metabolites are important for taste signaling in taste buds, and thus a clearance system for them would play critical roles in maintenance of gustatory function. A previous report revealed that mRNAs for ecto-5'-nucleotidase (NT5E and prostatic acid phosphatase (PAP were expressed by taste cells of taste buds, and NT5E-immunoreactivity was detected in taste cells. However, there was no information on PAP-immunoreactivity in taste buds. In this study, we examined the expression profile of PAP in rat taste buds. In the isolated rat taste buds, we detected expression of mRNA for PAP, but NT5E was not detected differing from the case of mouse ones (Dando et al., 2012, J Neuroscience. On immunohistochemical analysis, PAP-immunoreactivity was found predominantly in NTPDase2-positive type I and SNAP25-positive type III taste cells, while there were no apparent signals of it in PLC-β2-positive type II, α-gustducin-positive type II, AADC-positive type III and 5HT-positive type III ones. As for NT5E, we could not detect its immunoreactivity in rat taste buds, and co-localization of it with any taste cell markers, although mouse taste buds expressed NT5E as reported previously. These findings suggest that PAP expressed by type I and one of type III taste cells of rats may contribute to metabolic regulation of the extracellular levels of adenine nucleotides in the taste buds of circumvallate papillae, and the regulating mechanisms for adenine nucleotides in taste buds might be different between rats and mice.

  4. Diagnosis of prostate cancer using a radioimmunoassay for prostatic acid phosphatase in serum

    International Nuclear Information System (INIS)

    Lea, O.A.; Hoeisaeter, P.Aa.

    1981-01-01

    The paper describes the development and evaluation of a specific radioimmunoassay for the determination of prostatic acid phosphatase in serum as a useful aid in the detection of prostatic cancer. (Auth.)

  5. Acid phosphatase from stored Poa pratensis caryopses and its ability for binding to lectins

    Directory of Open Access Journals (Sweden)

    Irena Lorenc-Kubis

    2014-01-01

    Full Text Available The effect of the storage period of Poa pratensis caryopses on acid phosphatase activity and on the ability of this enzyme to interact with lectins has been studied. It has been shown that after ten years of caryopses storage, the activity of acid phosphatase decreased about 50 per cent, while the content of proteins and carbohydrates did not change. The decrease of enzyme activity during the long period of storage was found only in seeds, but not in chaffs. Acid phosphatase was isolated from caryopses stored one, two, three, five and ten years. The enzyme showed the ability to bind to immoblized as well as to free conA during the whole period of storage, hut did not react with Wheat Germen Agglutinin (WGA. The activation of acid phosphatase by binding to conA decreased with the length of storage period.

  6. Tetranucleotide repeat polymorphism at the human prostatic acid phosphatase (ACPP) gene

    Energy Technology Data Exchange (ETDEWEB)

    Polymeropoulos, M H; Xiao, Hong; Rath, D S; Merril, C R [National Inst. of Mental Health Neuroscience Center, Washington, DC (United States)

    1991-09-11

    The polymorphic (AAAT){sub n} repeat begins at base pair 2342 of the human prostatic acid phosphatase gene on chromosome 3q21-qter. The polymorphism can be typed using the polymerase chain reaction (PCR) as described previously. The predicted length of the amplified sequence was 275 bp. Co-dominant segregation was observed in two informative families. The human prostatic acid phosphatase gene has been assigned to chromosome 3q21-qter.

  7. The tillage effect on the soil acid and alkaline phosphatase activity

    Directory of Open Access Journals (Sweden)

    Lacramioara Oprica

    2011-12-01

    Full Text Available Phosphatases (acid and alkaline are important in soils because these extracellular enzymes catalyze the hydrolysis of organic phosphate esters to orthophosphate; thus they form an important link between biologically unavailable and mineral phosphorous. Phosphatase activity is sensitive to environmental perturbations such as organic amendments, tillage, waterlogging, compaction, fertilizer additions and thus it is often used as an environmental indicator of soil quality in riparian ecosystems. The aim of the study was to assess the effect of tillage systems on phosphatases activity in a field experiment carried out in Ezăreni farm. The phosphatase activitiy were determined at two depths (7-10 cm and 15-25cm layers of a chernozem soil submitted to conventional tillage (CT in a fertilised and unfertilised experiment. Monitoring soil alkaline phosphatase activity showed, generally, the same in fertilized soil profiles collected from both depths; the values being extremely close. In unfertilized soils, alkaline phosphatase activity is different only in soils that were exposed to unconventional work using disc harrows and 30cm tillage. Both works type (no tillage and conventional tillage cause an intense alkaline phosphatase activity in 7-10 cm soil profile. Acid phosphatase activity is highly fluctuating in both fertilized as well unfertilized soil, this enzyme being influenced by the performed works.

  8. Data on glycerol/tartaric acid-based copolymer containing ciprofloxacin for wound healing applications

    Directory of Open Access Journals (Sweden)

    E. De Giglio

    2016-06-01

    Full Text Available This data article is related to our recently published research paper “Exploiting a new glycerol-based copolymer as a route to wound healing: synthesis, characterization and biocompatibility assessment", De Giglio et al. (Colloids and Surfaces B: Biointerfaces 136 (2015 600–611 [1]. The latter described a new copolymer derived from glycerol and tartaric acid (PGT. Herein, an investigation about the PGT-ciprofloxacin (CIP interactions by means of Fourier Transform Infrared Spectroscopy (FT-IR acquired in Attenuated Total Reflectance (ATR mode and Differential Scanning Calorimetry (DSC was reported. Moreover, CIP release experiments on CIP-PGT patches were performed by High Performance Liquid Chromatography (HPLC at different pH values.

  9. Chemical characterization of composites developed from glycerol and dicarboxylic acids rein forced with piassava fiber

    International Nuclear Information System (INIS)

    Miranda, Cleidiene S.; Oliveira, Jamerson C.; Guimaraes, Danilo H.; Jose, Nadia M.; Carvalho, Ricardo F.

    2011-01-01

    In search of alternative technologies that enable the use of products with lower environmental impact, This study aims to develop a composite polymer-based piassava fiber. The sludge, waste and byproduct of commercial uses currently being used as reinforcement in polymer matrices, due to presence of lignocellulosic materials. The matrix polymer used was synthesized from glycerol with dicarboxylic acids, in order to open future perspectives on the use of glycerin generated from purified biodiesel production plastics. Composites with 2, 5, 10 wt% of piassava fiber cut into 5 mm raw and treated were obtained a mixture of solution. The materials were characterized by TGA, DSC, XRD and SEM. It was observed that the material under study is promising for the industrial market, because it has good compatibility with natural fibers allowing wider application of fiber natural and glycerol, producing semicrystalline composites and with good thermal properties. (author)

  10. Influence of acid phosphatase activity on the saccharification of potato maltodextrins by Aspergillus niger glucoamylase

    Energy Technology Data Exchange (ETDEWEB)

    Zyla, K. (Akademia Rolnicza, Cracow (Poland). Dept. of Biotechnology)

    1990-01-01

    A preparation of Aspergillus niger acid phosphatase, which had the temperature optimum 60deg C, pH optimum 1.8-3.0; good stability at pH 4-5, the ability to hydrolyze glucose-6-phosphate at a high rate, and substantial lack of glucogenic activities, was used simultaneously with a glucoamylase in order to learn its influence on the saccharification of potato maltodextrins. The addition of the acid phosphatase activity in amounts that gave the 50 fold increase, as compared to phosphatase activity which naturally occurs in the gluocoamylase (GA) preparation 'AMG-200', was found to influence on the DE level, mainly at the high substrate concentration (40% d.s.) and low glucoamylase dosage (60-100 GAU/kg d.s.). It may also be possible, when using the acid phosphatase addition, to shorten the saccharification time. (orig.).

  11. Synthesis of bio-additives: transesterification of ethyl acetate with glycerol using homogeneous or heterogeneous acid catalysts

    Energy Technology Data Exchange (ETDEWEB)

    Meireles, Bruno A.; Pereira, Vera Lucia P., E-mail: patrocinio@nppn.ufrj.br [Universidade Federal do Rio de Janeiro (UFRJ), RJ (Brazil). Centro de Ciencias da Saude. Nucleo de Pesquisas de Produtos Naturais

    2013-01-15

    A new catalytic route with potential practical interest to sustainable production of bioadditives from glycerol is described. Ethyl acetate was transesterified with glycerol, in the ratio glycerol:EtOAc 1:10, at 25 or 90 deg C using 0.1 equiv.of H{sub 2}SO{sub 4} or TsOH, as homogeneous catalysts. H{sub 2}SO{sub 4} led to the total glycerol consumption in 2 h. In the equilibrium, attained in 9 h, 100% yield of a diacetin:triacetin (55:45) mixture was formed. Using Amberlyst Registered-Sign 15 dry and Amberlyst Registered-Sign 16 wet in 1:30 glycerol:EtOAc ratio and reflux at 90 Degree-Sign C the total glycerol consumption was achieved in 2 and 10h, respectively. The lower reactivity of Amberlyst-16 wet was explained in terms of deactivation of acid sites and decrease in glycerol diffusion to the inner resin pores, both factors caused by adsorbed water. The kinetics of glycerol transformation and product distribution in the equilibrium in relation to the H{sub 2}SO{sub 4}, Amberlyst-15 (dry) and Amberlyst-16 (wet) catalyzed reactions were measured. (author)

  12. Purification and properties of acid phosphatase from Avena elatior L. seeds

    Directory of Open Access Journals (Sweden)

    E. Wieczorek

    2015-01-01

    Full Text Available Acid phosphatase F1 from Avena elatior seeds was isolated and partially purified by means of alcohol precepitation, DEAE-, CM-column chromatography, Sephadex G-150, Sephadex G-200 and Sepharose 4B - gel filtration. The enzyme was stable at 50°C, pH 5.1. The pH optimum for phosphatase activity was 4.2. Fluoride, Zn2+, molybdate were effective inhibitors. EDTA and l, 10-phenanthroline activated the enzyme.

  13. A study of the alkaline and acid phosphatase activities in acute uranium intoxication

    International Nuclear Information System (INIS)

    Bokova, N.; Pavlova, V.; Stancheva, Yu.; Khadzhirusev, S.; Kiradzhiev, G.

    1975-01-01

    Comparative study of the ability of the sodium salt of diethylbarbituric acid and acetazolamide to protect the kidneys is conducted under conditions of acute uranium intoxication in rats. The parameters studied are alkaline and acid phosphatase activities in the serum and urine and phosphatase activity in the kidneys (histochemically as described by Gomori) followed up until the 30th day after the total uranyl acetate dose was reached (2 or 7 mg per kg bodyweight). Either compound exerted only minor effect on serum alkaline phosphatase activity. Sodium diethylbarbiturate induced distinct fluctuations in urinary alkaline phosphatase activity throughout the entire study period, but the differences never reached statistical significance. Acetazolamide caused essential decrease in urinary alkaline phosphatase activity. In either case renal tissue protection from the action of the uranyl ion may be suggested. This assumption is supported by the histochemical analysis. The compounds appeared to have no effect on serum acid phosphatase activity which showed high variability both in control and in treated rats. (Ch.K.)

  14. Biosynthesis of Citric Acid from Glycerol by Acetate Mutants of Yarrowia lipolytica in Fed-Batch Fermentation

    Directory of Open Access Journals (Sweden)

    Anita Rywińska

    2009-01-01

    Full Text Available Pure and crude glycerol from biodiesel production have been used as substrates for citric acid production by acetate-negative mutants of Yarrowia lipolytica in fed-batch fermentation. Both the final concentration and the yield of the product were the highest when Y. lipolytica Wratislavia AWG7 strain was used in the culture with pure or crude glycerol. With a medium containing 200 g/L of glycerol, production reached a maximum of citric acid of 139 g/L after 120 h. This high yield of the product (up to 0.69 g of citric acid per gram of glycerol consumed was achieved with both pure and crude glycerol. Lower yield of citric acid in the culture with Y. lipolytica Wratislavia K1 strain (about 0.45 g/g resulted from increased erythritol concentrations (up to 40 g/L, accumulated simultaneously with the citric acid. The concentration of isocitric acid, a by-product in this fermentation, was very low, in the range from 2.6 to 4.6 g/L.

  15. Acid phosphatase turnover during repressed and derepressed cultivation of Aspergillus niger

    International Nuclear Information System (INIS)

    Komano, Teruya

    1975-01-01

    Enhancement of the activity of acid phosphatase (EC 3.1.3.2) by phosphate starvation in growing Aspergillus niger mycelia was prevented by cycloheximide. This indicates that the enhancement was due to de novo protein synthesis caused by derepression. Radioactive acid phosphatase extracted from mycelia labeled with 14 C-amino acid was separated into at least four fractions. Experiments on pulse labeling and the chasing of the four acid phosphatases revealed the synthesis and degradation of each fraction occurred at different rates; showing a different rate of turnover of the enzyme molecules. The results of similar experiments performed during culture in the presence of phosphate (partially repressed condition) suggested that the marked change in the activity ratios of the four acid phosphatases during cultivation was the result of the active turnover of enzyme molecules. In contrast, the slight changes in the ratios observed during derepressed cultivation seemed to be the result of similar of synthesis and degradation of each phosphatase fraction. (auth.)

  16. [Spectroscopic analysis of the interaction of ethanol and acid phosphatase from wheat germ].

    Science.gov (United States)

    Xu, Dong-mei; Liu, Guang-shen; Wang, Li-ming; Liu, Wei-ping

    2004-11-01

    Conformational and activity changes of acid phosphatase from wheat germ in ethanol solutions of different concentrations were measured by fluorescence spectra and differential UV-absorption spectra. The effect of ethanol on kinetics of acid phosphatase was determined by using the double reciprocal plot. The results indicate the ethanol has a significant effect on the activity and conformation of acid phosphatase. The activity of acid phosphatase decreased linearly with increasing the concentration of ethanol. Differential UV-absorption spectra of the enzyme denatured in ethanol solutions showed two positive peaks at 213 and 234 nm, respectively. The peaks on the differential UV-absorption spectra suggested that the conformation of enzyme molecule changed from orderly structure to out-of-order crispation. The fluorescence emission peak intensity of the enzyme gradually strengthened with increasing ethanol concentration, which is in concordance with the conformational change of the microenvironments of tyrosine and tryptophan residues. The results indicate that the expression of the enzyme activity correlates with the stability and integrity of the enzyme conformation to a great degree. Ethanol is uncompetitive inhibitor of acid phosphatase.

  17. Enterobacter sp. LU1 as a novel succinic acid producer - co-utilization of glycerol and lactose.

    Science.gov (United States)

    Podleśny, Marcin; Jarocki, Piotr; Wyrostek, Jakub; Czernecki, Tomasz; Kucharska, Jagoda; Nowak, Anna; Targoński, Zdzisław

    2017-03-01

    Succinic acid is an important C4-building chemical platform for many applications. A novel succinic acid-producing bacterial strain was isolated from goat rumen. Phylogenetic analysis based on the 16S rRNA sequence and physiological analysis indicated that the strain belongs to the genus Enterobacter. This is the first report of a wild bacterial strain from the genus Enterobacter that is capable of efficient succinic acid production. Co-fermentation of glycerol and lactose significantly improved glycerol utilization under anaerobic conditions, debottlenecking the utilization pathway of this valuable biodiesel waste product. Succinic acid production reached 35 g l -1 when Enterobacter sp. LU1 was cultured in medium containing 50 g l -1 of glycerol and 25 g l -1 of lactose as carbon sources. © 2016 The Authors. Microbial Biotechnology published by John Wiley & Sons Ltd and Society for Applied Microbiology.

  18. Crystallization of a newly discovered histidine acid phosphatase from Francisella tularensis

    Energy Technology Data Exchange (ETDEWEB)

    Felts, Richard L. [Department of Chemistry, University of Missouri-Columbia, Columbia, Missouri 65211 (United States); Reilly, Thomas J. [Department of Veterinary Pathobiology, College of Veterinary Medicine, University of Missouri-Columbia, Columbia, Missouri 65212 (United States); Veterinary Medical Diagnostic Laboratory, College of Veterinary Medicine, University of Missouri-Columbia, Columbia, Missouri 65212 (United States); Calcutt, Michael J. [Department of Veterinary Pathobiology, College of Veterinary Medicine, University of Missouri-Columbia, Columbia, Missouri 65212 (United States); Tanner, John J., E-mail: tannerjj@missouri.edu [Department of Chemistry, University of Missouri-Columbia, Columbia, Missouri 65211 (United States); Department of Biochemistry, University of Missouri-Columbia, Columbia, Missouri 65211 (United States)

    2006-01-01

    A histidine acid phosphatase from the CDC Category A pathogen F. tularensis has been crystallized in space group P4{sub 1}2{sub 1}2, with unit-cell parameters a = 61.96, c = 210.78 Å. A 1.75 Å resolution data set was collected at Advanced Light Source beamline 4.2.2. Francisella tularensis is a highly infectious bacterial pathogen that is considered by the Centers for Disease Control and Prevention to be a potential bioterrorism weapon. Here, the crystallization of a 37.2 kDa phosphatase encoded by the genome of F. tularensis subsp. holarctica live vaccine strain is reported. This enzyme shares 41% amino-acid sequence identity with Legionella pneumophila major acid phosphatase and contains the RHGXRXP motif that is characteristic of the histidine acid phosphatase family. Large diffraction-quality crystals were grown in the presence of Tacsimate, HEPES and PEG 3350. The crystals belong to space group P4{sub 1}2{sub 1}2, with unit-cell parameters a = 61.96, c = 210.78 Å. The asymmetric unit is predicted to contain one protein molecule, with a solvent content of 53%. A 1.75 Å resolution native data set was recorded at beamline 4.2.2 of the Lawrence Berkeley National Laboratory Advanced Light Source. Molecular-replacement trials using the human prostatic acid phosphatase structure as the search model (28% amino-acid sequence identity) did not produce a satisfactory solution. Therefore, the structure of F. tularensis histidine acid phosphatase will be determined by multiwavelength anomalous dispersion phasing using a selenomethionyl derivative.

  19. Crystallization of a newly discovered histidine acid phosphatase from Francisella tularensis

    International Nuclear Information System (INIS)

    Felts, Richard L.; Reilly, Thomas J.; Calcutt, Michael J.; Tanner, John J.

    2005-01-01

    A histidine acid phosphatase from the CDC Category A pathogen F. tularensis has been crystallized in space group P4 1 2 1 2, with unit-cell parameters a = 61.96, c = 210.78 Å. A 1.75 Å resolution data set was collected at Advanced Light Source beamline 4.2.2. Francisella tularensis is a highly infectious bacterial pathogen that is considered by the Centers for Disease Control and Prevention to be a potential bioterrorism weapon. Here, the crystallization of a 37.2 kDa phosphatase encoded by the genome of F. tularensis subsp. holarctica live vaccine strain is reported. This enzyme shares 41% amino-acid sequence identity with Legionella pneumophila major acid phosphatase and contains the RHGXRXP motif that is characteristic of the histidine acid phosphatase family. Large diffraction-quality crystals were grown in the presence of Tacsimate, HEPES and PEG 3350. The crystals belong to space group P4 1 2 1 2, with unit-cell parameters a = 61.96, c = 210.78 Å. The asymmetric unit is predicted to contain one protein molecule, with a solvent content of 53%. A 1.75 Å resolution native data set was recorded at beamline 4.2.2 of the Lawrence Berkeley National Laboratory Advanced Light Source. Molecular-replacement trials using the human prostatic acid phosphatase structure as the search model (28% amino-acid sequence identity) did not produce a satisfactory solution. Therefore, the structure of F. tularensis histidine acid phosphatase will be determined by multiwavelength anomalous dispersion phasing using a selenomethionyl derivative

  20. Evidence That Speciation of Oxovanadium Complexes Does Not Solely Account for Inhibition of Leishmania Acid Phosphatases

    Science.gov (United States)

    Dorsey, Benjamin M.; McLauchlan, Craig C.; Jones, Marjorie A.

    2018-01-01

    Leishmaniasis is an endemic disease affecting a diverse spectra of populations, with 1.6 million new cases reported each year. Current treatment options are costly and have harsh side effects. New therapeutic options that have been previously identified, but still underappreciated as potential pharmaceutical targets, are Leishmania secreted acid phosphatases (SAP). These acid phosphatases, which are reported to play a role in the survival of the parasite in the sand fly vector, and in homing to the host macrophage, are inhibited by orthovanadate and decavanadate. Here, we use L. tarentolae to further evaluate these inhibitors. Using enzyme assays, and UV-visible spectroscopy, we investigate which oxovanadium starting material (orthovanadate or decavanadate) is a better inhibitor of L. tarentolae secreted acid phosphatase activity in vitro at the same total moles of vanadium. Considering speciation and total vanadium concentration, decavanadate is a consistently better inhibitor of SAP in our conditions, especially at low substrate:inhibitor ratios. PMID:29707535

  1. Evidence that Speciation of Oxovanadium Complexes does not Solely Account for Inhibition of Leishmania Acid Phosphatases

    Science.gov (United States)

    Dorsey, Benjamin M.; McLauchlan, Craig C.; Jones, Marjorie A.

    2018-04-01

    Leishmaniasis is an endemic disease affecting a diverse spectra of populations, with 1.6 million new cases reported each year. Current treatment options are costly and have harsh side effects. New therapeutic options that have been previously identified, but still underappreciated as potential pharmaceutical targets, are Leishmania secreted acid phosphatases (SAP). These acid phosphatases, which are reported to play a role in the survival of the parasite in the sand fly vector, and in homing to the host macrophage, are inhibited by orthovanadate and decavanadate. Here, we use L. tarentolae to further evaluate these inhibitors. Using enzyme assays, and UV-visible spectroscopy, we investigate which oxovanadium starting material (orthovanadate or decavanadate) is a better inhibitor of L. tarentolae secreted acid phosphatase activity in vitro at the same total moles of vanadium. Considering speciation and total vanadium concentration, decavanadate is a consistently better inhibitor of SAP in our conditions, especially at low substrate:inhibitor ratios.

  2. The inhibitory effect of metals and other ions on acid phosphatase activity from Vigna aconitifolia seeds.

    Science.gov (United States)

    Srivastava, Pramod Kumar; Anand, Asha

    2015-01-01

    Sensitivity of acid phosphatase from Vigna aconitifolia seeds to metal ions, fluoride, and phosphate was examined. All the effectors had different degree of inhibitory effect on the enzyme. Among metal ions, molybdate and ferric ion were observed to be most potent inhibitors and both exhibited mixed type of inhibition. Acid phosphatase activity was inhibited by Cu2+ in a noncompetitive manner. Zn and Mn showed mild inhibition on the enzyme activity. Inhibition kinetics analysis explored molybdate as a potent inhibitor for acid phosphatase in comparison with other effectors used in this study. Fluoride was the next most strong inhibitor for the enzyme activity, and caused a mixed type of inhibition. Phosphate inhibited the enzyme competitively, which demonstrates that inhibition due to phosphate is one of the regulatory factors for enzyme activity.

  3. Diversity of Lactobacillus reuteri Strains in Converting Glycerol into 3-Hydroxypropionic Acid.

    Science.gov (United States)

    Burgé, G; Saulou-Bérion, C; Moussa, M; Pollet, B; Flourat, A; Allais, F; Athès, V; Spinnler, H E

    2015-10-01

    The present study aims at comparing the performances of three Lactobacillus reuteri strains (DSM 20016, DSM 17938, and ATCC 53608) in producing 3-hydroxypropionic acid (3-HP) from glycerol and at exploring inhibition phenomena during this bioconversion. Differences were highlighted between the three strains in terms of 3-HP production yield, kinetics of substrate consumption, and metabolite production. With a maximal productivity in non-optimal conditions (free pH) around 2 g.L(-1).h(-1) of 3-HP and 4 g.L(-1).h(-1) of 3-hydroxypropionaldehyde (3-HPA) depending on the strain, this study confirmed the potential of L. reuteri for the biotechnological production of 3-HP. Moreover, the molar ratios of 3-HP to 1,3-propanediol (1,3-PDO) obtained for the three strains (comprised between 1.25 and 1.65) showed systematically a higher 3-HP production. From these results, the DSM 17938 strain appeared to be the most promising strain. The impact of glycerol bioconversion on the bacteria's physiological state (a decrease of around 40 % in DSM 17938 cells showing an enzymatic activity after 3 h) and survival (total loss of cultivability after 2 or 3 h depending on the strains) was revealed and discussed. The effect of each metabolite on L. reuteri DSM 17938 was further investigated, displaying a drastic inhibition caused by 3-HPA, while 3-HP induced lower impact and only at acidic pH.

  4. Effects of carbon dioxide on cell growth and propionic acid production from glycerol and glucose by Propionibacterium acidipropionici.

    Science.gov (United States)

    Zhang, An; Sun, Jianxin; Wang, Zhongqiang; Yang, Shang-Tian; Zhou, Haiying

    2015-01-01

    The effects of CO2 on propionic acid production and cell growth in glycerol or glucose fermentation were investigated in this study. In glycerol fermentation, the volumetric productivity of propionic acid with CO2 supplementation reached 2.94g/L/day, compared to 1.56g/L/day without CO2. The cell growth using glycerol was also significantly enhanced with CO2. In addition, the yield and productivity of succinate, the main intermediate in Wood-Werkman cycle, increased 81% and 280%, respectively; consistent with the increased activities of pyruvate carboxylase and propionyl CoA transferase, two key enzymes in the Wood-Werkman cycle. However, in glucose fermentation CO2 had minimal effect on propionic acid production and cell growth. The carbon flux distributions using glycerol or glucose were also analyzed using a stoichiometric metabolic model. The calculated maintenance coefficient (mATP) increased 100%, which may explain the increase in the productivity of propionic acid in glycerol fermentation with CO2 supplement. Copyright © 2014 Elsevier Ltd. All rights reserved.

  5. Production of Fungal Biomass for Feed, Fatty Acids, and Glycerol by Aspergillus oryzae from Fat-Rich Dairy Substrates

    Directory of Open Access Journals (Sweden)

    Amir Mahboubi

    2017-09-01

    Full Text Available Dairy waste is a complex mixture of nutrients requiring an integrated strategy for valorization into various products. The present work adds insights into the conversion of fat-rich dairy products into biomass, glycerol, and fatty acids via submerged cultivation with edible filamentous fungi. The pH influenced fat degradation, where Aspergillus oryzae lipase was more active at neutral than acidic pH (17 g/L vs. 0.5 g/L of released glycerol; the same trend was found during cultivation in crème fraiche (12 g/L vs. 1.7 g/L of released glycerol. In addition to glycerol, as a result of fat degradation, up to 3.6 and 4.5 g/L of myristic and palmitic acid, respectively, were released during A. oryzae growth in cream. The fungus was also able to grow in media containing 16 g/L of lactic acid, a common contaminant of dairy waste, being beneficial to naturally increase the initial acidic pH and trigger fat degradation. Considering that lactose consumption is suppressed in fat-rich media, a two-stage cultivation for conversion of dairy waste is also proposed in this work. Such an approach would provide biomass for possibly feed or human consumption, fatty acids, and an effluent of low organic matter tackling environmental and social problems associated with the dairy sector.

  6. Gas-phase Dehydration of Glycerol over Supported Silicotungstic Acids Catalysts

    International Nuclear Information System (INIS)

    Kim, Yong Tae; Park, Eun Duck; Jung, Kwang Deog

    2010-01-01

    The gas-phase dehydration of glycerol to acrolein was carried out over 10 wt % HSiW catalysts supported on different supports, viz. γ-Al 2 O 3 , SiO 2 -Al 2 O 3 , TiO 2 , ZrO 2 , SiO 2 , AC, CeO 2 and MgO. The same reaction was also conducted over each support without HSiW for comparison. Several characterization techniques, N 2 -physisorption, thermogravimetric analysis (TGA), differential scanning calorimetry (DSC), the temperature-programmed desorption of ammonia (NH 3 - TPD), temperature-programmed oxidation (TPO) with mass spectroscopy and CHNS analysis were employed to characterize the catalysts. The glycerol conversion generally increased with increasing amount of acid sites. Ceria showed the highest 1-hydroxyacetone selectivity at 315 .deg. C among the various metal oxides. The supported HSiW catalyst showed superior catalytic activity to that of the corresponding support. Among the supported HSiW catalysts, HSiW/ZrO 2 and HSiW/SiO 2 -Al 2 O 3 showed the highest acrolein selectivity. In the case of HSiW/ZrO 2 , the initial catalytic activity was recovered after the removal of the accumulated carbon species at 550 .deg. C in the presence of oxygen

  7. Effects of sub-lethal dose of gamma-irradiation on levels of acid phosphatase in cerebellum of pigeons

    International Nuclear Information System (INIS)

    Shah, V.C.; Gadhia, P.K.

    1980-01-01

    The changes in the activities of acid phosphatase in the sham-irradiated and γ-irradiated cerebellum of pigeons have been studied both biochemically as well as histochemically after 400 rads. The specific activity of acid phosphatase decreased significantly after 48h and 72h of irradiation. The histochemical observations following total body irradiation confirmed the results obtained by quantitative biochemical studies. (author)

  8. The manometric determination of thiamine pyrophosphate and the inhibition of the acid yeast phosphatase

    NARCIS (Netherlands)

    Steyn-Parvé, Elizabeth P.

    1962-01-01

    Sodium molybdate is a powerful inhibitor of the acid yeast phosphatase in both fresh baker's yeast and dried brewer's yeast, provided that the yeast is suspended in a suitable buffer. It displays no action in citrate or phosphate buffers, but is active in acetate or maleate buffers, both at the

  9. The effect of potassium iodide on the production of acid phosphatase by Sporothrix schenckii

    Directory of Open Access Journals (Sweden)

    P. S. Grover

    2003-06-01

    Full Text Available The present study was undertaken to find out the in vitro effect of potassium iodide (KI on the production of acid phosphatase by fully characterized strain of S.schenckii isolated from a patient of Cutaneous Sporotrichosis. The enzyme acid phosphatase was estimated during the 3 phases of growth of S.schenckii, without and with three concentrations of KI incorporated in the culture medium. In the control and in the test proper, with various concentrations of KI, no adverse effect of KI was observed on the production of acid phosphatase in early and mid log phase of fungal growth. Whereas in the exponential phase in test proper, there was a statistical significant decrease in the enzyme production with 0.8% and 3.2% of KI. The low activity at 0.8% and 3.2% KI indicates that KI has inhibitory effect on the growth of S.schenckii and has led to decrease in the activity of the enzyme. (Med J Indones 2003; 12: 65-8 Keywords: S.schenckii, acid phosphatase, potassium iodide

  10. The effects of drought stress on the activity of acid phosphatase and ...

    African Journals Online (AJOL)

    A model of drought was created on pigweed and the effects of drought stress on the activity of acid phosphatase and its protective enzymes were examined. The pot-cultured pigweeds were divided into 4 groups (ten plants per group) when they reached 6 leaves. (1) In the control group, the culture media contained 70 ...

  11. Identification of soybean purple acid phosphatase genes and their expression responses to phosphorus availability and symbiosis

    Science.gov (United States)

    Background and Aims Purple acid phosphatases (PAPs) are members of the metallo-phosphoesterase family and have been known to play important roles in phosphorus (P) acquisition and recycling in plants. Low P availability is a major constraint to growth and production of soybean, Glycine max. Comparat...

  12. Selective oxidation of glycerol to formic acid in highly concentrated aqueous solutions with molecular oxygen using V-substituted phosphomolybdic acids

    KAUST Repository

    Zhang, Jizhe

    2014-01-01

    Formic acid is an important commodity chemical as well as a promising medium for hydrogen storage and hydrogen production. In this paper, we report that formic acid can be produced through selective oxidation of glycerol, a low-cost by-product of biodiesel, by using vanadium-substituted phosphomolybdic acids as catalysts and molecular oxygen as the oxidant. Significantly, this catalytic system allows for high-concentration conversions and thus leads to exceptional efficiency. Specifically, 3.64 g of formic acid was produced from 10 g of glycerol/water (50/50 in weight) solution. © 2014 the Partner Organisations.

  13. Hydrolytic and alcoholytic dephosphorylation of nucleotides by acid phosphatase in the presence of ethanol.

    Science.gov (United States)

    Tomaszewski, M; Buchowicz, J

    1971-08-01

    The effect of ethanol on the activity of acid phosphatase from wheat germ was studied, by using ribonucleoside monophosphates as the enzyme substrates. The nucleotides were effectively degraded to the corresponding nucleosides in the presence of ethanol at all concentrations tested, including a 96% (v/v) solution. However, the nucleotide dephosphorylation was accompanied by the liberation of orthophosphate only when the concentration of ethanol in the assay mixture did not exceed 15%. No inorganic phosphate was liberated when ethanol was present at higher concentrations. Instead, monoethyl phosphate was formed in quantities expected for orthophosphate. The results are explained in terms of phosphatase-catalysed alcoholysis.

  14. Polymeric blends from post-consumer PET and polyester becoming of glycerol and phthalic acid

    International Nuclear Information System (INIS)

    Miranda, C.S.; Brioude, M.; Fiuza, R.P.; Luporini, S.; Carvalho, R.F.; Jose, N.M.

    2010-01-01

    Preparation of physical mixture or polymer blends is a very important method to obtain a final product with excellent balance of properties, where one component can compensate for the poor property of another, and is often a modified low cost compared to development and synthesis of a new polymer. PET has become a major waste of post-consumer plastics and aiming to remedy this problem, this work aims to obtain blends from recycled PET and polyesters derived from glycerol and phthalic acid. The material with higher proportion of PET showed better thermal properties, observed by TGA and DSC, with a similar profile of pure PET. In XRD analysis showed a semicrystalline, while the SEM is a smooth surface on all materials, characteristic of pure polyester. The ratio of 50% its surface showed a probable immiscibility of polymers. (author)

  15. Esterification of Glycerol with Acetic Acid over Highly Active and Stable Alumina-based Catalysts: A Reaction Kinetics Study

    OpenAIRE

    Rane, S. A.; Pudi, S. M.; Biswas, P.

    2016-01-01

    The catalytic activity of Cu- or Ni monometallic and Cu-Ni bimetallic (Cu/Ni ratio = 3, 1, 0.33) catalysts supported on γ-Al2O3 and SO42–/γ-Al2O3 catalysts were evaluated for esterification of glycerol. The reactions were performed in a batch reactor under reflux at standard reaction conditions: temperature 110 °C, atmospheric pressure, glycerol to acetic acid molar ratio 1:9, and catalyst loading 0.25 g. The best catalytic activity was observed over 2 M SO42–/γ-Al2O3 catalyst, which showed t...

  16. Interaction of Myosin Phosphatase Target Subunit (MYPT1) with Myosin Phosphatase-RhoA Interacting Protein (MRIP): A Role of Glutamic Acids in the Interaction.

    Science.gov (United States)

    Lee, Eunhee; Stafford, Walter F

    2015-01-01

    Scaffold proteins bind to and functionally link protein members of signaling pathways. Interaction of the scaffold proteins, myosin phosphatase target subunit (MYPT1) and myosin phosphatase-RhoA interacting protein (MRIP), causes co-localization of myosin phosphatase and RhoA to actomyosin. To examine biophysical properties of interaction of MYPT1 with MRIP, we employed analytical ultracentrifugation and surface plasmon resonance. In regard to MRIP, its residues 724-837 are sufficient for the MYPT1/MRIP interaction. Moreover, MRIP binds to MYPT1 as either a monomer or a dimer. With respect to MYPT1, its leucine repeat region, LR (residues 991-1030) is sufficient to account for the MYPT1/MRIP interaction. Furthermore, point mutations that replace glutamic acids 998-1000 within LR reduced the binding affinity toward MRIP. This suggests that the glutamic acids of MYPT1 play an important role in the interaction.

  17. Requirements of glycerol and fatty acid for triglyceride synthesis and ketogenesis by hepatocytes from normal and triiodothyronine-treated rats

    International Nuclear Information System (INIS)

    Olubadewo, J.O.; Heimberg, M.

    1985-01-01

    Hepatocytes from T3-treated rats synthesized less triglyceride and more ketone bodies from [1- 14 C]oleate at all concentrations from 0-2 mM, than did hepatocytes from euthyroid animals; addition of 1.0 mM glycerol increased triglyceride synthesis and reduced ketogenesis in hepatocytes from T3-treated rats to the rates observed in euthyroid hepatocytes in the absence of added glycerol. Glycerol did not alter triglyceride synthesis, but reduced ketogenesis genesis by euthyroid hepatocytes. It is probable from these and other data that, in the hyperthyroid rat, glycero-3-P, and not fatty acid, is rate limiting for synthesis of triglyceride, and, secondarily for reducing rates of ketogenesis in the hepatocyte

  18. Green acetylation of solketal and glycerol formal by heterogeneous acid catalysts to form a biodiesel fuel additive.

    Science.gov (United States)

    Dodson, Jennifer R; Leite, Thays d C M; Pontes, Nathália S; Peres Pinto, Bianca; Mota, Claudio J A

    2014-09-01

    A glut of glycerol has formed from the increased production of biodiesel, with the potential to integrate the supply chain by using glycerol additives to improve biodiesel properties. Acetylated acetals show interesting cold flow and viscosity effects. Herein, a solventless heterogeneously catalyzed process for the acetylation of both solketal and glycerol formal to new products is demonstrated. The process is optimized by studying the effect of acetylating reagent (acetic acid and acetic anhydride), reagent molar ratios, and a variety of commercial solid acid catalysts (Amberlyst-15, zeolite Beta, K-10 Montmorillonite, and niobium phosphate) on the conversion and selectivities. High conversions (72-95%) and selectivities (86-99%) to the desired products results from using acetic anhydride as the acetylation reagent and a 1:1 molar ratio with all catalysts. Overall, there is a complex interplay between the solid catalyst, reagent ratio, and acetylating agent on the conversion, selectivities, and byproducts formed. The variations are discussed and explained in terms of reactivity, thermodynamics, and reaction mechanisms. An alternative and efficient approach to the formation of 100% triacetin involves the ring-opening, acid-catalyzed acetylation from solketal or glycerol formal with excesses of acetic anhydride. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  19. Inhibition of Protein Tyrosine Phosphatase 1B by Aurintricarboxylic Acid and Methylenedisalicylic Acid: Polymer versus Monomer

    International Nuclear Information System (INIS)

    Shrestha, Suja; Lee, Keun Hyeung; Cho, Hyeong Jin

    2004-01-01

    In this study, we examined whether the in vitro inhibitory activity of ATA against PTPases resides in the monomer or high molecular weight components. Not to mention commercial ATA, the ATA sample synthesized according to the method previously reported to produce monomer was also found to contain polymeric materials as described below. Therefore, monomeric component of ATA was prepared absolutely free of polymer. Also synthesized in a pure form was methylenedisalicylic acid (MDSA), one of the low molecular weight components formed in the conventional preparation of ATA. Commercial MDSA was also proved to contain polymeric substances. The inhibitory potency of ATA and MDSA synthesized in a polymer-free form was evaluated against human protein tyrosine phosphatase 1B (PTP1B). Commercial ATA, however, contains significant amounts of polymeric materials schematically represented as. In general, ATA is prepared by condensation of salicylic acid with formaldehyde and the branching reaction results in the formation of polymers of molecular weights up to several thousands Dalton

  20. Lowering of phytic acid content by enhancement of phytase and acid phosphatase activities during sunflower germination

    Directory of Open Access Journals (Sweden)

    Juliana da Silva Agostini

    2010-08-01

    Full Text Available The objective of this work was to investigate the germination of hybrid sunflowers BRS191 and C11 as a means of lowering phytic acid (PA content by enhancing the activity of endogenous phytase and acid phosphatase. The concentration of PA in hybrid sunflower achenes varied from 2.16 to 2.83g/100g of sample (p O objetivo deste trabalho foi investigar a germinação de girassóis híbridos BRS 191 e C11 com finalidade de reduzir o teor de AF e aumentar as atividades de phytases e fosfatases endógenas. A concentração do AF nos aquênios de girassóis híbridos variou de 2,16 a 2,83 g /100g de amostra (p< 0,005. As atividades de fitases e fosfatases de girassóis BRS191 e C11 foram elevadas no 4º e 5º dia de germinação, respectivamente, com liberação do fósforo necessário para o desenvolvimento da semente. Estes resultados indicam que o AF do girassol hibrido reduz e a atividade de phytase aumenta em períodos distintos da germinação, possibilitando assim a aplicação desta enzima no controle do teor de AF em cereais, melhorando o seu valor nutricional.

  1. Selective oxidation of glycerol to formic acid in highly concentrated aqueous solutions with molecular oxygen using V-substituted phosphomolybdic acids

    KAUST Repository

    Zhang, Jizhe; Sun, Miao; Han, Yu

    2014-01-01

    Formic acid is an important commodity chemical as well as a promising medium for hydrogen storage and hydrogen production. In this paper, we report that formic acid can be produced through selective oxidation of glycerol, a low-cost by-product

  2. Study on alkaline and acid phosphatase activity in acute uranium intoxication

    International Nuclear Information System (INIS)

    Bokova, N.V.; Pavlova, V.B.; Stancheva, Yu.A.; Khadzhirusev, S.B.; Kiradzhiev, G.D.

    1975-01-01

    The protective potential of diethyl barbituric acid sodium salt is studied, in comparison with that of acetazolamide, on kidneys under acute uranium intoxication. Experiments involved rats given intraperitoneal injections with uranyl acetate on 12 successive days up to a total dose of 0.5, 2.0 or 7.0 mg/kg. The resulting effects are measured by chemical assays of serum and urine for alkaline and acid phosphatase and histochemical assays for phosphatase activities in kidneys, kinetics being followed over a 30-day period after total dose administration. Protection of kidneys from toxic uranium effects was found to be of about the same degree with sodium diethyl barbiturate as with acetazolamide. (A.B.)

  3. Dephosphorylation of microtubule-binding sites at the neurofilament-H tail domain by alkaline, acid, and protein phosphatases.

    Science.gov (United States)

    Hisanaga, S; Yasugawa, S; Yamakawa, T; Miyamoto, E; Ikebe, M; Uchiyama, M; Kishimoto, T

    1993-06-01

    The dephosphorylation-induced interaction of neurofilaments (NFs) with microtubules (MTs) was investigated by using several phosphatases. Escherichia coli alkaline and wheat germ acid phosphatases increased the electrophoretic mobility of NF-H and NF-M by dephosphorylation, and induced the binding of NF-H to MTs. The binding of NFs to MTs was observed only after the electrophoretic mobility of NF-H approached the exhaustively dephosphorylated level when alkaline phosphatase was used. The number of phosphate remaining when NF-H began to bind to MTs was estimated by measuring phosphate bound to NF-H. NF-H did not bind to MTs even when about 40 phosphates from the total of 51 had been removed by alkaline phosphatase. The removal of 6 further phosphates finally resulted in the association of NF-H with MTs. A similar finding, that the restricted phosphorylation sites in the NF-H tail domain, but not the total amount of phosphates, were important for binding to MTs, was also obtained with acid phosphatases. In contrast to alkaline and acid phosphatases, four classes of protein phosphatases (protein phosphatases 1, 2A, 2B, and 2C) were ineffective for shifting the electrophoretic mobility of NF proteins and for inducing the association of NFs to MTs.

  4. Expression, purification and crystallization of an atypical class C acid phosphatase from Mycoplasma bovis

    International Nuclear Information System (INIS)

    Singh, Harkewal; Reilly, Thomas J.; Calcutt, Michael J.; Tanner, John J.

    2011-01-01

    Methods for the expression, purification and crystallization of the class C acid phosphatase from M. bovis are reported. This enzyme is atypical in that it is nearly 20 kDa larger than other known class C acid phosphatases. Class C acid phosphatases (CCAPs) are 25–30 kDa bacterial surface proteins that are thought to function as broad-specificity 5′,3′-nucleotidases. Analysis of the newly published complete genome sequence of Mycoplasma bovis PG45 revealed a putative CCAP with a molecular weight of 49.9 kDa. The expression, purification and crystallization of this new family member are described here. Standard purification procedures involving immobilized metal-ion affinity chromatography and ion-exchange chromatography yielded highly pure and crystallizable protein. Crystals were grown in sitting drops at room temperature in the presence of PEG 3350 and HEPES buffer pH 7.5 and diffracted to 2.3 Å resolution. Analysis of diffraction data suggested a primitive monoclinic space group, with unit-cell parameters a = 78, b = 101, c = 180 Å, β = 92°. The asymmetric unit is predicted to contain six molecules, which are likely to be arranged as three dimers

  5. Endocytosis of lysosomal acid phosphatase; involvement of mannose receptor and effect of lectins.

    Science.gov (United States)

    Imai, K; Yoshimura, T

    1994-08-01

    Acid phosphatase and beta-glucosidase are unique among lysosomal enzymes in that they have both high mannose and complex type sugasr chains, whereas oligosaccharide chains of lysosomal enzymes in matrix are of high mannose type. We have previously shown that beta-glucosidase was endocytosed into macrophages via an unidentified receptor different from a mannose/fucose receptor (K. Imai, Cell Struct. Funct. 13, 325-332, 1988). Here, we show that uptake of acid phosphatase purified from rat liver lysosomes into rat macrophages was inhibited by ligands for a mannose/fucose receptor and was mediated via an apparently single binding site with Kuptake of 24.7 nM. These results indicate that acid phosphatase and beta-glucosidase recognize different types of receptors even if they have similar sugar chains. Polyvalent concanavalin A which binds both to the enzyme and to macrophages specifically stimulated the uptake in a dose dependent manner, whereas wheat germ agglutinin and phytohaemagglutinin did not.

  6. A comparative evaluation of plasma glycerol and free fatty acids in patients with ischaemic heart disease

    Directory of Open Access Journals (Sweden)

    Singh V

    1979-01-01

    Full Text Available Plasma glycerol concentration was determined in 158 patients admitted to the hospital with acute chest pain. The patients were retrospectively divided into five groups according to their diagnosis, taking into account the presence or absence of myocardial infarc-tion and complicating arrythmias, The plasma glycerol concentra-tion was significantly higher in the group with complicating arrhythmias, irrespective of whether infarction was present or not. Therefore it is proposed that elevation of plasma glycerol may provide an important clue to determine those myocardial ischaemia cases who may develop cardiac arrythmias at a later stage.

  7. Preparation of polymer blends from glycerol, fumaric acid and of poly(ethylene terephthalate) (PET) recycled

    International Nuclear Information System (INIS)

    Medeiros, Marina A.O.; Guimaraes, Danilo H.; Brioude, Michel M.; Jose, Nadia M.; Prado, Luis A.S. de A.

    2011-01-01

    Polymer blends based on recycled poly(ethylene terephthalate) (PET) and poly(glycerol fumarate) polyesters were prepared in different PET concentrations. The PET powder was dispersed during the poly(glycerol fumarate) synthesis at 260 deg C. The resulting blends were characterized by X-ray diffraction. The thermal stability of the materials was evaluated by thermogravimetric analysis and differential scanning calorimetry. The morphology was studies by scanning electron microscopy. The blends were clearly immiscible. The possibility of (interfacial) compatibilization of the PET domains, caused by transesterification reactions between PET and glycerol were discussed. (author)

  8. Radioimmunoassay of human prostate-specific acid phosphatase in the diagnosis and follow-up of therapy of prostatic cancer

    International Nuclear Information System (INIS)

    Vihko, P.

    1981-01-01

    The author describes the development of a radioimmunoassay for the determination of serum prostate-specific acid phosphatase and studies its application to the diagnosis and follow-up of therapy of prostatic carcinoma. (Auth./C.F.)

  9. Human liver phosphatase 2A: cDNA and amino acid sequence of two catalytic subunit isotypes

    International Nuclear Information System (INIS)

    Arino, J.; Woon, Chee Wai; Brautigan, D.L.; Miller, T.B. Jr.; Johnson, G.L.

    1988-01-01

    Two cDNA clones were isolated from a human liver library that encode two phosphatase 2A catalytic subunits. The two cDNAs differed in eight amino acids (97% identity) with three nonconservative substitutions. All of the amino acid substitutions were clustered in the amino-terminal domain of the protein. Amino acid sequence of one human liver clone (HL-14) was identical to the rabbit skeletal muscle phosphatase 2A cDNA (with 97% nucleotide identity). The second human liver clone (HL-1) is encoded by a separate gene, and RNA gel blot analysis indicates that both mRNAs are expressed similarly in several human clonal cell lines. Sequence comparison with phosphatase 1 and 2A indicates highly divergent amino acid sequences at the amino and carboxyl termini of the proteins and identifies six highly conserved regions between the two proteins that are predicted to be important for phosphatase enzymatic activity

  10. A quantitative method for measurement of lysosomal acid phosphatase latency in cultured rat heart cells with 210Pb

    International Nuclear Information System (INIS)

    Hale, T.W.; Wenzel, D.G.

    1978-01-01

    A method is described for measuring the latency of lysomal acid phosphatase in cultured rat heart endotheloid cells. 210 Pb was added to a medium used to demonstrate acid phosphatase activity by the Gomori lead method, and the amount of lead deposited was measured with a liquid scintillation counter. Deposition rates were measured after enzyme activation pretreatments with acetate buffer (pH 5.0) at various osmolalities, and after formaldehyde fixation. Formaldehyde, alloxan, or fluoride in the Gomori medium were evaluated for their differential effects on lysosomal and non-lysosomal acid phosphatase The method was found to provide a sensitive, rapid and quantitative evaluation of acid phosphatase latency and should be useful for studying the integrity of lysosomes within cells. (author)

  11. The influence of a cryoprotective medium containing glycerol on the lyophilization of lactic acid bacteria (NOTE

    Directory of Open Access Journals (Sweden)

    JOSIP BARAS

    2001-07-01

    Full Text Available The aims of liophilization (freeze-drying of lactic acid bacteria are to preserve pure cultures or to prepare starters for the dairy industry. In both cases, the choice of the cryoprotectant is very important. In this work, samples of Bifidobacterium breve A71 and Bifidobacterium bifidum BbTD were freeze-dried in a new cryoprotective medium containing lactose, gelatine and glycerol (medium B. The reference medium contained saccharose, gelatine and skim milk (medium A. Before liophilization, the eutectic points of both media were determined, because the products must be cooled to a temperature below its freezing point. The success of the cryoprotectants was estimated in terms of the number of surviving organisms after lyophilization. Bifidobacterium breve A71 and Bifidobacterium bifidum BbTD freeze-dried in media A and B showed high survival rates. Bifidobacterium breve A71 showed a greater percentage survival in combination with medium B than with medium A. These results could be utilized in the manufacture of Bifidobacterium breve A71 as a starter in the diary industry because it is a human isolate which, except for acidification, has probiotic activity.

  12. The characterization of mechanical and surface properties of poly (glycerol-sebacate-lactic acid) during degradation in phosphate buffered saline

    Energy Technology Data Exchange (ETDEWEB)

    Sun Zhijie [Center for biomedical Materials and Engineering, Harbin Engineering University, Harbin 150001 (China)], E-mail: zhijiesun2005@yahoo.com.cn; Wu Lan; Lu Xili; Meng Zhaoxu; Zheng Yufeng [Center for biomedical Materials and Engineering, Harbin Engineering University, Harbin 150001 (China); Dong Deli [Department of Pharmacology, Harbin Medical University, Bio-pharmaceutical Key Laboratory of Heilongjiang Province, Harbin 150081 (China)

    2008-11-15

    The present study synthesized a poly (glycerol-sebacate-lactic acid) (PGSL) with 1:1:0.5 mole ratio of glycerol, sebacate and lactic acid and investigated the degradation characteristics of the polymer in phosphate buffered saline (PBS) at 37 deg. C in vitro by means of mass loss tests, geometry, differential scanning calorimeter (DSC) measurements, tensile analysis and scanning electron microscopy (SEM). The maintained geometry, linear mass loss, and minor crack formation on the surface during degradation characterized both the bulk degradation and surface erosion of the polymer. By day 30 of degradation, the mass lost reached 16%. The elastic modulus, tensile strength and elongation at breakage of PGSL were correlative to the period of degradation.

  13. Data of thermal degradation and dynamic mechanical properties of starch-glycerol based films with citric acid as crosslinking agent.

    Science.gov (United States)

    González Seligra, Paula; Medina Jaramillo, Carolina; Famá, Lucía; Goyanes, Silvia

    2016-06-01

    Interest in biodegradable edible films as packaging or coating has increased because their beneficial effects on foods. In particular, food products are highly dependents on thermal stability, integrity and transition process temperatures of the packaging. The present work describes a complete data of the thermal degradation and dynamic mechanical properties of starch-glycerol based films with citric acid (CA) as crosslinking agent described in the article titled: "Biodegradable and non-retrogradable eco-films based on starch-glycerol with citric acid as crosslinking agent" González Seligra et al. (2016) [1]. Data describes thermogravimetric and dynamical mechanical experiences and provides the figures of weight loss and loss tangent of the films as a function of the temperature.

  14. Secretion of acid phosphatase by axenic Entamoeba histolytica NIH-200 and properties of the extracellular enzyme.

    Science.gov (United States)

    Agrawal, A; Pandey, V C; Kumar, S; Sagar, P

    1989-01-01

    Entamoeba histolytica (NIH-200) secreted large amounts of acid phosphatase in its external environment when grown axenically in modified TPS-II medium. Fractionation by DEAE-cellulose chromatography of the precipitate obtained from the cell-free medium at 60% ammonium sulfate saturation yielded 3 distinct peaks of enzyme activity. The enzyme in all the peaks showed resistance to tartrate but was inhibited by fluoride, cupric chloride, ethylene diamine-tetra acetic acid, ammonium molybdate and cysteine; however, enzyme associated with different peaks differed in its polyacrylamide gel electrophoretic profiles and behavior towards concanavalin A.

  15. Alkaline and Acid Phosphatase Activity in Blood Plasma of Chickens Irradiated by Low dose Gamma Radiation

    International Nuclear Information System (INIS)

    Petar, K.; Marinko, V.; Saveta, M.; Miljenko, S.

    2004-01-01

    In our previous paper (Kraljevic et, al, 2000; Kraljevic et al 2002) we showed that the growth of the chickens hatched from eggs irradiated with 0.15 Gy gamma-rays before incubation was significantly higher than in controls during the fattening period (1-42 days). The concentration of total protein, glucose and cholesterol in the blood plasma of the same chickens was also significantly changed. In this paper an attempt was made to determine the effect of irradiation of eggs by low dose ionizing radiation before incubation upon activity of alkaline and acid phosphatase in the blood plasma of chickens hatched from irradiated eggs. The eggs of heavy breeding chickens were irradiated by dose of 0.15 Gy gamma radiation (60 Co) before incubation. Along with the chickens which were hatched from irradiated eggs, there was a control group of chickens hatched from nonirradiated eggs. All other conditions were the same for both groups. After hatching, blood samples were taken from the wing vein on days 1, 3, 5, 6, 10, 20, 30 and 42. The activity of both enzymes was determined spectrophotometrically by using Boehring Mannheim GmbH optimized kits. the activity of alkaline phosphatase in blood plasma was decreased on days 42, and the activity of acid phosphatase in the blood plasma of the same chickens was increased on day 42. Obtained results confirm our early obtained results that low dose of gamma radiation has effects upon metabolic processes in the chickens hatched from eggs irradiated before incubation. (Author)

  16. In vitro studies on the translocation of acid phosphatase into the endoplasmic reticulum of the yeast Saccharomyces cerevisiae.

    Science.gov (United States)

    Krebs, H O; Hoffschulte, H K; Müller, M

    1989-05-01

    We demonstrate here the in vitro translocation of yeast acid phosphatase into rough endoplasmic reticulum. The precursor of the repressible acid phosphatase from Saccharomyces cerevisiae encoded by the PHO5 gene, was synthesized in a yeast lysate programmed with in vitro transcribed PHO5 mRNA. In the presence of yeast rough microsomes up to 16% of the acid phosphatase synthesized was found to be translocated into the microsomes, as judged by proteinase resistance, and fully core-glycosylated. The translocation efficiency however, decreased to 3% if yeast rough microsomes were added after synthesis of acid phosphatase had been terminated. When a wheat-germ extract was used for in vitro synthesis, the precursor of acid phosphatase was translocated into canine pancreatic rough microsomes and thereby core-glycosylated in a signal-recognition-particle-dependent manner. Replacing canine with yeast rough microsomes in the wheat-germ translation system, however, resulted in a significant decrease in the ability to translocate and glycosylate the precursor. Translocation and glycosylation were partially restored by a high-salt extract prepared from yeast ribosomes. The results presented here suggest that yeast-specific factors are needed to translocate and glycosylate acid phosphatase efficiently in vitro.

  17. Isolation and characterization of a homogeneous isoenzyme of wheat germ acid phosphatase.

    Science.gov (United States)

    Waymack, P P; Van Etten, R L

    1991-08-01

    An acid phosphatase (orthophosphoric monoester phosphohydrolase, acid optimum; EC 3.1.3.2) isoenzyme from wheat germ was purified 7000-fold to homogeneity. The effect of wheat germ sources and their relationship to the isoenzyme content and purification behavior of acid phosphatases was investigated. Extensive information about the purification and stabilization of the enzyme is provided. The instability of isoenzymes in the latter stages of purification appeared to be the result of surface inactivation together with a sensitivity to dilution that could be partially offset by addition of Triton X-100 during chromatographic procedures. Added sulfhydryl protecting reagents had no effect on activity or stability, which was greatest in the pH range 4-7. The purified isoenzyme was homogeneous by polyacrylamide gel electrophoresis and exhibited the highest specific activity and turnover number reported for any acid phosphatase. The molecular weights of the pure isoenzyme and of related isoenzymes from wheat germ were found to be identical (58,000). The pure isoenzyme contained a single polypeptide chain and had a negligible carbohydrate content. The amino acid composition was determined. Of the various reasons that were considered to explain isoenzyme occurrence, a genetic basis was considered most likely. The enzyme was found to exhibit substrate inhibition with some substrates below pH 6, while above pH 8 it exhibited downwardly curving Lineweaver-Burk plots of the type that are generally described as "substrate activation". The observation of a phosphotransferase activity was consistent with the formation of a covalent phosphoenzyme intermediate, while inactivation by diethyl pyrocarbonate was consistent with the presence of an active site histidine.

  18. Effecf of pH and some cations on activity of acid phosphatase secreted from Ustilago sp. isolated from acid sulphate soil

    Directory of Open Access Journals (Sweden)

    Chairatana Nilnond

    2007-03-01

    Full Text Available Acid phosphatase secreted from Ustilago sp. is able to hydrolyze organic phosphorus. These soil yeast microorganisms were isolated from rice roots grown in acid sulphate soil that generally contains highamount of aluminum (Al, iron (Fe and manganese (Mn ions. Therefore, the objectives of this study were to examine the effect of pH and some cations on acid phosphatase activity. Two isolates of Ustilago sp., AR101and AR102, were cultured in 100 mL of modified Pikovskaya's broth containing Na-phytate, pH 4, and acid phosphatase activity was determined at pH 2.0-7.0. Effect of Al, Fe, and Mn, including calcium (Ca ions,on growth of AR101 and AR102, secreted acid phosphatase activity, and the ability of acid phosphatase on the phosphorus release from Na-phytate by Ustilago sp. were investigated. It was found that the optimum pH for acid phosphatase activity was 3.5-4.5. The activity of acid phosphatase secreted from AR101 (3,690nmol min-1 mL-1 was remarkably higher than that from AR102 (956 nmol min-1 mL-1. Aluminum, iron, manganese and calcium ions in the medium did not affect the growth of either isolate. The activity of secretedacid phosphatase of AR101 was inhibited by Al and Ca ion, and synthesis of acid phosphatase of Ustilago sp. AR102 was possibly stimulated by Fe ion. Both AR101 and AR102 solubilized Na-phytate, resulting in therelease of P. However, some amount of released P was then precipitated with Al and Fe ions as the highly insoluble Fe- or Al- phosphate.

  19. Effect of Al content on the gas-phase dehydration of glycerol over silica-alumina-supported silicotungstic acid catalysts

    International Nuclear Information System (INIS)

    Kim, Yong Tae; You, Su Jin; Park, Eun Duck; Jung, Kwangdeog

    2012-01-01

    The gas-phase dehydration of glycerol to acrolein was carried out over silicotungstic acid (H 4 SiW 12 O 40 ·xH 2 O, HSiW) catalysts supported on SiO 2 , η-Al 2 O 3 , and silica-alumina with different Al contents. The HSiW catalysts supported on silica-alumina showed higher glycerol conversions and acrolein yields during the initial 2 h at 315.deg.C than did SiO 2 - and η-Al 2 O 3 -supported HSiW catalysts. Among the tested catalysts, HSiW/Si 0.9 Al 0.1Ox exhibited the highest space-time yield during the initial 2 h. The loaded HSiW species can change the acid types and suppress the formation of carbonaceous species on Al-rich silica-alumina. The deactivated HSiW supported on silica-alumina can be fully regenerated after calcination in air at 500.deg.C. As long as the molar ratio between water and glycerol was in the range of 2-11, the acrolein selectivity increased significantly with increasing water content in the feed, while the surface carbon content decreased owing to the suppression of heavy compounds

  20. Prostatic acid phosphatase is required for the antinociceptive effects of thiamine and benfotiamine.

    Science.gov (United States)

    Hurt, Julie K; Coleman, Jennifer L; Fitzpatrick, Brendan J; Taylor-Blake, Bonnie; Bridges, Arlene S; Vihko, Pirkko; Zylka, Mark J

    2012-01-01

    Thiamine (Vitamin B1) is an essential vitamin that must be obtained from the diet for proper neurological function. At higher doses, thiamine and benfotiamine (S-benzoylthiamine O-monophosphate, BT)-a phosphorylated derivative of thiamine-have antinociceptive effects in animals and humans, although how these compounds inhibit pain is unknown. Here, we found that Prostatic acid phosphatase (PAP, ACPP) can dephosphorylate BT in vitro, in dorsal root ganglia (DRG) neurons and in primary-afferent axon terminals in the dorsal spinal cord. The dephosphorylated product S-benzoylthiamine (S-BT) then decomposes to O-benzoylthiamine (O-BT) and to thiamine in a pH-dependent manner, independent of additional enzymes. This unique reaction mechanism reveals that BT only requires a phosphatase for conversion to thiamine. However, we found that the antinociceptive effects of BT, thiamine monophosphate (TMP) and thiamine-a compound that is not phosphorylated-were entirely dependent on PAP at the spinal level. Moreover, pharmacokinetic studies with wild-type and Pap(-/-) mice revealed that PAP is not required for the conversion of BT to thiamine in vivo. Taken together, our study highlights an obligatory role for PAP in the antinociceptive effects of thiamine and phosphorylated thiamine analogs, and suggests a novel phosphatase-independent function for PAP.

  1. Prostatic acid phosphatase is required for the antinociceptive effects of thiamine and benfotiamine.

    Directory of Open Access Journals (Sweden)

    Julie K Hurt

    Full Text Available Thiamine (Vitamin B1 is an essential vitamin that must be obtained from the diet for proper neurological function. At higher doses, thiamine and benfotiamine (S-benzoylthiamine O-monophosphate, BT-a phosphorylated derivative of thiamine-have antinociceptive effects in animals and humans, although how these compounds inhibit pain is unknown. Here, we found that Prostatic acid phosphatase (PAP, ACPP can dephosphorylate BT in vitro, in dorsal root ganglia (DRG neurons and in primary-afferent axon terminals in the dorsal spinal cord. The dephosphorylated product S-benzoylthiamine (S-BT then decomposes to O-benzoylthiamine (O-BT and to thiamine in a pH-dependent manner, independent of additional enzymes. This unique reaction mechanism reveals that BT only requires a phosphatase for conversion to thiamine. However, we found that the antinociceptive effects of BT, thiamine monophosphate (TMP and thiamine-a compound that is not phosphorylated-were entirely dependent on PAP at the spinal level. Moreover, pharmacokinetic studies with wild-type and Pap(-/- mice revealed that PAP is not required for the conversion of BT to thiamine in vivo. Taken together, our study highlights an obligatory role for PAP in the antinociceptive effects of thiamine and phosphorylated thiamine analogs, and suggests a novel phosphatase-independent function for PAP.

  2. Novel Proton Conducting Solid Bio-polymer Electrolytes Based on Carboxymethyl Cellulose Doped with Oleic Acid and Plasticized with Glycerol

    Science.gov (United States)

    Chai, M. N.; Isa, M. I. N.

    2016-06-01

    The plasticized solid bio-polymer electrolytes (SBEs) system has been formed by introducing glycerol (Gly) as the plasticizer into the carboxymethyl cellulose (CMC) doped with oleic acid (OA) via solution casting techniques. The ionic conductivity of the plasticized SBEs has been studied using Electrical Impedance Spectroscopy. The highest conductivity achieved is 1.64 × 10-4 S cm-1 for system containing 40 wt. % of glycerol. FTIR deconvolution technique had shown that the conductivity of CMC-OA-Gly SBEs is primarily influenced by the number density of mobile ions. Transference number measurement has shown that the cation diffusion coefficient and ionic mobility is higher than anion which proved the plasticized polymer system is a proton conductor.

  3. Effect of perfluorooctane sulfonate on the conformation of wheat germ acid phosphatase.

    Science.gov (United States)

    Xu, Dongmei; Jin, Jianchang; Shen, Tong; Wang, Yanhua

    2013-11-01

    Fluorescence spectroscopy was used to study the quenching mechanism, the type of force and the binding sites of perfluorooctane sulfonate (PFOS) on wheat germ acid phosphatase (ACPase). The results showed that the quenching effect of PFOS on ACPase was mainly due to a static quenching mechanism that occurred via the formation of hydrogen bonds and van der Waals forces. The results from synchronous fluorescence spectroscopy demonstrated that PFOS interacts with ACPase close to the tryptophan residues. In addition, synchronous fluorescence spectroscopy also showed that PFOS increases the hydrophobicity of the microenvironment of the tyrosine residues, hence decreasing the local polarity.

  4. Substrate specificity and pH dependence of homogeneous wheat germ acid phosphatase.

    Science.gov (United States)

    Van Etten, R L; Waymack, P P

    1991-08-01

    The broad substrate specificity of a homogeneous isoenzyme of wheat germ acid phosphatase (WGAP) was extensively investigated by chromatographic, electrophoretic, NMR, and kinetic procedures. WGAP exhibited no divalent metal ion requirement and was unaffected upon incubation with EDTA or o-phenanthroline. A comparison of two catalytically homogeneous isoenzymes revealed little difference in substrate specificity. The specificity of WGAP was established by determining the Michaelis constants for a wide variety of substrates. p-Nitrophenyl phosphate, pyrophosphate, tripolyphosphate, and ATP were preferred substrates while lesser activities were seen toward sugar phosphates, trimetaphosphate, phosphoproteins, and (much less) phosphodiesters. An extensive table of Km and Vmax values is given. The pathway for the hydrolysis of trimetaphosphate was examined by colorimetric and 31P NMR methods and it was found that linear tripolyphosphate is not a free intermediate in the enzymatic reaction. In contrast to literature reports, homogeneous wheat germ acid phosphatase exhibits no measurable carboxylesterase activity, nor does it hydrolyze phenyl phosphonothioate esters or phytic acid at significant rates.

  5. Control of Acid Phosphatases Expression from Aspergillus niger by Soil Characteristics

    Directory of Open Access Journals (Sweden)

    Ely Nahas

    2015-10-01

    Full Text Available ABSTRACTThis work studied the acid phosphatase (APase activity from culture medium (extracellular, eAPase and mycelial extract (intracellular, iAPase ofAspergillus niger F111. The influence of fungus growth and phosphate concentration of the media on the synthesis and secretion of phosphatase was demonstrated. The effects of pH, substrate concentration and inorganic and organic compounds added to the reaction mixture on APase activity were also studied. Both enzymes were repressed by high concentrations of phosphate. Overexpression of iAPase in relation to eAPase was detected; iAPase activity was 46.1 times higher than eAPase. The maximal activity of eAPase was after 24h of fungus growth and for iAPase was after 96h. Optimal pH and substrate concentrations were 4.5 and 8.0 mM, respectively. Michaelis-Menten constant (Km for the hydrolysis of p-nitrophenyl phosphate was 0.57 mM with Vmax = 14,285.71 U mg-1 mycelium for the iAPase and 0.31 mM with V max = 147.06 U mg-1 mycelium for eAPase. Organic substances had little effect on acid phosphatases when compared with the salts. Both the APases were inhibited by 10 mM KH 2PO4 and 5 mM (NH42MoO4; eAPase was also inhibited by 1 mM CoCl2.

  6. Acid and Alkaline Phosphatase Levels in GCF during Orthodontic Tooth Movement

    Science.gov (United States)

    Farahani, Mohammad; Safavi, Seyed Mohammadreza; Dianat, Omid; Khoramian Tusi, Somayeh; Younessian, Farnaz

    2015-01-01

    Statement of the Problem The present constituents of gingival crevicular fluid (GCF) can reflect the changes occurring in underlying tissues. Considering variety of biologic bone markers, alkaline phosphatase and acid phosphatase have been examined as bone turn over markers in orthodontic tooth movement. Purpose The current study designed in a longitudinal pattern to determine the changes of acid and alkaline phosphatase (ACP & ALP) in GCF during orthodontic tooth movement. Materials and Method An upper canines from twelve patients (mean age: 14±2 years) undergoing extraction orthodontic treatment for distal movement served as the test tooth (DC), and its contralateral (CC) and antagonist (AC) canines were used as controls. The CC was included in orthodontic appliance without orthodontic force; the AC was free from any orthodontic appliance. The GCF around the experimental teeth was harvested from mesial and distal tooth sites immediately before appliance placement (T0), and 14 (T2) and 28 days (T3) after it and ALP and ACP concentration were determined spectrophotometrically. Results ALP concentration was elevated significantly in DC and CC groups at days 14 and 28 compared with the AC. In DC group, the ALP was significantly greater in mesial sites than distal site, while no significant changes were found between both sites of CC. The peak level of ALP was observed in mesial sites of DC at T2. Regarding ACP, significant elevation of this enzyme was seen in DC group both in mesial and distal sites at T2 and T3. The peak level of this enzyme was seen at T2. Conclusion Monitoring simultaneous changes of ALP and ACP levels in GCF can reflect the tissue responses occur in periodontium during bone formation and bone resorption during orthodontic tooth movement, respectively. PMID:26535403

  7. Photometric and fluorometric continuous kinetic assay of acid phosphatases with new substrates possessing longwave absorption and emission maxima.

    Science.gov (United States)

    Koller, E; Wolfbeis, O S

    1984-11-15

    A direct and continuous kinetic method for the photometric and fluorometric determination of various acid phosphatases is described. It is based on new coumarin-derived phosphates, which after enzymatic hydrolysis undergo dissociation to form intensely colored and strongly fluorescent phenolate anions. The latter have absorption maxima ranging from 385 to 505 nm, and fluorescence maxima between 470 and 595 nm. The new substrates were compared with respect to their rate of enzymatic hydrolysis, optimum pH, and detection limits of acid phosphatase from potato and wheat germ. Detection limits of 0.001 unit/ml were found by photometry, and as low as 0.00006 unit/ml by fluorometry. The principal advantages of the new substrates over existing ones are longwave absorptions and emissions, large Stokes shifts, and the low pKa values of the corresponding phenols, thus allowing a direct and continuous assay of acid phosphatase even in weakly acidic solutions.

  8. IMMOBILIZATION OF ACID PHOSPHATASE (TYPE I) FROM WHEAT GERM ON GLUTARALDEHYDE ACTIVATED CHITOSAN BEADS: OPTIMIZATION AND CHARACTERIZATION

    OpenAIRE

    K. Belho; S.R. Nongpiur; P.K. Ambasht

    2014-01-01

    Acid phosphatase from wheat germ (specific activity 1.327 U/mg protein) was used for immobilization on glutaraldehyde activated chitosan beads. Upon activation of chitosan beads, elongated fibers with pores were observed. The optimum percent immobilization obtained was 81.25%. The pH optimum of immobilized acid phosphatase was 5.5 with a shift of 0.5 units from the pH optimum of soluble enzyme (5.0). The values of Km for p-nitrophenylphosphate with soluble and immobilized acid pho...

  9. Prostatic acid phosphatase is an ectonucleotidase and suppresses pain by generating adenosine

    Science.gov (United States)

    Zylka, Mark J.; Sowa, Nathaniel A.; Taylor-Blake, Bonnie; Twomey, Margaret A.; Herrala, Annakaisa; Voikar, Vootele; Vihko, Pirkko

    2008-01-01

    SUMMARY Thiamine monophosphatase (TMPase, also known as Fluoride-Resistant Acid Phosphatase) is a classic histochemical marker of small-diameter dorsal root ganglia neurons. The molecular identity of TMPase is currently unknown. We found that TMPase is identical to the transmembrane isoform of Prostatic Acid Phosphatase (PAP), an enzyme with unknown molecular and physiological functions. We then found that PAP knockout mice have normal acute pain sensitivity but enhanced sensitivity in chronic inflammatory and neuropathic pain models. In gain-of-function studies, intraspinal injection of PAP protein has potent anti-nociceptive, anti-hyperalgesic and anti-allodynic effects that last longer than the opioid analgesic morphine. PAP suppresses pain by functioning as an ecto-5’-nucleotidase. Specifically, PAP dephosphorylates extracellular adenosine monophosphate (AMP) to adenosine and activates A1-adenosine receptors in dorsal spinal cord. Our studies reveal molecular and physiological functions for PAP in purine nucleotide metabolism and nociception and suggest a novel use for PAP in the treatment of chronic pain. PMID:18940592

  10. Human prostatic acid phosphatase: purification, characterization, and optimization of conditions for radioimmunoassay

    International Nuclear Information System (INIS)

    McCarthy, R.C.; Jakubowski, H.V.; Markowitz, H.

    1983-01-01

    Prostatic acid phosphatase was isolated from benign hypertrophic prostate tissue by ammonium sulfate precipitation and affinity chromatography procedures. The purified enzyme was characterized by two-dimensional gel electrophoresis and shown to have a cluster of protein spots with an apparent molecular weight of 48000 at pI 5.9 to 6.3 in 9 mol/l urea. The specific activity of the purified enzyme was 723 and 659 U/mg protein with α-naphthyl phosphate at 30 0 C and para-nitrophenyl phosphate at 37 0 C respectively. An antibody to the purified enzyme was raised in rabbits and used in a radioimmunoassay (RIA). The use of a phosphate buffer, pH 6.6, and iodination of prostatic acid phosphatase (PAP) by the Bolton-Hunter procedure improved the precision of the assay when compared to RIA's using a phosphate buffer, pH 7.0 or 7.3, or PAP iodinated by a chloramine-T procedure. The former RIA displaced 50% of the tracer at 2 μg of enzyme per liter of serum. The between-run coefficient of variation for 11 assays ranged from 3.9-7.7% with serum at 1.3 to 5.6 μg PAP/l. (Auth.)

  11. Trichoderma harzianum Produces a New Thermally Stable Acid Phosphatase, with Potential for Biotechnological Application.

    Science.gov (United States)

    Souza, Amanda Araújo; Leitão, Vanessa Oliveira; Ramada, Marcelo Henrique; Mehdad, Azadeh; Georg, Raphaela de Castro; Ulhôa, Cirano José; de Freitas, Sonia Maria

    2016-01-01

    Acid phosphatases (ACPases) are produced by a variety of fungi and have gained attention due their biotechnological potential in industrial, diagnosis and bioremediation processes. These enzymes play a specific role in scavenging, mobilization and acquisition of phosphate, enhancing soil fertility and plant growth. In this study, a new ACPase from Trichoderma harzianum, named ACPase II, was purified and characterized as a glycoprotein belonging to the acid phosphatase family. ACPase II presents an optimum pH and temperature of 3.8 and 65 °C, respectively, and is stable at 55 °C for 120 min, retaining 60% of its activity. The enzyme did not require metal divalent ions, but was inhibited by inorganic phosphate and tungstate. Affinity for several phosphate substrates was observed, including phytate, which is the major component of phosphorus in plant foods. The inhibition of ACPase II by tungstate and phosphate at different pH values is consistent with the inability of the substrate to occupy its active site due to electrostatic contacts that promote conformational changes, as indicated by fluorescence spectroscopy. A higher affinity for tungstate rather than phosphate at pH 4.0 was observed, in accordance with its highest inhibitory effect. Results indicate considerable biotechnological potential of the ACPase II in soil environments.

  12. Characterization of a unique class C acid phosphatase from Clostridium perfringens.

    Science.gov (United States)

    Reilly, Thomas J; Chance, Deborah L; Calcutt, Michael J; Tanner, John J; Felts, Richard L; Waller, Stephen C; Henzl, Michael T; Mawhinney, Thomas P; Ganjam, Irene K; Fales, William H

    2009-06-01

    Clostridium perfringens is a gram-positive anaerobe and a pathogen of medical importance. The detection of acid phosphatase activity is a powerful diagnostic indicator of the presence of C. perfringens among anaerobic isolates; however, characterization of the enzyme has not previously been reported. Provided here are details of the characterization of a soluble recombinant form of this cell-associated enzyme. The denatured enzyme was approximately 31 kDa and a homodimer in solution. It catalyzed the hydrolysis of several substrates, including para-nitrophenyl phosphate, 4-methylumbelliferyl phosphate, and 3' and 5' nucleoside monophosphates at pH 6. Calculated K(m)s ranged from 0.2 to 0.6 mM with maximum velocity ranging from 0.8 to 1.6 micromol of P(i)/s/mg. Activity was enhanced in the presence of some divalent cations but diminished in the presence of others. Wild-type enzyme was detected in all clinical C. perfringens isolates tested and found to be cell associated. The described enzyme belongs to nonspecific acid phosphatase class C but is devoid of lipid modification commonly attributed to this class.

  13. Characterization of a Unique Class C Acid Phosphatase from Clostridium perfringens▿

    Science.gov (United States)

    Reilly, Thomas J.; Chance, Deborah L.; Calcutt, Michael J.; Tanner, John J.; Felts, Richard L.; Waller, Stephen C.; Henzl, Michael T.; Mawhinney, Thomas P.; Ganjam, Irene K.; Fales, William H.

    2009-01-01

    Clostridium perfringens is a gram-positive anaerobe and a pathogen of medical importance. The detection of acid phosphatase activity is a powerful diagnostic indicator of the presence of C. perfringens among anaerobic isolates; however, characterization of the enzyme has not previously been reported. Provided here are details of the characterization of a soluble recombinant form of this cell-associated enzyme. The denatured enzyme was ∼31 kDa and a homodimer in solution. It catalyzed the hydrolysis of several substrates, including para-nitrophenyl phosphate, 4-methylumbelliferyl phosphate, and 3′ and 5′ nucleoside monophosphates at pH 6. Calculated Kms ranged from 0.2 to 0.6 mM with maximum velocity ranging from 0.8 to 1.6 μmol of Pi/s/mg. Activity was enhanced in the presence of some divalent cations but diminished in the presence of others. Wild-type enzyme was detected in all clinical C. perfringens isolates tested and found to be cell associated. The described enzyme belongs to nonspecific acid phosphatase class C but is devoid of lipid modification commonly attributed to this class. PMID:19363079

  14. Prognostic role of serum prostatic acid phosphatase for 103Pd-based radiation for prostatic carcinoma

    International Nuclear Information System (INIS)

    Dattoli, Michael; Wallner, Kent; True, Lawrence; Sorace, Richard; Koval, John; Cash, Jennifer; Acosta, Rudolph; Biswas, Mohendra; Binder, Michael; Sullivan, Brent; Lastarria, Emilio; Kirwan, Novelle; Stein, Douglas

    1999-01-01

    Purpose: To establish the prognostic role of serum enzymatic prostatic acid phosphatase (PAP) in patients treated with palladium ( 103 Pd) and supplemental external beam irradiation (EBRT) for clinically localized, high-risk prostate carcinoma. Methods and Materials: One hundred twenty-four consecutive patients with Stage T2a-T3 prostatic carcinoma were treated from 1992 through 1995. Each patient had at least one of the following risk factors for extracapsular disease extension: Stage T2b or greater (100 patients), Gleason score 7-10 (40 patients), pretreatment prostate specific antigen (PSA) > 15 ng/ml (32 patients), or elevated serum PAP (25 patients). Patients received 41 Gy conformal EBRT to a limited pelvic field, followed 4 weeks later by a 103 Pd boost (prescription dose 80 Gy). Biochemical failure was defined as a PSA greater than 1 ng/ml (normal < 4 ng/ml). Results: The overall, actuarial freedom from biochemical failure at 4 years after treatment was 79%. In Cox-proportional hazard multivariate analysis, the strongest predictor of failure was elevated pretreatment acid phosphatase (p = 0.02), followed by Gleason score (p = 0.1), and PSA (p = 0.14). Conclusion: PAP was the strongest predictor of long-term biochemical failure. It may be a more accurate indicator of micrometastatic disease than PSA, and as such, we suggest that it be reconsidered for general use in radiation-treated patients

  15. Enzymatic Synthesis of Glyserol-Coconut Oil Fatty Acid and Glycerol-Decanoic Acis Ester as Emulsifier and Antimicrobial Agents Using Candida rugosa Lipase EC 3.1.1.3

    Science.gov (United States)

    Handayani, Sri; Putri, Ayu Tanissa Tamara; Setiasih, Siswati; Hudiyono, Sumi

    2018-01-01

    In this research, enzymatic esterification was carried out between glycerol and fatty acid from coconut oil and decanoic acid using n-hexane as solvent. In this reaction Candida rugosa lipase was used as biocatalyst. Optimization esterification reaction was carried out for parameter of the substrate ratio. The mmol ratio between fatty acid and glycerol were used are 1:1, 1:2, 1:3, and 1: 4. The highest conversion percentage obtained at the mole ratio of 1: 4 with the value of 78.5% for the glycerol-decanoic acid ester and 55.4% for the glycerol coconut oil fatty acid ester. Esterification products were characterized by FT-IR. The FT-IR spectrum showed that the ester bond was formed as indicated by the wave number 1750-1739 cm-1. The esterification products were then examined by simple emulsion test and was proved to be an emulsifier. The glycerol-coconut oil fatty acid ester produced higher stability emulsion compare with glycerol decanoic ester. The antimicrobial activity assay using disc diffusion method showed that both glycerol-coconut oil fatty acid ester and glycerol-decanoic ester had the ability inhibiting the growth of Propionibacterium acnes and Staphylococcus epidermidis. Glycerol-decanoic ester shows higher antimicrobial activity than glycerol-coconut oil fatty acid ester.

  16. Dietary free fatty acids form alkaline phosphatase-enriched microdomains in the intestinal brush border membrane

    DEFF Research Database (Denmark)

    Hansen, Gert H; Rasmussen, Karina; Niels-Christiansen, Lise-Lotte

    2011-01-01

    this membrane passage in organ cultured intestinal mucosal explants. We found that in addition to a rapid uptake into the cytoplasm, a fraction of the fatty acid analogs were inserted directly into the brush border membrane. Furthermore, a brief exposure of microvillar membrane vesicles to a fat mixture...... mimicking a physiological solution of dietary mixed micelles, rearranged the lipid raft microdomain organization of the membranes. Thus, the fat mixture generated a low-density subpopulation of microvillar detergent resistant membranes (DRMs) highly enriched in alkaline phosphatase (AP). Since this GPI-linked...... enzyme is the membrane protein in the brush border with the highest affinity for lipid rafts, this implies that free fatty acids selectively insert stably into these membrane microdomains. We have previously shown that absorption of dietary lipids transiently induce a selective endocytosis of AP from...

  17. Research on Phosphatases of Belladona Leaves and Their Purification

    Directory of Open Access Journals (Sweden)

    M. Khorsand

    1957-01-01

    Full Text Available Through experimentation with several leaves it has been possible for us to point out the existance of two different acid phosphatases. We have studied in more detail the phosphatases of belldon a leaves (Atropa Belladona L. Solanacees. The great part of the phosphatase activity is water extractable. We have compared the activity of the soluble fraction with that not directly extractable by means of water. The insoluble fraction could not be solubilized in a satisfaetC'fY m.anner.The digestion by papaine produced a slight solubilizing effect; on the other hand salt solutions, neutral or alkaline, or water glycerol mixtures had no solubilizing effect on the enzyme, It has been possible to demonstrate the existence of two different phosphatases in the insoluble fraction: the first of the type II,

  18. Elimination of glycerol production in anaerobic cultures of a Saccharomyces cerevisiae strain engineered to use acetic acid as an electron acceptor.

    Science.gov (United States)

    Guadalupe Medina, Víctor; Almering, Marinka J H; van Maris, Antonius J A; Pronk, Jack T

    2010-01-01

    In anaerobic cultures of wild-type Saccharomyces cerevisiae, glycerol production is essential to reoxidize NADH produced in biosynthetic processes. Consequently, glycerol is a major by-product during anaerobic production of ethanol by S. cerevisiae, the single largest fermentation process in industrial biotechnology. The present study investigates the possibility of completely eliminating glycerol production by engineering S. cerevisiae such that it can reoxidize NADH by the reduction of acetic acid to ethanol via NADH-dependent reactions. Acetic acid is available at significant amounts in lignocellulosic hydrolysates of agricultural residues. Consistent with earlier studies, deletion of the two genes encoding NAD-dependent glycerol-3-phosphate dehydrogenase (GPD1 and GPD2) led to elimination of glycerol production and an inability to grow anaerobically. However, when the E. coli mhpF gene, encoding the acetylating NAD-dependent acetaldehyde dehydrogenase (EC 1.2.1.10; acetaldehyde+NAD++coenzyme Aacetyl coenzyme A+NADH+H+), was expressed in the gpd1Delta gpd2Delta strain, anaerobic growth was restored by supplementation with 2.0 g liter(-1) acetic acid. The stoichiometry of acetate consumption and growth was consistent with the complete replacement of glycerol formation by acetate reduction to ethanol as the mechanism for NADH reoxidation. This study provides a proof of principle for the potential of this metabolic engineering strategy to improve ethanol yields, eliminate glycerol production, and partially convert acetate, which is a well-known inhibitor of yeast performance in lignocellulosic hydrolysates, to ethanol. Further research should address the kinetic aspects of acetate reduction and the effect of the elimination of glycerol production on cellular robustness (e.g., osmotolerance).

  19. Effect of addition of lignin in physical-chemical properties of a polyesters based on glycerol, phthalic and adipic acids

    International Nuclear Information System (INIS)

    Guimaraes, D.H.; Viana, A.P.M.; Lima, A.S.C.; Goncalves, A.P.B.; Miranda, C.S.; Jose, N.M.

    2014-01-01

    In this paper the study of different addition amounts of lignin in the physicochemical properties of polyesters made from glycerol and different amounts of phthalic and adipic acids have been proposed. The following characterizations were made: XRD, FTIR, TGA, DSC and SEM. The variation in the percentage of adipic and phthalic acids had a direct effect on thermal and morphological properties. The thermal analysis showed that there was miscibility between the polyester and lignin, by means of displacement related to the temperature of thermal degradation events. In FTIR analysis was noted displacements of characteristic bands of hydrogen bonds and specific carbonyl ester groups. These shifts were more pronounced as it has larger amounts of phthalic acid as monomer and larger amounts of lignin in the compositions. (author)

  20. Localization of acid phosphatase activity in the apoplast of root nodules of pea (Pisum sativum

    Directory of Open Access Journals (Sweden)

    Marzena Sujkowska

    2011-01-01

    Full Text Available Changes in the activity of acid phosphatase (AcPase in the apoplast of pea root nodule were investigated. The activity was determined using lead and cerium methods. The results indicated a following sequence of AcPase activity appearance during the development of the infection thread: 1 low AcPase activity appears in the outer part of cells of symbiotic bacteria; 2 bacteria show increased AcPase activity, and the enzyme activity appears in the thread walls; 3 activity exhibits also matrix of the infection thread; 4 bacteria just before their release from the infection threads show high AcPase activity; 5 AcPase activity ceases after bacteria transformation into bacteroids. The increase in bacterial AcPase activity may reflect a higher demand for inorganic phosphorus necessary for propagation of the bacteria within the infection threads and/or involved in bacteria release from the infection threads.

  1. Hemagglutinating and acid phosphatase (AcPASE activities in developing seedlings of four species of Cucurbitaceae

    Directory of Open Access Journals (Sweden)

    Irena Lorenc-Kubis

    2014-01-01

    Full Text Available The acid phosphatase and hemagglutinating activities of four species of Cucurbitaceae were determined during seeds germination and seedlings development. In all cases traces of enzyme and hemagglutinating activities were found in dry and imbibided seeds. In developing seedlings of Cucumis sativus the activities increased to maximum on the 3rd day while in other species on the 6th day of germination and than fell down. Dot blot and Western blot techniques have shown that in seeds and seedlings of all investigated species present were proteins which cross-reacted with antibodies raised against lectins: CLBa and Con A. It has been shown that proteins from seeds and seedlings of Cucurbita maxima var. bambino, Cucurbita pepo var. giromontia and Cucumis sativus had more pronounced antigenical similarity to lectin CLBa (from Cucurbitaceae than Con A, while proteins from cotyledons of Cucurbita pepo var. patissonina reacted better with antibodies raised against Con A (the lectin from Papilionaceae than with CLBa.

  2. Cloning and Characterization of Purple Acid Phosphatase Phytases from Wheat, Barley, Maize and Rice

    DEFF Research Database (Denmark)

    Dionisio, Giuseppe; Madsen, Claus Krogh; Holm, Preben Bach

    2011-01-01

    development and germination. In wheat, it was demonstrated that a and b isogene expression is driven by different promoters (approximately 31% identity). TaPAPhy_a/b promoter reporter gene expression in transgenic grains and peptide mapping of TaPAPhy purified from wheat bran and germinating grains confirmed......Barley (Hordeum vulgare) and wheat (Triticum aestivum) possess significant phytase activity in the mature grains. Maize (Zea mays) and rice (Oryza sativa) possess little or virtually no preformed phytase activity in the mature grain and depend fully on de novo synthesis during germination. Here......, it is demonstrated that wheat, barley, maize, and rice all possess purple acid phosphatase (PAP) genes that, expressed in Pichia pastoris, give fully functional phytases (PAPhys) with very similar enzyme kinetics. Preformed wheat PAPhy was localized to the protein crystalloid of the aleurone vacuole. Phylogenetic...

  3. Phospholipid metabolism and nuclear function: roles of the lipin family of phosphatidic acid phosphatases.

    Science.gov (United States)

    Siniossoglou, Symeon

    2013-03-01

    Phospholipids play important roles in nuclear function as dynamic building blocks for the biogenesis of the nuclear membrane, as well as signals by which the nucleus communicates with other organelles, and regulate a variety of nuclear events. The mechanisms underlying the nuclear roles of phospholipids remain poorly understood. Lipins represent a family of phosphatidic acid (PA) phosphatases that are conserved from yeasts to humans and perform essential functions in lipid metabolism. Several studies have identified key roles for lipins and their regulators in nuclear envelope organization, gene expression and the maintenance of lipid homeostasis in yeast and metazoans. This review discusses recent advances in understanding the roles of lipins in nuclear structure and function. This article is part of a Special Issue entitled Phospholipids and Phospholipid Metabolism. Copyright © 2012 Elsevier B.V. All rights reserved.

  4. Defects in the acid phosphatase ACPT cause recessive hypoplastic amelogenesis imperfecta.

    Science.gov (United States)

    Smith, Claire El; Whitehouse, Laura LE; Poulter, James A; Brookes, Steven J; Day, Peter F; Soldani, Francesca; Kirkham, Jennifer; Inglehearn, Chris F; Mighell, Alan J

    2017-08-01

    We identified two homozygous missense variants (c.428C>T, p.(T143M) and c.746C>T, p.(P249L)) in ACPT, the gene encoding acid phosphatase, testicular, which segregates with hypoplastic amelogenesis imperfecta in two unrelated families. ACPT is reported to play a role in odontoblast differentiation and mineralisation by supplying phosphate during dentine formation. Analysis by computerised tomography and scanning electron microscopy of a primary molar tooth from an individual homozygous for the c.746C>T variant revealed an enamel layer that was hypoplastic, but mineralised with prismatic architecture. These findings implicate variants in ACPT as a cause of early failure of amelogenesis during the secretory phase.

  5. Glycerol tertiary butyl ethers via etherification of glycerol with isobutene

    Energy Technology Data Exchange (ETDEWEB)

    Behr, A. [Dortmund Univ. (Germany). Chair of Chemical Process Development/Technical Chemistry A

    2007-07-01

    Glycerol and isobutene can react to a mixture of glycerol tertiary butyl ethers (GTBE) which can be used as additives for gasoline, diesel or biodiesel. This reaction was investigated in lab scale yielding a proposal for a process flow diagram containing reaction, extraction, flash and rectification units. This process has the advantages that only the suitable higher ethers are formed and that both glycerol and isobutene are fully converted. The homogeneous acid catalyst is low-priced and can be completely recycled. (orig.)

  6. Soil properties influence kinetics of soil acid phosphatase in response to arsenic toxicity.

    Science.gov (United States)

    Wang, Ziquan; Tan, Xiangping; Lu, Guannan; Liu, Yanju; Naidu, Ravi; He, Wenxiang

    2018-01-01

    Soil phosphatase, which plays an important role in phosphorus cycling, is strongly inhibited by Arsenic (As). However, the inhibition mechanism in kinetics is not adequately investigated. In this study, we investigated the kinetic characteristics of soil acid phosphatase (ACP) in 14 soils with varied properties, and also explored how kinetic properties of soil ACP changed with different spiked As concentrations. The results showed that the Michaelis constant (K m ) and maximum reaction velocity (V max ) values of soil ACP ranged from 1.18 to 3.77mM and 0.025-0.133mMh -1 in uncontaminated soils. The kinetic parameters of soil ACP in different soils changed differently with As contamination. The K m remained unchanged and V max decreased with increase of As concentration in most acid and neutral soils, indicating a noncompetitive inhibition mechanism. However, in alkaline soils, the K m increased linearly and V max decreased with increase of As concentration, indicating a mixed inhibition mechanism that include competitive and noncompetitive. The competitive inhibition constant (K ic ) and noncompetitive inhibition constant (K iu ) varied among soils and ranged from 0.38 to 3.65mM and 0.84-7.43mM respectively. The inhibitory effect of As on soil ACP was mostly affected by soil organic matter and cation exchange capacity. Those factors influenced the combination of As with enzyme, which resulted in a difference of As toxicity to soil ACP. Catalytic efficiency (V max /K m ) of soil ACP was a sensitive kinetic parameter to assess the ecological risks of soil As contamination. Copyright © 2017 Elsevier Inc. All rights reserved.

  7. Histochemical study on effects of low dose γ-irradiation on acid phosphatase in liver of the pigeons Columbus livia intermedia Strickland

    International Nuclear Information System (INIS)

    Gadhia, P.K.; Shah, V.C.

    1982-01-01

    Effects of total body γ-irradiation with sub-lethal dose (400 rads) on acid phosphatase have been studied in the liver of pigeon. The histochemical study showed increased activity of acid phosphatase in liver after 48 hr and 72 hr of irradiation. (author)

  8. Iron content and acid phosphatase activity in hepatic parenchymal lysosomes of patients with hemochromatosis before and after phlebotomy treatment

    International Nuclear Information System (INIS)

    Cleton, M.I.; de Bruijn, W.C.; van Blokland, W.T.; Marx, J.J.; Roelofs, J.M.; Rademakers, L.H.

    1988-01-01

    Lysosomal structures in liver parenchymal cells of 3 patients with iron overload and of 3 subjects without iron-storage disorders were investigated. A combination of enzyme cytochemistry--with cerium as a captive ion to demonstrate lysosomal acid phosphatase activity--and electron probe X-ray microanalysis (EPMA) was used. We were able (1) to define and quantify lysosomal structures as lysosomes, siderosomes, or residual bodies, (2) to quantify the amount of iron and cerium simultaneously in these structures, and (3) to evaluate a possible relation between iron storage and enzyme activity. With histopathologically increased iron storage, the number of siderosomes had increased at the cost of lysosomes, with a corresponding increase in acid phosphatase activity in both organelles. In histopahtologically severe iron overload, however, acid phosphatase activity was low or not detectable and most of the iron was stored in residual bodies. After phlebotomy treatment, the number of siderosomes had decreased in favor of the lysosomes, approaching values obtained in control subjects, and acid phosphatase activity was present in all iron-containing structures. In this way a relationship between iron storage and enzyme activity was established. The iron content of the individual lysosomal structures per unit area had increased with histopathologically increased iron storage and had decreased after phlebotomy treatment. From this observation, it is concluded that the iron status of the patient is not only reflected by the amount of iron-containing hepatocytes but, as well, by the iron content lysosomal unit area

  9. Characterization of a soluble phosphatidic acid phosphatase in bitter melon (Momordica charantia).

    Science.gov (United States)

    Cao, Heping; Sethumadhavan, Kandan; Grimm, Casey C; Ullah, Abul H J

    2014-01-01

    Momordica charantia is often called bitter melon, bitter gourd or bitter squash because its fruit has a bitter taste. The fruit has been widely used as vegetable and herbal medicine. Alpha-eleostearic acid is the major fatty acid in the seeds, but little is known about its biosynthesis. As an initial step towards understanding the biochemical mechanism of fatty acid accumulation in bitter melon seeds, this study focused on a soluble phosphatidic acid phosphatase (PAP, 3-sn-phosphatidate phosphohydrolase, EC 3.1.3.4) that hydrolyzes the phosphomonoester bond in phosphatidate yielding diacylglycerol and P(i). PAPs are typically categorized into two subfamilies: Mg(2+)-dependent soluble PAP and Mg(2+)-independent membrane-associated PAP. We report here the partial purification and characterization of an Mg(2+)-independent PAP activity from developing cotyledons of bitter melon. PAP protein was partially purified by successive centrifugation and UNOsphere Q and S columns from the soluble extract. PAP activity was optimized at pH 6.5 and 53-60 °C and unaffected by up to 0.3 mM MgCl2. The K(m) and Vmax values for dioleoyl-phosphatidic acid were 595.4 µM and 104.9 ηkat/mg of protein, respectively. PAP activity was inhibited by NaF, Na(3)VO(4), Triton X-100, FeSO4 and CuSO4, but stimulated by MnSO4, ZnSO4 and Co(NO3)2. In-gel activity assay and mass spectrometry showed that PAP activity was copurified with a number of other proteins. This study suggests that PAP protein is probably associated with other proteins in bitter melon seeds and that a new class of PAP exists as a soluble and Mg(2+)-independent enzyme in plants.

  10. Vanadyl complexes with dansyl-labelled di-picolinic acid ligands: synthesis, phosphatase inhibition activity and cellular uptake studies.

    Science.gov (United States)

    Collins, Juliet; Cilibrizzi, Agostino; Fedorova, Marina; Whyte, Gillian; Mak, Lok Hang; Guterman, Inna; Leatherbarrow, Robin; Woscholski, Rudiger; Vilar, Ramon

    2016-04-28

    Vanadium complexes have been previously utilised as potent inhibitors of cysteine based phosphatases (CBPs). Herein, we present the synthesis and characterisation of two new fluorescently labelled vanadyl complexes (14 and 15) with bridged di-picolinic acid ligands. These compounds differ significantly from previous vanadyl complexes with phosphatase inhibition properties in that the metal-chelating part is a single tetradentate unit, which should afford greater stability and scope for synthetic elaboration than the earlier complexes. These new complexes inhibit a selection of cysteine based phosphatases (CBPs) in the nM range with some selectivity. Fluorescence spectroscopic studies (including fluorescence anisotropy) were carried out to demonstrate that the complexes are not simply acting as vanadyl delivery vehicles but they interact with the proteins. Finally, we present preliminary fluorescence microscopy studies to demonstrate that the complexes are cell permeable and localise throughout the cytoplasm of NIH3T3 cells.

  11. Recessive Mutations in ACPT, Encoding Testicular Acid Phosphatase, Cause Hypoplastic Amelogenesis Imperfecta.

    Science.gov (United States)

    Seymen, Figen; Kim, Youn Jung; Lee, Ye Ji; Kang, Jenny; Kim, Tak-Heun; Choi, Hwajung; Koruyucu, Mine; Kasimoglu, Yelda; Tuna, Elif Bahar; Gencay, Koray; Shin, Teo Jeon; Hyun, Hong-Keun; Kim, Young-Jae; Lee, Sang-Hoon; Lee, Zang Hee; Zhang, Hong; Hu, Jan C-C; Simmer, James P; Cho, Eui-Sic; Kim, Jung-Wook

    2016-11-03

    Amelogenesis imperfecta (AI) is a heterogeneous group of genetic disorders affecting tooth enamel. The affected enamel can be hypoplastic and/or hypomineralized. In this study, we identified ACPT (testicular acid phosphatase) biallelic mutations causing non-syndromic, generalized hypoplastic autosomal-recessive amelogenesis imperfecta (AI) in individuals from six apparently unrelated Turkish families. Families 1, 4, and 5 were affected by the homozygous ACPT mutation c.713C>T (p.Ser238Leu), family 2 by the homozygous ACPT mutation c.331C>T (p.Arg111Cys), family 3 by the homozygous ACPT mutation c.226C>T (p.Arg76Cys), and family 6 by the compound heterozygous ACPT mutations c.382G>C (p.Ala128Pro) and 397G>A (p.Glu133Lys). Analysis of the ACPT crystal structure suggests that these mutations damaged the activity of ACPT by altering the sizes and charges of key amino acid side chains, limiting accessibility of the catalytic core, and interfering with homodimerization. Immunohistochemical analysis confirmed localization of ACPT in secretory-stage ameloblasts. The study results provide evidence for the crucial function of ACPT during amelogenesis. Copyright © 2016 American Society of Human Genetics. Published by Elsevier Inc. All rights reserved.

  12. Evidence of a New Role for the High-Osmolarity Glycerol Mitogen-Activated Protein Kinase Pathway in Yeast: Regulating Adaptation to Citric Acid Stress†

    OpenAIRE

    Lawrence, Clare L.; Botting, Catherine H.; Antrobus, Robin; Coote, Peter J.

    2004-01-01

    Screening the Saccharomyces cerevisiae disruptome, profiling transcripts, and determining changes in protein expression have identified an important new role for the high-osmolarity glycerol (HOG) mitogen-activated protein kinase (MAPK) pathway in the regulation of adaptation to citric acid stress. Deletion of HOG1, SSK1, PBS2, PTC2, PTP2, and PTP3 resulted in sensitivity to citric acid. Furthermore, citric acid resulted in the dual phosphorylation, and thus activation, of Hog1p. Despite mino...

  13. Uncertainty & sensitivity analysis of economic assessment of lactic acid production from crude glycerol - impact of price correlations

    DEFF Research Database (Denmark)

    Loureiro da Costa Lira Gargalo, Carina; Carvalho, Ana; Gernaey, Krist V.

    2017-01-01

    In this work, we investigate the impact of the expected price volatility and correlations on the overall economic assessment of lactic acid production from crude glycerol. In particular, the goals of this study are three-fold: (i) to understand how uncertainty in the inputs propagates to the model...... outputs; (ii) to understand the effect of the degree of pairwise correlation between input uncertainties on each other and on the outputs from the economic model (Net Present Value); and lastly, (iii) to estimate the first-order as well as independent sensitivity indices so as to identify which...... of the input uncertainties in the economic analysis affect the estimated NPV the most. To this end, we implemented algorithms in Matlab (R2015a) based on Monte Carlo sampling with permutation using Latin Hypercube Sampling with Iman Conover correlation control (Sin et al., 2009).The results have shown...

  14. Differences in sialic acid residues among bone alkaline phosphatase isoforms: a physical, biochemical, and immunological characterization.

    Science.gov (United States)

    Magnusson, P; Farley, J R

    2002-12-01

    High-performance liquid chromatography (HPLC) separates three human bone alkaline phosphatase (BALP) isoforms in serum; two major BALP isoforms, B1 and B2, and a minor fraction, B/I, which is composed on average of 70% bone and 30% intestinal ALP. The current studies were intended to identify an in vitro source of the BALP isoforms for physical, biochemical, and immunological characterizations. The three BALP isoforms were identified in extracts of human osteosarcoma (SaOS-2) cells, by HPLC, after separation by anion-exchange chromatography. All three BALP isoforms were similar with respect to freeze-thaw stability, solubility, heat inactivation, and inhibition by L-phenylalanine, L-homoarginine, and levamisole. The isoforms were also kinetically similar (i.e., maximal velocity and KM at pH 8.8 and pH 10.0). The isoforms differed, however, with respect to sensitivity to precipitation with wheat germ agglutinin (WGA), P acid residues was estimated to be 29 and 45, for each B1 and B2 homodimer, respectively. Apparent discrepancies between these estimates of molecular weight and estimates based on gel filtration chromatography were attributed to nonspecific interactions between carbohydrate residues and the gel filtration beads. All three BALP isoforms showed similar dose-dependent linearity in the commercial Alkphase-B and Tandem-MP Ostase immunoassays, r = 0.944 and r = 0.985, respectively (P acid residues compared with B/I, which mainly explains the apparent differences in molecular weight. Future investigations will focus on the clinical and functional significance of the revealed differences in sialic acid residues.

  15. Transmembrane prostatic acid phosphatase (TMPAP interacts with snapin and deficient mice develop prostate adenocarcinoma.

    Directory of Open Access Journals (Sweden)

    Ileana B Quintero

    Full Text Available The molecular mechanisms underlying prostate carcinogenesis are poorly understood. Prostatic acid phosphatase (PAP, a prostatic epithelial secretion marker, has been linked to prostate cancer since the 1930's. However, the contribution of PAP to the disease remains controversial. We have previously cloned and described two isoforms of this protein, a secretory (sPAP and a transmembrane type-I (TMPAP. The goal in this work was to understand the physiological function of TMPAP in the prostate. We conducted histological, ultra-structural and genome-wide analyses of the prostate of our PAP-deficient mouse model (PAP(-/- with C57BL/6J background. The PAP(-/- mouse prostate showed the development of slow-growing non-metastatic prostate adenocarcinoma. In order to find out the mechanism behind, we identified PAP-interacting proteins byyeast two-hybrid assays and a clear result was obtained for the interaction of PAP with snapin, a SNARE-associated protein which binds Snap25 facilitating the vesicular membrane fusion process. We confirmed this interaction by co-localization studies in TMPAP-transfected LNCaP cells (TMPAP/LNCaP cells and in vivo FRET analyses in transient transfected LNCaP cells. The differential gene expression analyses revealed the dysregulation of the same genes known to be related to synaptic vesicular traffic. Both TMPAP and snapin were detected in isolated exosomes. Our results suggest that TMPAP is involved in endo-/exocytosis and disturbed vesicular traffic is a hallmark of prostate adenocarcinoma.

  16. Behavior of soluble and immobilized acid phosphatase in hydro-organic media.

    Science.gov (United States)

    Wan, H; Horvath, C

    1975-11-20

    The hydrolysis of p-nitrophenyl phosphate by wheat germ acid phosphatase (orthophosphoric monoester phosphohydrolase, EC 3.1.3.2) has been investigated in mixtures of aqueous buffers with acetone, dioxane and acetonitrile. The enzyme was either in free solution or immobilized on a pellicular support which consisted of a porous carbonaceous layer on solid glass beads. The highest enzyme activity was obtained in acetone and acetonitrile mixed with citrate buffer over a wide range of organic solvent concentration. In 50% (v/v) acetone both V and Km of the immobilized enzyme were about half of the values in the neat aqueous buffer, but the Ki for inorganic phosphate was unchanged. In 50% (v/v) mixtures of various solvents and citrate buffers of different pH, the enzymic activity was found to depend on the pH of the aqueous buffer component rather than the pH of the hydro-organic mixture as measured with the glass-calomel electrode. The relatively high rates of p-nitrophenol liberation in the presence of glucose even at high organic solvent concentrations suggest that transphosphorylation is facilitated at low water activity.

  17. Mice deficient in transmembrane prostatic acid phosphatase display increased GABAergic transmission and neurological alterations.

    Directory of Open Access Journals (Sweden)

    Heidi O Nousiainen

    Full Text Available Prostatic acid phosphatase (PAP, the first diagnostic marker and present therapeutic target for prostate cancer, modulates nociception at the dorsal root ganglia (DRG, but its function in the central nervous system has remained unknown. We studied expression and function of TMPAP (the transmembrane isoform of PAP in the brain by utilizing mice deficient in TMPAP (PAP-/- mice. Here we report that TMPAP is expressed in a subpopulation of cerebral GABAergic neurons, and mice deficient in TMPAP show multiple behavioral and neurochemical features linked to hyperdopaminergic dysregulation and altered GABAergic transmission. In addition to increased anxiety, disturbed prepulse inhibition, increased synthesis of striatal dopamine, and augmented response to amphetamine, PAP-deficient mice have enlarged lateral ventricles, reduced diazepam-induced loss of righting reflex, and increased GABAergic tone in the hippocampus. TMPAP in the mouse brain is localized presynaptically, and colocalized with SNARE-associated protein snapin, a protein involved in synaptic vesicle docking and fusion, and PAP-deficient mice display altered subcellular distribution of snapin. We have previously shown TMPAP to reside in prostatic exosomes and we propose that TMPAP is involved in the control of GABAergic tone in the brain also through exocytosis, and that PAP deficiency produces a distinct neurological phenotype.

  18. Studies on alkaline and acid phosphatase activity of neutrophil leukicytes, 2

    International Nuclear Information System (INIS)

    Niki, Yoko

    1983-01-01

    With a view to analyzing the inhibiting effect of anticancer drugs and irradiation on hematopoiesis in rabbits neutrophil (pseudoeosinophil) counts and the neutrophilic activities of alkaline phosphatase (AP) and acid phosphatase (SP) were serially followed up after drug administration or irradiation. The enzym activity was estimated histochemically, using azo-dye staining. Each rabbit was given cyclophosphamid (CP) (25mg/kg x 10, at intervals of 5 - 7 days ; 50mg/kg x 5, every day; or 100mg/kg x 1, i.m.), Thio-TEPA (4mg/kg x 1, i.m.), Vinblastin (VBT) (1mg/kg x 1, i.v.), 6MP (25mg/kg x 1, p.o.), or Mitomycin C (MMC) (1.5mg/kg x 1, i.v.). The results obtained were as follows : 1) The neutrophil counts became slightly elevated at 24 hrs, reached their nadir at 48 to 72 hrs, and recovered to normal in 5 to 6 days thereafter, except with 6 MP which produced no significant change but for a temporary elevation after dosages. 2) Except in the group administrated 6MP, which caused no significant hematorogical changes, the AP changes were similar in all of the animal groups : after temporary depression, it became elevated for 5 to 6 days, and recovered to normal about 9 days thereafter. 3) SP showed no changes in the 25mg/kg x 10 CP and the 6MP groups, it became elevated in 2 or 3 days after the administration of MMC, VBT, or Thio-TEPA to recover to normal in 5 to 10 days thereafter. 4) 60 Co irradiation (1,000 rad/whole body x 1) led to a temporary ascent in phil count followed by a descent from the 6th day on, and then a slow recovery to normal. AP was elevated from the third to the sixth days, and, after a depression on the tenth day, it returned to normal 24 days after irradiation, while SP showed a continued elevation from the 2nd to the 13th day. (author)

  19. Activity of acid phosphatase in tissues of dogs exposed to γ-radiation at low dose rates and treated with adenosine triphosphate

    International Nuclear Information System (INIS)

    Bichejkina, N.I.; Tikhomirova, M.V.; Romantsev, E.F.; Rogozkin, V.D.

    1979-01-01

    A study was made of the activity of acid phosphatase in the liver, spleen and blood of dogs under various experimental conditions: (a) exposure to γ-rays at low dose rates, (b) preventive and therapeutic application of ATP and (c) administration of ATP to intact animals. It was demonstrated that the activity of acid phosphatase in the liver and spleen was invariable after the first 24 h and decreased after 72 h of observation in each of the experimental variants. Preventive and therapeutic administration of ATP to dogs not substantially influence the activity of acid phosphatase throughout the entire period of observation

  20. Flux analysis of the Lactobacillus reuteri propanediol-utilization pathway for production of 3-hydroxypropionaldehyde, 3-hydroxypropionic acid and 1,3-propanediol from glycerol.

    Science.gov (United States)

    Dishisha, Tarek; Pereyra, Luciana P; Pyo, Sang-Hyun; Britton, Robert A; Hatti-Kaul, Rajni

    2014-05-27

    Lactobacillus reuteri converts glycerol to 3-hydroxypropionic acid (3HP) and 1,3-propanediol (1,3PDO) via 3-hydroxypropionaldehyde (3HPA) as an intermediate using enzymes encoded in its propanediol-utilization (pdu) operon. Since 3HP, 1,3PDO and 3HPA are important building blocks for the bio-based chemical industry, L. reuteri can be an attractive candidate for their production. However, little is known about the kinetics of glycerol utilization in the Pdu pathway in L. reuteri. In this study, the metabolic fluxes through the Pdu pathway were determined as a first step towards optimizing the production of 3HPA, and co-production of 3HP and 1,3PDO from glycerol. Resting cells of wild-type (DSM 20016) and recombinant (RPRB3007, with overexpressed pdu operon) strains were used as biocatalysts. The conversion rate of glycerol to 3HPA by the resting cells of L. reuteri was evaluated by in situ complexation of the aldehyde with carbohydrazide to avoid the aldehyde-mediated inactivation of glycerol dehydratase. Under operational conditions, the specific 3HPA production rate of the RPRB3007 strain was 1.9 times higher than that of the wild-type strain (1718.2 versus 889.0 mg/gCDW.h, respectively). Flux analysis of glycerol conversion to 1,3PDO and 3HP in the cells using multi-step variable-volume fed-batch operation showed that the maximum specific production rates of 3HP and 1,3PDO were 110.8 and 93.7 mg/gCDW.h, respectively, for the wild-type strain, and 179.2 and 151.4 mg/gCDW.h, respectively, for the RPRB3007 strain. The cumulative molar yield of the two compounds was ~1 mol/mol glycerol and their molar ratio was ~1 mol3HP/mol1,3PDO. A balance of redox equivalents between the glycerol oxidative and reductive pathway branches led to equimolar amounts of the two products. Metabolic flux analysis was a useful approach for finding conditions for maximal conversion of glycerol to 3HPA, 3HP and 1,3PDO. Improved specific production rates were obtained with resting cells of

  1. Study of possible changes brought about by plutonium oxide in the acid phosphatase activity of alveolar macrophages of the rabbit

    International Nuclear Information System (INIS)

    Rouvroy, Huguette

    1970-06-01

    This report describes the various techniques used for determining the acid phosphatase activity of alveolar rabbit macrophages after inhalation of radioactive plutonium oxide particles, exposure of the animals, removal and sampling of the alveolar cells, and technical dosage. The results obtained are presented; they do not make it possible, in this particular case, to affirm that an important change in the enzymatic activity studied occurs. (author) [fr

  2. An Additional Method for Analyzing the Reversible Inhibition of an ?Enzyme Using Acid Phosphatase as a Model

    OpenAIRE

    Baumhardt, Jordan M.; Dorsey, Benjamin M.; McLauchlan, Craig C.; Jones, Marjorie A.

    2015-01-01

    Using wheat germ acid phosphatase and sodium orthovanadate as a competitive inhibitor, a novel method for analyzing reversible inhibition was carried out. Our alternative approach involves plotting the initial velocity at which product is formed as a function of the ratio of substrate concentration to inhibitor concentration at a constant enzyme concentration and constant assay conditions. The concept of initial concentrations driving equilibrium leads to the chosen axes. Three apparent const...

  3. Vanillic acid derivatives from the green algae Cladophora socialis as potent protein tyrosine phosphatase 1B inhibitors.

    Science.gov (United States)

    Feng, Yunjiang; Carroll, Anthony R; Addepalli, Rama; Fechner, Gregory A; Avery, Vicky M; Quinn, Ronald J

    2007-11-01

    A novel vanillic acid derivative (1) and its sulfate adduct (2) were isolated from a green algae, Cladophora socialis. The structures of 1 and 2 were elucidated from NMR and HRESIMS experiments. Both compounds showed potent inhibitory activity against protein tyrosine phosphatase 1B (PTP1B), an enzyme involved in the regulation of insulin cell signaling. Compounds 1 and 2 had IC50 values of 3.7 and 1.7 microM, respectively.

  4. Protein phosphatase 2Cm is a critical regulator of branched-chain amino acid catabolism in mice and cultured cells.

    Science.gov (United States)

    Lu, Gang; Sun, Haipeng; She, Pengxiang; Youn, Ji-Youn; Warburton, Sarah; Ping, Peipei; Vondriska, Thomas M; Cai, Hua; Lynch, Christopher J; Wang, Yibin

    2009-06-01

    The branched-chain amino acids (BCAA) are essential amino acids required for protein homeostasis, energy balance, and nutrient signaling. In individuals with deficiencies in BCAA, these amino acids can be preserved through inhibition of the branched-chain-alpha-ketoacid dehydrogenase (BCKD) complex, the rate-limiting step in their metabolism. BCKD is inhibited by phosphorylation of its E1alpha subunit at Ser293, which is catalyzed by BCKD kinase. During BCAA excess, phosphorylated Ser293 (pSer293) becomes dephosphorylated through the concerted inhibition of BCKD kinase and the activity of an unknown intramitochondrial phosphatase. Using unbiased, proteomic approaches, we have found that a mitochondrial-targeted phosphatase, PP2Cm, specifically binds the BCKD complex and induces dephosphorylation of Ser293 in the presence of BCKD substrates. Loss of PP2Cm completely abolished substrate-induced E1alpha dephosphorylation both in vitro and in vivo. PP2Cm-deficient mice exhibited BCAA catabolic defects and a metabolic phenotype similar to the intermittent or intermediate types of human maple syrup urine disease (MSUD), a hereditary disorder caused by defects in BCKD activity. These results indicate that PP2Cm is the endogenous BCKD phosphatase required for nutrient-mediated regulation of BCKD activity and suggest that defects in PP2Cm may be responsible for a subset of human MSUD.

  5. Comparative studies on the carbohydrate, protein and acid phosphatase contents in seeds of some rye (Secale cereale varieties

    Directory of Open Access Journals (Sweden)

    B. Morawiecka

    2015-01-01

    Full Text Available The contents of sugars. proteins and acid phosphatase extracted with 0.1 M acetate buffer, pH 5.1, from some rye varieties were determined. The total sugar level amounted to 3.25-9.70 g per 100 g of seeds; the estimates for pentoses were 1.7-2.9 g and those for proteins 0.91-1.60 g per 100 g of seeds. Acid phosphatase showed and activity level between 0.18 and 1.26 units/mg protein. After disc electrophoresis proteins were separated into 10 to 11 bands: at pH 9.4 or into 4-7 bands at pH 3.8. Essential variety differences were expressed in protein patterns after electrophoresis at pH 3.8. Acid phosphatase was separated into 5 and 4 activity bands at pH 9.4 and 3.3,. respectively. No variations in zymogram patterns were observed in respect to variety differences or cultivation in various climate and soil conditions.

  6. Acid phosphatase patterns in microfilariae of Onchocerca volvulus s.l. from the Upper Orinoco Basin, Venezuela.

    Science.gov (United States)

    Yarzàbal, L; Petralanda, I; Arango, M; Lobo, L; Botto, C

    1983-06-01

    The patterns of acid phosphatase in strains of Onchocerca volvulus s.l. which parasitize an Amerindian population (Yanomami) in Venezuela's Upper Orinoco Basin were examined by using the naphthol AS-TR phosphate method. The study sample consisted of 40 Yanomami inhabiting a savannah area at 950 m above sea level and 21 Yanomami residents of a tropical rainforest area at an altitude of 250 m. Stained intrauterine microfilariae, still within the egg case, exhibited a diffuse distribution of the enzyme in the early stages of embryonic development and a negative reaction at a more developed stage. Four of the five enzyme staining patterns described by Omar (1978) were found in the 3157 microfilariae examined from skin snips. Their distribution was: Type I--17.2%, Type III--0.5%, Type IV--75.6% and Type V--6.6%. No examples of Type II were observed. The results indicate that acid phosphatase patterns of the Upper Orinoco Onchocerca strain most resemble those of strains from Guatemala and Yemen, and are different from the African strains found in Upper Volta and Liberia. The relative frequency of acid phosphatase patterns was modified by cryopreservation of microfilariae.

  7. A Novel Phytase with Sequence Similarity to Purple Acid Phosphatases Is Expressed in Cotyledons of Germinating Soybean Seedlings 1

    Science.gov (United States)

    Hegeman, Carla E.; Grabau, Elizabeth A.

    2001-01-01

    Phytic acid (myo-inositol hexakisphosphate) is the major storage form of phosphorus in plant seeds. During germination, stored reserves are used as a source of nutrients by the plant seedling. Phytic acid is degraded by the activity of phytases to yield inositol and free phosphate. Due to the lack of phytases in the non-ruminant digestive tract, monogastric animals cannot utilize dietary phytic acid and it is excreted into manure. High phytic acid content in manure results in elevated phosphorus levels in soil and water and accompanying environmental concerns. The use of phytases to degrade seed phytic acid has potential for reducing the negative environmental impact of livestock production. A phytase was purified to electrophoretic homogeneity from cotyledons of germinated soybeans (Glycine max L. Merr.). Peptide sequence data generated from the purified enzyme facilitated the cloning of the phytase sequence (GmPhy) employing a polymerase chain reaction strategy. The introduction of GmPhy into soybean tissue culture resulted in increased phytase activity in transformed cells, which confirmed the identity of the phytase gene. It is surprising that the soybean phytase was unrelated to previously characterized microbial or maize (Zea mays) phytases, which were classified as histidine acid phosphatases. The soybean phytase sequence exhibited a high degree of similarity to purple acid phosphatases, a class of metallophosphoesterases. PMID:11500558

  8. Diffusion of intracerebrally injected [1-14C]arachidonic acid and [2-3H]glycerol in the mouse brain. Effects of ischemia and electroconvulsive shock

    International Nuclear Information System (INIS)

    Pediconi, M.F.; Rodriguez de Turco, E.B.; Bazan, N.G.

    1982-01-01

    [2- 3 H]Glycerol and [1- 14 C]arachidonic acid were injected into the region of the frontal horn of the left ventricle of mice and were distributed rapidly throughout the brain. After 10 sec, most of the radioactive fatty acid was found in the hemisphere near the injection site; after 10 min, it was recovered in similar proportions in the cerebellum and brain stem. [2- 3 H]Glycerol showed a heterogeneous distribution, with most of the label remaining in the left hemisphere even after 10 min. On a fresh weight basis, cerebrum, cerebellum, and brain stem were found to contain similar amounts of labeled glycerol. However, the amount of [1- 14 C]arachidonate in cerebrum was only 50% of that recovered from cerebellum or brain stem. Brain ischemia or a single electroconvulsive shock reduced the spread of the label, producing an accumulation of radioactivity in the injected hemisphere, except for an increase in [2- 3 H]glycerol in the brain stem during ischemia. Despite the significant decrease in available precursor in the cerebellum and brain stem after electroshock, the amount of label incorporated into lipids was not altered in these areas and only slightly diminished in the cerebrum

  9. Circulating Endothelial Microparticles and Correlation of Serum 1,25-Dihydroxyvitamin D with Adiponectin, Nonesterified Fatty Acids, and Glycerol from Middle-Aged Men in China

    Directory of Open Access Journals (Sweden)

    Zhongxiao Wan

    2016-01-01

    Full Text Available The aim of the present study is (1 to determine the correlation between circulating 1,25-dihydroxyvitamin D [25(OHD] and adiponectin, nonesterified fatty acids (NEFAs, and glycerol and (2 to determine the alterations in circulating endothelial microparticles (EMPs in Chinese male subjects with increased body mass index (BMI. A total of 45 male adults were enrolled with varied BMI [i.e., lean, overweight (OW, and obese (OB, N=15 per group]. Blood samples were collected under overnight fasting condition, and plasma was isolated for the measurement of endothelial microparticles (EMPs, total and high-molecular weight (HMW adiponectin, 25(OHD, nonesterified fatty acids (NEFAs, and glycerol. Circulating 25(OHD levels were inversely associated with total adiponectin, NEFA, and glycerol levels. There is no difference for CD62E+ or CD31+/CD42b− EMPs among 3 groups. In Chinese male adults with varied BMI, an inverse correlation existed between 25(OHD levels and total adiponectin, NEFA, and glycerol levels; and there is no significant difference for CD62E+ or CD31+/CD42b− EMPs among lean, overweight, and obese subjects.

  10. Transmembrane Prostatic Acid Phosphatase (TMPAP) Interacts with Snapin and Deficient Mice Develop Prostate Adenocarcinoma

    Science.gov (United States)

    Quintero, Ileana B.; Herrala, Annakaisa M.; Araujo, César L.; Pulkka, Anitta E.; Hautaniemi, Sampsa; Ovaska, Kristian; Pryazhnikov, Evgeny; Kulesskiy, Evgeny; Ruuth, Maija K.; Soini, Ylermi; Sormunen, Raija T.; Khirug, Leonard; Vihko, Pirkko T.

    2013-01-01

    The molecular mechanisms underlying prostate carcinogenesis are poorly understood. Prostatic acid phosphatase (PAP), a prostatic epithelial secretion marker, has been linked to prostate cancer since the 1930's. However, the contribution of PAP to the disease remains controversial. We have previously cloned and described two isoforms of this protein, a secretory (sPAP) and a transmembrane type-I (TMPAP). The goal in this work was to understand the physiological function of TMPAP in the prostate. We conducted histological, ultra-structural and genome-wide analyses of the prostate of our PAP-deficient mouse model (PAP−/−) with C57BL/6J background. The PAP−/− mouse prostate showed the development of slow-growing non-metastatic prostate adenocarcinoma. In order to find out the mechanism behind, we identified PAP-interacting proteins byyeast two-hybrid assays and a clear result was obtained for the interaction of PAP with snapin, a SNARE-associated protein which binds Snap25 facilitating the vesicular membrane fusion process. We confirmed this interaction by co-localization studies in TMPAP-transfected LNCaP cells (TMPAP/LNCaP cells) and in vivo FRET analyses in transient transfected LNCaP cells. The differential gene expression analyses revealed the dysregulation of the same genes known to be related to synaptic vesicular traffic. Both TMPAP and snapin were detected in isolated exosomes. Our results suggest that TMPAP is involved in endo-/exocytosis and disturbed vesicular traffic is a hallmark of prostate adenocarcinoma. PMID:24039861

  11. Isolation and partial characterization of an acid phosphatase from Artemisia vulgaris pollen extract

    Directory of Open Access Journals (Sweden)

    RATKO M. JANKOV

    2002-09-01

    Full Text Available An acid phosphatase from an extract of mugwort (Artemisia vulgaris pollen was purified by a factor of 48 by a combination of ion exchange and gel-chromatography. The molecular weights of the enzyme were 76 kDa and 73 kDa, determined by gel filtration on a Sephadex G-100 sf column and by SDS PAGE (under reducing and non-reducing conditions, respectively. In analytical isoelectrofocusing, the enzyme appears as two very close bands, pI at about 4.2. The optimum pH for the enzyme is 5.4. The apparent Km for p-nitrophenyl phosphate was estimated to be 0.16 mM. The purified enzyme has broad specificity, and hydrolyses p-nitrophenyl phosphate and a-naphthyl phosphate. Pyrophosphate and O-phospho-L-tyrosine were estimated to be the best substrates for this enzyme as potential in vivo substrates. The enzyme is inhibited competitively by phosphate (Ki = 1.25 mM, molybdate (Ki = 0.055 mM and pyrophosphate (Ki = 6.7 mM and non-competitively by fluoride (Ki = 9.8 mM. Metal ions such as Hg2+, Cu2+ and Zn2+ express an inhibitory effect on the enzyme, while the enzyme is slightly activated by non-ionic detergents, Tween 20 and Triton X-100. There is no change in the enzyme activity in the presence of tartrate, citrate, EDTA, 1,10-phenanthroline and sulfhydryl-group modifiers such as p-chloromercuribenzoate and N-ethylmaleimide.

  12. Phosphate solubilization and acid phosphatase activity of Serratia sp. isolated from mangrove soil of Mahanadi river delta, Odisha, India

    Directory of Open Access Journals (Sweden)

    B.C. Behera

    2017-06-01

    Full Text Available Phosphorus is an essential element for all life forms. Phosphate solubilizing bacteria are capable of converting phosphate into a bioavailable form through solubilization and mineralization processes. Hence in the present study a phosphate solubilizing bacterium, PSB-37, was isolated from mangrove soil of the Mahanadi river delta using NBRIP-agar and NBRIP-BPB broth containing tricalcium phosphate as the phosphate source. Based on phenotypic and molecular characterization, the strain was identified as Serratia sp. The maximum phosphate solubilizing activity of the strain was determined to be 44.84 μg/ml, accompanied by a decrease in pH of the growth medium from 7.0 to 3.15. During phosphate solubilization, various organic acids, such as malic acid (237 mg/l, lactic acid (599.5 mg/l and acetic acid (5.0 mg/l were also detected in the broth culture through HPLC analysis. Acid phosphatase activity was determined by performing p-nitrophenyl phosphate assay (pNPP of the bacterial broth culture. Optimum acid phosphatase activity was observed at 48 h of incubation (76.808 U/ml, temperature of 45 °C (77.87 U/ml, an agitation rate of 100 rpm (80.40 U/ml, pH 5.0 (80.66 U/ml and with glucose as a original carbon source (80.6 U/ml and ammonium sulphate as a original nitrogen source (80.92 U/ml. Characterization of the partially purified acid phosphatase showed maximum activity at pH 5.0 (85.6 U/ml, temperature of 45 °C (97.87 U/ml and substrate concentration of 2.5 mg/ml (92.7 U/ml. Hence the present phosphate solubilizing and acid phosphatase production activity of the bacterium may have probable use for future industrial, agricultural and biotechnological application.

  13. Ontogeny and distribution of alkaline and acid phosphatases in the digestive system of California halibut larvae (Paralichthys californicus).

    Science.gov (United States)

    Zacarias-Soto, Magali; Barón-Sevilla, Benjamín; Lazo, Juan P

    2013-10-01

    Studies aimed to assess the digestive physiology of marine fish larvae under culture conditions are important to further understand the functional characteristics and digestive capacities of the developing larvae. Most studies to date concentrate on intestinal lumen digestion and little attention to the absorption process. Thus, the objectives of this study were to histochemically detect and quantify some of the enzymes responsible for absorption and intracellular digestion of nutrients in the anterior and posterior intestine of California halibut larvae. Alkaline and acid phosphatases were detected from the first days post-hatch (dph). Alkaline phosphatase maintained a high level of activity during the first 20 dph in both intestinal regions. Thereafter, a clear intestinal regionalization of the activity was observed with the highest levels occurring in the anterior intestine. Acid phosphatase activity gradually increased in both intestinal regions during development, and a regionalization of the activity was not observed until late in development, once the ocular migration began. Highest levels were observed in the anterior intestine at the end of metamorphosis concomitant with the stomach development. The results from this study show some morphological and physiological changes are occurring during larval development and a clear regionalization of the absorption process as the larvae develops. These ontological changes must be considered in the elaboration of diets according to the digestive capacity of the larvae.

  14. Elevated serum tartrate-resistant acid phosphatase isoform 5a levels in metabolic syndrome.

    Science.gov (United States)

    Huang, Yi-Jhih; Huang, Tsai-Wang; Chao, Tsu-Yi; Sun, Yu-Shan; Chen, Shyi-Jou; Chu, Der-Ming; Chen, Wei-Liang; Wu, Li-Wei

    2017-09-29

    Tartrate-resistant phosphatase isoform 5a is expressed in tumor-associated macrophages and is a biomarker of chronic inflammation. Herein, we correlated serum tartrate-resistant phosphatase isoform 5a levels with metabolic syndrome status and made comparisons with traditional markers of inflammation, including c-reactive protein and interleukin-6. One hundred healthy volunteers were randomly selected, and cut-off points for metabolic syndrome related inflammatory biomarkers were determined using receiver operating characteristic curves. Linear and logistic regression models were subsequently used to correlate inflammatory markers with the risk of metabolic syndrome. Twenty-two participants met the criteria for metabolic syndrome, and serum tartrate-resistant phosphatase isoform 5a levels of >5.8 μg/L were associated with metabolic syndrome (c-statistics, 0.730; p = 0.001; 95% confidence interval, 0.618-0.842). In addition, 1 μg/L increases in tartrate-resistant phosphatase isoform 5a levels were indicative of a 1.860 fold increase in the risk of metabolic syndrome (p = 0.012). Elevated serum tartrate-resistant phosphatase isoform 5a levels are associated with the risk of metabolic syndrome, with a cut-off level of 5.8 μg/L.

  15. Development of a bioprocess to convert PET derived terephthalic acid and biodiesel derived glycerol to medium chain length polyhydroxyalkanoate

    Energy Technology Data Exchange (ETDEWEB)

    Kenny, Shane T.; Nikodinovic Runic, Jasmina; O' Connor, Kevin E. [University College Dublin (Ireland). School of Biomolecular and Biomedical Sciences; Kaminsky, Walter [Hamburg Univ. (Germany). Inst. of Technical and Macromolecular Chemistry; Woods, Trevor; Babu, Ramesh P. [Dublin Univ. (Ireland). Materials Ireland Polymer Research Center

    2012-08-15

    Sodium terephthalate (TA) produced from a PET pyrolysis product and waste glycerol (WG) from biodiesel manufacture were supplied to Pseudomonas putida GO16 in a fed-batch bioreactor. Six feeding strategies were employed by altering the sequence of TA and WG feeding. P. putida GO16 reached 8.70 g/l cell dry weight (CDW) and 2.61 g/l PHA in 48 h when grown on TA alone. When TA and WG were supplied in combination, biomass productivity (g/l/h) was increased between 1.3- and 1.7-fold and PHA productivity (g/l/h) was increased 1.8- to 2.2-fold compared to TA supplied alone. The monomer composition of the PHA accumulated from TA or WG was predominantly composed of 3-hydroxydecanoic acid. PHA monomers 3-hydroxytetradeeanoic acid and 3-hydroxytetradecenoic acid were not present in PHA accumulated from TA alone but were present when WG was supplied to the fermentation. When WG was either the sole carbon source or the predominant carbon source supplied to the fermentation the molecular weight of PHA accumulated was lower compared to PHA accumulated when TA was supplied as the sole substrate. Despite similarities in data for the properties of the polymers, PHAs produced with WG present in the PHA accumulation phase were tacky while PHA produced where TA was the sole carbon substrate in the polymer accumulation phase exhibited little or no tackiness at room temperature. The co-feeding of WG to fermentations allows for increased utilisation of TA. The order of feeding of WG and TA has an effect on TA utilisation and polymer properties. (orig.)

  16. Polyesters production from the mixture of phthalic acid, terephthalic and glycerol

    International Nuclear Information System (INIS)

    Carvalho, A.L.S.; Oliveira, J.C.; Miranda, C.S.; Boaventura, J.S.; Jose, N.M.; Carvalho, R.F.

    2010-01-01

    Glycerin, a byproduct of biodiesel is currently an environmental and economic problem for producers of this renewable fuel in Brazil and in others parts of the world. In order to offer new proposals for recovery, it is used for the manufacture of polyesters used in applications in diverse areas such as construction and automobile industry. This work reports the production of polymer from the mixture of terephthalic and phthalic acid in three different proportions. The polyesters showed good thermal stability, analyzed by TGA and DSC, with an increase proportional to the terephthalic acid content. The X-ray diffraction patterns show that the samples are semi crystalline polymers. The micrographs indicated the presence of a smoother surface in the polyester that has a larger amount of phthalic acid, as reported in the literature. Therefore, the materials showed good thermal properties and morphological characteristics, so it consists in a new alternative to use glycerin. (author)

  17. Selective Oxidation of Glycerol to Glyceric Acid in Base-Free Aqueous Solution at Room Temperature Catalyzed by Platinum Supported on Carbon Activated with Potassium Hydroxide

    KAUST Repository

    Tan, Hua

    2016-04-18

    Pt supported on KOH-activated mesoporous carbon (K-AMC) was used to catalyze glycerol oxidation under base-free conditions at room temperature. To study the relationship between the carbon surface chemistry and the catalytic performance of the K-AMC-based Pt catalysts, different levels of surface oxygen functional groups (SOFGs) on the AMC supports were induced by thermal treatment at different temperatures under inert or H2 gas. A strong effect of the surface chemistry was observed on AMC-supported Pt catalysts for glycerol oxidation. The presence of carboxylic acid groups impedes the adsorption of glycerol, which leads to the reduction of catalytic activity, whereas the presence of high-desorption-temperature SOFGs, such as phenol, ether, and carbonyl/quinone groups, provide hydrophilicity to the carbon surface that improves the adsorption of glycerol molecules on Pt metal surface, which is beneficial for the catalytic activity. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  18. Pine Wood Treated with a Citric Acid and Glycerol Mixture: Biomaterial Performance Improved by a Bio-byproduct

    Directory of Open Access Journals (Sweden)

    Gatien Geraud Essoua Essoua

    2016-02-01

    Full Text Available Wood material is a good reservoir for biogenic carbon storage. The use of wood material for outdoor products such as siding in the building construction sector presents limits. These limits are bound to the nature of wood material (hygroscopic property and anatomical structure. They are responsible for the dimensional variation associated with moisture content variations. Fungal attacks and coating layers adhesion on wood surface, are other problems. This research investigated the feasibility of impregnation with environmentally friendly chemicals, i.e., a citric acid-glycerol mixture (CA-G. The anti-swelling efficiency (ASE, hardness, biodegradation, and coating adhesion tests were performed on softwood specimens. ASE results were up to 53%. The equilibrium moisture content of the treated specimens was less than half of the untreated ones. FTIR spectroscopy showed bands at 1720 to 1750 cm-1, indicating the presence of ester bonds, and scanning electron microscopy images confirmed the polymerization and condensation of treatment solution inside the wood structure. Hardness and decay resistance were increased; however, treatment reduces coating adhesion. In conclusion, CA-G represents a promising eco-responsible solution for improving the technical performance of outdoor wood products.

  19. The IBO germination quantitative trait locus encodes a phosphatase 2C-related variant with a nonsynonymous amino acid change that interferes with abscisic acid signaling.

    Science.gov (United States)

    Amiguet-Vercher, Amélia; Santuari, Luca; Gonzalez-Guzman, Miguel; Depuydt, Stephen; Rodriguez, Pedro L; Hardtke, Christian S

    2015-02-01

    Natural genetic variation is crucial for adaptability of plants to different environments. Seed dormancy prevents precocious germination in unsuitable conditions and is an adaptation to a major macro-environmental parameter, the seasonal variation in temperature and day length. Here we report the isolation of IBO, a quantitative trait locus (QTL) that governs c. 30% of germination rate variance in an Arabidopsis recombinant inbred line (RIL) population derived from the parental accessions Eilenburg-0 (Eil-0) and Loch Ness-0 (Lc-0). IBO encodes an uncharacterized phosphatase 2C-related protein, but neither the Eil-0 nor the Lc-0 variant, which differ in a single amino acid, have any appreciable phosphatase activity in in vitro assays. However, we found that the amino acid change in the Lc-0 variant of the IBO protein confers reduced germination rate. Moreover, unlike the Eil-0 variant of the protein, the Lc-0 variant can interfere with the activity of the phosphatase 2C ABSCISIC ACID INSENSITIVE 1 in vitro. This suggests that the Lc-0 variant possibly interferes with abscisic acid signaling, a notion that is supported by physiological assays. Thus, we isolated an example of a QTL allele with a nonsynonymous amino acid change that might mediate local adaptation of seed germination timing. © 2014 The Authors. New Phytologist © 2014 New Phytologist Trust.

  20. Conversion of Glycerol to 3-Hydroxypropanoic Acid by Genetically Engineered Bacillus subtilis

    DEFF Research Database (Denmark)

    Kalantari, Aida; Chen, Tao; Ji, Boyang

    2017-01-01

    3-Hydroxypropanoic acid (3-HP) is an important biomass-derivable platform chemical that can be converted into a number of industrially relevant compounds. There have been several attempts to produce 3-HP from renewable sources in cell factories, focusing mainly on Escherichia coli, Klebsiella pne...

  1. Simultaneous determination of wine sugars, glycerol and organic acids 13C/12C isotopic ratio by ion chromatography-co-IRMS

    Directory of Open Access Journals (Sweden)

    Guyon Francois

    2014-01-01

    Full Text Available Ion chromatography (IC isotope ratio mass spectrometry (IRMS coupling is possible using a liquid interface allowing chemical oxidation (co of organic compounds. Synthetic solutions containing a mixture of glycerol, sugars (sucrose, glucose and fructose and organic acids (gluconic, lactic, malic, tartaric, oxalic, fumaric, citric and isocitric were elaborated to estimate analytical applications of two different IC systems. It appears that the use of carbonated solution in the eluting phase is a perturbation for 13C isotope measurements as it creates a δ13C deviation from the expected values. A sample of authentic sweet wine was analyzed by IC-co-IRMS using KOH gradient. Ratios of isotopic, ratios of organic acids and glycerol was found to be, in average, equal 1.01 ± 0.04 that is in accordance with our previous results.

  2. A vaccine strategy with multiple prostatic acid phosphatase-fused cytokines for prostate cancer treatment.

    Science.gov (United States)

    Fujio, Kei; Watanabe, Masami; Ueki, Hideo; Li, Shun-Ai; Kinoshita, Rie; Ochiai, Kazuhiko; Futami, Junichiro; Watanabe, Toyohiko; Nasu, Yasutomo; Kumon, Hiromi

    2015-04-01

    Immunotherapy is one of the attractive treatment strategies for advanced prostate cancer. The US Food and Drug Administration (FDA) previously approved the therapeutic vaccine, sipuleucel-T, which is composed of autologous antigen-presenting cells cultured with a fusion protein [prostatic acid phosphatase (PAP) and granulocyte-macrophage colony-stimulating factor (GMCSF)]. Although sipuleucel-T has been shown to prolong the median survival of patients for 4.1 months, more robust therapeutic effects may be expected by modifying the vaccination protocol. In the present study, we aimed to develop and validate a novel vaccination strategy using multiple PAP-fused cytokines for prostate cancer treatment. Using a super gene expression (SGE) system that we previously established to amplify the production of a recombinant protein, significant amounts of PAP-fused cytokines [human GMCSF, interleukin-2 (IL2), IL4, IL7 and mouse GMCSF and IL4] were obtained. We examined the activity of the fusion proteins in vitro to validate their cytokine functions. A significant upregulation of dendritic cell differentiation from monocytes was achieved by PAP-GMCSF when used with the other PAP-fused cytokines. The PAP-fused human IL2 significantly increased the proliferation of lymphocytes, as determined by flow cytometry. We also investigated the in vivo therapeutic effects of multiple PAP-fused cytokines in a mouse prostate cancer model bearing prostate-specific antigen (PSA)- and PAP-expressing tumors. The simultaneous intraperitoneal administration of PAP-GMCSF, -IL2, -IL4 and -IL7 significantly prevented tumor induction and inhibited the tumor growth in the PAP-expressing tumors, yet not in the PSA-expressing tumors. The in vivo therapeutic effects with the multiple PAP-fused cytokines were superior to the effects of PAP-GMCSF alone. We thus demonstrated the advantages of the combined use of multiple PAP-fused cytokines including PAP-GMCSF, and propose a promising prostatic

  3. Identification of genes required for secretion of the Francisella oxidative burst-inhibiting acid phosphatase AcpA

    Directory of Open Access Journals (Sweden)

    John S Gunn

    2016-04-01

    Full Text Available Francisella tularensis is a Tier 1 bioterror threat and the intracellular pathogen responsible for tularemia in humans and animals. Upon entry into the host, Francisella uses multiple mechanisms to evade killing. Our previous studies have shown that after entering its primary cellular host, the macrophage, Francisella immediately suppresses the oxidative burst by secreting a series of acid phosphatases including AcpA-B-C and HapA, thereby evading the innate immune response of the macrophage and enhancing survival and further infection. However, the mechanism of acid phosphatase secretion by Francisella is still unknown. In this study, we screened for genes required for AcpA secretion in Francisella. We initially demonstrated that the known secretion systems, the putative Francisella-pathogenicity island (FPI-encoded Type VI secretion system and the Type IV pili, do not secrete AcpA. Using random transposon mutagenesis in conjunction with ELISA, Western blotting and acid phosphatase enzymatic assays, a transposon library of 5450 mutants was screened for strains with a minimum 1.5-fold decrease in secreted (culture supernatant AcpA, but no defect in cytosolic AcpA. Three mutants with decreased supernatant AcpA were identified. The transposon insertion sites of these mutants were revealed by direct genomic sequencing or inverse-PCR and sequencing. One of these mutants has a severe defect in AcpA secretion (at least 85% decrease and is a predicted hypothetical inner membrane protein. Interestingly, this mutant also affected the secretion of the FPI-encoded protein, VgrG. Thus, this screen identified novel protein secretion factors involved in the subversion of host defenses.

  4. Acid phosphatase activity in the liver of Indian desert gerbil (Meriones hurrianae, Jerdon) exposed to internal β-irradiation

    International Nuclear Information System (INIS)

    Gupta, N.K.; Kumar, A.; Sharma, S.

    1985-01-01

    Alterations in acid phosphatase activity in the liver of Indian desert gerbil after administration of 45 Ca are reported. There is an increase in the enzyme activity during early periods after 45 Ca administration. The response of the enzyme to internal irradiation was dose dependent. The enzyme activity remained elevated for a longer period in animals given the higher dose. With starting repair, the activity declined and control values were nearly obtained on the 28 posttreatment day in gerbils having received 37 kBq/g body weight of 45 Ca. Animals with higher doses could not survive till this period

  5. Characterization and optimization of carboxylesterase-catalyzed esterification between capric acid and glycerol for the production of 1-monocaprin in reversed micellar system.

    Science.gov (United States)

    Park, Kyung Min; Kwon, Oh Taek; Ahn, Seon Min; Lee, JaeHwan; Chang, Pahn-Shick

    2010-02-28

    Calotropis procera R. Br. carboxylesterase (EC 3.1.1.1) solubilized in reversed micellar glycerol droplets containing a very small amount of water (less than 5ppm) and stabilized by a surfactant effectively catalyzed the esterification between glycerol and capric acid to produce 1-monocaprin. Reaction variables including surfactant types, organic solvent media, reaction time, G-value ([glycerol]/[capric acid]), R-value ([water]/[surfactant]), pH, temperature, and types of metal ion inhibitors on the carboxylesterase-catalyzed esterification were characterized and optimized to efficiently produce 1-monocaprin. Bis(2-ethylhexyl) sodium sulfosuccinate (AOT) and isooctane were the most effective surfactant and organic solvent medium, respectively, for 1-monocaprin formation in reversed micelles. The optimum G- and R-values were 3.0 and 0.05, respectively, and the optimum pH and temperature were determined to be 10.0 and 60 degrees C, respectively. K(m,app.) and V(max,app.) were calculated from a Hanes-Woolf plot, and the values were 9.64 mM and 2.45 microM/min mg protein, respectively. Among various metal ions, Cu(2+) and Fe(2+) severely inhibited carboxylesterase-catalyzed esterification activity (less than 6.0% of relative activity). Copyright 2009 Elsevier B.V. All rights reserved.

  6. Lysophosphatidic acid activates peroxisome proliferator activated receptor-γ in CHO cells that over-express glycerol 3-phosphate acyltransferase-1.

    Directory of Open Access Journals (Sweden)

    Cliona M Stapleton

    2011-04-01

    Full Text Available Lysophosphatidic acid (LPA is an agonist for peroxisome proliferator activated receptor-γ (PPARγ. Although glycerol-3-phosphate acyltransferase-1 (GPAT1 esterifies glycerol-3-phosphate to form LPA, an intermediate in the de novo synthesis of glycerolipids, it has been assumed that LPA synthesized by this route does not have a signaling role. The availability of Chinese Hamster Ovary (CHO cells that stably overexpress GPAT1, allowed us to analyze PPARγ activation in the presence of LPA produced as an intracellular intermediate. LPA levels in CHO-GPAT1 cells were 6-fold higher than in wild-type CHO cells, and the mRNA abundance of CD36, a PPARγ target, was 2-fold higher. Transactivation assays showed that PPARγ activity was higher in the cells that overexpressed GPAT1. PPARγ activity was enhanced further in CHO-GPAT1 cells treated with the PPARγ ligand troglitazone. Extracellular LPA, phosphatidic acid (PA or a membrane-permeable diacylglycerol had no effect, showing that PPARγ had been activated by LPA generated intracellularly. Transient transfection of a vector expressing 1-acylglycerol-3-phosphate acyltransferase-2, which converts endogenous LPA to PA, markedly reduced PPARγ activity, as did over-expressing diacylglycerol kinase, which converts DAG to PA, indicating that PA could be a potent inhibitor of PPARγ. These data suggest that LPA synthesized via the glycerol-3-phosphate pathway can activate PPARγ and that intermediates of de novo glycerolipid synthesis regulate gene expression.

  7. Relation of fatty acid composition in lead-exposed mallards to fat mobilization, lipid peroxidation and alkaline phosphatase activity

    Science.gov (United States)

    Mateo, R.; Beyer, W.N.; Spann, J.W.; Hoffman, D.J.

    2003-01-01

    The increase of n-6 polyunsaturated fatty acids (PUFA) in animal tissues has been proposed as a mechanism of lead (Pb) poisoning through lipid peroxidation or altered eicosanoids metabolism. We have studied fatty acid (FA) composition in liver and brain of mallards (Anas platyrhynchos) feeding for 3 weeks on diets containing combinations of low or high levels of vitamin E (20 or 200 UI/kg) and Pb (0 or 2 g/kg). Saturated FA, n-6 PUFA and total concentrations of FA were higher in livers of Pb-exposed mallards, but not in their brains. The percentage of n-6 PUFA in liver and brain was slightly higher in Pb-exposed mallards. The increase of n-6 PUFA in liver was associated with decreased triglycerides and increased cholesterol in plasma, thus could be in part attributed to feed refusal and fat mobilization. The hepatic ratios between adrenic acid (22:4 n-6) and arachidonic acid (20:4 n-6) or between adrenic acid and linoleic acid (18:2 n-6) were higher in Pb exposed birds, supporting the existing hypothesis of increased fatty acid elongation by Pb. Among the possible consequences of increased n-6 PUFA concentration in tissues, we found increased lipid peroxidation in liver without important histopathological changes, and decreased plasma alkaline phosphatase activity that may reflect altered bone metabolism in birds.

  8. The effect of water and salt stresses on the phosphorus content and acid phosphatase activity in oilseed rape

    Directory of Open Access Journals (Sweden)

    Stanisław Flasiński

    2014-01-01

    Full Text Available Oilseed rape plants responded to water and salt stresses (-0.5 MPa, PEG 6000 and NaCI by reduction of the fresh and dry weights of shoots and roots. When PEG was used, the ratio of dry weights of roots:shoots surpassed that of controls. The leaf protein content increased considerably. The phosphorus content decreased only in the roots, most significantly after three days of stress. Immediately after the stresses were induced, an increase in the acid phosphatase (AP activity was noted. Water and salt stresses caused four- and two-fold increases in AP activity in leaves, respectively. Changes in the enzyme activity were negligible in stems and roots. There are nine forms of AP in young leaves of oilseed rape. In the stressed plants, from No. 5 revealed lower activity and forms Nos 8 and 9, higher activities than in the control. The increase in AP activity was directly accompanied by the decrease in the water potential of the tissues. Oilseed rape is considerably less sensitive to salt stress than to water stress, which is manifested as the lower inhibition of plant growth and also by a smaller increase in acid phosphatase activity.

  9. Biosynthesis of acid phosphatase of baker's yeast . Characterization of a protoplast-bound fraction containing precursors of the exo-enzyme

    NARCIS (Netherlands)

    Boer, Pieter; Rijn, Herman J.M. van; Reinking, A.; Steyn-Parvé, Elizabeth P.

    1975-01-01

    1. 1.|Yest protoplasts, secreting acid phosphatase (orthophosphoric-monoester phosphohydrolase (acid optimum) EC 3.1.3.2) contain a small amount of firmly bound enzyme, even after lysis (Van Rijn, H.J.M.; Boer, P. and Steyn-Parvé, E.P. (1972) Biochim. Biophys. Acta 268, 431–441). The major part

  10. Green and sustainable succinic acid production from crude glycerol by engineered Yarrowia lipolytica via agricultural residue based in situ fibrous bed bioreactor.

    Science.gov (United States)

    Li, Chong; Gao, Shi; Yang, Xiaofeng; Lin, Carol Sze Ki

    2018-02-01

    In situ fibrous bed bioreactor (isFBB) for efficient succinic acid (SA) production by Yarrowia lipolytica was firstly developed in our former study. In this study, agricultural residues including wheat straw, corn stalk and sugarcane bagasse were investigated for the improvement of isFBB, and sugarcane bagasse was demonstrated to be the best immobilization material. With crude glycerol as the sole carbon source, optimization for isFBB batch fermentation was carried out. Under the optimal conditions of 20g sugarcane bagasse as immobilization material, 120gL -1 crude glycerol as carbon source and 4Lmin -1 of aeration rate, the resultant SA concentration was 53.6gL -1 with an average productivity of 1.45gL -1 h -1 and a SA yield of 0.45gg -1 . By feeding crude glycerol, SA titer up to 209.7gL -1 was obtained from fed batch fermentation, which was the highest value that ever reported. Copyright © 2017 Elsevier Ltd. All rights reserved.

  11. Phosphate activity of Poa pratensis seeds. III. Effect of fluoride, citrate, urea and other substances on the activity of acid phosphatase Ia/sub 2/ and Ia/sub 3/

    Energy Technology Data Exchange (ETDEWEB)

    Lorenc-Kubis, I.; Morawiecka, B.

    1978-01-01

    Effects of fluoride, citrate, urea and other substances on the activity of acid phosphatase a/sub 2/ and a/sub 3/ toward p-nitrophenylphosphate and phenylphosphate were investigated. Both enyzmes were inhibited by fluoride, p-chloro-mercuribenzoate and oxalate. Fluoride inhibited acid phosphatase a/sub 2/ non-competitively with p-nitrophenylphosphate, whereas acid phosphatase a/sub 3/ showed mixed type inhibition. Hydrolysis of phenylphosphate by both acid phosphatases was activated by citrate. Cytosine and uridine inhibited the activity of phosphatase a/sub 2/ toward p-nitrophenylphosphate and phenylphosphate, but no effect was observed in case of acid phosphatase a/sub 3/. After 30 min. incubation with 4 M urea both enzymes lost about 30% of their activity. 11 references, 5 figures, 1 table.

  12. Low Soil Phosphorus Availability Increases Acid Phosphatases Activities and Affects P Partitioning in Nodules, Seeds and Rhizosphere of Phaseolus vulgaris

    Directory of Open Access Journals (Sweden)

    Jean-Jacques Drevon

    2012-06-01

    Full Text Available The effect of phosphorus (P deficiency on phosphatases activities in N2-fixing legumes has been widely studied in hydroponic culture. However, the response of acid phosphatase (APase and phytase in rhizosphere, nodules and seeds of Phaseolus vulgaris to low soil’s P-availability is not yet fully understood. In this study, six genotypes of N2-fixing P. vulgaris were grown under contrasting soil P-availabilities; i.e., low  (4.3 mg P kg−1 and sufficient (16.7 mg P kg−1 in the Haouz region of Morocco. At flowering and maturity stages, plants were harvested and analyzed for their phosphatases activities, growth and P content. Results show that, low P decreased nodulation, growth, P uptake and N accumulation in all the genotypes, but to a greater extent in the sensitive recombinant inbreed line 147. In addition, while seed P content was slightly reduced under low P soil; a higher P was noticed in the Flamingo and Contender large seeded-beans (6.15 to 7.11 mg g−1. In these latter genotypes, high APase and phytase activities in seeds and nodules were associated with a significant decline in rhizosphere’s available P. APase activity was mainly stimulated in nodules, whereas phytase activity was highly induced in seeds (77%. In conclusion, the variations of APase and phytase activities in nodules and seeds depend on genotype and can greatly influence the internal utilization of P, which might result in low P soil tolerance in N2-fixing legumes.

  13. Cdk1 and okadaic acid-sensitive phosphatases control assembly of nuclear pore complexes in Drosophila embryos.

    Science.gov (United States)

    Onischenko, Evgeny A; Gubanova, Natalia V; Kiseleva, Elena V; Hallberg, Einar

    2005-11-01

    Disassembly and reassembly of the nuclear pore complexes (NPCs) is one of the major events during open mitosis in higher eukaryotes. However, how this process is controlled by the mitotic machinery is not clear. To investigate this we developed a novel in vivo model system based on syncytial Drosophila embryos. We microinjected different mitotic effectors into the embryonic cytoplasm and monitored the dynamics of disassembly/reassembly of NPCs in live embryos using fluorescently labeled wheat germ agglutinin (WGA) or in fixed embryos using electron microscopy and immunostaining techniques. We found that in live embryos Cdk1 activity was necessary and sufficient to induce disassembly of NPCs as well as their cytoplasmic mimics: annulate lamellae pore complexes (ALPCs). Cdk1 activity was also required for keeping NPCs and ALPCs disassembled during mitosis. In agreement recombinant Cdk1/cyclin B was able to induce phosphorylation and dissociation of nucleoporins from the NPCs in vitro. Conversely, reassembly of NPCs and ALPCs was dependent on the activity of protein phosphatases, sensitive to okadaic acid (OA). Our findings suggest a model where mitotic disassembly/reassembly of the NPCs is regulated by a dynamic equilibrium of Cdk1 and OA-sensitive phosphatase activities and provide evidence that mitotic phosphorylation mediates disassembly of the NPC.

  14. Studies on the oligosaccharide heterogeneity of the isoelectric forms of the lower molecular weight acid phosphatase of frog liver.

    Science.gov (United States)

    Kubicz, A; Szalewicz, A; Chrambach, A

    1991-01-01

    1. The lower molecular weight, heterogeneous acid phosphatase (AcPase) from the frog liver (Rana esculenta) containing AcPase I, II, III and IV was separated into enzymatically active components by isoelectric focusing in an immobilized pH gradient. 2. The blotted enzyme bands were characterized by their different binding patterns obtained with the lectins concanavalin A, wheat germ agglutinin (WGA), Lens culinaris hemagglutinin (LcH) and peanut agglutinin (PNA). 3. In situ neuraminidase treatment reduced the staining intensity of some WGA-bands and increased that of PNA-bands. 4. The finding that AcPases I, II, III and IV differ in their carbohydrate chain composition, together with previous results showing different bioactivities of AcPases III and IV, indicates a correlation between the glycosylation state of enzyme forms and their physiological action.

  15. Phosphate or phosphite addition promotes the proteolytic turnover of phosphate-starvation inducible tomato purple acid phosphatase isozymes.

    Science.gov (United States)

    Bozzo, Gale G; Singh, Vinay K; Plaxton, William C

    2004-08-27

    Within 48 h of the addition of 2.5 mM phosphate (HPO42-, Pi) or phosphite (H2PO3-, Phi) to 8-day-old Pi-starved (-Pi) tomato suspension cells: (i) secreted and intracellular purple acid phosphatase (PAP) activities decreased by about 12- and 6-fold, respectively and (ii) immunoreactive PAP polypeptides either disappeared (secreted PAPs) or were substantially reduced (intracellular PAP). The degradation of both secreted PAP isozymes was correlated with the de novo synthesis of two extracellular serine proteases having M(r)s of 137 and 121 kDa. In vitro proteolysis of purified secreted tomato PAP isozymes occurred following their 24 h incubation with culture filtrate from Pi-resupplied cells. The results indicate that Pi or Phi addition to -Pi tomato cells induces serine proteases that degrade Pi-starvation inducible extracellular proteins.

  16. A novel fluorescence biosensor for sensitivity detection of tyrosinase and acid phosphatase based on nitrogen-doped graphene quantum dots.

    Science.gov (United States)

    Qu, Zhengyi; Na, Weidan; Liu, Xiaotong; Liu, Hua; Su, Xingguang

    2018-01-02

    In this paper, we developed a sensitive fluorescence biosensor for tyrosinase (TYR) and acid phosphatase (ACP) activity detection based on nitrogen-doped graphene quantum dots (N-GQDs). Tyrosine could be catalyzed by TYR to generate dopaquinone, which could efficiently quench the fluorescence of N-GQDs, and the degree of fluorescence quenching of N-GQDs was proportional to the concentration of TYR. In the presence of ACP, l-Ascorbic acid-2-phosphate (AAP) was hydrolyzed to generate ascorbic acid (AA), and dopaquinone was reduced to l-dopa, resulting in the fluorescence recovery of the quenched fluorescence by dopaquinone. Thus, a novel fluorescence biosensor for the detection of TYR and ACP activity based on N-GQDs was constructed. Under the optimized experimental conditions, the fluorescence intensity was linearly correlated with the concentration of TYR and ACP in the range of 0.43-3.85 U mL -1 and 0.04-0.7 mU mL -1 with a detection limit of 0.15 U mL -1 and 0.014 mU mL -1 , respectively. The feasibility of the proposed biosensor in real samples assay was also studied and satisfactory results were obtained. Copyright © 2017 Elsevier B.V. All rights reserved.

  17. Inhibition of hydrolytic enzymes by gold compounds. I. beta-Glucuronidase and acid phosphatase by sodium tetrachloroaurate (III) and potassium tetrabromoaurate (III).

    Science.gov (United States)

    Lee, M T; Ahmed, T; Friedman, M E

    1989-01-01

    Purified bovine liver beta-glucuronidase (beta-D-glucuronide glucuronohydrolase, EC 3.2.1.32) and wheat germ acid phosphatase (orthophosphoric monoesterphosphohydrolase, EC 3.1.3.2) were inhibited with freshly dissolved and 24 h aquated tetrahaloaurate (III) compounds. Rate and equilibrium inhibition constants were measured. From this data two acid phosphatases species were observed. Equilibrium inhibition constants ranged from 1 to 12.5 microM for the various gold compounds toward both enzymes. The first order rate constants ranged between 0.005 and 0.04 min.-1 for most reactions with the exception of the fast reacting acid phosphatase which had values as high as 2.6 and 2.8 min.-1. It is observed that the beta-glucuronidase is rapidly inhibited during the equilibrium phase before the more slower reaction covalent bond formation takes place. The acid phosphatases form the covalent bonds more rapidly, especially the faster reacting species suggesting a unique difference in the active site geometry to that of the more slowly reacting species. The tightly bonded gold (III)-enzyme complex is probably the reason for its toxicity and non-anti-inflammatory use as a drug.

  18. High mature grain phytase activity in the Triticeae has evolved by duplication followed by neofunctionalization of the purple acid phosphatase phytase (PAPhy) gene

    DEFF Research Database (Denmark)

    Madsen, Claus Krogh; Dionisio, Giuseppe; Holme, Inger

    2013-01-01

    The phytase activity in food and feedstuffs is an important nutritional parameter. Members of the Triticeae tribe accumulate purple acid phosphatase phytases (PAPhy) during grain filling. This accumulation elevates mature grain phytase activities (MGPA) up to levels between ~650 FTU/kg for barley...

  19. Application of ascorbic acid 2-phosphate as a new voltammetric substrate for alkaline phosphatase determination in human serum

    Directory of Open Access Journals (Sweden)

    Wei Sun

    2005-12-01

    Full Text Available An electrochemical assay of the enzyme alkaline phosphatase (ALP using ascorbic acid 2-phosphate (AAP as a new voltammetric substrate has been described in this paper. In the alkaline buffer solution the ALP enzymatic hydrolysis product of AAP was ascorbic acid (AA, which was an electro-active substance and had a sensitive differential pulse voltammetric (DPV oxidative response on glassy carbon electrode (GCE at +380 mV (versus Ag/AgCl, so the activity of ALP could be monitored voltammetrically of the oxidative peak current of AA. The electrochemical behaviours of AA were carefully studied and the AA standard solution could be measured by DPV method in the linear range from 10.0 to 1000.0 μmol/L with the detection limit of 8.0 μmol/L. The optimal conditions for ALP enzymatic reaction and the voltammetric detection were optimized. Under the optimal conditions the calibration curve for ALP assay exhibited a linear range from 0.4 to 2000.0 U/L with a detection limit of 0.3 U/L. This proposed method was further applied to determine the ALP content in healthy human serum and the results were in good agreement with the traditional p-nitrophenyl phosphate spectrophotometric method. The kinetic constants of enzymatic reaction were also investigated with the apparent kinetic constant Km as 2.77 mmol/L and the maximum velocity Vmax as 0.33 mol/min.

  20. Voltage-dependent motion of the catalytic region of voltage-sensing phosphatase monitored by a fluorescent amino acid.

    Science.gov (United States)

    Sakata, Souhei; Jinno, Yuka; Kawanabe, Akira; Okamura, Yasushi

    2016-07-05

    The cytoplasmic region of voltage-sensing phosphatase (VSP) derives the voltage dependence of its catalytic activity from coupling to a voltage sensor homologous to that of voltage-gated ion channels. To assess the conformational changes in the cytoplasmic region upon activation of the voltage sensor, we genetically incorporated a fluorescent unnatural amino acid, 3-(6-acetylnaphthalen-2-ylamino)-2-aminopropanoic acid (Anap), into the catalytic region of Ciona intestinalis VSP (Ci-VSP). Measurements of Anap fluorescence under voltage clamp in Xenopus oocytes revealed that the catalytic region assumes distinct conformations dependent on the degree of voltage-sensor activation. FRET analysis showed that the catalytic region remains situated beneath the plasma membrane, irrespective of the voltage level. Moreover, Anap fluorescence from a membrane-facing loop in the C2 domain showed a pattern reflecting substrate turnover. These results indicate that the voltage sensor regulates Ci-VSP catalytic activity by causing conformational changes in the entire catalytic region, without changing their distance from the plasma membrane.

  1. Valproic acid induces hair regeneration in murine model and activates alkaline phosphatase activity in human dermal papilla cells.

    Directory of Open Access Journals (Sweden)

    Soung-Hoon Lee

    Full Text Available Alopecia is the common hair loss problem that can affect many people. However, current therapies for treatment of alopecia are limited by low efficacy and potentially undesirable side effects. We have identified a new function for valproic acid (VPA, a GSK3β inhibitor that activates the Wnt/β-catenin pathway, to promote hair re-growth in vitro and in vivo.Topical application of VPA to male C3H mice critically stimulated hair re-growth and induced terminally differentiated epidermal markers such as filaggrin and loricrin, and the dermal papilla marker alkaline phosphatase (ALP. VPA induced ALP in human dermal papilla cells by up-regulating the Wnt/β-catenin pathway, whereas minoxidil (MNX, a drug commonly used to treat alopecia, did not significantly affect the Wnt/β-catenin pathway. VPA analogs and other GSK3β inhibitors that activate the Wnt/β-catenin pathway such as 4-phenyl butyric acid, LiCl, and BeCl(2 also exhibited hair growth-promoting activities in vivo. Importantly, VPA, but not MNX, successfully stimulate hair growth in the wounds of C3H mice.Our findings indicate that small molecules that activate the Wnt/β-catenin pathway, such as VPA, can potentially be developed as drugs to stimulate hair re-growth.

  2. Effect of mercuric chloride on cellular morphology and acid phosphatase of tissue culture cells cultivated in suspension

    Energy Technology Data Exchange (ETDEWEB)

    Li, M F; Traxler, G S

    1974-01-01

    Cells exposed to HgCl/sub 2/ (0.5 mg/liter) increased dramatically in size and stained poorly with May-Grunwald Giemsa stain and exhibited incompleteness in cell division. When the cell DNA was stained by the Feulgen technique, many multinucleated cells were apparent in the cultures treated with HgCl/sub 2/. Additionally, enlargement and alteration of the nucleoli were evident. Electron-micrographs of the experimental cells revealed that microvilli, ribosomes, mitochondria, and endoplasmic reticula were abundant in the control cells, but in contrast a scarcity of these organelles was observed together with notable cytoplasmic vacuolation in the HgCl/sub 2/-treated cells. In addition the nucleolini of the treated cells were enlarged and had begun to fuse, producing a mulberry appearance. Electronmicroscopic detection of acid phosphatase activity in the cells indicated that the periplasmic enzyme activity was present in control cells, but not in the cells exposed to HgCl/sub 2/. The possible reaction of Hg/sup + +/ with deoxyribonucleic acid and disulfides is discussed with respect to the observed cytopathic effect and impaired enzyme activity. 10 references, 5 figures.

  3. Voltage-dependent motion of the catalytic region of voltage-sensing phosphatase monitored by a fluorescent amino acid

    Science.gov (United States)

    Sakata, Souhei; Jinno, Yuka; Kawanabe, Akira; Okamura, Yasushi

    2016-01-01

    The cytoplasmic region of voltage-sensing phosphatase (VSP) derives the voltage dependence of its catalytic activity from coupling to a voltage sensor homologous to that of voltage-gated ion channels. To assess the conformational changes in the cytoplasmic region upon activation of the voltage sensor, we genetically incorporated a fluorescent unnatural amino acid, 3-(6-acetylnaphthalen-2-ylamino)-2-aminopropanoic acid (Anap), into the catalytic region of Ciona intestinalis VSP (Ci-VSP). Measurements of Anap fluorescence under voltage clamp in Xenopus oocytes revealed that the catalytic region assumes distinct conformations dependent on the degree of voltage-sensor activation. FRET analysis showed that the catalytic region remains situated beneath the plasma membrane, irrespective of the voltage level. Moreover, Anap fluorescence from a membrane-facing loop in the C2 domain showed a pattern reflecting substrate turnover. These results indicate that the voltage sensor regulates Ci-VSP catalytic activity by causing conformational changes in the entire catalytic region, without changing their distance from the plasma membrane. PMID:27330112

  4. Mitigating crystallization of saturated FAMES (fatty acid methyl esters) in biodiesel: 4. The phase behavior of 1,3-dioleoyl-2-palmitoyl glycerol – Methyl stearate binary system

    International Nuclear Information System (INIS)

    Mohanan, Athira; Bouzidi, Laziz; Narine, Suresh S.

    2016-01-01

    The present study examines the phase behavior of a model binary system made of OPO (1,3-dioleoyl-2-palmitoyl glycerol); a TAG (triacylglycerol) highly effective in depressing onset of crystallization of biodiesel, and MeS (methyl stearate); a prevalent saturated FAMEs (fatty acid methyl esters) in biodiesel. The thermal behavior, crystal structure and microstructure of the OPO/MeS mixtures were investigated with DSC (differential scanning calorimetry), XRD (X-ray diffraction) and PLM (polarized light microscope). The OPO/MeS system presented a phase diagram with peritectic and eutectic transitions. A simple thermodynamic modeling of the liquidus line indicated a relatively complex mixing behavior, and highlighted the prevailing effect of the peritectic compound on solubility. Different types of microstructures that were more or less influenced by MeS, OPO or/and compound microstructures were observed in the mixtures. They are associated with the crystal phases and the thermal transitions. Furthermore, MeS, OPO and compound crystal structures (monoclinic, orthorhombic and triclinic, respectively) served as templates for the crystal forms of the coexisting phases. The singularities in the liquidus line are attributed to chain length mismatch between the palmitic acid and the FAME (fatty acid methyl ester). The phase diagram achieved for OPO/MeS system is complete and can help in designing additive formulations to improve the cold flow behavior of biodiesel. - Highlights: • 1,3-dioleoyl-2-palmitoyl glycerol/methyl stearate (OPO/MeS) studied in detail. • Phase diagram with thermal transitions, polymorphism, microstructure achieved. • Phase trajectory singularities attributed to length mismatch of linear chains. • Mechanism for disruption of crystallization of biodiesel evidenced and explained.

  5. Histochemical demonstration of activity of acid phosphatase and beta-glucuronidase in bovine incisor tooth germs

    DEFF Research Database (Denmark)

    Kirkeby, S; Salling, E; Moe, D

    1983-01-01

    . After initiation of enamel formation, a change in localization and intensity of the colored reaction product was observed in the ameloblasts. The activity appeared stronger and was restricted to a narrow zone just apical to the nucleus. It is proposed that the acid hydrolases in the tooth forming cells...

  6. The genetics of feto-placental development: A study of acid phosphatase locus 1 and adenosine deaminase polymorphisms in a consecutive series of newborn infants

    Directory of Open Access Journals (Sweden)

    Bergamaschi Antonio

    2008-09-01

    Full Text Available Abstract Background Acid phosphatase locus 1 and adenosine deaminase locus 1 polymorphisms show cooperative effects on glucose metabolism and immunological functions. The recent observation of cooperation between the two systems on susceptibility to repeated spontaneous miscarriage prompted us to search for possible interactional effects between these genes and the correlation between birth weight and placental weight. Deviation from a balanced development of the feto-placental unit has been found to be associated with perinatal morbidity and mortality and with cardiovascular diseases in adulthood. Methods We examined 400 consecutive newborns from the Caucasian population of Rome. Birth weight, placental weight, and gestational length were registered. Acid phosphatase locus 1 and adenosine deaminase locus 1 phenotypes were determined by starch gel electrophoresis and correlation analysis was performed by SPSS programs. Informed verbal consent to participate in the study was obtained from the mothers. Results Highly significant differences in birth weight-placental weight correlations were observed among acid phosphatase locus 1 phenotypes (p = 0.005. The correlation between birth weight and placental weight was markedly elevated in subjects carrying acid phosphatase locus 1 phenotypes with medium-low F isoform concentration (A, CA and CB phenotypes compared to those carrying acid phosphatase locus 1 phenotypes with medium-high F isoform concentration (BA and B phenotypes (p = 0.002. Environmental and developmental variables were found to exert a significant effect on birth weight-placental weight correlation in subjects with medium-high F isoform concentrations, but only a marginal effect was observed in those with medium-low F isoform concentrations. The correlation between birth weight and placental weight is higher among carriers of the adenosine deaminase locus 1 allele*2, which is associated with low activity, than in homozygous adenosine

  7. Microbial recycling of glycerol to biodiesel.

    Science.gov (United States)

    Yang, Liu; Zhu, Zhi; Wang, Weihua; Lu, Xuefeng

    2013-12-01

    The sustainable supply of lipids is the bottleneck for current biodiesel production. Here microbial recycling of glycerol, byproduct of biodiesel production to biodiesel in engineered Escherichia coli strains was reported. The KC3 strain with capability of producing fatty acid ethyl esters (FAEEs) from glucose was used as a starting strain to optimize fermentation conditions when using glycerol as sole carbon source. The YL15 strain overexpressing double copies of atfA gene displayed 1.7-fold increase of FAEE productivity compared to the KC3 strain. The titer of FAEE in YL15 strain reached to 813 mg L(-1) in minimum medium using glycerol as sole carbon source under optimized fermentation conditions. The titer of glycerol-based FAEE production can be significantly increased by both genetic modifications and fermentation optimization. Microbial recycling of glycerol to biodiesel expands carbon sources for biodiesel production. Copyright © 2013 Elsevier Ltd. All rights reserved.

  8. A spheroid-based 3-D culture model for pancreatic cancer drug testing, using the acid phosphatase assay

    International Nuclear Information System (INIS)

    Wen, Z.; Liao, Q.; Hu, Y.; You, L.; Zhou, L.; Zhao, Y.

    2013-01-01

    Current therapy for pancreatic cancer is multimodal, involving surgery and chemotherapy. However, development of pancreatic cancer therapies requires a thorough evaluation of drug efficacy in vitro before animal testing and subsequent clinical trials. Compared to two-dimensional culture of cell monolayer, three-dimensional (3-D) models more closely mimic native tissues, since the tumor microenvironment established in 3-D models often plays a significant role in cancer progression and cellular responses to the drugs. Accumulating evidence has highlighted the benefits of 3-D in vitro models of various cancers. In the present study, we have developed a spheroid-based, 3-D culture of pancreatic cancer cell lines MIAPaCa-2 and PANC-1 for pancreatic drug testing, using the acid phosphatase assay. Drug efficacy testing showed that spheroids had much higher drug resistance than monolayers. This model, which is characteristically reproducible and easy and offers rapid handling, is the preferred choice for filling the gap between monolayer cell cultures and in vivo models in the process of drug development and testing for pancreatic cancer

  9. A spheroid-based 3-D culture model for pancreatic cancer drug testing, using the acid phosphatase assay

    Directory of Open Access Journals (Sweden)

    Z. Wen

    2013-08-01

    Full Text Available Current therapy for pancreatic cancer is multimodal, involving surgery and chemotherapy. However, development of pancreatic cancer therapies requires a thorough evaluation of drug efficacy in vitro before animal testing and subsequent clinical trials. Compared to two-dimensional culture of cell monolayer, three-dimensional (3-D models more closely mimic native tissues, since the tumor microenvironment established in 3-D models often plays a significant role in cancer progression and cellular responses to the drugs. Accumulating evidence has highlighted the benefits of 3-D in vitro models of various cancers. In the present study, we have developed a spheroid-based, 3-D culture of pancreatic cancer cell lines MIAPaCa-2 and PANC-1 for pancreatic drug testing, using the acid phosphatase assay. Drug efficacy testing showed that spheroids had much higher drug resistance than monolayers. This model, which is characteristically reproducible and easy and offers rapid handling, is the preferred choice for filling the gap between monolayer cell cultures and in vivo models in the process of drug development and testing for pancreatic cancer.

  10. An Additional Method for Analyzing the Reversible Inhibition of an 
Enzyme Using Acid Phosphatase as a Model.

    Science.gov (United States)

    Baumhardt, Jordan M; Dorsey, Benjamin M; McLauchlan, Craig C; Jones, Marjorie A

    2015-08-01

    Using wheat germ acid phosphatase and sodium orthovanadate as a competitive inhibitor, a novel method for analyzing reversible inhibition was carried out. Our alternative approach involves plotting the initial velocity at which product is formed as a function of the ratio of substrate concentration to inhibitor concentration at a constant enzyme concentration and constant assay conditions. The concept of initial concentrations driving equilibrium leads to the chosen axes. Three apparent constants can be derived from this plot: K max , K min , and K inflect . K max and K min represent the substrate to inhibitor concentration ratio for complete inhibition and minimal inhibition, respectively. K inflect represents the substrate to inhibitor concentration ratio at which the enzyme-substrate complex is equal to the inhibitory complex. These constants can be interpolated from the graph or calculated using the first and second derivative of the plot. We conclude that a steeper slope and a shift of the line to the right (increased x-axis values) would indicate a better inhibitor. Since initial velocity is not a linear function of the substrate/inhibitor ratio, this means that inhibition changes more quickly with the change in the [S]/ [I] ratio. When preincubating the enzyme with substrate before the addition of inhibitor, preincubating the enzyme with inhibitor before the addition of substrate or with concurrent addition of both substrate and inhibitor, modest changes in the slopes and y-intercepts were obtained. This plot appears useful for known competitive and non-competitive inhibitors and may have general applicability.

  11. The human tartrate-resistant acid phosphatase (TRAP): involvement of the hemin responsive elements (HRE) in transcriptional regulation.

    Science.gov (United States)

    Fleckenstein, E C; Dirks, W G; Drexler, H G

    2000-02-01

    The biochemical properties and protein structure of the tartrate-resistant acid phosphatase (TRAP), an iron-containing lysosomal glycoprotein in cells of the mononuclear phagocyte system, are well known. In contrast, little is known about the physiology and genic structure of this unique enzyme. In some diseases, like hairy cell leukemia, Gaucher's disease and osteoclastoma, cytochemically detected TRAP expression is used as a disease-associated marker. In order to begin to elucidate the regulation of this gene we generated different deletion constructs of the TRAP 5'-flanking region, placed them upstream of the luciferase reporter gene and assayed them for their ability to direct luciferase expression in human 293 cells. Treatment of these cells with the iron-modulating reagents transferrin and hemin causes opposite effects on the TRAP promoter activity. Two regulatory GAGGC tandem repeat sequences (the hemin responsive elements, HRE) within the 5'-flanking region of the human TRAP gene were identified. Studies with specific HRE-deletion constructs of the human TRAP 5'-flanking region upstream of the luciferase reporter gene document the functionality of these HRE-sequences which are apparently responsible for mediating transcriptional inhibition upon exposure to hemin. In addition to the previously published functional characterization of the murine TRAP HRE motifs, these results provide the first description of a new iron/hemin-responsive transcriptional regulation in the human TRAP gene.

  12. Root-exuded acid phosphatase and 32Pi-uptake kinetics of wheat, rye and triticale under phosphorus starvation

    International Nuclear Information System (INIS)

    Pandey, Renu

    2006-01-01

    A nutrient culture experiment was conducted with cereal species viz., wheat (Triticum aestivum L.) cv. PBW-343), rye (Secale cereale L cv. R-308) and triticale (Triticale octoploide L. cv. DT-46), a hybrid of wheat and rye, to examine the genetic variation in root-exuded acid phosphatase (ACPase) activity and kinetics of 32 Pi-uptake under P deficient condition. The ACPase activity was assayed in the extract (intra-) and on surface (extra-cellular) or root, using p-nitrophenyl phosphate as substrate. Significantly higher ACPase activity was observed in wheat followed by rye and triticale both on the root surface and in root extract. In general, root surface ACPase activity was 2.2-fold higher than that in root extract. A strong correlation (r 2 = 0.87**) between extra and intra-cellular ACPase activity was observed. In terms of kinetic parameters, it was observed that 32 Pi uptake and I max values were significantly higher in rye while C min and K m were lowest compared to wheat and triticale. The dry weights of shoot, root and total plant were significantly higher in rye compared to wheat and triticale. Rye also had higher amount of total plant P content The superiority of rye over wheat and triticale in P uptake was observed mainly due to efficient Pi-uptake system, which needs further studies to ascertain the enhancement of Pi-induced high-affinity P transporter in these cereals. (author)

  13. Cold exposure enhances fat utilization but not non-esterified fatty acids, glycerol or catecholamines availability during submaximal walking and running

    Directory of Open Access Journals (Sweden)

    Dominique Daniel Gagnon

    2013-05-01

    Full Text Available Cold exposure modulates the use of carbohydrates and fat during exercise. This phenomenon has mostly been observed in controlled cycling studies, but not during walking and running when core temperature and oxygen consumption are controlled, as both may alter energy metabolism. This study aimed at examining energy substrate availability and utilization during walking and running in the cold when core temperature and oxygen consumption are maintained. Ten lightly clothed male subjects walked or ran for 60-min, at 50% and 70% of maximal oxygen consumption, respectively, in a climatic chamber set at 0°C or 22°C. Thermal, cardiovascular, and oxidative responses were measured every 15-min during exercise. Blood samples for serum non-esterified fatty acids, glycerol, glucose, beta-hydroxybutyrate, plasma catecholamines, and serum lipids were collected immediately prior, and at 30- and 60-min of exercise. Skin temperature strongly decreased while core temperature did not change during cold trials. Heart rate was also lower in cold trials. A rise in fat utilization in the cold was seen through lower respiratory quotient (-0.03 ± 0.02, greater fat oxidation (+0.14 ± 0.13 g•min-1 and contribution of fat to total energy expenditure (+1.62 ± 1.99 kcal•min-1. No differences from cold exposure were observed in blood parameters. During submaximal walking and running, a greater reliance on derived fat sources occurs in the cold, despite the absence of concurrent alterations in non-esterified fatty acids, glycerol, or catecholamine concentrations. This disparity may suggest a greater reliance on intra-muscular energy sources such as triglycerides during both walking and running.

  14. Synthesis and applications of 13C glycerol

    International Nuclear Information System (INIS)

    Stocking, E.; Khalsa, O.; Martinez, R.A.; Silks, L.A. III

    1994-01-01

    Due in part to the use of labeled glycerol for the 13 C enrichment of biomolecules, we are currently developing new synthetic routes to various isotopomers of glycerol. Judging from our experience, traditional methods of glycerol synthesis are not easily adapted for isotopic enrichment and/or have poor overall yields (12 to 15%). Furthermore, the use of glycerol for enrichment can be prohibitively expensive and its availability is limited by the level of demand. We are presently developing a short de novo synthesis of glycerol from carbon dioxide (∼53% overall yield for four steps) and are examining the feasibility of synthesizing site-specific 13 C-labeled glycerol and dihydroxyacetone (DHA) from labeled methanol and carbon dioxide. One application of 13 C glycerol we have examined is enzymatic conversion of glycerol to glyceraldehyde-3-monophosphate or dihydroxyacetone monophosphate (DHAP) with yields ranging from 25 to 50% (as determined by NMR spectroscopy). We are also pursuing the chemical conversion of 13 C-labeled DHA to DHAP. We are especially interested in 13 C-labeled DHAP because we are investigating its use as a chemo-enzymatic precursor for both labeled 2-deoxyribose and 2-deoxyribonucleic acids

  15. Characterization of N-type glycosylation sites and glycan structures of Purple Acid Phosphatase Phytases from Wheat (Triticum aestivum L.)

    DEFF Research Database (Denmark)

    Dionisio, Giuseppe; Brinch-Pedersen, Henrik; Welinder, Karen Gjesing

    2011-01-01

    Wheat (Triticum aestivum L.) possesses preformed phytase activity in the grain that is essential to make phosphate available to cell metabolism and in food and feed (Brejnholt S. et al., 2011). Cereals contain the purple acid phosphatase type of phytases, PAPhy (Dionisio G. et al., 2011a). Mature......., Skov L. Brinch-Pedersen H. (2011). The degradation of phytate by microbial and wheat phytases is dependent on the phytate matrix and the phytase origin. J. Sci. Food Agri. (in press). Dionisio G., Madsen C.K., Holm P.B., Welinder K.G., Jørgensen M., Stoger E., Arcalis E., Brinch-Pedersen H. (2011a......) Cloning and Characterization of Purple Acid Phosphatase Phytases from Wheat (Triticum aestivum L.), Barley (Hordeum vulgare L.), Maize (Zea maize L.) and Rice (Oryza sativa L.). Plant Physiol. [in press, Jan 10, Epub ahead of print] Dionisio G., Brinch-Pedersen H., Welinder K.G., Jørgensen M. (2011b...

  16. Dimethyl carbonate-mediated lipid extraction and lipase-catalyzed in situ transesterification for simultaneous preparation of fatty acid methyl esters and glycerol carbonate from Chlorella sp. KR-1 biomass.

    Science.gov (United States)

    Jo, Yoon Ju; Lee, Ok Kyung; Lee, Eun Yeol

    2014-04-01

    Fatty acid methyl esters (FAMEs) and glycerol carbonate were simultaneously prepared from Chlorella sp. KR-1 containing 40.9% (w/w) lipid using a reactive extraction method with dimethyl carbonate (DMC). DMC was used as lipid extraction agent, acyl acceptor for transesterification of the extracted triglycerides, substrate for glycerol carbonate synthesis from glycerol, and reaction medium for the solvent-free reaction system. For 1g of biomass, 367.31 mg of FAMEs and 16.73 mg of glycerol carbonate were obtained under the optimized conditions: DMC to biomass ratio of 10:1 (v/w), water content of 0.5% (v/v), and Novozyme 435 to biomass ratio of 20% (w/w) at 70°C for 24h. The amount of residual glycerol was only in the range of 1-2.5mg. Compared to conventional method, the cost of FAME production with the proposed technique could be reduced by combining lipid extraction with transesterification and omitting the extraction solvent recovery process. Copyright © 2014 Elsevier Ltd. All rights reserved.

  17. Detection of Ca2+-dependent acid phosphatase activity identifies neuronal integrity in damaged rat central nervous system after application of bacterial melanin

    Directory of Open Access Journals (Sweden)

    Tigran R Petrosyan

    2016-01-01

    Full Text Available The study aims to confirm the neuroregenerative effects of bacterial melanin (BM on central nervous system injury using a special staining method based on the detection of Ca2+-dependent acid phosphatase activity. Twenty-four rats were randomly assigned to undergo either unilateral destruction of sensorimotor cortex (group I; n = 12 or unilateral rubrospinal tract transection at the cervical level (C3–4 (group II; n = 12. In each group, six rats were randomly selected after surgery to undergo intramuscular injection of BM solution (BM subgroup and the remaining six rats were intramuscularly injected with saline (saline subgroup. Neurological testing confirmed that BM accelerated the recovery of motor function in rats from both BM and saline subgroups. Two months after surgery, Ca2+-dependent acid phosphatase activity detection in combination with Chilingarian's calcium adenoside triphosphate method revealed that BM stimulated the sprouting of fibers and dilated the capillaries in the brain and spinal cord. These results suggest that BM can promote the recovery of motor function of rats with central nervous system injury; and detection of Ca2+-dependent acid phosphatase activity is a fast and easy method used to study the regeneration-promoting effects of BM on the injured central nervous system.

  18. Formation of 3-MCPD Fatty Acid Esters from Monostearoyl Glycerol and the Thermal Stability of 3-MCPD Monoesters.

    Science.gov (United States)

    Zhao, Yue; Zhang, Yaqiong; Zhang, Zhongfei; Liu, Jie; Wang, Yi-Lin; Gao, Boyan; Niu, Yuge; Sun, Xiangjun; Yu, Liangli

    2016-11-23

    Formation of 3-monochloropropanediol (3-MCPD) esters from monostearoyl glycerol (MSG) was investigated under high temperature and low moisture conditions. Different organic and inorganic chlorides, including lindane, KCl, CaCl 2 , NaCl, MgCl 2 , AlCl 3 , CuCl 2 , MnCl 2 , SnCl 2 , ZnCl 2 , and FeCl 3 , were evaluated for their potential to react with MSG to form 3-MCPD and glycidyl esters at 120 and 240 °C using a UPLC-Q-TOF MS analysis. The results indicated that different chlorine compounds differed in their capacity to react with MSG and formed different products including 3-MCPD mono- and diesters, distearoylglycerol, and glycidyl esters. According to electron spin resonance (ESR) and Fourier transform infrared (FT-IR) spectroscopies, free radical mediated formation mechanisms involving either five-membered or six-membered cyclic acyloxonium free radicals (CAFR) from monoacylglycerol (MAG) were proposed. Tandem quadrupole-time-of-flight (Q-TOF) MS and MS/MS analyses confirmed the free radical mechanisms. In addition, the results from the present study showed that 3-MCPD monoester could be degraded upon thermal treatment and suggested a possible catalytic role of Fe 3+ under the experimental conditions.

  19. Production of polyhydroxybutyrate and alginate from glycerol by Azotobacter vinelandii under nitrogen-free conditions.

    Science.gov (United States)

    Yoneyama, Fuminori; Yamamoto, Mayumi; Hashimoto, Wataru; Murata, Kousaku

    2015-01-01

    Glycerol is an interesting feedstock for biomaterials such as biofuels and bioplastics because of its abundance as a by-product during biodiesel production. Here we demonstrate glycerol metabolism in the nitrogen-fixing species Azotobacter vinelandii through metabolomics and nitrogen-free bacterial production of biopolymers, such as poly-d-3-hydroxybutyrate (PHB) and alginate, from glycerol. Glycerol-3-phosphate was accumulated in A. vinelandii cells grown on glycerol to the exponential phase, and its level drastically decreased in the cells grown to the stationary growth phase. A. vinelandii also overexpressed the glycerol-3-phosphate dehydrogenase gene when it was grown on glycerol. These results indicate that glycerol was first converted to glycerol-3-phosphate by glycerol kinase. Other molecules with industrial interests, such as lactic acid and amino acids including γ-aminobutyric acid, have also been accumulated in the bacterial cells grown on glycerol. Transmission electron microscopy revealed that glycerol-grown A. vinelandii stored PHB within the cells. The PHB production level reached 33% per dry cell weight in nitrogen-free glycerol medium. When grown on glycerol, alginate-overproducing mutants generated through chemical mutagenesis produced 2-fold the amount of alginate from glycerol than the parental wild-type strain. To the best of our knowledge, this is the first report on bacterial production of biopolymers from glycerol without addition of any nitrogen source.

  20. Pathogen exploitation of an abscisic acid- and jasmonate-inducible MAPK phosphatase and its interception by Arabidopsis immunity.

    Science.gov (United States)

    Mine, Akira; Berens, Matthias L; Nobori, Tatsuya; Anver, Shajahan; Fukumoto, Kaori; Winkelmüller, Thomas M; Takeda, Atsushi; Becker, Dieter; Tsuda, Kenichi

    2017-07-11

    Phytopathogens promote virulence by, for example, exploiting signaling pathways mediated by phytohormones such as abscisic acid (ABA) and jasmonate (JA). Some plants can counteract pathogen virulence by invoking a potent form of immunity called effector-triggered immunity (ETI). Here, we report that ABA and JA mediate inactivation of the immune-associated MAP kinases (MAPKs), MPK3 and MPK6, in Arabidopsis thaliana ABA induced expression of genes encoding the protein phosphatases 2C (PP2Cs), HAI1 , HAI2 , and HAI3 through ABF/AREB transcription factors. These three HAI PP2Cs interacted with MPK3 and MPK6 and were required for ABA-mediated MPK3/MPK6 inactivation and immune suppression. The bacterial pathogen Pseudomonas syringae pv. tomato ( Pto ) DC3000 activates ABA signaling and produces a JA-mimicking phytotoxin, coronatine (COR), that promotes virulence. We found that Pto DC3000 induces HAI1 through COR-mediated activation of MYC2, a master transcription factor in JA signaling. HAI1 dephosphorylated MPK3 and MPK6 in vitro and was necessary for COR-mediated suppression of MPK3/MPK6 activation and immunity. Intriguingly, upon ETI activation, A. thaliana plants overcame the HAI1-dependent virulence of COR by blocking JA signaling. Finally, we showed conservation of induction of HAI PP2Cs by ABA and JA in other Brassicaceae species. Taken together, these results suggest that ABA and JA signaling pathways, which are hijacked by the bacterial pathogen, converge on the HAI PP2Cs that suppress activation of the immune-associated MAPKs. Also, our data unveil interception of JA-signaling activation as a host counterstrategy against the bacterial suppression of MAPKs during ETI.

  1. Purkinje Cell Compartmentation in the Cerebellum of the Lysosomal Acid Phosphatase 2 Mutant Mouse (Nax - Naked-Ataxia Mutant Mouse)

    Science.gov (United States)

    Bailey, Karen; Rahimi Balaei, Maryam; Mannan, Ashraf; Del Bigio, Marc R.; Marzban, Hassan

    2014-01-01

    The Acp2 gene encodes the beta subunit of lysosomal acid phosphatase, which is an isoenzyme that hydrolyzes orthophosphoric monoesters. In mice, a spontaneous mutation in Acp2 results in severe cerebellar defects. These include a reduced size, abnormal lobulation, and an apparent anterior cerebellar disorder with an absent or hypoplastic vermis. Based on differential gene expression in the cerebellum, the mouse cerebellar cortex can normally be compartmentalized anteroposteriorly into four transverse zones and mediolaterally into parasagittal stripes. In this study, immunohistochemistry was performed using various Purkinje cell compartmentation markers to examine their expression patterns in the Acp2 mutant. Despite the abnormal lobulation and anterior cerebellar defects, zebrin II and PLCβ4 showed similar expression patterns in the nax mutant and wild type cerebellum. However, fewer stripes were found in the anterior zone of the nax mutant, which could be due to a lack of Purkinje cells or altered expression of the stripe markers. HSP25 expression was uniform in the central zone of the nax mutant cerebellum at around postnatal day (P) 18–19, suggesting that HSP25 immunonegative Purkinje cells are absent or delayed in stripe pattern expression compared to the wild type. HSP25 expression became heterogeneous around P22–23, with twice the number of parasagittal stripes in the nax mutant compared to the wild type. Aside from reduced size and cortical disorganization, both the posterior zone and nodular zone in the nax mutant appeared less abnormal than the rest of the cerebellum. From these results, it is evident that the anterior zone of the nax mutant cerebellum is the most severely affected, and this extends beyond the primary fissure into the rostral central zone/vermis. This suggests that ACP2 has critical roles in the development of the anterior cerebellum and it may regulate anterior and central zone compartmentation. PMID:24722417

  2. Increase in tartrate-resistant acid phosphatase of bone at the early stage of ascorbic acid deficiency in the ascorbate-requiring Osteogenic Disorder Shionogi (ODS) rat.

    Science.gov (United States)

    Goto, A; Tsukamoto, I

    2003-08-01

    The effect of ascorbic acid deficiency on bone metabolism was evaluated using the ascorbate-requiring Osteogenic Disorder Shionogi (ODS) rat model. Ascorbic acid (Asc)-deficient rats gained body weight in a manner similar to Asc-supplemented rats (control) during 3 weeks, but began to lose weight during the 4th week of Asc deficiency. The tartrate-resistant acid phosphatase (TRAP) activity in serum increased to about 2-fold the control value in the rats fed the Asc-free diet for 2, 3, and 4 weeks (AscD2, AscD3, and AscD4), while a decrease in the alkaline phosphatase (ALP) activity was observed only in AscD4 rats. The serum pyridinoline cross-linked carboxyterminal telopeptide of type I collagen (ICTP) level significantly increased to 1.3-, 1.4-, and 1.9-fold of that in the controls in AscD2, D3, and D4, respectively. The ALP activity in the distal femur was unchanged in AscD1, D2, and D3, but decreased to 50% of the control level in AscD4 rats. The TRAP activity in the distal femur increased to about 2-fold of that in the controls in the AscD2 and D3 and decreased to the control level in the AscD4 rats. The amount of hydroxyproline in the distal femur significantly decreased to about 80%, 70%, and 60% of the control in AscD2, D3, and D4 rats, respectively. These decreases were associated with a similar reduction in the calcium content of the distal femur. Histochemical analysis of the distal femur showed an increase in TRAP-positive cells in AscD2 and AscD3 rats and a decrease in the trabecular bone in AscD2, D3, and D4 rats. These results suggested that a deficiency of Asc stimulated bone resorption at an early stage, followed by a decrease in bone formation in mature ODS rats which already had a well-developed collagen matrix and fully differentiated osteoblasts.

  3. Chemical equilibrium of glycerol carbonate synthesis from glycerol

    International Nuclear Information System (INIS)

    Li Jiabo; Wang Tao

    2011-01-01

    Research highlights: → Transesterification of glycerol with cyclic carbonates or alkyl carbonates is thermodynamically favourable for the preparation of glycerol carbonate from glycerol. → The reaction of glycerol and carbon dioxide is thermodynamically limited. → High temperature and low pressure is favourable to the reaction of glycerol and urea. → Increasing temperature can increase the chemical equilibrium constant for the reaction of glycerol and dimethyl carbonate. → For the reaction of glycerol and ethylene carbonate, increasing temperature can decrease the chemical equilibrium constant. - Abstract: In this paper, the chemical equilibrium for the glycerol carbonate preparation from glycerol was investigated. The chemical equilibrium constants were calculated for the reactions to produce glycerol carbonate from glycerol. The theoretical calculation was compared with the experimental results for the transesterification of glycerol with dimethyl carbonate. Transesterification of glycerol with cyclic carbonates or alkyl carbonates is thermodynamically favourable for producing glycerol carbonate from glycerol according to the equilibrium constant. Increasing temperature can increase the chemical equilibrium constant for the reaction of glycerol with dimethyl carbonate. For the reaction of glycerol with ethylene carbonate, increasing temperature can decrease the chemical equilibrium constant. The reaction of glycerol with carbon dioxide is thermodynamically limited. High temperature and low pressure are favourable to the reaction of glycerol and urea.

  4. Elimination of Glycerol Production in Anaerobic Cultures of a Saccharomyces cerevisiae Strain Engineered To Use Acetic Acid as an Electron Acceptor

    NARCIS (Netherlands)

    Medina, V.G.; Almering, M.J.H.; Van Maris, A.J.A.; Pronk, J.T.

    2009-01-01

    In anaerobic cultures of wild-type Saccharomyces cerevisiae, glycerol production is essential to reoxidize NADH produced in biosynthetic processes. Consequently, glycerol is a major by-product during anaerobic production of ethanol by S. cerevisiae, the single largest fermentation process in

  5. EFEITO DE FATORES AMBIENTAIS DA FOSFATASE ÁCIDA NO FEIJOEIRO EFFECTS OF ENVIRONMENTAL FACTORS ON THE ACTIVITY OF ACID PHOSPHATASE IN COMMON BEAN

    Directory of Open Access Journals (Sweden)

    José Renato de Freitas

    2007-09-01

    Full Text Available

    Plantas com 15 dias após a germinação foram colhidas em experimentos de campo com a finalidade de conhecer o pH, temperatura e tempo necessários para melhor expressar a atividade da fosfatase ácida em três variedades do feijoeiro (Phaseolus vulgaris L., Carioca, EMP-84 e CNF-l0, na presença e na ausência de fósforo. Os maiores valores de atividade da fosfatase ácida foram observadas quando as plantas foram colocadas em solução em pH 5,5 durante 120 minutos à temperatura de 30°C. A utilização de substâncias tamponantes como PNPP + Triton X-100 expressaram melhor a atividade da fosfatase ácida. As condições de vácuo constituíram um fator positivo para a atividade da fosfatase ácida. As plantas desenvolvidas sob estresse hídrico apresentaram menor atividade da fosfatase ácida. A relação folha-raiz da atividade da fosfatase ácida atingiu 5,72 para a variedade Carioca, 4,91 para a variedade EMP-84 e 4,36 para a variedade CNF-10.

    PALAVRAS-CHAVE: pH; temperatura; solução tamponada; tempo de reação; Phaseolus vulgaris.

    Plants with 15 days after the germination were picked in field experiments with the purpose of knowing the best pH, temperature and the necessary time to express the activity of the phosphatase acid in three bean varieties (Phaseolus vulgaris L., Carioca, EMP-84 and CNF-10, in the presence and in the phosphorus absence. The largest values of activity of the phosphatase acid were observed when the plants were tested in pH 5.5 solution during 120 minutes at the temperature of 30°C. The use of buffer substances as PNPP + Triton X-100 expressed better the activity of the phosphatase acid. The vacuum condition constituted a positive factor to express the activity of the phosphatase acid. The plants

  6. Synthesis and applications of 13C glycerol

    International Nuclear Information System (INIS)

    Stocking, E.; Khalsa, O.; Martinez, R.; Silks, L.A. III

    1994-01-01

    The authors are currently developing new synthetic routes to the various isotopomers of glycerol. Labeled glycerol is useful for 13 C enrichment of biomolecules. However, traditional methods of glycerol synthesis are not easily adapted for isotopic enrichment or have poor overall yields (12-15%). In addition, the use of glycerol for enrichment can be prohibitively expensive and its availability depends on the level of demand. The authors have developed a short de novo synthesis of [U- 13 C]glycerol from carbon dioxide (∼53% overall yield for four steps) and are currently examining the feasibility of synthesizing site-specific 13 C labeled glycerol and dihydroxyacetone (DHA) from methanol and carbon dioxide. The authors have examined the enzymatic conversion of [U- 13 C]glycerol to glyceraldehyde-3-monophosphate or dihydroxyacetone monophosphate (DHAP) with yields ranging from 25-50% (as determined by NMR spectroscopy). The authors are also pursuing the chemical conversion of 13 C labeled DHA to DHAP and the results are presented. Labeled DHAP is a possible enzymatic precursor for both labeled 2-deoxyribose and 2-deoxyribonucleic acids

  7. Reduction of the degradation activity of umami-enhancing purinic ribonucleotide supplement in miso by the targeted suppression of acid phosphatases in the Aspergillus oryzae starter culture.

    Science.gov (United States)

    Marui, Junichiro; Tada, Sawaki; Fukuoka, Mari; Wagu, Yutaka; Shiraishi, Yohei; Kitamoto, Noriyuki; Sugimoto, Tatsuya; Hattori, Ryota; Suzuki, Satoshi; Kusumoto, Ken-Ichi

    2013-09-02

    Miso (fermented soybean paste) is a traditional Japanese fermented food, and is now used worldwide. The solid-state culture of filamentous fungus, Aspergillus oryzae, grown on rice is known as rice-koji, and is important as a starter for miso fermentation because of its prominent hydrolytic enzyme activities. Recently, commercial miso products have been supplemented with purinic ribonucleotides, such as inosine monophosphate (IMP) and guanine monophosphate, to enhance the characteristic umami taste of glutamate in miso. Because the purinic ribonucleotides are degraded by enzymes such as acid phosphatases in miso, heat inactivation is required prior to the addition of these flavorings. However, heat treatment is a costly process and reduces the quality of miso. Therefore, an approach to lower acid phosphatase activities in koji culture is necessary. Transcriptional analysis using an A. oryzae KBN8048 rice-koji culture showed that eight of the 13 acid phosphatase (aph) genes were significantly down-regulated by the addition of phosphoric acid in the preparation of the culture in a concentration-dependent manner, while aphC expression was markedly up-regulated under the same conditions. The eight down-regulated genes might be under the control of the functional counterpart of the Saccharomyces cerevisiae transcriptional activator Pho4, which specifically regulates phosphatase genes in response to the ambient phosphate availability. However, the regulatory mechanism of aphC was not clear. The IMP dephosphorylation activities in rice-koji cultures of KBN8048 and the aphC deletion mutant (ΔaphC) were reduced by up to 30% and 70%, respectively, in cultures with phosphoric acid, while protease and amylase activity, which is important for miso fermentation, was minimally affected. The miso products fermented using the rice-koji cultures of KBN8048 and ΔaphC prepared with phosphoric acid had reductions in IMP dephosphorylation activity of 80% and 90%, respectively, without

  8. The myeloperoxidase-derived oxidant hypothiocyanous acid inhibits protein tyrosine phosphatases via oxidation of key cysteine residues

    DEFF Research Database (Denmark)

    Cook, Naomi L.; Moeke, Cassidy H.; Fantoni, Luca I.

    2016-01-01

    Phosphorylation of protein tyrosine residues is critical to cellular processes, and is regulated by kinases and phosphatases (PTPs). PTPs contain a redox-sensitive active site Cys residue, which is readily oxidized. Myeloperoxidase, released from activated leukocytes, catalyzes thiocyanate ion (SCN...

  9. Impact of impurities in biodiesel-derived crude glycerol on the fermentation by Clostridium pasteurianum ATCC 6013

    Energy Technology Data Exchange (ETDEWEB)

    Venkataramanan, Keerthi P.; Boatman, Judy J.; Taconi, Katherine A. [Alabama Univ., Huntsville, AL (United States). Dept. of Chemical and Materials Engineering; Kurniawan, Yogi; Bothun, Geoffrey D. [Rhode Island Univ., Kingston, RI (United States). Dept. of Chemical Engineering; Scholz, Carmen [Alabama Univ., Huntsville, AL (United States). Dept. of Chemistry

    2012-02-15

    During the production of biodiesel, crude glycerol is produced as a byproduct at 10% (w/w). Clostridium pasteurianum has the inherent potential to grow on glycerol and produce 1,3-propanediol and butanol as the major products. Growth and product yields on crude glycerol were reported to be slower and lower, respectively, in comparison to the results obtained from pure glycerol. In this study, we analyzed the effect of each impurity present in the biodiesel-derived crude glycerol on the growth and metabolism of glycerol by C. pasteurianum. The crude glycerol contains methanol, salts (in the form of potassium chloride or sulfate), and fatty acids that were not transesterified. Salt and methanol were found to have no negative effects on the growth and metabolism of the bacteria on glycerol. The fatty acid with a higher degree of unsaturation, linoleic acid, was found to have strong inhibitory effect on the utilization of glycerol by the bacteria. The fatty acid with lower or no degrees of unsaturation such as stearic and oleic acid were found to be less detrimental to substrate utilization. The removal of fatty acids from crude glycerol by acid precipitation resulted in a fermentation behavior that is comparable to the one on pure glycerol. These results show that the fatty acids in the crude glycerol have a negative effect by directly affecting the utilization of glycerol as the carbon source, and hence their removal from crude glycerol is an essential step towards the utilization of crude glycerol. (orig.)

  10. Glycerol from biodiesel production: the new corn for dairy cattle

    Directory of Open Access Journals (Sweden)

    Shawn S Donkin

    2008-07-01

    Full Text Available Glycerol, also known as glycerin, is a colorless, odorless, hygroscopic, and sweet-tasting viscous liquid. It is a sugar alcohol with high solubility index in water and has a wide range of applications in the food, pharmaceutical, and cosmetic industries. The use of glycerol in diets for dairy cattle is not novel; however, this interest has been renewed due to the increased availability and favorable pricing of glycerol as a consequence of recent growth in the biofuels industry. Experimental evidence supports the use of glycerol as a transition cow therapy but feeding rates are low, ranging from 5 to 8 % of the diet DM. There is a paucity of research that examines the use of glycerol as a macro-ingredient in rations for lactating dairy cows. Most reports indicate a lack of effect of addition of glycerol to the diet when it replaces corn or corn starch. Recent feeding experiments with lactating dairy cows indicate replacing corn with glycerol to a level of 15% of the ration DM does not adversely effect milk production or composition. Milk production was 37.0, 36.9, 37.3, 36.4 ± 0.6 kg/d and feed intake was 24.0, 24.5, 24.6, 24.1 ± 0.5 kg/d for 0, 5, 10 and 15% glycerol treatments respectively and did not differ (P > 0.05 except for a modest reduction in feed intake during the first 7 days for the 15% glycerol treatment. Glycerol fed to dairy cattle is fermented to volatile fatty acids in the rumen and early reports indicated that glycerol is almost entirely fermented to propionate. In vitro data indicates glycerol fermentation increases the production of propionate and butyrate at the expense of acetate. Rumen microbes appear to adapt to glycerol feeding and consequently, cows fed glycerol also require an adaptation period to glycerol inclusion. Debate exists regarding the fate of glycerol in the rumen and although most reports suggest that glycerol is largely fermented in the rumen, the extent of rumen digestion may depend on level of

  11. Topical glycerol monooleate/propylene glycol formulations enhance 5-aminolevulinic acid in vitro skin delivery and in vivo protophorphyrin IX accumulation in hairless mouse skin.

    Science.gov (United States)

    Steluti, Regilene; De Rosa, Fernanda Scarmato; Collett, John; Tedesco, Antônio Cláudio; Bentley, Maria Vitória Lopes Badra

    2005-08-01

    Photodynamic therapy (PDT), a potential therapy for cancer treatment, utilizes exogenously applied or endogenously formed photosensitizers, further activated by light in an appropriate wavelength and dose to induce cell death through free radical formation. 5-Aminolevulinic acid (5-ALA) is a pro-drug which can be converted to the effective photosensitizer, protoporphyrin IX (PpIX). However, the use of 5-ALA in PDT is limited by the low penetration capacity of this highly hydrophilic molecule into appropriate skin layers. In the present study, we propose to increase 5-ALA penetration by using formulations containing glycerol monooleate (GMO), an interesting and useful component of pharmaceutical formulations. Propylene glycol solutions containing different concentrations of GMO significantly increased the in vitro skin permeation/retention of 5-ALA in comparison to control solutions. In vivo studies also showed increased PpIX accumulation in mouse hairless skin, after the use of topical 5-ALA formulations containing GMO in a concentration-dependent manner. The results show that skin 5-ALA penetration and PpIX accumulation, important factors for the success of topical 5-ALA-PDT in skin cancer, are optimized by GMO/propylene glycol formulations.

  12. Metabolic engineering for high glycerol production by the anaerobic cultures of Saccharomyces cerevisiae.

    Science.gov (United States)

    Semkiv, Marta V; Dmytruk, Kostyantyn V; Abbas, Charles A; Sibirny, Andriy A

    2017-06-01

    Glycerol is used by the cosmetic, paint, automotive, food, and pharmaceutical industries and for production of explosives. Currently, glycerol is available in commercial quantities as a by-product from biodiesel production, but the purity and the cost of its purification are prohibitive. The industrial production of glycerol by glucose aerobic fermentation using osmotolerant strains of the yeasts Candida sp. and Saccharomyces cerevisiae has been described. A major drawback of the aerobic process is the high cost of production. For this reason, the development of yeast strains that effectively convert glucose to glycerol anaerobically is of great importance. Due to its ability to grow under anaerobic conditions, the yeast S. cerevisiae is an ideal system for the development of this new biotechnological platform. To increase glycerol production and accumulation from glucose, we lowered the expression of TPI1 gene coding for triose phosphate isomerase; overexpressed the fused gene consisting the GPD1 and GPP2 parts coding for glycerol-3-phosphate dehydrogenase and glycerol-3-phosphate phosphatase, respectively; overexpressed the engineered FPS1 gene that codes for aquaglyceroporin; and overexpressed the truncated gene ILV2 that codes for acetolactate synthase. The best constructed strain produced more than 20 g of glycerol/L from glucose under micro-aerobic conditions and 16 g of glycerol/L under anaerobic conditions. The increase in glycerol production led to a drop in ethanol and biomass accumulation.

  13. Electrochemical Oxidation of Glycerol Using Gold Electrode

    International Nuclear Information System (INIS)

    Mohamed Rozali Othman; Amirah Ahmad

    2015-01-01

    Cyclic voltammetry, potential linear V and chronocuolometry methods were carried out to gain electrochemical behavior of glycerol at a gold electrode. Potassium hydroxide and sulfuric acid were chosen to be the electrolyte for the electro-oxidation of this organic compound. Besides gold plate electrode, gold composite electrode (Au-PVC) was also used as the working electrode. The Au-PVC composite electrode was characterized by Scanning Electron Microscopy (SEM) to determine its morphological aspects before and after used in electrochemical oxidation of glycerol. In alkaline solution, the adsorption of hydroxide species onto the surface of both gold plate and composite Au-PVC electrodes occurs at potential around 500 mV vs SCE. However, at gold plate electrode, there was a small, broad peak before the drastic escalation of current densities which indicates the charge transfer of the chemisorbed OH - anion. In acidic media, the gold oxide was formed after potential 1.0 V. From the cyclic voltammogram glycerol undergo oxidation twice in potassium hydroxide at gold plate and Au-PVC composite electrodes, while in sulfuric acid, oxidation reaction happened once for glycerol on the gold plate electrode. Overall, electrochemical oxidation of glycerol was more effective in alkaline media. Tafel graph which plotted from potential linear V method shows that Au-PVC composite electrode is better than gold plate electrode for the electro-oxidation of glycerol in alkaline solution. Electrochemical oxidation of glycerol products as analyzed by Gas Chromatography-Mass Spectrometry (GC-MS) produced several carboxylic acids and phenolic compounds. (author)

  14. Effect of PUFAs from Pteleopsis suberosa stem bark on androgenic enzymes, cellular ATP and prostatic acid phosphatase in mercury chloride – Exposed rat

    Directory of Open Access Journals (Sweden)

    J.K. Akintunde

    2017-09-01

    Full Text Available Occupational and environmental exposure to mercury causes varieties of adverse reproductive disorders in mammals. The present study was designed to investigate the unsaturated fatty acids of Pteleopsis suberosa stem bark extract (PTSSBE, evaluate its antioxidant properties and examine its biochemical targets on sub-acute mercury-induced testicular dysfunctions. Rats were divided into five groups of 10 animals each. Group I was given distilled water; group II, III, IV and V was orally administered with mercury at a dose of 3.75 mg/kg body weight. Group III, IV and V were co-treated with PTSSBE of 25, 50 and 100 mg/kg body weight respectively, for 10 days. Rats exposed to mercury significantly decreased the activities of catalase (CAT, lactate dehydrogenase (LDH, and the level of reduced glutathione (GSH, while the formation of malondialdehyde (MDA was increased. There was also a marked significant decrease (p < 0.05 in testicular activities of Δ5-3β-hydroxysteroid dehydrogenase and Δ5 17β-hydroxysteroid dehydrogenase. Moreover, the activities of prostatic acid phosphatase, total acid phosphatase and prostatic alkaline phosphatase, were significantly (p < 0.05 elevated in mercury treated rats. These effects were prevented by co-treatment with PTSSBE in mercury-induced testicular toxicity in rats. Aphrosidiac effects of Pteleopsis suberosa, may find clinical application in reproductive abnormalities. Isolation and translation of individual active ingredient would help to find new drugs to cure and/or prevent male infertility among mercury exposed workers.

  15. Fosfatasa ácida en Oxisoles bajo cultivo de tabaco Acid phosphatase in Oxisols under tobacco cropping

    Directory of Open Access Journals (Sweden)

    Toledo Marcela

    2010-07-01

    Full Text Available En suelos ácidos de trópicos y subtrópicos, caracterizados por una baja disponibilidad de P para las plantas, el papel de las fosfatasas ácidas en la mineralización del P orgánico es fundamental, constituyendo una variable promisoria para estimar la calidad del suelo. El objetivo del trabajo fue evaluar la actividad de la fosfatasa ácida en Oxisoles bajo uso tabacalero, como indicador sensible de calidad. En la provincia de Misiones ubicada al nordeste de la República Argentina, se estableció un ensayo sobre Eutrudoxes Ródicos, familia arcillosa fina, hipertérmica, aplicándose un diseño con cuatro bloques completos aleatorizados. Se establecieron 2 tratamientos: selva subtropical (Sv y uso tabacalero (Ta. Se tomaron muestras compuestas a 3 profundidades: 0-10; 10-20; 20-30 cm. Se determinaron las siguientes variables: actividad de la fosfatasa ácida (APA, pH, contenido de arcilla, carbono orgánico edáfico (CO, nitrógeno total (N, fósforo asimilable (P, materia orgánica particulada (MOP, y respiración del suelo (RES. En los casos estudiados, la APA fue mayor en los primeros diez centímetros de suelo, y fue disminuyendo con el aumento de la profundidad del perfil, en estrecha relación con los contenidos orgánicos del suelo. El 70% de la variabilidad de la APA se explicó por el nitrógeno total, íntimamente relacionado con la materia orgánica del suelo (pSoil biological parameters are of great value as sensitive indicators of transformations occurring under different uses and management practices (Mijangos et al., 2006. The aim of this study was to evaluate the activity of the acid phosphatase enzyme in Oxisols under tobacco cropping. The experimental design was in randomized complete blocks, with two treatments: subtropical rainforest (Sv and tobacco cropping (Ta (Nicotiana tabacum L.. Soil samples were taken from 0-10, 10 -20 and 20 -30 cm-deep layers. The variables measured were: APA, pH, clay content, total nitrogen (N

  16. The structure of a purple acid phosphatase involved in plant growth and pathogen defence exhibits a novel immunoglobulin-like fold

    Directory of Open Access Journals (Sweden)

    Svetlana Vladimirovna Antonyuk

    2014-03-01

    Full Text Available Phosphatases function in the production, transport and recycling of inorganic phosphorus, which is crucial for cellular metabolism and bioenergetics, as well as in bacterial killing, since they are able to generate reactive oxygen species via Fenton chemistry. Diphosphonucleotide phosphatase/phosphodiesterase (PPD1, a glycoprotein plant purple acid phosphatase (PAP from yellow lupin seeds, contains a bimetallic Fe–Mn catalytic site which is most active at acidic pH. Unlike other plant PAPs, PPD1 cleaves the pyrophosphate bond in diphosphonucleotides and the phosphodiester bond in various phosphodiesters. The homohexameric organization of PPD1, as revealed by a 1.65 Å resolution crystal structure and confirmed by solution X-ray scattering, is unique among plant PAPs, for which only homodimers have previously been reported. A phosphate anion is bound in a bidentate fashion at the active site, bridging the Fe and Mn atoms in a binding mode similar to that previously reported for sweet potato PAP, which suggests that common features occur in their catalytic mechanisms. The N-terminal domain of PPD1 has an unexpected and unique fibronectin type III-like fold that is absent in other plant PAPs. Here, the in vitro DNA-cleavage activity of PPD1 is demonstrated and it is proposed that the fibronectin III-like domain, which `overhangs' the active site, is involved in DNA selectivity, binding and activation. The degradation of DNA by PPD1 implies a role for PPD1 in plant growth and repair and in pathogen defence.

  17. Genetic variation of an acid phosphatase (Acp-2) in the laboratory rat: possible homology with mouse AP-1 and human ACP2.

    Science.gov (United States)

    Bender, K; Bissbort, S; Kuhn, A; Nagel, M; Günther, E

    1986-02-01

    A genetic locus controlling the electrophoretic mobility of an acid phosphatase in the rat (Rattus norvegicus) is described. The locus, designed Acp-2, is not expressed in erythrocytes but is expressed in all other tissues studied. The product of Acp-2 hydrolyzes a wide variety of phosphate monoesters and is inhibited by L(+)-tartaric acid. Inbred rat strains have fixed either allele Acp-2a or allele Acp-2b. Codominant expression is observed in the respective F1 hybrids. Backcross progenies revealed the expected 1:1 segregation ratio. Possible loose linkage was found between the Acp-2 and the Pep-3 gene loci at a recombination frequency of 0.36 +/- 0.06.

  18. The Role of DmCatD, a Cathepsin D-Like Peptidase, and Acid Phosphatase in the Process of Follicular Atresia in Dipetalogaster maxima (Hemiptera: Reduviidae), a Vector of Chagas' Disease

    Science.gov (United States)

    Leyria, Jimena; Fruttero, Leonardo L.; Nazar, Magalí; Canavoso, Lilián E.

    2015-01-01

    In this work, we have investigated the involvement of DmCatD, a cathepsin D-like peptidase, and acid phosphatase in the process of follicular atresia of Dipetalogaster maxima, a hematophagous insect vector of Chagas’ disease. For the studies, fat bodies, ovaries and hemolymph were sampled from anautogenous females at representative days of the reproductive cycle: pre-vitellogenesis, vitellogenesis as well as early and late atresia. Real time PCR (qPCR) and western blot assays showed that DmCatD was expressed in fat bodies and ovaries at all reproductive stages, being the expression of its active form significantly higher at the atretic stages. In hemolymph samples, only the immunoreactive band compatible with pro-DmCatD was observed by western blot. Acid phosphatase activity in ovarian tissues significantly increased during follicular atresia in comparison to pre-vitellogenesis and vitellogenesis. A further enzyme characterization with inhibitors showed that the high levels of acid phosphatase activity in atretic ovaries corresponded mainly to a tyrosine phosphatase. Immunofluorescence assays demonstrated that DmCatD and tyrosine phosphatase were associated with yolk bodies in vitellogenic follicles, while in atretic stages they displayed a different cellular distribution. DmCatD and tyrosine phosphatase partially co-localized with vitellin. Moreover, their interaction was supported by FRET analysis. In vitro assays using homogenates of atretic ovaries as the enzyme source and enzyme inhibitors demonstrated that DmCatD, together with a tyrosine phosphatase, were necessary to promote the degradation of vitellin. Taken together, the results strongly suggested that both acid hydrolases play a central role in early vitellin proteolysis during the process of follicular atresia. PMID:26091289

  19. Synthesis and characterization of poly(glycerol citrate/sebacate)

    International Nuclear Information System (INIS)

    Brioude, Michel M.; Guimaraes, Danilo H.; Fiuza, Raigenis P.; Boaventura, Jaime S.; Jose, Nadia M.

    2011-01-01

    In this work were prepared and characterized the poly(glycerol citrate/sebacate) in three different ratios between acids. The polymers were prepared by a polycondensation reaction between glycerol and citric/sebacic acids and characterized by X-ray diffraction (XRD), infrared spectroscopy (FTIR), thermogravimetric analysis (TGA), scanning differential calorimetry (DSC), scanning electron microscopy (SEM). The results showed that the polymers are polyesters and its crystallinity, thermal and morphological properties were modified by sebacic acid adding. (author)

  20. The structure of teichoic acid from Bacillus subtilis var. niger WM as determined by 13C nuclear-magnetic-resonance spectroscopy

    International Nuclear Information System (INIS)

    De Boer, W.R.; Kruyssen, F.J.; Wouters, J.T.M.; Kruk, C.

    1976-01-01

    The walls of Bacillus subtilis var. niger WM, grown in a Mg 2+ -limited chemostat culture (carbon source glucose, dilution rate = 0.2 h -1 , 37 0 C, pH 7) contained 45% (w/w) teichoic acid, a polymer composed of glycerol, phosphate and glucose in the molar ratio 1.00 : 1.00 : 0.88. Alkaline hydrolysis of this teichoic acid yielded 1-O-β-glucosylglycerol phosphate (together with small amounts of glycerol phosphate), and 13 C nuclear magnetic resonance spectra of this hydrolysis product, and its derivative after alkaline phosphatase treatment, confirmed that the monomeric unit was 1-O-β-glucosylglycerol-3-phosphate. Assignment of the resonances in the spectrum of undegraded teichoic acid revealed that the polymer was a poly[(2,3)glycerol phosphate], glucosidically substituted on C-1 of glycerol with β-glucose. (orig.) [de

  1. Radiometric assays for glycerol, glucose, and glycogen

    International Nuclear Information System (INIS)

    Bradley, D.C.; Kaslow, H.R.

    1989-01-01

    We have developed radiometric assays for small quantities of glycerol, glucose and glycogen, based on a technique described by Thorner and Paulus for the measurement of glycerokinase activity. In the glycerol assay, glycerol is phosphorylated with [32P]ATP and glycerokinase, residual [32P]ATP is hydrolyzed by heating in acid, and free [32P]phosphate is removed by precipitation with ammonium molybdate and triethylamine. Standard dose-response curves were linear from 50 to 3000 pmol glycerol with less than 3% SD in triplicate measurements. Of the substances tested for interference, only dihydroxyacetone gave a slight false positive signal at high concentration. When used to measure glycerol concentrations in serum and in media from incubated adipose tissue, the radiometric glycerol assay correlated well with a commonly used spectrophotometric assay. The radiometric glucose assay is similar to the glycerol assay, except that glucokinase is used instead of glycerokinase. Dose response was linear from 5 to 3000 pmol glucose with less than 3% SD in triplicate measurements. Glucosamine and N-acetylglucosamine gave false positive signals when equimolar to glucose. When glucose concentrations in serum were measured, the radiometric glucose assay agreed well with hexokinase/glucose-6-phosphate dehydrogenase (H/GDH)-based and glucose oxidase/H2O2-based glucose assays. The radiometric method for glycogen measurement incorporates previously described isolation and digestion techniques, followed by the radiometric assay of free glucose. When used to measure glycogen in mouse epididymal fat pads, the radiometric glycogen assay correlated well with the H/GDH-based glycogen assay. All three radiometric assays offer several practical advantages over spectral assays

  2. Serum Bone Resorption Markers after Parathyroidectomy for Renal Hyperparathyroidism: Correlation Analyses for the Cross-Linked N-telopeptide of Collagen I and Tartrate-Resistant Acid Phosphatase

    Directory of Open Access Journals (Sweden)

    Kuo-Chin Hung

    2012-01-01

    Full Text Available Patients on long-term dialysis may develop secondary hyperparathyroidism (SHPT with increased serum concentrations of bone resorption markers such as the cross-linked N-telopeptide of type I collagen (NTX and type-5b tartrate-resistant acid phosphatase (TRAP. When SHPT proves refractory to treatment, parathyroidectomy (PTX may be needed. Renal patients on maintenance HD who received PTX for refractory SHPT (n=23 or who did not develop refractory SHPT (control subjects; n=25 were followed prospectively for 4 weeks. Serum intact parathyroid hormone (iPTH, NTX, TRAP, and bone alkaline phosphatase (BAP concentrations were measured serially and correlation analyses were performed. iPTH values decreased rapidly and dramatically. BAP values increased progressively with peak increases observed at 2 weeks after surgery. NTX and TRAP values decreased concurrently and progressively through 4 weeks following PTX. A significant correlation between TRAP and NTX values was observed before PTX but not at 4 weeks after PTX. Additionally, the fractional changes in serum TRAP were larger than those in serum NTX at all times examined after PTX. Serum iPTH, TRAP, and NTX values declined rapidly following PTX for SHPT. Serum TRAP values declined to greater degrees than serum NTX values throughout the 4-week period following PTX.

  3. Use of Nonspecific, Glutamic Acid-Free, Media and High Glycerol or High Amylase as Inducing Parameters for Screening Bacillus Isolates Having High Yield of Polyglutamic Acid.

    Science.gov (United States)

    Baxi, Nandita N

    2014-01-01

    Out of fifty-five Bacillus isolates obtained from ten different regional locations and sources, seven showed the ability to consistently produce specific extracellular polymeric substance (EPS) on rich as well as synthetic but nonspecific media which did not contain glutamic acid. The isolates were identified as either Bacillus licheniformis or Bacillus subtilis. The EPS from all isolates was resistant to alpha protease, proteinase K, and was thus of high molecular weight. Further it was detected after SDS-PAGE by methylene blue but not by coomassie blue R staining as in case of proteins with high proportion of acidic amino acids. Cell-free EPS, after acid hydrolysis, showed absence of carbohydrates and presence of only glutamic acid. Thus the native the EPS from all seven isolates was confirmed to be gamma polyglutamic acid (PGA) and not exopolysaccharide. The Bacillus isolate T which produced maximum polymer on all media tested had higher amylase: protease activity as compared to other strains. If inoculum was developed in rich medium as compared to synthetic medium, the PGA produced increased by twofold in the subsequent synthetic production medium. Similarly, use of inoculum consisting of young and vegetative cells also increased the PGA production by twofold though amount of inoculum did not affect yield of PGA. Though PGA was produced in even in the absence of glutamic acid supplementation in the production medium by all isolates, the yield of PGA increased by fourfold in the presence glutamic acid and the maximum yield was 30 g/l for isolate K. The supplementation of glutamine instead of glutamic acid into the medium caused an increase in the viscosity of the non-Newtonian solution of PGA.

  4. Simultaneous demonstration of acid phosphatase and glucose-6-phosphate dehydrogenase in mouse hepatocytes. A novel electron-microscopic dual staining enzyme-cytochemistry

    Directory of Open Access Journals (Sweden)

    S Matsubara

    2010-01-01

    Full Text Available Acid phosphatase (ACPase and glucose-6-phosphate dehydrogenase (G6PD play important roles in cell biology/disease pathophysiology in various organs including the liver. The purpose of the present report is to introduce a new enzymecytochemical method to simultaneously demonstrate the subcellular localization of ACPase and G6PD within the same hepatocyte in the mouse liver. The ultrastructural localization of ACPase and G6PD were demonstrated, with concomitant use of the cerium method and the copper-ferrocyanide method, respectively. ACPase labelings were localized in the lysosomes, and G6PD labelings were visible in the cytoplasm and on the cytosolic side of the endoplasmic reticulum of the hepatocyte. This novel double staining procedure may be a useful histochemical tool for the study of liver functions in both physiological and pathological conditions.

  5. Modulation of fatty acid synthase degradation by concerted action of p38 MAP kinase, E3 ligase COP1, and SH2-tyrosine phosphatase Shp2.

    Science.gov (United States)

    Yu, Jianxiu; Deng, Rong; Zhu, Helen H; Zhang, Sharon S; Zhu, Changhong; Montminy, Marc; Davis, Roger; Feng, Gen-Sheng

    2013-02-08

    The Src-homology 2 (SH2) domain-containing tyrosine phosphatase Shp2 has been known to regulate various signaling pathways triggered by receptor and cytoplasmic tyrosine kinases. Here we describe a novel function of Shp2 in control of lipid metabolism by mediating degradation of fatty acid synthase (FASN). p38-phosphorylated COP1 accumulates in the cytoplasm and subsequently binds FASN through Shp2 here as an adapter, leading to FASN-Shp2-COP1 complex formation and FASN degradation mediated by ubiquitination pathway. By fasting p38 is activated and stimulates FASN protein degradation in mice. Consistently, the FASN protein levels are dramatically elevated in mouse liver and pancreas in which Shp2/Ptpn11 is selectively deleted. Thus, this study identifies a new activity for Shp2 in lipid metabolism.

  6. Disruption of a Guard Cell–Expressed Protein Phosphatase 2A Regulatory Subunit, RCN1, Confers Abscisic Acid Insensitivity in Arabidopsis

    Science.gov (United States)

    Kwak, June M.; Moon, Ji-Hye; Murata, Yoshiyuki; Kuchitsu, Kazuyuki; Leonhardt, Nathalie; DeLong, Alison; Schroeder, Julian I.

    2002-01-01

    Pharmacological studies have led to a model in which the phytohormone abscisic acid (ABA) may be positively transduced via protein phosphatases of the type 1 (PP1) or type 2A (PP2A) families. However, pharmacological evidence also exists that PP1s or PP2As may function as negative regulators of ABA signaling. Furthermore, recessive disruption mutants in protein phosphatases that function in ABA signal transduction have not yet been identified. A guard cell–expressed PP2A gene, RCN1, which had been characterized previously as a molecular component affecting auxin transport and gravity response, was isolated. A T-DNA disruption mutation in RCN1 confers recessive ABA insensitivity to Arabidopsis. The rcn1 mutation impairs ABA-induced stomatal closing and ABA activation of slow anion channels. Calcium imaging analyses show a reduced sensitivity of ABA-induced cytosolic calcium increases in rcn1, whereas mechanisms downstream of cytosolic calcium increases show wild-type responses, suggesting that RCN1 functions in ABA signal transduction upstream of cytosolic Ca2+ increases. Furthermore, rcn1 shows ABA insensitivity in ABA inhibition of seed germination and ABA-induced gene expression. The PP1 and PP2A inhibitor okadaic acid phenocopies the rcn1 phenotype in wild-type plants both in ABA-induced cytosolic calcium increases and in seed germination, and the wild-type RCN1 genomic DNA complements rcn1 phenotypes. These data show that RCN1 functions as a general positive transducer of early ABA signaling. PMID:12417706

  7. Acute inhibition of hepatic glucose-6-phosphatase does not affect gluconeogenesis but directs gluconeogenic flux toward glycogen in fasted rats. A pharmacological study with the chlorogenic acid derivative S4048

    NARCIS (Netherlands)

    van Dijk, T. H.; van der Sluijs, F. H.; Wiegman, C. H.; Baller, J. F.; Gustafson, L. A.; Burger, H. J.; Herling, A. W.; Kuipers, F.; Meijer, A. J.; Reijngoud, D. J.

    2001-01-01

    Effects of acute inhibition of glucose-6-phosphatase activity by the chlorogenic acid derivative S4048 on hepatic carbohydrate fluxes were examined in isolated rat hepatocytes and in vivo in rats. Fluxes were calculated using tracer dilution techniques and mass isotopomer distribution analysis in

  8. Acute inhibition of hepatic glucose-6-phosphatase does not affect gluconeogenesis but directs gluconeogenic flux toward glycogen in fasted rats - A pharmacological study with the chlorogenic acid derivative S4048

    NARCIS (Netherlands)

    van Dijk, TH; van der Sluijs, FH; Wiegman, CH; Baller, JFW; Gustafson, LA; Burger, HJ; Herling, AW; Kuipers, F; Meijer, AJ; Reijngoud, DJ

    2001-01-01

    Effects of acute inhibition of glucose-6-phosphatase activity by the chlorogenic acid derivative S4048 on hepatic carbohydrate fluxes were examined in isolated rat hepatocytes and in vivo in rats. Fluxes were calculated using tracer dilution techniques and mass isotopomer distribution analysis in

  9. AtPP2CG1, a protein phosphatase 2C, positively regulates salt tolerance of Arabidopsis in abscisic acid-dependent manner

    International Nuclear Information System (INIS)

    Liu, Xin; Zhu, Yanming; Zhai, Hong; Cai, Hua; Ji, Wei; Luo, Xiao; Li, Jing; Bai, Xi

    2012-01-01

    Highlights: ► AtPP2CG1 positively regulates salt tolerance in ABA-dependent manner. ► AtPP2CG1 up-regulates the expression of marker genes in different pathways. ► AtPP2CG1 expresses in the vascular system and trichomes of Arabidopsis. -- Abstract: AtPP2CG1 (Arabidopsis thaliana protein phosphatase 2C G Group 1) was predicted as an abiotic stress candidate gene by bioinformatic analysis in our previous study. The gene encodes a putative protein phosphatase 2C that belongs to Group G of PP2C. There is no report of Group G genes involved in abiotic stress so far. Real-time RT-PCR analysis showed that AtPP2CG1 expression was induced by salt, drought, and abscisic acid (ABA) treatment. The expression levels of AtPP2CG1 in the ABA synthesis-deficient mutant abi2–3 were much lower than that in WT plants under salt stress suggesting that the expression of AtPP2CG1 acts in an ABA-dependent manner. Over-expression of AtPP2CG1 led to enhanced salt tolerance, whereas its loss of function caused decreased salt tolerance. These results indicate that AtPP2CG1 positively regulates salt stress in an ABA-dependent manner. Under salt treatment, AtPP2CG1 up-regulated the expression levels of stress-responsive genes, including RD29A, RD29B, DREB2A and KIN1. GUS activity was detected in roots, leaves, stems, flower, and trichomes of AtPP2CG1 promoter–GUS transgenic plants. AtPP2CG1 protein was localized in nucleus and cytoplasm via AtPP2CG1:eGFP and YFP:AtPP2CG1 fusion approaches.

  10. Multiplexing spheroid volume, resazurin and acid phosphatase viability assays for high-throughput screening of tumour spheroids and stem cell neurospheres.

    Directory of Open Access Journals (Sweden)

    Delyan P Ivanov

    Full Text Available Three-dimensional cell culture has many advantages over monolayer cultures, and spheroids have been hailed as the best current representation of small avascular tumours in vitro. However their adoption in regular screening programs has been hindered by uneven culture growth, poor reproducibility and lack of high-throughput analysis methods for 3D. The objective of this study was to develop a method for a quick and reliable anticancer drug screen in 3D for tumour and human foetal brain tissue in order to investigate drug effectiveness and selective cytotoxic effects. Commercially available ultra-low attachment 96-well round-bottom plates were employed to culture spheroids in a rapid, reproducible manner amenable to automation. A set of three mechanistically different methods for spheroid health assessment (Spheroid volume, metabolic activity and acid phosphatase enzyme activity were validated against cell numbers in healthy and drug-treated spheroids. An automated open-source ImageJ macro was developed to enable high-throughput volume measurements. Although spheroid volume determination was superior to the other assays, multiplexing it with resazurin reduction and phosphatase activity produced a richer picture of spheroid condition. The ability to distinguish between effects on malignant and the proliferating component of normal brain was tested using etoposide on UW228-3 medulloblastoma cell line and human neural stem cells. At levels below 10 µM etoposide exhibited higher toxicity towards proliferating stem cells, whereas at concentrations above 10 µM the tumour spheroids were affected to a greater extent. The high-throughput assay procedures use ready-made plates, open-source software and are compatible with standard plate readers, therefore offering high predictive power with substantial savings in time and money.

  11. Synthesis and applications of {sup 13}C glycerol

    Energy Technology Data Exchange (ETDEWEB)

    Stocking, E.; Khalsa, O.; Martinez, R.A.; Silks, L.A. III [Los Alamos National Laboratory, NM (United States)

    1994-12-01

    Due in part to the use of labeled glycerol for the {sup 13}C enrichment of biomolecules, we are currently developing new synthetic routes to various isotopomers of glycerol. Judging from our experience, traditional methods of glycerol synthesis are not easily adapted for isotopic enrichment and/or have poor overall yields (12 to 15%). Furthermore, the use of glycerol for enrichment can be prohibitively expensive and its availability is limited by the level of demand. We are presently developing a short de novo synthesis of glycerol from carbon dioxide ({approximately}53% overall yield for four steps) and are examining the feasibility of synthesizing site-specific {sup 13}C-labeled glycerol and dihydroxyacetone (DHA) from labeled methanol and carbon dioxide. One application of {sup 13}C glycerol we have examined is enzymatic conversion of glycerol to glyceraldehyde-3-monophosphate or dihydroxyacetone monophosphate (DHAP) with yields ranging from 25 to 50% (as determined by NMR spectroscopy). We are also pursuing the chemical conversion of {sup 13}C-labeled DHA to DHAP. We are especially interested in {sup 13}C-labeled DHAP because we are investigating its use as a chemo-enzymatic precursor for both labeled 2-deoxyribose and 2-deoxyribonucleic acids.

  12. An improved glycerol biosensor with an Au-FeS-NAD-glycerol-dehydrogenase anode.

    Science.gov (United States)

    Mahadevan, Aishwarya; Fernando, Sandun

    2017-06-15

    An improved glycerol biosensor was developed via direct attachment of NAD + -glycerol dehydrogenase coenzyme-apoenzyme complex onto supporting gold electrodes, using novel inorganic iron (II) sulfide (FeS)-based single molecular wires. Sensing performance factors, i.e., sensitivity, a detection limit and response time of the FeS and conventional pyrroloquinoline quinone (PQQ)-based biosensor were evaluated by dynamic constant potential amperometry at 1.3V under non-buffered conditions. For glycerol concentrations ranging from 1 to 25mM, a 77% increase in sensitivity and a 53% decrease in detection limit were observed for the FeS-based biosensor when compared to the conventional PQQ-based counterpart. The electrochemical behavior of the FeS-based glycerol biosensor was analyzed at different concentrations of glycerol, accompanied by an investigation into the effects of applied potential and scan rate on the current response. Effects of enzyme stimulants ((NH 4 ) 2 SO 4 and MnCl 2 ·4H 2 O) concentrations and buffers/pH (potassium phosphate buffer pH 6-8, Tris buffer pH 8-10) on the current responses generated by the FeS-based glycerol biosensor were also studied. The optimal detection conditions were 0.03M (NH 4 ) 2 SO 4 and 0.3µm MnCl 2 ·4H 2 O in non-buffered aqueous electrolyte under stirring whereas under non-stirring, Tris buffer at pH 10 with 0.03M (NH 4 ) 2 SO 4 and 30µm MnCl 2 ·4H 2 O were found to be optimal detection conditions. Interference by glucose, fructose, ethanol, and acetic acid in glycerol detection was studied. The observations indicated a promising enhancement in glycerol detection using the novel FeS-based glycerol sensing electrode compared to the conventional PQQ-based one. These findings support the premise that FeS-based bioanodes are capable of biosensing glycerol successfully and may be applicable for other enzymatic biosensors. Copyright © 2016 Elsevier B.V. All rights reserved.

  13. Ethylene signalling is involved in regulation of phosphate starvation-induced gene expression and production of acid phosphatases and anthocyanin in Arabidopsis

    KAUST Repository

    Lei, Mingguang

    2010-11-30

    With the exception of root hair development, the role of the phytohormone ethylene is not clear in other aspects of plant responses to inorganic phosphate (Pi) starvation. The induction of AtPT2 was used as a marker to find novel signalling components involved in plant responses to Pi starvation. Using genetic and chemical approaches, we examined the role of ethylene in the regulation of plant responses to Pi starvation. hps2, an Arabidopsis mutant with enhanced sensitivity to Pi starvation, was identified and found to be a new allele of CTR1 that is a key negative regulator of ethylene responses. 1-aminocyclopropane-1-carboxylic acid (ACC), the precursor of ethylene, increases plant sensitivity to Pi starvation, whereas the ethylene perception inhibitor Ag+ suppresses this response. The Pi starvation-induced gene expression and acid phosphatase activity are also enhanced in the hps2 mutant, but suppressed in the ethylene-insensitive mutant ein2-5. By contrast, we found that ethylene signalling plays a negative role in Pi starvation-induced anthocyanin production. These findings extend the roles of ethylene in the regulation of plant responses to Pi starvation and will help us to gain a better understanding of the molecular mechanism underlying these responses. © 2010 The Authors. New Phytologist © 2010 New Phytologist Trust.

  14. Improvement of Student Understanding of How Kinetic Data Facilitates the Determination of Amino Acid Catalytic Function through an Alkaline Phosphatase Structure/Mechanism Bioinformatics Exercise

    Science.gov (United States)

    Grunwald, Sandra K.; Krueger, Katherine J.

    2008-01-01

    Laboratory exercises, which utilize alkaline phosphatase as a model enzyme, have been developed and used extensively in undergraduate biochemistry courses to illustrate enzyme steady-state kinetics. A bioinformatics laboratory exercise for the biochemistry laboratory, which complements the traditional alkaline phosphatase kinetics exercise, was…

  15. Glycerol (byproduct of biodiesel production) as a source of fuels and chemicals : mini review

    Energy Technology Data Exchange (ETDEWEB)

    Fan, X.; Burton, R. [Piedmont Biofuels Industrial, Pittsboro, NC (United States); Zhou, Y. [Yonezawa Hamari Chemical, Ltd., Yonezawa, Yamagata (Japan)

    2010-07-01

    Glycerol, a byproduct of biodiesel production, is a potential renewable feedstock for the production of functional chemicals. This paper reviewed recent developments in the conversion of glycerol into value-added products, including citric acid, lactic acid, 1,3-dihydroxyacetone (DHA), 1,3-propanediol (1,3-PD), dichloro-2-propanol (DCP), acrolein, hydrogen, and ethanol. The new applications of glycerol will improve the economic viability of the biodiesel industry and capitalize on the oversupply of crude glycerol that the biodiesel industry has produced. Increasing abundance and attractive pricing make glycerol an attractive feedstock for deriving value-added chemical compounds. The processes turn glycerol into chemicals, materials, and fuels and fuel additives. Whereas glycerol from first-generation biodiesel production has low purity, glycerol from second-generation biodiesel production, which uses non-edible oil as a feedstock, produces a higher purity glycerol, minimizing the related impurity problem and potentially increasing the applications of glycerol. Glycerol is also being looked at as a carbon source for algal biomass fermentation. 36 refs.

  16. Retinoic Acid Modulates Interferon-γ Production by Hepatic Natural Killer T Cells via Phosphatase 2A and the Extracellular Signal-Regulated Kinase Pathway

    Science.gov (United States)

    Chang, Heng-Kwei

    2015-01-01

    Retinoic acid (RA), an active metabolite converted from vitamin A, plays an active role in immune function, such as defending against infections and immune regulation. Although RA affects various types of immune cells, including antigen-presenting cells, B lymphocytes, and T lymphocytes, whether it affects natural killer T (NKT) cells remain unknown. In this study, we found that RA decreased interferon (IFN)-γ production by activated NKT cells through T-cell receptor (TCR) and CD28. We also found that RA reduced extracellular signal-regulated kinase (ERK) phosphorylation, but increased phosphatase 2A (PP2A) activity in TCR/CD28-stimulated NKT cells. The increased PP2A activity, at least partly, contributed to the reduction of ERK phosphorylation. Since inhibition of ERK activation decreases IFN-γ production by TCR/CD28-stimulated NKT cells, RA may downregulate IFN-γ production by TCR/CD28-stimulated NKT cells through the PP2A-ERK pathway. Our results demonstrated a novel function of RA in modulating the IFN-γ expression by activated NKT cells. PMID:25343668

  17. Serial lectin affinity chromatography with concavalin A and wheat germ agglutinin demonstrates altered asparagine-linked sugar-chain structures of prostatic acid phosphatase in human prostate carcinoma.

    Science.gov (United States)

    Yoshida, K I; Honda, M; Arai, K; Hosoya, Y; Moriguchi, H; Sumi, S; Ueda, Y; Kitahara, S

    1997-08-01

    Differences between human prostate carcinoma (PCA, five cases) and benign prostatic hyperplasia (BPH, five cases) in asparagine-linked (Asn) sugar-chain structure of prostatic acid phosphatase (PAP) were investigated using lectin affinity chromatography with concanavalin A (Con A) and wheat germ agglutinin (WGA). PAP activities were significantly decreased in PCA-derived PAP, while no significant differences between the two PAP preparations were observed in the enzymatic properties (Michaelis-Menten value, optimal pH, thermal stability, and inhibition study). In these PAP preparations, all activities were found only in the fractions which bound strongly to the Con A column and were undetectable in the Con A unbound fractions and in the fractions which bound weakly to the Con A column. The relative amounts of PAP which bound strongly to the Con A column but passed through the WGA column, were significantly greater in BPH-derived PAP than in PCA-derived PAP. In contrast, the relative amounts of PAP which bound strongly to the Con A column and bound to the WGA column, were significantly greater in PCA-derived PAP than in BPH-derived PAP. The findings suggest that Asn-linked sugar-chain structures are altered during oncogenesis in human prostate and also suggest that studies of qualitative differences of sugar-chain structures of PAP might lead to a useful diagnostic tool for PCA.

  18. Spinal cord projections of the rat main forelimb nerves, studied by transganglionic transport of WGA-HRP and by the disappearance of acid phosphatase.

    Science.gov (United States)

    Castro-Lopes, J M; Coimbra, A

    1991-03-01

    The spinal cord projections of the 3 main forelimb nerves-median, radial and ulnar, were studied in the rat dorsal horn with transganglionic transport of wheat germ agglutinin-horseradish peroxidase (WGA-HRP), or using the disappearance of fluoride resistant acid phosphatase (FRAP) after nerve section. The projection patterns in lamina II were similar following the two procedures. The median and the radial nerve fibers projected to the medial and the intermediate thirds, respectively, of the dorsal horn lamina II in spinal cord segments C4-C8. The ulnar nerve projected to segments C6-C8 between the areas occupied by the other two nerves. The FRAP method also showed that the lateral part of lamina II, which was not filled by radial nerve fibers, received the projections from the dorsal cutaneous branches of cervical spinal nerves. In addition, FRAP disappeared from the medial end of segment T1 after skin incisions extending from the medial brachium to the axilla, which seemed due to severance of the cutaneous branchlets of the lateral anterior thoracic nerve. The FRAP procedure is thus sensitive enough to detect fibers in lamina II arising from small peripheral nerves, and may be used as an alternative to the anterograde tracing methods whenever there are no overlapping projections.

  19. Inhibition of several enzymes by gold compounds. II. beta-Glucuronidase, acid phosphatase and L-malate dehydrogenase by sodium thiomalatoraurate (I), sodium thiosulfatoaurate (I) and thioglucosoaurate (I).

    Science.gov (United States)

    Lee, M T; Ahmed, T; Haddad, R; Friedman, M E

    1989-01-01

    Bovine liver beta-D-glucuronide glucuronohydrolase, EC 3.2.1.32), wheat germ acid phosphatase (orthophosphoric monoesterphosphohydrolase, EC 3.1.3.2) and bovine liver L-malate dehydrogenase (L-malate: NAD oxidoreductase, EC 1.1.1.37) were inhibited by a series of gold (I) complexes that have been used as anti-inflammatory drugs. Both sodium thiosulfatoaurate (I) (Na AuTs) and sodium thiomalatoraurate (NaAuTM) effectively inhibited all three enzymes, while thioglucosoaurate (I) (AuTG) only inhibited L-malate dehydrogenase. The equilibrium constants (K1) ranged from nearly 4000 microM for the NaAuTM-beta-glucuronidase interaction to 24 microM for the NaAuTS-beta-glucuronidase interaction. The rate of covalent bond formation (kp) ranged from 0.00032 min-1 for NaAuTM-beta-glucuronidase formation to 1.7 min-1 for AuTG-L-malate dehydrogenase formation. The equilibrium data shows that the gold (I) drugs bind by several orders lower than the gold (III) compounds, suggesting a significantly stronger interaction between the more highly charged gold ion and the enzyme. Yet the rate of covalent bond formation depends as much on the structure of the active site as upon the lability of the gold-ligand bond. It was also observed that the more effective the gold inhibition the more toxic the compound.

  20. Theoretical investigation of the reaction mechanism for the phosphate diester hydrolysis using an asymmetric dinuclear metal complex as a biomimetic model of the purple acid phosphatase enzyme.

    Science.gov (United States)

    Ferreira, Dalva E C; De Almeida, Wagner B; Neves, Ademir; Rocha, Willian R

    2008-12-14

    In this work we have applied quantum mechanical calculations, at the density functional theory level, to investigate the phosphate diester hydrolysis promoted by a cationic heterodinuclear Fe(III)...Zn(II) complex that mimics the structural and functional properties of the purple acid phosphatase (PAP) enzymes. The hydrolysis of the dimethyl phosphate diester was investigated in the gas phase and in solution by means of the continuum PCM model, using the B3LYP hybrid exchange-correlation functional. Our computed results showed that the hydrolysis of the dimethyl phosphate ester takes place in two steps. The first step corresponds to a slow P-O bond formation through nucleophilic attack of the coordinated (Fe(III))-OH group. The second step consists of a proton transfer process followed by the release of a methanol molecule. The first step is rate determining with activation free energy of 12.3 kcal mol(-1), which is about 3 times lower than the activation free energy for the uncatalyzed reaction. We also show that the heterodinuclear site plays an important role favoring an associative mechanism for the phosphate diester hydrolysis, favoring the formation of a high energy intermediate phosphorane, and orienting the phosphate group to the nucleophilic attack.

  1. Calibrating the glycerol dialkyl glycerol tetraether temperature signalin speleothems

    NARCIS (Netherlands)

    Blyth, A.J.; Schouten, S.

    2013-01-01

    Palaeotemperature proxies based on glycerol dialkyl glycerol tetraethers (GDGTs) lipids have been established for marine and lacustrine environments, but there has been relatively little study of their application in speleothems. In this study we analyse the GDGT content of 33 speleothem samples

  2. Calibrating the glycerol dialkyl glycerol tetraether temperature signal in speleothems

    NARCIS (Netherlands)

    Blyth, A.J.; Schouten, S.|info:eu-repo/dai/nl/137124929

    2013-01-01

    Palaeotemperature proxies based on glycerol dialkyl glycerol tetraethers (GDGTs) lipids have been established for marine and lacustrine environments, but there has been relatively little study of their application in speleothems. In this study we analyse the GDGT content of 33 speleothem samples

  3. AtPP2CG1, a protein phosphatase 2C, positively regulates salt tolerance of Arabidopsis in abscisic acid-dependent manner

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Xin, E-mail: fangfei6073@126.com [Plant Bioengineering Laboratory, Northeast Agricultural University, Harbin 150030 (China); Zhu, Yanming, E-mail: ymzhu2001@neau.edu.cn [Plant Bioengineering Laboratory, Northeast Agricultural University, Harbin 150030 (China); Zhai, Hong, E-mail: Zhai.h@neigaehrb.ac.cn [Northeast Institute of Geography and Agroecology, Chinese Academy of Sciences, Harbin 150040 (China); Cai, Hua, E-mail: small-big@sohu.com [Plant Bioengineering Laboratory, Northeast Agricultural University, Harbin 150030 (China); Ji, Wei, E-mail: iwei_j@hotmail.com [Plant Bioengineering Laboratory, Northeast Agricultural University, Harbin 150030 (China); Luo, Xiao, E-mail: luoxiao2010@yahoo.cn [Plant Bioengineering Laboratory, Northeast Agricultural University, Harbin 150030 (China); Li, Jing, E-mail: lijing@neau.edu.cn [Plant Secondary Metabolism Laboratory, Northeast Agricultural University, Harbin 150030 (China); Bai, Xi, E-mail: baixi@neau.edu.cn [Plant Bioengineering Laboratory, Northeast Agricultural University, Harbin 150030 (China)

    2012-06-15

    Highlights: Black-Right-Pointing-Pointer AtPP2CG1 positively regulates salt tolerance in ABA-dependent manner. Black-Right-Pointing-Pointer AtPP2CG1 up-regulates the expression of marker genes in different pathways. Black-Right-Pointing-Pointer AtPP2CG1 expresses in the vascular system and trichomes of Arabidopsis. -- Abstract: AtPP2CG1 (Arabidopsis thaliana protein phosphatase 2C G Group 1) was predicted as an abiotic stress candidate gene by bioinformatic analysis in our previous study. The gene encodes a putative protein phosphatase 2C that belongs to Group G of PP2C. There is no report of Group G genes involved in abiotic stress so far. Real-time RT-PCR analysis showed that AtPP2CG1 expression was induced by salt, drought, and abscisic acid (ABA) treatment. The expression levels of AtPP2CG1 in the ABA synthesis-deficient mutant abi2-3 were much lower than that in WT plants under salt stress suggesting that the expression of AtPP2CG1 acts in an ABA-dependent manner. Over-expression of AtPP2CG1 led to enhanced salt tolerance, whereas its loss of function caused decreased salt tolerance. These results indicate that AtPP2CG1 positively regulates salt stress in an ABA-dependent manner. Under salt treatment, AtPP2CG1 up-regulated the expression levels of stress-responsive genes, including RD29A, RD29B, DREB2A and KIN1. GUS activity was detected in roots, leaves, stems, flower, and trichomes of AtPP2CG1 promoter-GUS transgenic plants. AtPP2CG1 protein was localized in nucleus and cytoplasm via AtPP2CG1:eGFP and YFP:AtPP2CG1 fusion approaches.

  4. Overexpression of a Protein Phosphatase 2C from Beech Seeds in Arabidopsis Shows Phenotypes Related to Abscisic Acid Responses and Gibberellin Biosynthesis1

    Science.gov (United States)

    Reyes, David; Rodríguez, Dolores; González-García, Mary Paz; Lorenzo, Oscar; Nicolás, Gregorio; García-Martínez, José Luis; Nicolás, Carlos

    2006-01-01

    A functional abscisic acid (ABA)-induced protein phosphatase type 2C (PP2C) was previously isolated from beech (Fagus sylvatica) seeds (FsPP2C2). Because transgenic work is not possible in beech, in this study we overexpressed this gene in Arabidopsis (Arabidopsis thaliana) to provide genetic evidence on FsPP2C2 function in seed dormancy and other plant responses. In contrast with other PP2Cs described so far, constitutive expression of FsPP2C2 in Arabidopsis, under the cauliflower mosaic virus 35S promoter, produced enhanced sensitivity to ABA and abiotic stress in seeds and vegetative tissues, dwarf phenotype, and delayed flowering, and all these effects were reversed by gibberellic acid application. The levels of active gibberellins (GAs) were reduced in 35S:FsPP2C2 plants, although transcript levels of AtGA20ox1 and AtGA3ox1 increased, probably as a result of negative feedback regulation, whereas the expression of GASA1 was induced by GAs. Additionally, FsPP2C2-overexpressing plants showed a strong induction of the Responsive to ABA 18 (RAB18) gene. Interestingly, FsPP2C2 contains two nuclear targeting sequences, and transient expression assays revealed that ABA directed this protein to the nucleus. Whereas other plant PP2Cs have been shown to act as negative regulators, our results support the hypothesis that FsPP2C2 is a positive regulator of ABA. Moreover, our results indicate the existence of potential cross-talk between ABA signaling and GA biosynthesis. PMID:16815952

  5. Composite glycerol/graphite/aromatic acid matrices for thin-layer chromatography/matrix-assisted laser desorption/ionization mass spectrometry of heterocyclic compounds.

    Science.gov (United States)

    Esparza, Cesar; Borisov, R S; Varlamov, A V; Zaikin, V G

    2016-10-28

    New composite matrices have been suggested for the analysis of mixtures of different synthetic organic compounds (N-containing heterocycles and erectile dysfunction drugs) by thin layer chromatography/matrix-assisted laser desorption ionization time-of-flight mass spectrometry (TLC/MALDI-TOF). Different mixtures of classical MALDI matrices and graphite particles dispersed in glycerol were used for the registration of MALDI mass spectra directly from TLC plates after analytes separation. In most of cases, the mass spectra possessed [M+H] + ions; however, for some analytes only [M+Na] + and [M+K] + ions were observed. These ions have been used to generate visualized TLC chromatograms. The described approach increases the desorption/ionization efficiencies of analytes separated by TLC, prevent spot blurring, simplifies and decrease time for sample preparation. Copyright © 2016 Elsevier B.V. All rights reserved.

  6. Psychophysical estimation of acid intensity and determination of sweet-acid interaction in a fish paste containing glycerol Estimação psicofísica da intensidade ácida e determinação da interação ácido-doce em patê de pescado contendo glicerol

    Directory of Open Access Journals (Sweden)

    Gabriela Leonor Sánchez Pascua

    2010-05-01

    Full Text Available In a fish paste made with cooked Brazilian flathead (Percophis brasiliensis, glycerol (17%, sodium chloride (1.5% and potassium sorbate (0.1% the following acid percentages: 0.2; 0.4; 0.6; 0.8, 1 and 1.5% w/w were incorporated to determine the relationship between added acetic acid and the sensorially perceived intensity, and the effects of the combination of sweet-acid tastes. Tests for paired comparison, ranking and structured verbal scales for sweet and acid attributes and psychophysical test were carried out. There was a perceptible difference among samples for differences of 0.4 units of acid concentration. Samples indicated as sweeter by 89.47% of the judges were those containing a lesser acid concentration. A reduction in glycerol sweetness when increasing acid levels was observed. Acetic acid reduced the sweetness of glycerol and inversely glycerol reduced the acidity of acetic acid. The data obtained with the magnitude estimation test agree with Steven's law.Foram incorporados glicerol (17%, cloreto de sódio (1,5% e sorbato de potássio (0.1% nas seguintes porcentagens de ácido: 0,2; 0,4; 0,6; 0,8; 1 e 1,5% p/p, em um patê elaborado a partir de congro-real (Percophis brasiliensis cozido, com o intuito de determinar a relação entre o ácido acético adicionado e a intensidade sensorialmente percebida, assim como o efeito da combinação dos gostos doce e ácido. Foram realizados testes de comparação pareada, de classificação e também estruturada uma escala verbal para os atributos ácido e doce, e testes psicofísicos. Foi percebida diferença entre as amostras com diferença de 0,4 unidades de concentração de ácido. As amostras indicadas como as mais doces por 89,47% dos julgadores foram as que continham menor concentração de ácido. Foi observada a redução da doçura do glicerol quando aumentaram os níveis de ácido. O ácido acético reduziu a doçura do glicerol e, inversamente, o glicerol reduziu a acidez do

  7. Modeling of an immobilized lipase tubular reactor for the production of glycerol and fatty acids from oils; Modelado de un reactor tubular de lipasas inmovilizadas para la produccion de glicerol y acidos grasos a partir de aceites

    Energy Technology Data Exchange (ETDEWEB)

    Oddone, S.; Grasselli, M.; Cuellas, A.

    2010-07-01

    Advances in the design of a bioreactor in the fats and oils industry have permitted the hydrolysis of triglycerides in mild conditions and improved productivity while avoiding the formation of unwanted byproducts. The present work develops a mathematical model that describes the hydrolytic activity of a tubular reactor with immobilized lipases for the production of glycerol and fatty acids from the oil trade. Runge Kuttas numerical method of high order has been applied, considering that there is no accumulation of the substratum in the surface of the membrane, where the enzyme is. At the same time, different equations based on the kinetic model of Michaelis Mentens and the Ping-Pong bi-bi mechanism were examined. Experimental data in discontinuous systems are the basis for the development of the quantitative mathematical model that was used to simulate the process computationally. The obtained results allow for optimizing both the operative variables and the economic aspects of industrial processes. (Author)

  8. Polymeric blends from post-consumer PET and polyester becoming of glycerol and phthalic acid; Misturas polimericas a partir do PET pos-consumo e poliesteres derivados do gliceraol e acido ftalico

    Energy Technology Data Exchange (ETDEWEB)

    Miranda, C.S.; Brioude, M.; Fiuza, R.P.; Luporini, S.; Carvalho, R.F.; Jose, N.M., E-mail: cleidienesm@gmail.co [Universidade Federal da Bahia (GECIM/UFBA), Salvador, BA (Brazil). Inst. de Quimica. Grupo de Energia e Ciencias dos Materiais

    2010-07-01

    Preparation of physical mixture or polymer blends is a very important method to obtain a final product with excellent balance of properties, where one component can compensate for the poor property of another, and is often a modified low cost compared to development and synthesis of a new polymer. PET has become a major waste of post-consumer plastics and aiming to remedy this problem, this work aims to obtain blends from recycled PET and polyesters derived from glycerol and phthalic acid. The material with higher proportion of PET showed better thermal properties, observed by TGA and DSC, with a similar profile of pure PET. In XRD analysis showed a semicrystalline, while the SEM is a smooth surface on all materials, characteristic of pure polyester. The ratio of 50% its surface showed a probable immiscibility of polymers. (author)

  9. Increased amount of phosphorylated proinflammatory osteopontin in rheumatoid arthritis synovia is associated to decreased tartrate-resistant acid phosphatase 5B/5A ratio.

    Directory of Open Access Journals (Sweden)

    Jani Luukkonen

    Full Text Available Osteopontin (OPN is an immunoregulatory protein which production increases in both rheumatoid arthritis (RA and osteoarthritis (OA. Phosphorylated osteopontin (Phospho-OPN is known to increase macrophage and osteoclast activation, this process is controlled by extracellular tartrate-resistant acid phosphatase (TRAcP, also a biomarker for RA. Here, we evaluated the phosphorylation status of OPN in RA and OA synovia, as well as its correlation with TRAcP isoforms.Synovial tissue and fluid were obtained from 24 RA (14 seropositive and 10 seronegative and 24 OA patients. Western blotting was used to analyze the extent of OPN phosphorylation. TRAcP isoforms were measured in synovial fluid using ELISA; immunohistochemistry assessed the distribution of OPN and TRAcP expressing cells in the synovial tissue, especially distinguishing between the TRAcP isoforms.Full-length OPN was more phosphorylated in RA than in OA (p<0.05. The thrombin cleaved C-terminal end of OPN was also more phosphorylated in RA (p<0.05. RA patients had a lower concentration of TRAcP 5B and higher concentration of less active 5A in their synovial fluid compared to OA patients. The TRAcP 5B/5A ratio was decreased in RA and correlated negatively with the amount of phospho-OPN (p<0.05. TRAcP positive cells for both isoforms were found all along the synovial lining; OPN antibody staining was localized in the extracellular matrix.Our data suggests that in RA the synovial fluid contains insufficient amounts of TRAcP 5B which increase levels of the proinflammatory phospho-OPN. This may lead to increased macrophage and osteoclast activation, resulting in the increased local inflammation and bone resorption present in RA joints.

  10. Microarray Expression Analyses of Arabidopsis Guard Cells and Isolation of a Recessive Abscisic Acid Hypersensitive Protein Phosphatase 2C MutantW⃞

    Science.gov (United States)

    Leonhardt, Nathalie; Kwak, June M.; Robert, Nadia; Waner, David; Leonhardt, Guillaume; Schroeder, Julian I.

    2004-01-01

    Oligomer-based DNA Affymetrix GeneChips representing about one-third of Arabidopsis (Arabidopsis thaliana) genes were used to profile global gene expression in a single cell type, guard cells, identifying 1309 guard cell–expressed genes. Highly pure preparations of guard cells and mesophyll cells were isolated in the presence of transcription inhibitors that prevented induction of stress-inducible genes during cell isolation procedures. Guard cell expression profiles were compared with those of mesophyll cells, resulting in identification of 64 transcripts expressed preferentially in guard cells. Many large gene families and gene duplications are known to exist in the Arabidopsis genome, giving rise to redundancies that greatly hamper conventional genetic and functional genomic analyses. The presented genomic scale analysis identifies redundant expression of specific isoforms belonging to large gene families at the single cell level, which provides a powerful tool for functional genomic characterization of the many signaling pathways that function in guard cells. Reverse transcription–PCR of 29 genes confirmed the reliability of GeneChip results. Statistical analyses of promoter regions of abscisic acid (ABA)–regulated genes reveal an overrepresented ABA responsive motif, which is the known ABA response element. Interestingly, expression profiling reveals ABA modulation of many known guard cell ABA signaling components at the transcript level. We further identified a highly ABA-induced protein phosphatase 2C transcript, AtP2C-HA, in guard cells. A T-DNA disruption mutation in AtP2C-HA confers ABA-hypersensitive regulation of stomatal closing and seed germination. The presented data provide a basis for cell type–specific genomic scale analyses of gene function. PMID:14973164

  11. Identification of Open Stomata1-Interacting Proteins Reveals Interactions with Sucrose Non-fermenting1-Related Protein Kinases2 and with Type 2A Protein Phosphatases That Function in Abscisic Acid Responses1[OPEN

    Science.gov (United States)

    Waadt, Rainer; Manalansan, Bianca; Rauniyar, Navin; Munemasa, Shintaro; Booker, Matthew A.; Brandt, Benjamin; Waadt, Christian; Nusinow, Dmitri A.; Kay, Steve A.; Kunz, Hans-Henning; Schumacher, Karin; DeLong, Alison; Yates, John R.; Schroeder, Julian I.

    2015-01-01

    The plant hormone abscisic acid (ABA) controls growth and development and regulates plant water status through an established signaling pathway. In the presence of ABA, pyrabactin resistance/regulatory component of ABA receptor proteins inhibit type 2C protein phosphatases (PP2Cs). This, in turn, enables the activation of Sucrose Nonfermenting1-Related Protein Kinases2 (SnRK2). Open Stomata1 (OST1)/SnRK2.6/SRK2E is a major SnRK2-type protein kinase responsible for mediating ABA responses. Arabidopsis (Arabidopsis thaliana) expressing an epitope-tagged OST1 in the recessive ost1-3 mutant background was used for the copurification and identification of OST1-interacting proteins after osmotic stress and ABA treatments. These analyses, which were confirmed using bimolecular fluorescence complementation and coimmunoprecipitation, unexpectedly revealed homo- and heteromerization of OST1 with SnRK2.2, SnRK2.3, OST1, and SnRK2.8. Furthermore, several OST1-complexed proteins were identified as type 2A protein phosphatase (PP2A) subunits and as proteins involved in lipid and galactolipid metabolism. More detailed analyses suggested an interaction network between ABA-activated SnRK2-type protein kinases and several PP2A-type protein phosphatase regulatory subunits. pp2a double mutants exhibited a reduced sensitivity to ABA during seed germination and stomatal closure and an enhanced ABA sensitivity in root growth regulation. These analyses add PP2A-type protein phosphatases as another class of protein phosphatases to the interaction network of SnRK2-type protein kinases. PMID:26175513

  12. Design and analysis of biorefineries based on raw glycerol: addressing the glycerol problem.

    Science.gov (United States)

    Posada, John A; Rincón, Luis E; Cardona, Carlos A

    2012-05-01

    Glycerol as a low-cost by-product of the biodiesel industry can be considered a renewable building block for biorefineries. In this work, the conversion of raw glycerol to nine added-value products obtained by chemical (syn-gas, acrolein, and 1,2-propanediol) or bio-chemical (ethanol, 1,3-propanediol, d-lactic acid, succinic acid, propionic acid, and poly-3-hydroxybutyrate) routes were considered. The technological schemes for these synthesis routes were designed, simulated, and economically assessed using Aspen Plus and Aspen Icarus Process Evaluator, respectively. The techno-economic potential of a glycerol-based biorefinery system for the production of fuels, chemicals, and plastics was analyzed using the commercial Commercial Sale Price/Production Cost ratio criteria, under different production scenarios. More income can be earned from 1,3-propanediol and 1,2-propanediol production, while less income would be obtained from hydrogen and succinic acid. This analysis may be useful mainly for biodiesel producers since several profitable alternatives are presented and discussed. Copyright © 2012 Elsevier Ltd. All rights reserved.

  13. Effects of visceral adiposity on glycerol pathways in gluconeogenesis.

    Science.gov (United States)

    Neeland, Ian J; Hughes, Connor; Ayers, Colby R; Malloy, Craig R; Jin, Eunsook S

    2017-02-01

    To determine the feasibility of using oral 13 C labeled glycerol to assess effects of visceral adiposity on gluconeogenic pathways in obese humans. Obese (BMI ≥30kg/m 2 ) participants without type 2 diabetes underwent visceral adipose tissue (VAT) assessment and stratification by median VAT into high VAT-fasting (n=3), low VAT-fasting (n=4), and high VAT-refed (n=2) groups. Participants ingested [U- 13 C 3 ] glycerol and blood samples were subsequently analyzed at multiple time points over 3h by NMR spectroscopy. The fractions of plasma glucose (enrichment) derived from [U- 13 C 3 ] glycerol via hepatic gluconeogenesis, pentose phosphate pathway (PPP), and tricarboxylic acid (TCA) cycle were assessed using 13 C NMR analysis of glucose. Mixed linear models were used to compare 13 C enrichment in glucose between groups. Mean age, BMI, and baseline glucose were 49years, 40.1kg/m 2 , and 98mg/dl, respectively. Up to 20% of glycerol was metabolized in the TCA cycle prior to gluconeogenesis and PPP activity was minor (gluconeogenesis from glycerol in obese humans. Our findings provide preliminary evidence that excess visceral fat disrupts multiple pathways in hepatic gluconeogenesis from glycerol. Copyright © 2016 Elsevier Inc. All rights reserved.

  14. The homeodomain-leucine zipper (HD-Zip) class I transcription factors ATHB7 and ATHB12 modulate abscisic acid signalling by regulating protein phosphatase 2C and abscisic acid receptor gene activities.

    Science.gov (United States)

    Valdés, Ana Elisa; Overnäs, Elin; Johansson, Henrik; Rada-Iglesias, Alvaro; Engström, Peter

    2012-11-01

    Plants perceiving drought activate multiple responses to improve survival, including large-scale alterations in gene expression. This article reports on the roles in the drought response of two Arabidopsis thaliana homeodomain-leucine zipper class I genes; ATHB7 and ATHB12, both strongly induced by water-deficit and abscisic acid (ABA). ABA-mediated transcriptional regulation of both genes is shown to depend on the activity of protein phosphatases type 2C (PP2C). ATHB7 and ATHB12 are, thus, targets of the ABA signalling mechanism defined by the PP2Cs and the PYR/PYL family of ABA receptors, with which the PP2C proteins interact. Our results from chromatin immunoprecipitation and gene expression analyses demonstrate that ATHB7 and ATHB12 act as positive transcriptional regulators of PP2C genes, and thereby as negative regulators of abscisic acid signalling. In support of this notion, our results also show that ATHB7 and ATHB12 act to repress the transcription of genes encoding the ABA receptors PYL5 and PYL8 in response to an ABA stimulus. In summary, we demonstrate that ATHB7 and ATHB12 have essential functions in the primary response to drought, as mediators of a negative feedback effect on ABA signalling in the plant response to water deficit.

  15. Age-related changes of serum tartrate-resistant acid phosphatase 5b and the relationship with bone mineral density in Chinese women

    Institute of Scientific and Technical Information of China (English)

    Yue-juan QIN; Zhen-lin ZHANG; Hao ZHANG; Wei-wei HU; Yu-juan LIU; Yun-qiu HU; Miao LI; Jie-mei GU; Jin-wei HE

    2008-01-01

    Aim: Ostcoclastic activity is mainly assessed by measurement of urinary markers (eg C-terminal cross-linked telopeptides of type I collagen, N-terminal cross-linked telopeptides of type I collagen etc), the levels of which could often be affected by renal clearance. Recently, serum tartrate-resistant acid phosphatase 5b (TRACP5b) has been used as an alternative serum marker to evaluate osteoclastic activity. We investigated the age-related changes of TRACP5b level and its association with bone mineral density (BMD) in Chinese women. Methods: Seven-hundred and twenty-two Chinese mainland women aged 20-79 years were recruited in the study. Serum TRACP5b level was measured using immunoassay to evaluate the state of bone resorption. Bone mineral density (BMD) (g/cm2) at lumbar spine 1-4 and proximal femur were measured by duel-energy X-ray absorptiometry. Results: The serum TRACP5b level reached a bottom value in premenopausal women aged 30-39, gradually increased in women aged 40-49, rapidly rose in women aged 50-59, and culminated with a maximum value in women aged 60-69 before a slow drop in women aged 70-79. The average level of TRACPSb was significantly higher in postmenopausal women [(3.29±1.07) U/L] than in premenopausal women ([1.70±0.59] U/L). The levels of TRACP5b were inversely correlated with BMD at all measured sites (P<0.001). Furthermore, the level of TRACP5b was obviously higher in women with osteoporosis and osteopenia than those with normal bone mass (P<0.001). Conclusion: We have established the reference values of serum TRACPSb in Chinese mainland women, and found that postmenopausal women had higher TRACP5b concentration than younger women. The results showed that serum TRACPSb was a sensitive and useful parameter for the evaluation of age-related changes of bone absorption.

  16. A widespread amino acid polymorphism at codon 905 of the glycogen-associated regulatory subunit of protein phosphatase-1 is associated with insulin resistance and hypersecretion of insulin

    DEFF Research Database (Denmark)

    Hansen, L; Hansen, T; Vestergaard, H

    1995-01-01

    The regulatory G-subunit of the glycogen-associated form of protein phosphatase 1 (PP1) plays a crucial part in muscle tissue glycogen synthesis and breakdown. As impaired insulin stimulated glycogen synthesis in peripheral tissues is considered to be a pathogenic factor in subsets of non-insulin...

  17. Optimization for microwave-assisted direct liquefaction of bamboo residue in glycerol/methanol mixtures

    Science.gov (United States)

    Jiulong Xie; Jinqiu Qi; Chungyun Hse; Todd F. Shupe

    2015-01-01

    Bamboo residues were liquefied in a mixture of glycerol and methanol in the presence of sulfuric acid using microwave energy. We investigated the effects of liquefaction conditions, including glycerol/methanol ratio, liquefaction temperature, and reaction time on the conversion yield. The optimal liquefaction conditions were under the temperature of 120

  18. Synthesis of biodiesel fuel additives from glycerol using green chemistry and supercritical fluids

    Science.gov (United States)

    For every 3 moles of fatty acid esters produced, 1 mole of glycerol remains, ~11% of the biodiesel volume. One new method of glycerol use could be as a biodiesel fuel additive/extender using eco-friendly heterogeneous catalysts and supercritical fluids (SFs). SFs have advantages such as greater diff...

  19. Glycerol acetals, kinetic study of the reaction between glycerol and formaldehyde

    International Nuclear Information System (INIS)

    Agirre, I.; Garcia, I.; Requies, J.; Barrio, V.L.; Gueemez, M.B.; Cambra, J.F.; Arias, P.L.

    2011-01-01

    The acetalization reaction between glycerol and formaldehyde using Amberlyst 47 acidic ion exchange resin was studied. These acetals can be obtained from renewable sources (bioalcohols and bioalcohol derived aldehydes) and seem to be good candidates for different applications such as oxygenated diesel additives. A preliminary kinetic study was performed in a batch stirred tank reactor studying the influence of different process parameters like temperature, feed composition and the stirring speed. A pseudo homogenous kinetic model able to explain the reaction mechanism was adjusted. Thus, the corresponding order of reaction was determined. Amberlyst 47 acidic ion exchange resin showed a fairly good behavior allowing 100% of selectivity towards acetals formation. However, the studied acetalization reaction showed high thermodynamic limitations achieving glycerol conversions around 50% using a stoichiometric feed ratio at 353 K. The product is a mixture of two isomers (1,3-Dioxan-5-ol and 1,3-dioxolane-4-methanol) and the conversion of 1,3-dioxolane-4-methanol into 1,3-Dioxan-5-ol was also observed. -- Highlights: → The reaction between glycerol and acetaldehyde shows thermodynamic limitations. → Amberlyst 47 ion exchange resins show 100% of selectivity. → A pseudo-homogeneous kinetic model is able to predict the reaction progress. → Isomerization reactions were observed from dioxalanes to dioxanes.

  20. Application of Glycerol for Induced Powdery Mildew Resistance in Triticum aestivum L.

    Science.gov (United States)

    Li, Yinghui; Song, Na; Zhao, Chuanzhi; Li, Feng; Geng, Miaomiao; Wang, Yuhui; Liu, Wanhui; Xie, Chaojie; Sun, Qixin

    2016-01-01

    Previous work has demonstrated that glycerol-3-phosphate (G3P) and oleic acid (18:1) are two important signal molecules associated with plant resistance to fungi. In this article, we provide evidence that a 3% glycerol spray application 1-2 days before powdery mildew infection and subsequent applications once every 4 days was sufficient to stimulate the plant defense responses without causing any significant damage to wheat leaves. We found that G3P and oleic acid levels were markedly induced by powdery mildew infection. In addition, TaGLI1 (encoding a glycerol kinase) and TaSSI2 (encoding a stearoylacyl carrier protein fatty acid desaturase), two genes associated with the glycerol and fatty acid (FA) pathways, respectively, were induced by powdery mildew infection, and their promoter regions contain some fungal response elements. Moreover, exogenous application of glycerol increased the G3P level and decreased the level of oleic acid (18:1). Glycerol application induced the expression of pathogenesis-related ( PR ) genes ( TaPR-1, TaPR-2, TaPR-3, TaPR-4 , and TaPR-5 ), induced the generation of reactive oxygen species (ROS) before powdery mildew infection, and induced salicylic acid (SA) accumulation in wheat leaves. Further, we sprayed glycerol in a wheat field and found that it significantly ( p powdery mildew disease and lessened disease-associated kernel weight loss, all without causing any noticeable degradation in wheat seed quality.

  1. N-Glycosylation Improves the Pepsin Resistance of Histidine Acid Phosphatase Phytases by Enhancing Their Stability at Acidic pHs and Reducing Pepsin's Accessibility to Its Cleavage Sites

    Science.gov (United States)

    Niu, Canfang; Luo, Huiying; Shi, Pengjun; Huang, Huoqing; Wang, Yaru; Yang, Peilong

    2015-01-01

    N-Glycosylation can modulate enzyme structure and function. In this study, we identified two pepsin-resistant histidine acid phosphatase (HAP) phytases from Yersinia kristensenii (YkAPPA) and Yersinia rohdei (YrAPPA), each having an N-glycosylation motif, and one pepsin-sensitive HAP phytase from Yersinia enterocolitica (YeAPPA) that lacked an N-glycosylation site. Site-directed mutagenesis was employed to construct mutants by altering the N-glycosylation status of each enzyme, and the mutant and wild-type enzymes were expressed in Pichia pastoris for biochemical characterization. Compared with those of the N-glycosylation site deletion mutants and N-deglycosylated enzymes, all N-glycosylated counterparts exhibited enhanced pepsin resistance. Introduction of the N-glycosylation site into YeAPPA as YkAPPA and YrAPPA conferred pepsin resistance, shifted the pH optimum (0.5 and 1.5 pH units downward, respectively) and improved stability at acidic pH (83.2 and 98.8% residual activities at pH 2.0 for 1 h). Replacing the pepsin cleavage sites L197 and L396 in the immediate vicinity of the N-glycosylation motifs of YkAPPA and YrAPPA with V promoted their resistance to pepsin digestion when produced in Escherichia coli but had no effect on the pepsin resistance of N-glycosylated enzymes produced in P. pastoris. Thus, N-glycosylation may improve pepsin resistance by enhancing the stability at acidic pH and reducing pepsin's accessibility to peptic cleavage sites. This study provides a strategy, namely, the manipulation of N-glycosylation, for improvement of phytase properties for use in animal feed. PMID:26637601

  2. Acrolein Production by Gas-Phase Glycerol Dehydration Using PO₄/Nb₂O5 Catalysts.

    Science.gov (United States)

    Lee, Kyu Am; Ryoo, HeeKyoung; Ma, Byung Chol; Kim, Youngchul

    2018-02-01

    In this study, modified niobium oxide were prepared to study the addictive effects on the catalytic performance for gas-phase glycerol dehydration. The catalysts were characterized by N2 adsorption/desorption, XRD, NH3-TPD, FT-IR. The amount of phosphoric acid was up to 50 wt% in niobium. As a result, the highest glycerol conversion was achieved over 20 wt% PO4/Nb2O5. It indicates that the optimal amount of phosphoric acid leads the catalyst to have appropriate acidity which is an important factor for gas-phase glycerol dehydration.

  3. Modelando a coordenação de fosfato com o sítio ativo das fosfatases ácidas púrpuras Modeling the coordination of phosphate to the active site of purple acid phosphatases

    OpenAIRE

    Marcos Aires de Brito; Ademir Neves; Luiz R. Zilli

    1997-01-01

    We present a new binuclear complex, Fe2III(BBPMP)(OH)(O2 P(OPh)2) ClO4.CH3OH, 3, where BBPMP is the anion of 2,6-bis(2-hydroxybenzyl)(2-pyridylmethyl) aminomethyl-4-methylphenol, as a suitable model for the chromophoric site of purple acid phosphatases coordinated to phosphate. The complex was obtained by the reaction of complex 2, Fe2III(BBPMP)(O2P(OPh) 2)2 ClO4.H2O, in CH3CN with one equivalent of triethylamine. Based on the chromophoric properties of the model complex, lmax = 560 nm/ e = 4...

  4. Concentrations of testosterone, luteal hormone and prolactin in the serum as well as comparisons of sensitivity between radioimmunoassays and enzyme assays for the detection of acid prostate phosphatase in the presence of carcinomas of the prostate

    International Nuclear Information System (INIS)

    Vopelius-Feldt, F. von.

    1986-01-01

    The relationship between carcinomas of the prostate and the plasma levels of testosterone, luteal hormone and prolactin as well as the possible influence of these neoplasms on the testosterone binding capacity and free testosterone index are investigated for various tumour stages and degrees of histological differentiation, in connection with several forms of local therapy as well as a variety of contrasexual methods. The sensitivity of enzyme assays and radioimmunoassays for the detection of acid prostate phosphatase is evaluated within the framework of this study. (MBL) [de

  5. Glycerol Production from Glucose and Fructose by 3T3-L1 Cells: A Mechanism of Adipocyte Defense from Excess Substrate.

    Directory of Open Access Journals (Sweden)

    María del Mar Romero

    Full Text Available Cultured adipocytes (3T3-L1 produce large amounts of 3C fragments; largely lactate, depending on medium glucose levels. Increased glycolysis has been observed also in vivo in different sites of rat white adipose tissue. We investigated whether fructose can substitute glucose as source of lactate, and, especially whether the glycerol released to the medium was of lipolytic or glycolytic origin. Fructose conversion to lactate and glycerol was lower than that of glucose. The fast exhaustion of medium glucose was unrelated to significant changes in lipid storage. Fructose inhibited to a higher degree than glucose the expression of lipogenic enzymes. When both hexoses were present, the effects of fructose on gene expression prevailed over those of glucose. Adipocytes expressed fructokinase, but not aldolase b. Substantive release of glycerol accompanied lactate when fructose was the substrate. The mass of cell triacylglycerol (and its lack of change could not justify the comparatively higher amount of glycerol released. Consequently, most of this glycerol should be derived from the glycolytic pathway, since its lipolytic origin could not be (quantitatively sustained. Proportionally (with respect to lactate plus glycerol, more glycerol was produced from fructose than from glucose, which suggests that part of fructose was catabolized by the alternate (hepatic fructose pathway. Earlier described adipose glycerophophatase activity may help explain the glycolytic origin of most of the glycerol. However, no gene is known for this enzyme in mammals, which suggests that this function may be carried out by one of the known phosphatases in the tissue. Break up of glycerol-3P to yield glycerol, may be a limiting factor for the synthesis of triacylglycerols through control of glycerol-3P availability. A phosphatase pathway such as that described may have a potential regulatory function, and explain the production of glycerol by adipocytes in the absence of

  6. Polyesters production from the mixture of phthalic acid, terephthalic and glycerol; Producao de poliesteres a partir da mistura de acido ftalico, tereftalico e glicerol

    Energy Technology Data Exchange (ETDEWEB)

    Carvalho, A.L.S.; Oliveira, J.C.; Miranda, C.S.; Boaventura, J.S.; Jose, N.M., E-mail: adrianaequfba@gmail.co [Universidade Federal da Bahia (GECIM/UFBA), Salvador, BA (Brazil). Inst. de Quimica. Grupo de Energia e Ciencias dos Materiais; Carvalho, R.F. [Universidade Federal da Bahia (UFBA), Salvador, BA (Brazil). Escola Politecnica. Curso de Mestrado em Engenharia Ambiental Urbana

    2010-07-01

    Glycerin, a byproduct of biodiesel is currently an environmental and economic problem for producers of this renewable fuel in Brazil and in others parts of the world. In order to offer new proposals for recovery, it is used for the manufacture of polyesters used in applications in diverse areas such as construction and automobile industry. This work reports the production of polymer from the mixture of terephthalic and phthalic acid in three different proportions. The polyesters showed good thermal stability, analyzed by TGA and DSC, with an increase proportional to the terephthalic acid content. The X-ray diffraction patterns show that the samples are semi crystalline polymers. The micrographs indicated the presence of a smoother surface in the polyester that has a larger amount of phthalic acid, as reported in the literature. Therefore, the materials showed good thermal properties and morphological characteristics, so it consists in a new alternative to use glycerin. (author)

  7. Preparation of polymer blends from glycerol, fumaric acid and of poly(ethylene terephthalate) (PET) recycled; Preparacao de blendas polimericas a partir do glicerol, acido fumarico e do politereftalato de etileno (PET) pos consumo

    Energy Technology Data Exchange (ETDEWEB)

    Medeiros, Marina A.O.; Guimaraes, Danilo H.; Brioude, Michel M.; Jose, Nadia M. [Instituto de Quimica, Universidade Federal da Bahia, Salvador, BA (Brazil); Prado, Luis A.S. de A. [Institut fuer Kunststoffe und Verbundwerkstoffe - Technische Universitaet Hamburg-Harburg, Hamburg (Germany)

    2011-07-01

    Polymer blends based on recycled poly(ethylene terephthalate) (PET) and poly(glycerol fumarate) polyesters were prepared in different PET concentrations. The PET powder was dispersed during the poly(glycerol fumarate) synthesis at 260 deg C. The resulting blends were characterized by X-ray diffraction. The thermal stability of the materials was evaluated by thermogravimetric analysis and differential scanning calorimetry. The morphology was studies by scanning electron microscopy. The blends were clearly immiscible. The possibility of (interfacial) compatibilization of the PET domains, caused by transesterification reactions between PET and glycerol were discussed. (author)

  8. Acute effect on satiety, resting energy expenditure, respiratory quotient, glucagon-like peptide-1, free fatty acids, and glycerol following consumption of a combination of bioactive food ingredients in overweight subjects.

    Science.gov (United States)

    Rondanelli, Mariangela; Opizzi, Annalisa; Perna, Simone; Faliva, Milena; Solerte, Sebastiano Bruno; Fioravanti, Marisa; Klersy, Catherine; Edda, Cava; Maddalena, Paolini; Luciano, Scavone; Paola, Ceccarelli; Emanuela, Castellaneta; Claudia, Savina; Donini, Lorenzo Maria

    2013-01-01

    A combination of bioactive food ingredients (capsaicinoids, epigallocatechin gallate, piperin, and l-carnitine, CBFI) may promote satiety and thermogenesis. The study was conducted in order to assess whether there is any effect on satiety, resting energy expenditure (REE), respiratory quotient, glucagon-like peptide-1 (GLP-1), free fatty acids (FFA) and glycerol release, following a standardized mixed meal with or without single consumption of a CBFI. An 8-week randomized double-blind placebo-controlled trial. Dietetic and Metabolic Unit, Azienda di Servizi alla Persona, University of Pavia and "Villa delle Querce" Clinical Rehabilitation Institute, Rome, Italy. Thirty-seven overweight adults (body mass index [BMI]: 25-35). Nineteen overweight subjects were included in the supplemented group (14 women, 5 men; age 46.4 ± 6.4; BMI: 30.5 ± 3.3) and 18 in the placebo group (13 women, 5 men; age 40.8 ± 11.5; BMI: 30.1 ± 2.6). Satiety was assessed using 100-mm visual analogue scales (VAS) and the area under the curve was calculated. All measured parameters increased significantly in comparison with baseline in response to meal, both with CBFI and with placebo. However, throughout the study day, the supplemented group experienced a significantly greater increase than the placebo group in their sensation of satiety following acute administration of the supplement. CBFI may therefore be of great value in the treatment of overweight patients by increasing satiety and stimulating thermogenesis.

  9. Biochemical Characterization of Mycobacterium smegmatis RnhC (MSMEG_4305), a Bifunctional Enzyme Composed of Autonomous N-Terminal Type I RNase H and C-Terminal Acid Phosphatase Domains.

    Science.gov (United States)

    Jacewicz, Agata; Shuman, Stewart

    2015-08-01

    Mycobacterium smegmatis encodes several DNA repair polymerases that are adept at incorporating ribonucleotides, which raises questions about how ribonucleotides in DNA are sensed and removed. RNase H enzymes, of which M. smegmatis encodes four, are strong candidates for a surveillance role. Here, we interrogate the biochemical activity and nucleic acid substrate specificity of M. smegmatis RnhC, a bifunctional RNase H and acid phosphatase. We report that (i) the RnhC nuclease is stringently specific for RNA:DNA hybrid duplexes; (ii) RnhC does not selectively recognize and cleave DNA-RNA or RNA-DNA junctions in duplex nucleic acid; (iii) RnhC cannot incise an embedded monoribonucleotide or diribonucleotide in duplex DNA; (iv) RnhC can incise tracts of 4 or more ribonucleotides embedded in duplex DNA, leaving two or more residual ribonucleotides at the cleaved 3'-OH end and at least one or two ribonucleotides on the 5'-PO4 end; (v) the RNase H activity is inherent in an autonomous 140-amino-acid (aa) N-terminal domain of RnhC; and (vi) the C-terminal 211-aa domain of RnhC is an autonomous acid phosphatase. The cleavage specificity of RnhC is clearly distinct from that of Escherichia coli RNase H2, which selectively incises at an RNA-DNA junction. Thus, we classify RnhC as a type I RNase H. The properties of RnhC are consistent with a role in Okazaki fragment RNA primer removal or in surveillance of oligoribonucleotide tracts embedded in DNA but not in excision repair of single misincorporated ribonucleotides. RNase H enzymes help cleanse the genome of ribonucleotides that are present either as ribotracts (e.g., RNA primers) or as single ribonucleotides embedded in duplex DNA. Mycobacterium smegmatis encodes four RNase H proteins, including RnhC, which is characterized in this study. The nucleic acid substrate and cleavage site specificities of RnhC are consistent with a role in initiating the removal of ribotracts but not in single-ribonucleotide surveillance. Rnh

  10. Etherification of Glycerol with Propylene or 1-Butene for Fuel Additives

    Directory of Open Access Journals (Sweden)

    Chakrapong Saengarun

    2017-01-01

    Full Text Available The etherification of glycerol with propylene over acidic heterogeneous catalysts, Amberlyst-15, S100, and S200 resins, produced mono-propyl glycerol ethers (MPGEs, 1,3-di- and 1,2-di-propyl glycerol ethers (DPGEs, and tri-propyl glycerol ether (TPGE. The propylation of glycerol over Amberlyst-15 yielded only TPGE. The glycerol etherification with 1-butene over Amberlyst-15 and S200 resins produced 1-mono-, 2-mono-, 1,2-di-, and 1,3-di-butyl glycerol ethers (1-MBGE, 2-MBGE, 1,2-DBGE, and 1,3-DBGE. The use of Amberlyst-15 resulted in the propylation and butylation of glycerol with higher yields than those obtained from the S100 and S200 resins. The PGEs, TPGE, and BGEs were evaluated as cold flow improvers and octane boosters. These alkyl glycerol ethers can reduce the cloud point of blended palm biodiesels with diesel. They can increase the research octane number and the motor octane number of gasoline.

  11. Engineering of the glycerol decomposition pathway and cofactor regulation in an industrial yeast improves ethanol production.

    Science.gov (United States)

    Zhang, Liang; Tang, Yan; Guo, Zhongpeng; Shi, Guiyang

    2013-10-01

    Glycerol is a major by-product of industrial ethanol production and its formation consumes up to 4 % of the sugar substrate. This study modified the glycerol decomposition pathway of an industrial strain of Saccharomyces cerevisiae to optimize the consumption of substrate and yield of ethanol. This study is the first to couple glycerol degradation with ethanol formation, to the best of our knowledge. The recombinant strain overexpressing GCY1 and DAK1, encoding glycerol dehydrogenase and dihydroxyacetone kinase, respectively, in glycerol degradation pathway, exhibited a moderate increase in ethanol yield (2.9 %) and decrease in glycerol yield (24.9 %) compared to the wild type with the initial glucose concentration of 15 % under anaerobic conditions. However, when the mhpF gene, encoding acetylating NAD⁺-dependent acetaldehyde dehydrogenase from Escherichia coli, was co-expressed in the aforementioned recombinant strain, a further increase in ethanol yield by 5.5 % and decrease in glycerol yield by 48 % were observed for the resultant recombinant strain GDMS1 when acetic acid was added into the medium prior to inoculation compared to the wild type. The process outlined in this study which enhances glycerol consumption and cofactor regulation in an industrial yeast is a promising metabolic engineering strategy to increase ethanol production by reducing the formation of glycerol.

  12. Towards the sustainable production of acrolein by glycerol dehydration.

    Science.gov (United States)

    Katryniok, Benjamin; Paul, Sébastien; Capron, Mickaël; Dumeignil, Franck

    2009-01-01

    The massive increase in biodiesel production by transesterification of vegatable oils goes hand-in-hand with the availability of a large volume of glycerol, which must be valorized. Glycerol dehydration to acrolein over acid catalysts is one of the most promising ways of valorization, because this compound is an important chemical intermediate used in, for example, the DL-methionine synthesis. In this Minireview, we give a detailed critical view of the state-of-the-art of this dehydration reaction. The processes developed in both the liquid and the gas phases are detailed and the best catalytic results obtained so far are reported as a benchmark for future developments. The advances on the understanding of the reaction mechanism are also discussed and we further focus particularly on the main obstacles for an immediate industrial application of this technology, namely catalyst coking and crude glycerol direct-use issues.

  13. Penggunaan H-Zeolit dan Tawas dalam Pemurnian Crude Glycerol dengan Proses Adsorpsi dan Koagulasi

    Directory of Open Access Journals (Sweden)

    Isalmi Aziz, M.T

    2017-05-01

    Full Text Available Production of biodiesel from used cooking oil byproducts such as crude glycerol with low purity. The crude glycerol containing compounds impurities such as free fatty acids, alcohol, soap, catalyst and water. Compound adsorption of impurities can be done with the H-zeolite as adsorbent, but the resulting quality is still not good. To improve its quality, this research was added alum (coagulation process so that the adsorption of colloidal-sized compound impurities which can be separated from the glycerol. The purpose of this research is determine optimal condition of adsorption and coagulation impurity compounds of crude glycerol by using H-zeolite and  alum and  also determine quality of glycerol  was obtained. First, crude glycerol acidified by phosphoric acid 85% (pure analysis until desired pH ±2.5. It was obtained purity of glycerol 72.797%. The next process is adsorption with activated H-zeolite and it obtained purity of glycerol 77.079%. The last process in this research is adsorption and coagulation by using H-zeolite and alum. The highest purity glycerol 93.803% was obtained from condition of adsorption and coagulation for 75 minutes; alum’s concentration 80 ppm; and temperature 60 ºC. The glycerol discharged from adsorption and coagulation process by using H-zeolite and alum is qualify Indonesia National Standard number 06-1564-1995 with 3.512% water content; 2.438% ash content; 0.247% MONG content; has no sugar; 1.259 g/mL density of glycerol; 0.2356% potassium content and 0.0410% aluminium content; and brighter color.DOI: http://dx.doi.org/10.15408/jkv.v0i0.5143

  14. Redox regulation of protein tyrosine phosphatase 1B (PTP1B): Importance of steric and electronic effects on the unusual cyclization of the sulfenic acid intermediate to a sulfenyl amide

    Science.gov (United States)

    Sarma, Bani Kanta

    2013-09-01

    The redox regulation of protein tyrosine phosphatase 1B (PTP1B) via the unusual transformation of its sulfenic acid (PTP1B-SOH) to a cyclic sulfenyl amide intermediate is studied by using small molecule chemical models. These studies suggest that the sulfenic acids derived from the H2O2-mediated reactions o-amido thiophenols do not efficiently cyclize to sulfenyl amides and the sulfenic acids produced in situ can be trapped by using methyl iodide. Theoretical calculations suggest that the most stable conformer of such sulfenic acids are stabilized by nO → σ*S-OH orbital interactions, which force the -OH group to adopt a position trans to the S⋯O interaction, leading to an almost linear arrangement of the O⋯S-O moiety and this may be the reason for the slow cyclization of such sulfenic acids to their corresponding sulfenyl amides. On the other hand, additional substituents at the 6-position of o-amido phenylsulfenic acids that can induce steric environment and alter the electronic properties around the sulfenic acid moiety by S⋯N or S⋯O nonbonded interactions destabilize the sulfenic acids by inducing strain in the molecule. This may lead to efficient the cyclization of such sulfenic acids. This model study suggests that the amino acid residues in the close proximity of the sulfenic acid moiety in PTP1B may play an important role in the cyclization of PTP1B-SOH to produce the corresponding sulfenyl amide.

  15. Biohydrogen Production from Glycerol using Thermotoga spp

    NARCIS (Netherlands)

    Maru, B.T.; Bielen, A.A.M.; Kengen, S.W.M.; Constantini, M.; Medina, F.

    2012-01-01

    Given the highly reduced state of carbon in glycerol and its availability as a substantial byproduct of biodiesel production, glycerol is of special interest for sustainable biofuel production. Glycerol was used as a substrate for biohydrogen production using the hyperthermophilic bacterium,

  16. Cdc14 phosphatase

    DEFF Research Database (Denmark)

    Machín, Félix; Quevedo Rodriguez, Oliver; Ramos-Pérez, Cristina

    2016-01-01

    and cancer cells uncontrollably divide, much attention has been put into knocking down CDK activity. However, much less is known on the consequences of interfering with the phosphatases that put an end to the cell cycle. We have addressed in recent years the consequences of transiently inactivating the only...

  17. Cross-validated stable-isotope dilution GC-MS and LC-MS/MS assays for monoacylglycerol lipase (MAGL) activity by measuring arachidonic acid released from the endocannabinoid 2-arachidonoyl glycerol.

    Science.gov (United States)

    Kayacelebi, Arslan Arinc; Schauerte, Celina; Kling, Katharina; Herbers, Jan; Beckmann, Bibiana; Engeli, Stefan; Jordan, Jens; Zoerner, Alexander A; Tsikas, Dimitrios

    2017-03-15

    2-Arachidonoyl glycerol (2AG) is an endocannabinoid that activates cannabinoid (CB) receptors CB1 and CB2. Monoacylglycerol lipase (MAGL) inactivates 2AG through hydrolysis to arachidonic acid (AA) and glycerol, thus modulating the activity at CB receptors. In the brain, AA released from 2AG by the action of MAGL serves as a substrate for cyclooxygenases which produce pro-inflammatory prostaglandins. Here we report stable-isotope GC-MS and LC-MS/MS assays for the reliable measurement of MAGL activity. The assays utilize deuterium-labeled 2AG (d 8 -2AG; 10μM) as the MAGL substrate and measure deuterium-labeled AA (d 8 -AA; range 0-1μM) as the MAGL product. Unlabelled AA (d 0 -AA, 1μM) serves as the internal standard. d 8 -AA and d 0 -AA are extracted from the aqueous buffered incubation mixtures by ethyl acetate. Upon solvent evaporation the residue is reconstituted in the mobile phase prior to LC-MS/MS analysis or in anhydrous acetonitrile for GC-MS analysis. LC-MS/MS analysis is performed in the negative electrospray ionization mode by selected-reaction monitoring the mass transitions [M-H] - →[M-H - CO 2 ] - , i.e., m/z 311→m/z 267 for d 8 -AA and m/z 303→m/z 259 for d 0 -AA. Prior to GC-MS analysis d 8 -AA and d 0 -AA were converted to their pentafluorobenzyl (PFB) esters by means of PFB-Br. GC-MS analysis is performed in the electron-capture negative-ion chemical ionization mode by selected-ion monitoring the ions [M-PFB] - , i.e., m/z 311 for d 8 -AA and m/z 303 for d 0 -AA. The GC-MS and LC-MS/MS assays were cross-validated. Linear regression analysis between the concentration (range, 0-1μM) of d 8 -AA measured by LC-MS/MS (y) and that by GC-MS (x) revealed a straight line (r 2 =0.9848) with the regression equation y=0.003+0.898x, indicating a good agreement. In dog liver, we detected MAGL activity that was inhibitable by the MAGL inhibitor JZL-184. Exogenous eicosatetraynoic acid is suitable as internal standard for the quantitative determination

  18. Cloning and expression of a widely expressed receptor tyrosine phosphatase

    DEFF Research Database (Denmark)

    Sap, J; D'Eustachio, P; Givol, D

    1990-01-01

    We describe the identification of a widely expressed receptor-type (transmembrane) protein tyrosine phosphatase (PTPase; EC 3.1.3.48). Screening of a mouse brain cDNA library under low-stringency conditions with a probe encompassing the intracellular (phosphatase) domain of the CD45 lymphocyte...... antigen yielded cDNA clones coding for a 794-amino acid transmembrane protein [hereafter referred to as receptor protein tyrosine phosphatase alpha (R-PTP-alpha)] with an intracellular domain displaying clear homology to the catalytic domains of CD45 and LAR (45% and 53%, respectively). The 142-amino acid...

  19. Influence of crude glycerol on the biomass and lipid content of microalgae

    International Nuclear Information System (INIS)

    Choi, Hee-Jeong; Yu, Sung-Whan

    2015-01-01

    The growth of the algae Chlorella vulgaris, Botryococcus braunii and Scenedesmus sp. under mixotrophic conditions in the presence of different concentrations of crude glycerol was evaluated with the objective of increasing the biomass growth and algal oil content. A high biomass concentration was characteristic of these strains when grown on crude glycerol compared to autotrophic growth, and 5 g/L glycerol yielded the highest biomass concentration for these strains. Mixotrophic conditions improved both the growth of the microalgae and the accumulation of triacylglycerols (TAGs). The maximum amount of TAGs in the algae biomass was obtained in the 5 g/L glycerol growth medium. The fatty acid profiles of the oil for the cultures met the necessary requirements and the strains are promising resources for biofuel production. Keywords: biomass; glycerol; microalgae; mixotrophic; oil content

  20. Effects of 2-deoxy-D-glucose, oligomycin and theophylline on in vitro glycerol metabolism in rat adipose tissue: response to insulin and epinephrine

    Energy Technology Data Exchange (ETDEWEB)

    Dominguez, M C; Herrera, E [Barcelona Univ. (Spain). Catedra de Fisiologia General

    1976-01-01

    The effects of 2-deoxy-D-glucose (2DG), oligomycin and theophylline on the in vitro production and metabolism of glycerol and its response to insulin and epinephrine were studied in epididymal fat pads from fed rats. 2-DG failed to affect basic or epinephrine-stimulated glycerol production but decreased the uptake of 1-/sup 14/C-glycerol by the tissue and its conversion to glyceride-glycerol. Oligomycin also failed to affect the basic production of glycerol, but it inhibited the affect of epinephrine on this parameter as well as the uptake and utilization of 1-/sup 14/C-glycerol. Theophylline enhanced the production of glycerol by the tissue, and this effect was not further augmented by epinephrine. Theophylline also inhibited the uptake and utilization of 1-/sup 14/C-glycerol; the most pronounced effect of theophylline was observed in the formation of /sup 14/C-fatty acids from 1-/sup 14/C-glycerol in the presence of glucose. Insulin, but not epinephrine, decreased the inhibitory effect of theophylline on glycerol utilization. It is concluded that these compounds affect the ability of adipose tissue to metabolize glycerol more intensely than the ability to release it through lipolysis. The pathway for glycerol utilization in adipose tissue appears to be more sensitive to changes in the availability of ATP than the mechanisms for the release of glycerol from the tissue.

  1. Correlations between calcineurin phosphatase inhibition and cyclosporine metabolites concentrations in kidney transplant recipients: Implications for immunoassays

    DEFF Research Database (Denmark)

    Jørgensen, Kaj Anker; Karamperis, Nikolaos; Koefoed-Nielsen, Pernille Bundgaard

    2006-01-01

    by inhibiting the enzyme calcineurin phosphatase. Determination of the enzyme's activity is one of the most promising pharmacodynamic markers. It is unknown how calcineurin phosphatase inhibition correlates with various cyclosporine monitoring assays and what is the potential impact of metabolites...... by the enzyme multiplied immunoassay technique (EMIT) and by the polyclonal fluorescence polarization immunoassay (pFPIA). Calcineurin phosphatase activity was measured by its ability to dephosphorylate a previously phosphorylated 19-amino acid peptide. We found that calcineurin phosphatase inhibition...

  2. Correlations between calcineurin phosphatase inhibition and cyclosporine metabolites concentrations in kidney transplant recipients: implications for immunoassays

    DEFF Research Database (Denmark)

    Karamperis, N; Koefoed-Nielsen, PB; Brahe, P

    2006-01-01

    by inhibiting the enzyme calcineurin phosphatase. Determination of the enzyme's activity is one of the most promising pharmacodynamic markers. It is unknown how calcineurin phosphatase inhibition correlates with various cyclosporine monitoring assays and what is the potential impact of metabolites...... by the enzyme multiplied immunoassay technique (EMIT) and by the polyclonal fluorescence polarization immunoassay (pFPIA). Calcineurin phosphatase activity was measured by its ability to dephosphorylate a previously phosphorylated 19-amino acid peptide. We found that calcineurin phosphatase inhibition...

  3. Reaction pathways for catalytic gas-phase oxidation of glycerol over mixed metal oxides

    Energy Technology Data Exchange (ETDEWEB)

    Suprun, W.; Glaeser, R.; Papp, H. [Leipzig Univ. (Germany). Inst. of Chemical Technology

    2011-07-01

    Glycerol as a main by-product from bio-diesel manufacture is a cheap raw material with large potential for chemical or biochemical transformations to value-added C3-chemicals. One possible way of glycerol utilization involves its catalytic oxidation to acrylic acid as an alternative to petrochemical routes. However, this catalytic conversion exhibits various problems such as harsh reaction conditions, severe catalyst coking and large amounts of undesired by-products. In this study, the reaction pathways for gas-phase conversion of glycerol over transition metal oxides (Mo, V und W) supported on TiO{sub 2} and SiO{sub 2} were investigated by two methods: (i) steady state experiments of glycerol oxidation and possible reactions intermediates, i.e., acrolein, 3-hydroxy propionaldehyde and acetaldehyde, and (ii) temperature-programmed surface reaction (TPSR) studies of glycerol conversion in the presence and in the absence of gas-phase oxygen. It is shown that the supported W-, V and Mo-oxides possess an ability to catalyze the oxidation of glycerol to acrylic acid. These investigations allowed us to gain a deeper insight into the reaction mechanism. Thus, based on the obtained results, three possible reactions pathways for the selective oxidation of glycerol to acrylic acid on the transition metal-containing catalysts are proposed. The major pathways in presence of molecular oxygen are a fast successive destructive oxidation of glycerol to CO{sub x} and the dehydration of glycerol to acrolein which is a rate-limiting step. (orig.)

  4. Effect of growth conditions on expression of the acid phosphatase (cyx-appA) operon and the appY gene, which encodes a transcriptional activator of Escherichia coli

    DEFF Research Database (Denmark)

    Brøndsted, Lone; Atlung, Tove

    1996-01-01

    The expression and transcriptional regulation of the Escherichia coli cyx-appA operon and the appY gene has been investigated during different environmental conditions using single copy transcriptional lacZ fusions. The cyx-appA operon encodes acid phosphatase and a putative cytochrome oxidase...... of the cyx-appA operon. The nitrate repression was partially dependent on NarL. A high expression of the operon was obtained in glucose medium supplemented with formate, where E.coli obtains energy by fermentation. The formate induction was independent of the fhlA gene product. The results presented...... in this paper indicate a clear difference in the regulation of the cyx-appA operon compared to the cyd operon, encoding the cytochrome d oxidase complex. The results suggest that cytochrome x oxidase has a function at even more oxygen limiting conditions than cytochrome d oxidase. The expression of the app...

  5. Presence of multiple acid phosphatases activity in seedlings of cucumber, radish and rocket salad Presença de atividade de múltiplas fosfatases ácidas em plântulas de pepino, rabanete e rúcula

    Directory of Open Access Journals (Sweden)

    Luciane Almeri Tabaldi

    2008-06-01

    Full Text Available Acid phosphatases (3.1.3.2 are a group of enzymes widely distributed in nature, which catalyze the hydrolysis of a variety of phosphate esters in the pH range of 4-6. We confirmed the presence of acid phosphatases in seedlings of cucumber (Cucumis sativus, radish (Raphanus sativus and rocket salad (Eruca vesicaria under different assay conditions using a rapid and simple preparation. The results showed that the optimum pH and temperature used for all species were close to 5.5 and 35°C, respectively. The enzyme was inhibited by molybdate, fluoride, azide, levamisole, orthovanadate, Zn2+ and Cu2+. Suramin had no effect on enzyme activity. The acid phosphatase from cucumber, radish and rocket salad hydrolyzed a wide variety of phosphate esters and the highest activity was observed with PPi, ATP and GTP. These results demonstrate that the enzyme investigated in this study is different from well known ester phosphate cleaving plant enzymes (apyrase and inorganic pyrophosphatases and this preparation could be a useful tool to future toxicological studies and to study initially all isoforms of acid phosphatase.As fosfatases ácidas (3.1.3.2 são um grupo de enzimas amplamente distribuídas na natureza, as quais catalisam a hidrólise de uma variedade de ésteres de fosfato com uma variação de pH entre quatro e seis. Foi confirmada a presença de fosfatases ácidas em plântulas de pepino (Cucumis sativus, rabanete (Raphanus sativus e rúcula (Eruca vesicaria sob diferentes condições de ensaio usando uma preparação rápida e simples. Os resultados mostraram que o pH e a temperatura ótimos para todas as espécies foram 5,5 e 35°C, respectivamente. A enzima foi inibida por molibdato, fluoreto, azida, levamisole, ortovanadato, Zn2+ e Cu2+. O inibidor suramim não afetou a atividade enzimática. As fosfatases ácidas de pepino, rabanete e rúcula hidrolisaram uma ampla variedade de ésteres de fosfato e a maior atividade foi observada com PPi, ATP

  6. Metabolic engineering of a glycerol-oxidative pathway in Lactobacillus panis PM1 for utilization of bioethanol thin stillage: potential to produce platform chemicals from glycerol.

    Science.gov (United States)

    Kang, Tae Sun; Korber, Darren R; Tanaka, Takuji

    2014-12-01

    Lactobacillus panis PM1 has the ability to produce 1,3-propanediol (1,3-PDO) from thin stillage (TS), which is the major waste material after bioethanol production, and is therefore of significance. However, the fact that L. panis PM1 cannot use glycerol as a sole carbon source presents a considerable problem in terms of utilization of this strain in a wide range of industrial applications. Accordingly, L. panis PM1 was genetically engineered to directly utilize TS as a fermentable substrate for the production of valuable platform chemicals without the need for exogenous nutrient supplementation (e.g., sugars and nitrogen sources). An artificial glycerol-oxidative pathway, comprised of glycerol facilitator, glycerol kinase, glycerol 3-phosphate dehydrogenase, triosephosphate isomerase, and NADPH-dependent aldehyde reductase genes of Escherichia coli, was introduced into L. panis PM1 in order to directly utilize glycerol for the production of energy for growth and value-added chemicals. A pH 6.5 culture converted glycerol to mainly lactic acid (85.43 mM), whereas a significant amount of 1,3-propanediol (59.96 mM) was formed at pH 7.5. Regardless of the pH, ethanol (82.16 to 83.22 mM) was produced from TS fermentations, confirming that the artificial pathway metabolized glycerol for energy production and converted it into lactic acid or 1,3-PDO and ethanol in a pH-dependent manner. This study demonstrates the cost-effective conversion of TS to value-added chemicals by the engineered PM1 strain cultured under industrial conditions. Thus, application of this strain or these research findings can contribute to reduced costs of bioethanol production. Copyright © 2014, American Society for Microbiology. All Rights Reserved.

  7. Glycerol metabolism of Lactobacillus rhamnosus ATCC 7469: cloning and expression of two glycerol kinase genes.

    Science.gov (United States)

    Alvarez, María de Fátima; Medina, Roxana; Pasteris, Sergio E; Strasser de Saad, Ana M; Sesma, Fernando

    2004-01-01

    Lactobacillus rhamnosus ATCC 7469 was able to grow in glycerol as the sole source of energy in aerobic conditions, producing lactate, acetate, and diacetyl. A biphasic growth was observed in the presence of glucose. In this condition, glycerol consumption began after glucose was exhausted from the culture medium. Glycerol kinase activity was detected in L. rhamnosus ATCC 7469, a characteristic of microorganisms which catabolize glycerol in aerobic conditions. Genetic analysis revealed that this strain possesses two glycerol kinase genes: gykA and glpK, that encode for two different glycerol kinases GykA and GlpK, respectively. The glpK geneis associated in an operon with alpha-glycerophosphate oxidase (glpO) and glycerol facilitator (glpF) genes. Transcriptional analysis revealed that only glpK is expressed when L. rhamnosus was grown on glycerol. Copyright 2004 S. Karger AG, Basel

  8. Seasonal variability of branched glycerol dialkyl glycerol tetraethers (brGDGTs) in a temperate lake system

    NARCIS (Netherlands)

    Loomis, S.E.; Russell, J.M.; Heureux, A.M.; D'Andrea, W.J.; Sinninghe Damsté, J.S.

    2014-01-01

    Quantitative climate reconstructions are crucial for understanding the magnitude of and mechanisms behind natural and anthropogenic climate change, yet there are few proxies that can reliably reconstruct terrestrial temperature. Branched glycerol dialkyl glycerol tetraethers (brGDGTs) are bacterial

  9. Penggunaan H-Zeolit dan Tawas dalam Pemurnian Crude Glycerol dengan Proses Adsorpsi dan Koagulasi

    OpenAIRE

    Isalmi Aziz, M.T; Nur Hijjah Bayani Fadhilah; Hendrawati Hendrawati

    2017-01-01

    Production of biodiesel from used cooking oil byproducts such as crude glycerol with low purity. The crude glycerol containing compounds impurities such as free fatty acids, alcohol, soap, catalyst and water. Compound adsorption of impurities can be done with the H-zeolite as adsorbent, but the resulting quality is still not good. To improve its quality, this research was added alum (coagulation) process so that the adsorption of colloidal-sized compound impurities which can be separated from...

  10. Penggunaan H-Zeolit Dan Tawas Dalam Pemurnian Crude Glycerol Dengan Proses Adsorpsi Dan Koagulasi

    OpenAIRE

    Aziz, M.T, Isalmi; Fadhilah, Nur Hijjah Bayani; Hendrawati, Hendrawati

    2017-01-01

    Production of biodiesel from used cooking oil byproducts such as crude glycerol with low purity. The crude glycerol containing compounds impurities such as free fatty acids, alcohol, soap, catalyst and water. Compound adsorption of impurities can be done with the H-zeolite as adsorbent, but the resulting quality is still not good. To improve its quality, this research was added alum (coagulation) process so that the adsorption of colloidal-sized compound impurities which can be separated from...

  11. Synthesis and characterization of poly(glycerol citrate/sebacate); Preparacao de caracterizacao do poli(glicerol citrato/sebacato)

    Energy Technology Data Exchange (ETDEWEB)

    Brioude, Michel M.; Guimaraes, Danilo H.; Fiuza, Raigenis P.; Boaventura, Jaime S.; Jose, Nadia M., E-mail: mbrioude@gmail.com [Universidade Federal da Bahia - UFBA, Instituto de Quimica, Salvador, BA (Brazil)

    2011-07-01

    In this work were prepared and characterized the poly(glycerol citrate/sebacate) in three different ratios between acids. The polymers were prepared by a polycondensation reaction between glycerol and citric/sebacic acids and characterized by X-ray diffraction (XRD), infrared spectroscopy (FTIR), thermogravimetric analysis (TGA), scanning differential calorimetry (DSC), scanning electron microscopy (SEM). The results showed that the polymers are polyesters and its crystallinity, thermal and morphological properties were modified by sebacic acid adding. (author)

  12. HD-PTP is a catalytically inactive tyrosine phosphatase due to a conserved divergence in its phosphatase domain.

    Directory of Open Access Journals (Sweden)

    Marie-Claude Gingras

    Full Text Available The HD-PTP protein has been described as a tumor suppressor candidate and based on its amino acid sequence, categorized as a classical non-transmembrane protein tyrosine phosphatase (PTP. To date, no HD-PTP phosphorylated substrate has been identified and controversial results concerning its catalytic activity have been recently reported.Here we report a rigorous enzymatic analysis demonstrating that the HD-PTP protein does not harbor tyrosine phosphatase or lipid phosphatase activity using the highly sensitive DiFMUP substrate and a panel of different phosphatidylinositol phosphates. We found that HD-PTP tyrosine phosphatase inactivity is caused by an evolutionary conserved amino acid divergence of a key residue located in the HD-PTP phosphatase domain since its back mutation is sufficient to restore the HD-PTP tyrosine phosphatase activity. Moreover, in agreement with a tumor suppressor activity, HD-PTP expression leads to colony growth reduction in human cancer cell lines, independently of its catalytic PTP activity status.In summary, we demonstrate that HD-PTP is a catalytically inactive protein tyrosine phosphatase. As such, we identify one residue involved in its inactivation and show that its colony growth reduction activity is independent of its PTP activity status in human cancer cell lines.

  13. Simplified preparation of a phosphatase inhibitor and further studies of its action.

    Science.gov (United States)

    Coburn, S P; Schaltenbrand, W E

    1978-05-01

    1-Pyrrolidinecarbothioic acid (2-pyridylmethylene) hydrazide chelates Zn2+ but not Mg2+. This compound is about twice as effective as EDTA for inhibiting alkaline phosphatase from calf mucosa, and approx. 1000-fold more effective than EDTA for inhibiting acid phosphatase from wheat germ. The compound did not inhibit pyridoxine kinase activity in human leucocytes at the highest concentration tested (33 micron). Therefore it may be a useful tool for either examining or eliminating the effects of phosphatases in complex enzyme systems.

  14. The expression of glycerol facilitators from various yeast species improves growth on glycerol of Saccharomyces cerevisiae

    Directory of Open Access Journals (Sweden)

    Mathias Klein

    2016-12-01

    Full Text Available Glycerol is an abundant by-product during biodiesel production and additionally has several assets compared to sugars when used as a carbon source for growing microorganisms in the context of biotechnological applications. However, most strains of the platform production organism Saccharomyces cerevisiae grow poorly in synthetic glycerol medium. It has been hypothesized that the uptake of glycerol could be a major bottleneck for the utilization of glycerol in S. cerevisiae. This species exclusively relies on an active transport system for glycerol uptake. This work demonstrates that the expression of predicted glycerol facilitators (Fps1 homologues from superior glycerol-utilizing yeast species such as Pachysolen tannophilus, Komagataella pastoris, Yarrowia lipolytica and Cyberlindnera jadinii significantly improves the growth performance on glycerol of the previously selected glycerol-consuming S. cerevisiae wild-type strain (CBS 6412-13A. The maximum specific growth rate increased from 0.13 up to 0.18 h−1 and a biomass yield coefficient of 0.56 gDW/gglycerol was observed. These results pave the way for exploiting the assets of glycerol in the production of fuels, chemicals and pharmaceuticals based on baker's yeast. Keywords: Yeast, Saccharomyces cerevisiae, Glycerol, Transport, Glycerol facilitator, Fps1, Stl1

  15. A new continuous-flow process for catalytic conversion of glycerol to oxygenated fuel additive: Catalyst screening

    International Nuclear Information System (INIS)

    Nanda, Malaya R.; Yuan, Zhongshun; Qin, Wensheng; Ghaziaskar, Hassan S.; Poirier, Marc-Andre; Xu, Chunbao

    2014-01-01

    Highlights: • A continuous-flow process for catalytic synthesis of solketal from glycerol. • Six different heterogeneous acid catalysts were studied in the process. • Glycerol conversion and solketal yield of 90% and 88% respectively were achieved. • The process has the potential to be scaled-up for industrial applications. - Abstract: A new continuous-flow reactor was designed for the conversion of glycerol to solketal, an oxygenated fuel additive, through ketalization with acetone. Six heterogeneous catalysts were investigated with respect to their catalytic activity and stability in a flow reactor. The acidity of the catalysts positively influences the catalyst’s activity. Among all the solid acid catalysts tested, the maximum solketal yield from experiments at 40 °C, 600 psi and WHSV of 4 h −1 attained 73% and 88% at the acetone/glycerol molar ratio of 2.0 and 6.0, respectively, with Amberlyst Wet. Based on the solketal yield and glycerol conversion results, the activity of all catalysts tested follows the following order of sequence: Amberlyst Wet ≈ Zeolite ≈ Amberlyst Dry > Zirconium Sulfate > Montmorillonite > Polymax. An increase in acetone/glycerol molar ratio or a decrease in WHSV enhanced the glycerol conversion as expected. This process offers an attractive route for converting glycerol, the main by-product of biodiesel, to solketal – a value-added green product with potential industrial applications as a valuable fuel additive or combustion promoter for gasoline engines

  16. Direct determination of phosphatase activity from physiological substrates in cells.

    Directory of Open Access Journals (Sweden)

    Zhongyuan Ren

    Full Text Available A direct and continuous approach to determine simultaneously protein and phosphate concentrations in cells and kinetics of phosphate release from physiological substrates by cells without any labeling has been developed. Among the enzymes having a phosphatase activity, tissue non-specific alkaline phosphatase (TNAP performs indispensable, multiple functions in humans. It is expressed in numerous tissues with high levels detected in bones, liver and neurons. It is absolutely required for bone mineralization and also necessary for neurotransmitter synthesis. We provided the proof of concept that infrared spectroscopy is a reliable assay to determine a phosphatase activity in the osteoblasts. For the first time, an overall specific phosphatase activity in cells was determined in a single step by measuring simultaneously protein and substrate concentrations. We found specific activities in osteoblast like cells amounting to 116 ± 13 nmol min(-1 mg(-1 for PPi, to 56 ± 11 nmol min(-1 mg(-1 for AMP, to 79 ± 23 nmol min(-1 mg(-1 for beta-glycerophosphate and to 73 ± 15 nmol min(-1 mg(-1 for 1-alpha-D glucose phosphate. The assay was also effective to monitor phosphatase activity in primary osteoblasts and in matrix vesicles. The use of levamisole--a TNAP inhibitor--served to demonstrate that a part of the phosphatase activity originated from this enzyme. An IC50 value of 1.16 ± 0.03 mM was obtained for the inhibition of phosphatase activity of levamisole in osteoblast like cells. The infrared assay could be extended to determine any type of phosphatase activity in other cells. It may serve as a metabolomic tool to monitor an overall phosphatase activity including acid phosphatases or other related enzymes.

  17. Effect of addition of lignin in physical-chemical properties of a polyesters based on glycerol, phthalic and adipic acids; Efeito da adicao de lignina nas propriedades fisico-quimicas de poliesteres a base de glicerol e acidos ftalico e adipico

    Energy Technology Data Exchange (ETDEWEB)

    Guimaraes, D.H.; Viana, A.P.M.; Lima, A.S.C.; Goncalves, A.P.B.; Miranda, C.S.; Jose, N.M., E-mail: dhanseng@yahoo.com.br [Universidade Federal da Bahia (UFBA), alvador, BA (Brazil)

    2014-07-01

    In this paper the study of different addition amounts of lignin in the physicochemical properties of polyesters made from glycerol and different amounts of phthalic and adipic acids have been proposed. The following characterizations were made: XRD, FTIR, TGA, DSC and SEM. The variation in the percentage of adipic and phthalic acids had a direct effect on thermal and morphological properties. The thermal analysis showed that there was miscibility between the polyester and lignin, by means of displacement related to the temperature of thermal degradation events. In FTIR analysis was noted displacements of characteristic bands of hydrogen bonds and specific carbonyl ester groups. These shifts were more pronounced as it has larger amounts of phthalic acid as monomer and larger amounts of lignin in the compositions. (author)

  18. The Lubricity of Glycerol and its Solutions

    DEFF Research Database (Denmark)

    Sivebæk, Ion Marius; Jakobsen, J.

    2016-01-01

    Glycerol has been recognised as an excellent diesel fuel and lubricant. It is a liquid that can originate from the transesterification of plant oil that also results in plant oil metyl (or ethyl) ester (biodiesel). Machine elements lubricated by glycerol show very low friction, in fact lower than...

  19. Distribution of glycerol dialkyl glycerol tetraethers in Tibetan hot springs

    Directory of Open Access Journals (Sweden)

    Liu He

    2012-05-01

    Full Text Available Isoprenoidal glycerol dialkyl glycerol tetraethers (iGDGTs from the Gulu hot springs (23–83.6 °C, pH > 7 and Yangbajing hot springs (80–128 °C, pH > 7 were analyzed in order to investigate the distribution of archaeal lipids among different hot springs in Tibet. A soil sample from Gulu was incubated at different temperatures and analyzed for changes in iGDGTs to help evaluate whether surrounding soil may contribute to the iGDGTs in hot springs. The sources of bacterial GDGTs (bGDGTs in these hot springs were also investigated. The results revealed different profiles of iGDGTs between Gulu and Yangbajing hot springs. Core iGDGTs and polar iGDGTs also presented different patterns in each hot spring. The PCA analysis showed that the structure of polar iGDGTs can be explained by three factors and suggested multiple sources of these compounds. Bivariate correlation analysis showed significant positive correlations between polar and core bGDGTs, suggesting the in situ production of bGDGTs in the hot springs. Furthermore, in the soil incubation experiment, temperature had the most significant influence on concentration of bGDGTs rather than iGDGTs, and polar bGDGTs had greater variability than core bGDGTs with changing temperature. Our results indicated that soil input had little influence on the composition of GDGTs in Tibetan hot springs. On the other hand, ring index and TEX86 values were both positively correlated with incubation temperature, suggesting that the structure of archaeal lipids changed in response to varying temperature during incubation.

  20. Biosynthesis of glycerol carbonate from glycerol by lipase in dimethyl carbonate as the solvent.

    Science.gov (United States)

    Lee, Kyung Hwa; Park, Chang-Ho; Lee, Eun Yeol

    2010-11-01

    Glycerol carbonate was synthesized from renewable glycerol and dimethyl carbonate using lipase in solvent-free reaction system in which excess dimethyl carbonate played as the reaction medium. A variety of lipases have been tested for their abilities to catalyze transesterification reaction, and Candida antartica lipase B and Novozyme 435 exhibited higher catalytic activities. The silica-coated glycerol with a 1:1 ratio was supplied to prevent two-phase formation between hydrophobic dimethyl carbonate and hydrophilic glycerol. Glycerol carbonate was successfully synthesized with more than 90% conversion from dimethyl carbonate and glycerol with a molar ratio of 10 using Novozyme 435-catalyzed transesterification at 70 °C. The Novozyme 435 [5% (w/w) and 20% (w/w)] and silica gel were more than four times recycled with good stability in a repeated batch operation for the solvent-free synthesis of glycerol carbonate.

  1. Application of glycerol as a foliar spray activates the defence response and enhances disease resistance of Theobroma cacao.

    Science.gov (United States)

    Zhang, Yufan; Smith, Philip; Maximova, Siela N; Guiltinan, Mark J

    2015-01-01

    Previous work has implicated glycerol-3-phosphate (G3P) as a mobile inducer of systemic immunity in plants. We tested the hypothesis that the exogenous application of glycerol as a foliar spray might enhance the disease resistance of Theobroma cacao through the modulation of endogenous G3P levels. We found that exogenous application of glycerol to cacao leaves over a period of 4 days increased the endogenous level of G3P and decreased the level of oleic acid (18:1). Reactive oxygen species (ROS) were produced (a marker of defence activation) and the expression of many pathogenesis-related genes was induced. Notably, the effects of glycerol application on G3P and 18:1 fatty acid content, and gene expression levels, in cacao leaves were dosage dependent. A 100 mm glycerol spray application was sufficient to stimulate the defence response without causing any observable damage, and resulted in a significantly decreased lesion formation by the cacao pathogen Phytophthora capsici; however, a 500 mm glycerol treatment led to chlorosis and cell death. The effects of glycerol treatment on the level of 18:1 and ROS were constrained to the locally treated leaves without affecting distal tissues. The mechanism of the glycerol-mediated defence response in cacao and its potential use as part of a sustainable farming system are discussed. © 2014 BSPP AND JOHN WILEY & SONS LTD.

  2. Comparing cellular performance of Yarrowia lipolytica during growth on glucose and glycerol in submerged cultivations

    DEFF Research Database (Denmark)

    Workman, Mhairi; Holt, Philippe; Thykær, Jette

    2013-01-01

    . Growth on glycerol proceeded at approximately 0.30 h-1, and the substrate uptake rate was 0.02 mol L-1 h-1 regardless of the starting glycerol concentration (10, 20 or 45 g L-1). Utilisation of glycerol was accompanied by higher oxygen uptake rates compared to glucose growth, indicating import......Yarrowia lipolytica is an attractive host for sustainable bioprocesses due to its ability to utilize a variety of carbon substrates and convert them to a range of different product types (including lipids, organic acids and polyols) under specific conditions. Despite an increasing number...... of applications for this yeast, relatively few studies have focused on uptake and metabolism of carbon sources, and the metabolic basis for carbon flow to the different products. The focus of this work was quantification of the cellular performance of Y. lipolytica during growth on glycerol, glucose or a mixture...

  3. Synthesis of high purity monoglycerides from crude glycerol and palm stearin

    Directory of Open Access Journals (Sweden)

    Pakamas Chetpattananondh

    2008-07-01

    Full Text Available The optimum conditions for the glycerolysis of palm stearin and crude glycerol derived from biodiesel process werefound to be a reaction temperature of 200oC with a molar ratio of crude glycerol to palm stearin of 2.5:1, and a reaction timeof 20 minutes. The yield and purity of monoglycerides obtained under these conditions was satisfactory as compared withthe glycerolysis of pure glycerol. To increase the purity of monoglycerides a two-step process, removal of residual glyceroland crystallization, was proposed instead of either vacuum or molecular distillation. Residual glycerol was removed byadding hydrochloric acid followed by washing with hot water. Optimum conditions for crystallization were achieved byusing isooctane as a solvent and a turbine impeller speed of 200 rpm at a crystallization temperature of 35oC. A purity notexceeding 99 percent of monoglycerides was obtained with monopalmitin as the major product.

  4. Swelling and tensile properties of starch glycerol system with various crosslinking agents

    Science.gov (United States)

    Mohamed, R.; Mohd, N.; Nurazzi, N.; Siti Aisyah, M. I.; Fauzi, F. Mohd

    2017-07-01

    Brittle properties of starch had been overcome by the modification process. In this work, sago starch is being modified with variable amount of plasticiser, namely glycerol at 20 and 40% and crosslinking agent had been added to the system. The film of the modification and characterizations of the starch glycerol system with various crosslinking systems were produced by casting method. The film properties of the starch glycerol system were then characterized by tensile strength (mechanical properties) and swelling (physical properties). The modification of the starch glycerol had improved that system by increasing the tensile strength, modulus however lowering its elongation. The increasing in percentage of the water absorption and also swelling are due to the intrinsic hydroxyl groups presence from the starch and glycerol itself that can attract more water to the system. Upon crosslinking, films casted with chemicals namely, glyoxal, malonic acid, borax, PEG were characterised. It was found that, all the film of sago starch crosslinked and undergoing easy film formation. From this modification, borax and malonic acid crosslinking agent had been determined as the best crosslinking agent to the starch glycerol system.

  5. Co-ordinate changes in enzymes of fatty acid synthesis, activation and esterification in rabbit mammary gland druing pregnancy and lactation.

    Science.gov (United States)

    Short, V J; Brindley, D N; Dils, R

    1977-01-01

    1. The activities of fatty acid synthetase, acyl-CoA synthetase, glycerol phosphate acyltransferase and phosphatidate phosphatase were measured in the mammary glands of rabbits from day 16 of pregnancy to day 15 of post partum. 2. There were significant correlations between the increases in activities of these enzymes during this period. This was the case whether the activities were expressed per mg of homogenate protein, per g wet wt. of tissue or per total wet weight of the whole glands. The only exception was the lack of correlation between the activities of fatty acid synthetase and of phosphatidate phosphatase per g wet wt. of tissue. 3. These co-ordinate increases are discussed in relation to the changes which occur in fatty acid metabolism in the mammary gland during pregnancy and lactation. PMID:192226

  6. Experimental drought reduced acid and alkaline phosphatase activity and increased organic extractable P in soil in a Quercus ilex Mediterranean forest

    NARCIS (Netherlands)

    Sardans, J.; Penuelas, J.; Ogaya, R.

    2008-01-01

    A six-year (1999-2005) experiment of drought manipulation was conducted in a Quercus ilex Mediterranean forest (Southern Catalonia) to simulate predicted climatic conditions projected for the decades to come. The aim was to investigate the direct and indirect effects of drought conditions on acid

  7. An Experimental Insight into Extracellular Phosphatases – Differential Induction of Cell-Specific Activity in Green Algae Cultured under Various Phosphorus Conditions

    Directory of Open Access Journals (Sweden)

    Jaroslav Vrba

    2018-02-01

    Full Text Available Extracellular phosphatase activity (PA has been used as an overall indicator of P depletion in lake phytoplankton. However, detailed insights into the mechanisms of PA regulation are still limited, especially in the case of acid phosphatases. The novel substrate ELF97 phosphate allows for tagging PA on single cells in an epifluorescence microscope. This fluorescence-labeled enzyme activity (FLEA assay enables for autecological studies in natural phytoplankton and algal cultures. We combined the FLEA assay with image analysis to measure cell-specific acid PA in two closely related species of the genus Coccomyxa (Trebouxiophyceae, Chlorophyta isolated from two acidic lakes with distinct P availability. The strains were cultured in a mineral medium supplied with organic (beta-glycerol phosphate or inorganic (orthophosphate P at three concentrations. Both strains responded to experimental conditions in a similar way, suggesting that acid extracellular phosphatases were regulated irrespectively of the origin and history of the strains. We found an increase in cell-specific PA at low P concentration and the cultures grown with organic P produced significantly higher (ca. 10-fold PA than those cultured with the same concentrations of inorganic P. The cell-specific PA measured in the cultures grown with the lowest organic P concentration roughly corresponded to those of the original Coccomyxa population from an acidic lake with impaired P availability. The ability of Coccomyxa strains to produce extracellular phosphatases, together with tolerance for both low pH and metals can be one of the factors enabling the dominance of the genus in extreme conditions of acidic lakes. The analysis of frequency distribution of the single-cell PA documented that simple visual counting of ‘active’ (labeled and ‘non-active’ (non-labeled cells can lead to biased conclusions regarding algal P status because the actual PA of the ‘active’ cells can vary from

  8. An improved synthesis of 14C labelled glycerol using sodium borohydride

    International Nuclear Information System (INIS)

    Chander, H.; Ramamurthy, T.V.; Viswanathan, K.V.

    1987-01-01

    [1- 14 C]Glyceric acid has been reduced to [1(3)- 14 C]glycerol in high yields via the methyl ester of [1- 14 C]glyceric acid by sodium borohydride in the presence of t-butyl alcohol and methanol. The importance of the procedure is highlighted in relation to other procedures involving lithium aluminium hydride reduction. (author)

  9. Detection of phosphatase activity in aquatic and terrestrial cyanobacterial strains

    Directory of Open Access Journals (Sweden)

    Babić Olivera B.

    2013-01-01

    Full Text Available Cyanobacteria, as highly adaptable microorganisms, are characterized by an ability to survive in different environmental conditions, in which a significant role belongs to their enzymes. Phosphatases are enzymes produced by algae in relatively large quantities in response to a low orthophosphate concentration and their activity is significantly correlated with their primary production. The activity of these enzymes was investigated in 11 cyanobacterial strains in order to determine enzyme synthesis depending on taxonomic and ecological group of cyanobacteria. The study was conducted with 4 terrestrial cyanobacterial strains, which belong to Nostoc and Anabaena genera, and 7 filamentous water cyanobacteria of Nostoc, Oscillatoria, Phormidium and Microcystis genera. The obtained results showed that the activity of acid and alkaline phosphatases strongly depended on cyanobacterial strain and the environment from which the strain originated. Higher activity of alkaline phosphatases, ranging from 3.64 to 85.14 μmolpNP/s/dm3, was recorded in terrestrial strains compared to the studied water strains (1.11-5.96 μmolpNP/s/dm3. The activity of acid phosphatases was higher in most tested water strains (1.67-6.28 μmolpNP/s/dm3 compared to the activity of alkaline phosphatases (1.11-5.96 μmolpNP/s/dm3. Comparing enzyme activity of nitrogen fixing and non-nitrogen fixing cyanobacteria, it was found that most nitrogen fixing strains had a higher activity of alkaline phosphatases. The data obtained in this work indicate that activity of phosphatases is a strain specific property. The results further suggest that synthesis and activity of phosphatases depended on eco-physiological characteristics of the examined cyanobacterial strains. This can be of great importance for the further study of enzymes and mechanisms of their activity as a part of cyanobacterial survival strategy in environments with extreme conditions. [Projekat Ministarstva nauke Republike

  10. Selective hydrolysis of phosphate monoester by a supramolecular phosphatase formed by the self-assembly of a bis(Zn(2+)-cyclen) complex, cyanuric acid, and copper in an aqueous solution (cyclen = 1,4,7,10-tetraazacyclododecane).

    Science.gov (United States)

    Zulkefeli, Mohd; Suzuki, Asami; Shiro, Motoo; Hisamatsu, Yosuke; Kimura, Eiichi; Aoki, Shin

    2011-10-17

    In Nature, organized nanoscale structures such as proteins and enzymes are formed in aqueous media via intermolecular interactions between multicomponents. Supramolecular and self-assembling strategies provide versatile methods for the construction of artificial chemical architectures for controlling reaction rates and the specificities of chemical reactions, but most are designed in hydrophobic environments. The preparation of artificial catalysts that have potential in aqueous media mimicking natural enzymes such as hydrolases remains a great challenge in the fields of supramolecular chemistry. Herein, we describe that a dimeric Zn(2+) complex having a 2,2'-bipyridyl linker, cyanuric acid, and a Cu(2+) ion automatically assembles in an aqueous solution to form a 4:4:4 complex, which is stabilized by metal-ligand coordination bonds, π-π-stacking interactions, and hydrogen bonding and contains μ-Cu(2)(OH)(2) cores analogous to the catalytic centers of phosphatase, a dinuclear metalloenzyme. The 4:4:4 complex selectively accelerates the hydrolysis of a phosphate monoester, mono(4-nitrophenyl)phosphate, at neutral pH.

  11. Tartrate-resistant acid phosphatase (TRAP/ACP5) promotes metastasis-related properties via TGFβ2/TβR and CD44 in MDA-MB-231 breast cancer cells.

    Science.gov (United States)

    Reithmeier, Anja; Panizza, Elena; Krumpel, Michael; Orre, Lukas M; Branca, Rui M M; Lehtiö, Janne; Ek-Rylander, Barbro; Andersson, Göran

    2017-09-15

    Tartrate-resistant acid phosphatase (TRAP/ACP5), a metalloenzyme that is characteristic for its expression in activated osteoclasts and in macrophages, has recently gained considerable focus as a driver of metastasis and was associated with clinically relevant parameters of cancer progression and cancer aggressiveness. MDA-MB-231 breast cancer cells with different TRAP expression levels (overexpression and knockdown) were generated and characterized for protein expression and activity levels. Functional cell experiments, such as proliferation, migration and invasion assays were performed as well as global phosphoproteomic and proteomic analysis was conducted to connect molecular perturbations to the phenotypic changes. We identified an association between metastasis-related properties of TRAP-overexpressing MDA-MB-231 breast cancer cells and a TRAP-dependent regulation of Transforming growth factor (TGFβ) pathway proteins and Cluster of differentiation 44 (CD44). Overexpression of TRAP increased anchorage-independent and anchorage-dependent cell growth and proliferation, induced a more elongated cellular morphology and promoted cell migration and invasion. Migration was increased in the presence of the extracellular matrix (ECM) proteins osteopontin and fibronectin and the basement membrane proteins collagen IV and laminin I. TRAP-induced properties were reverted upon shRNA-mediated knockdown of TRAP or treatment with the small molecule TRAP inhibitor 5-PNA. Global phosphoproteomics and proteomics analyses identified possible substrates of TRAP phosphatase activity or signaling intermediates and outlined a TRAP-dependent regulation of proteins involved in cell adhesion and ECM organization. Upregulation of TGFβ isoform 2 (TGFβ2), TGFβ receptor type 1 (TβR1) and Mothers against decapentaplegic homolog 2 (SMAD2), as well as increased intracellular phosphorylation of CD44 were identified upon TRAP perturbation. Functional antibody-mediated blocking and chemical

  12. Probing protein phosphatase substrate binding

    DEFF Research Database (Denmark)

    Højlys-Larsen, Kim B.; Sørensen, Kasper Kildegaard; Jensen, Knud Jørgen

    2012-01-01

    Proteomics and high throughput analysis for systems biology can benefit significantly from solid-phase chemical tools for affinity pull-down of proteins from complex mixtures. Here we report the application of solid-phase synthesis of phosphopeptides for pull-down and analysis of the affinity...... profile of the integrin-linked kinase associated phosphatase (ILKAP), a member of the protein phosphatase 2C (PP2C) family. Phosphatases can potentially dephosphorylate these phosphopeptide substrates but, interestingly, performing the binding studies at 4 °C allowed efficient binding to phosphopeptides......, without the need for phosphopeptide mimics or phosphatase inhibitors. As no proven ILKAP substrates were available, we selected phosphopeptide substrates among known PP2Cδ substrates including the protein kinases: p38, ATM, Chk1, Chk2 and RSK2 and synthesized directly on PEGA solid supports through a BAL...

  13. Protein tyrosine phosphatases: regulatory mechanisms.

    NARCIS (Netherlands)

    den Hertog, J.; Ostman, A.; Bohmer, F.D.

    2008-01-01

    Protein-tyrosine phosphatases are tightly controlled by various mechanisms, ranging from differential expression in specific cell types to restricted subcellular localization, limited proteolysis, post-translational modifications affecting intrinsic catalytic activity, ligand binding and

  14. Integral process of obtaining glycerol as a by-product of biodiesel production from castor oil

    Directory of Open Access Journals (Sweden)

    Leonel Romero

    2012-12-01

    Full Text Available The biodiesel is obtained from about 10 years ago in Europe, and now that it has taken hold as fuel for diesel engines, it is expected a clear increase in the production of this class of fuels in a the near future. The biodiesel is derived from the transesterification reaction of castor oil with methanol, which is the main by-product the glycerol with an approximate content of 10%. Besides catalyst residuals, soaps, methanol traces, mono and diglycerides in small percentages are presented. This study proposes the separation, purification and characterization of the glycerol obtained from the transesterificación reaction of the castor oil, in order to be able to market it in the national or international market, so that it fulfills the standards of quality, which means getting a pure glycerol and the appropriate physico-chemical characteristics and techniques. The glycerin-methyl esters separation is carried out by decantation being obtained a percentage of around 70% glycerol. This percentage is subsequently increased through the purification process, using hydrochloric acid. Glycerol characterization was carried out by physicochemical and organoleptic tests. The purification process allowed us to obtain a glycerol with a percentage of purity close to 98%. It was also tested by comparison with theoretical data that remnants influenced in the physiochemical properties

  15. Biodiesel biorefinery: opportunities and challenges for microbial production of fuels and chemicals from glycerol waste.

    Science.gov (United States)

    Almeida, João R M; Fávaro, Léia C L; Quirino, Betania F

    2012-07-18

    The considerable increase in biodiesel production worldwide in the last 5 years resulted in a stoichiometric increased coproduction of crude glycerol. As an excess of crude glycerol has been produced, its value on market was reduced and it is becoming a "waste-stream" instead of a valuable "coproduct". The development of biorefineries, i.e. production of chemicals and power integrated with conversion processes of biomass into biofuels, has been singled out as a way to achieve economically viable production chains, valorize residues and coproducts, and reduce industrial waste disposal. In this sense, several alternatives aimed at the use of crude glycerol to produce fuels and chemicals by microbial fermentation have been evaluated. This review summarizes different strategies employed to produce biofuels and chemicals (1,3-propanediol, 2,3-butanediol, ethanol, n-butanol, organic acids, polyols and others) by microbial fermentation of glycerol. Initially, the industrial use of each chemical is briefly presented; then we systematically summarize and discuss the different strategies to produce each chemical, including selection and genetic engineering of producers, and optimization of process conditions to improve yield and productivity. Finally, the impact of the developments obtained until now are placed in perspective and opportunities and challenges for using crude glycerol to the development of biodiesel-based biorefineries are considered. In conclusion, the microbial fermentation of glycerol represents a remarkable alternative to add value to the biodiesel production chain helping the development of biorefineries, which will allow this biofuel to be more competitive.

  16. Abscisic acid affects transcription of chloroplast genes via protein phosphatase 2C-dependent activation of nuclear genes: repression by guanosine-3'-5'-bisdiphosphate and activation by sigma factor 5.

    Science.gov (United States)

    Yamburenko, Maria V; Zubo, Yan O; Börner, Thomas

    2015-06-01

    Abscisic acid (ABA) represses the transcriptional activity of chloroplast genes (determined by run-on assays), with the exception of psbD and a few other genes in wild-type Arabidopsis seedlings and mature rosette leaves. Abscisic acid does not influence chloroplast transcription in the mutant lines abi1-1 and abi2-1 with constitutive protein phosphatase 2C (PP2C) activity, suggesting that ABA affects chloroplast gene activity by binding to the pyrabactin resistance (PYR)/PYR1-like or regulatory component of ABA receptor protein family (PYR/PYL/RCAR) and signaling via PP2Cs and sucrose non-fermenting protein-related kinases 2 (SnRK2s). Further we show by quantitative PCR that ABA enhances the transcript levels of RSH2, RSH3, PTF1 and SIG5. RelA/SpoT homolog 2 (RSH2) and RSH3 are known to synthesize guanosine-3'-5'-bisdiphosphate (ppGpp), an inhibitor of the plastid-gene-encoded chloroplast RNA polymerase. We propose, therefore, that ABA leads to an inhibition of chloroplast gene expression via stimulation of ppGpp synthesis. On the other hand, sigma factor 5 (SIG5) and plastid transcription factor 1 (PTF1) are known to be necessary for the transcription of psbD from a specific light- and stress-induced promoter (the blue light responsive promoter, BLRP). We demonstrate that ABA activates the psbD gene by stimulation of transcription initiation at BLRP. Taken together, our data suggest that ABA affects the transcription of chloroplast genes by a PP2C-dependent activation of nuclear genes encoding proteins involved in chloroplast transcription. © 2015 The Authors The Plant Journal © 2015 John Wiley & Sons Ltd.

  17. Glycerol transesterification with ethyl acetate to synthesize acetins using ethyl acetate as reactant and entrainer

    Directory of Open Access Journals (Sweden)

    Amin Shafiei

    2017-03-01

    Full Text Available Transesterification of glycerol with ethyl acetate was performed over acidic catalysts in the batch and semi-batch systems. Ethyl acetate was used as reactant and entrainer to remove the produced ethanol during the reaction, through azeotrope formation. Since the azeotrope of ethyl acetate and ethanol forms at 70 oC, all the experiments were performed at this temperature. Para-toluene sulfonic acid, sulfuric acid, and Amberlyst 36 were used as catalyst. The effect of process parameters including ethyl acetate to glycerol molar ratio (6-12, reaction time (3-9 h, and the catalyst to glycerol weight (2.5-9.0%, on the conversion and products selectivities were investigated. Under reflux conditions, 100% glycerol conversion was obtained with 45%, 44%, and 11% selectivity to monoacetin, diacetin, and triacetin, respectively. Azeotropic reactive distillation led to 100% conversion of glycerol with selectivities of 3%, 48% and 49% for monoacetin, diacetin, and triacetin. During the azeotropic reactive distillation, it was possible to remove ethanol to shift the equilibrium towards diacetin and triacetin. Therefore, the total selectivity to diacetin and triacetin was increased from 55% to 97% through azeotropic distillation.

  18. Valorization of crude glycerol from biodiesel production

    Directory of Open Access Journals (Sweden)

    Konstantinović Sandra S.

    2016-01-01

    Full Text Available The increased production of biodiesel as an alternative fuel involves the simultaneous growth in production of crude glycerol as its main by-product. Therefore, the feasibility and sustainability of biodiesel production requires the effective utilization of crude glycerol. This review describes various uses of crude glycerol as a potential green solvent for chemical reactions, a starting raw material for chemical and biochemical conversions into value-added chemicals, a substrate or co-substrate in microbial fermentations for synthesis of valuable chemicals and production of biogas and biohydrogen as well as a feedstuff for animal feed. A special attention is paid to various uses of crude glycerol in biodiesel production. [Projekat Ministarstva nauke Republike Srbije, br. III 45001

  19. Glucose-6-phosphatase deficiency

    Directory of Open Access Journals (Sweden)

    Labrune Philippe

    2011-05-01

    Full Text Available Abstract Glucose-6-phosphatase deficiency (G6P deficiency, or glycogen storage disease type I (GSDI, is a group of inherited metabolic diseases, including types Ia and Ib, characterized by poor tolerance to fasting, growth retardation and hepatomegaly resulting from accumulation of glycogen and fat in the liver. Prevalence is unknown and annual incidence is around 1/100,000 births. GSDIa is the more frequent type, representing about 80% of GSDI patients. The disease commonly manifests, between the ages of 3 to 4 months by symptoms of hypoglycemia (tremors, seizures, cyanosis, apnea. Patients have poor tolerance to fasting, marked hepatomegaly, growth retardation (small stature and delayed puberty, generally improved by an appropriate diet, osteopenia and sometimes osteoporosis, full-cheeked round face, enlarged kydneys and platelet dysfunctions leading to frequent epistaxis. In addition, in GSDIb, neutropenia and neutrophil dysfunction are responsible for tendency towards infections, relapsing aphtous gingivostomatitis, and inflammatory bowel disease. Late complications are hepatic (adenomas with rare but possible transformation into hepatocarcinoma and renal (glomerular hyperfiltration leading to proteinuria and sometimes to renal insufficiency. GSDI is caused by a dysfunction in the G6P system, a key step in the regulation of glycemia. The deficit concerns the catalytic subunit G6P-alpha (type Ia which is restricted to expression in the liver, kidney and intestine, or the ubiquitously expressed G6P transporter (type Ib. Mutations in the genes G6PC (17q21 and SLC37A4 (11q23 respectively cause GSDIa and Ib. Many mutations have been identified in both genes,. Transmission is autosomal recessive. Diagnosis is based on clinical presentation, on abnormal basal values and absence of hyperglycemic response to glucagon. It can be confirmed by demonstrating a deficient activity of a G6P system component in a liver biopsy. To date, the diagnosis is most

  20. Overexpression of Human Bone Alkaline Phosphatase in Pichia Pastoris

    Science.gov (United States)

    Karr, Laurel; Malone, Christine, C.; Rose, M. Franklin (Technical Monitor)

    2000-01-01

    The Pichiapastoris expression system was utilized to produce functionally active human bone alkaline phosphatase in gram quantities. Bone alkaline phosphatase is a key enzyme in bone formation and biomineralization, yet important questions about its structural chemistry and interactions with other cellular enzymes in mineralizing tissues remain unanswered. A soluble form of human bone alkaline phosphatase was constructed by deletion of the 25 amino acid hydrophobic C-terminal region of the encoding cDNA and inserted into the X-33 Pichiapastoris strain. An overexpression system was developed in shake flasks and converted to large-scale fermentation. Alkaline phosphatase was secreted into the medium to a level of 32mgAL when cultured in shake flasks. Enzyme activity was 12U/mg measured by a spectrophotometric assay. Fermentation yielded 880mgAL with enzymatic activity of 968U/mg. Gel electrophoresis analysis indicates that greater than 50% of the total protein in the fermentation is alkaline phosphatase. A purification scheme has been developed using ammonium sulfate precipitation followed by hydrophobic interaction chromatography. We are currently screening crystallization conditions of the purified recombinant protein for subsequent X-ray diffraction analyses. Structural data should provide additional information on the role of alkaline phosphatase in normal bone mineralization and in certain bone mineralization anomalies.

  1. Growth and extracellular phosphatase activity of arbuscular mycorrhizal hyphae as influenced by soil organic matter

    DEFF Research Database (Denmark)

    Joner, E.J.; Jakobsen, I.

    1995-01-01

    Two experiments were set up to investigate the influence of soil organic matter on growth of arbuscular mycorrhizal (AM) hyphae and concurrent changes in soil inorganic P, organic P and phosphatase activity. A sandy loam soil was kept for 14 months under two regimes (outdoor where surplus...... additions. In soil with added clover alkaline phosphatase activity increased due to the presence of mycorrhizal hyphae. We suggest that mycorrhizas may influence the exudation of acid phosphatase by roots. Hyphae of G. invermaium did apparently not excrete extracellular phosphatases, but their presence may...

  2. Domain-to-domain coupling in voltage-sensing phosphatase.

    Science.gov (United States)

    Sakata, Souhei; Matsuda, Makoto; Kawanabe, Akira; Okamura, Yasushi

    2017-01-01

    Voltage-sensing phosphatase (VSP) consists of a transmembrane voltage sensor and a cytoplasmic enzyme region. The enzyme region contains the phosphatase and C2 domains, is structurally similar to the tumor suppressor phosphatase PTEN, and catalyzes the dephosphorylation of phosphoinositides. The transmembrane voltage sensor is connected to the phosphatase through a short linker region, and phosphatase activity is induced upon membrane depolarization. Although the detailed molecular characteristics of the voltage sensor domain and the enzyme region have been revealed, little is known how these two regions are coupled. In addition, it is important to know whether mechanism for coupling between the voltage sensor domain and downstream effector function is shared among other voltage sensor domain-containing proteins. Recent studies in which specific amino acid sites were genetically labeled using a fluorescent unnatural amino acid have enabled detection of the local structural changes in the cytoplasmic region of Ciona intestinalis VSP that occur with a change in membrane potential. The results of those studies provide novel insight into how the enzyme activity of the cytoplasmic region of VSP is regulated by the voltage sensor domain.

  3. Determination of steady state and nonsteady-state glycerol kinetics in humans using deuterium-labeled tracer

    International Nuclear Information System (INIS)

    Beylot, M.; Martin, C.; Beaufrere, B.; Riou, J.P.; Mornex, R.

    1987-01-01

    Using deuterium-labeled glycerol as tracer and gas-liquid chromatography-mass spectrometry techniques for the determination of isotopic enrichment, we have developed a simple and ethically acceptable method of determining glycerol appearance rate in humans under steady-state and nonsteady-state conditions. In normal subjects, the appearance rate of glycerol in the post-absorptive state was 2.22 +/- 0.20 mumol X kg-1 X min-1, a value in agreement with those reported in studies with radioactively labeled tracers. The ratio nonesterified fatty acid (NEFA) appearance rate/glycerol appearance rate ranged from 1.95 to 3.40. In insulin-dependent diabetic patients with a mild degree of metabolic control, the appearance rate of glycerol was 2.48 +/- 0.29 mumol X kg-1 X min-1. The volume of distribution of glycerol, determined by the bolus injection technique, was (mean) 0.306 l X kg-1 in normal subjects and 0.308 l X kg-1 in insulin-independent diabetic patients. To evaluate the usefulness of the method for determination of glycerol kinetics in nonsteady-state conditions, we infused six normal subjects with natural glycerol and calculated the isotopically determined glycerol appearance rate using a single compartment model (volume of distribution 0.31 l X kg-1). During these tests, the expected glycerol appearance rates were successively 5.03 +/- 0.33, 7.48 +/- 0.39, 9.94 +/- 0.34, 7.48 +/- 0.39, and 5.03 +/- 0.33 mumol +/- kg-1 X min-1, whereas the corresponding isotopically determined appearance rates were 4.62 +/- 0.45, 6.95 +/- 0.56, 10.85 +/- 0.51, 7.35 +/- 0.34, and 5.28 +/- 0.12 mumol X kg-1 X min-1

  4. Dephosphorylation of chicken cardiac myofibril C-protein by protein phosphatases 1 and 2A

    International Nuclear Information System (INIS)

    Thysseril, T.J.; Hegazy, M.G.; Schlender, K.K.

    1987-01-01

    C-Protein, which is a regulatory component of cardiac muscle myofibrils, is phosphorylated in response to β-adrenergic agonists by a cAMP-dependent mechanism and dephosphorylated in response to cholinergic agonists. It is believed that the cAMP-dependent phosphorylation is due to cAMP-dependent protein kinase. The protein phosphatase(s) involved in the dephosphorylation of C-protein has not been determined. In this study, chicken cardiac C-protein was phosphorylated with the cAMP-dependent protein kinase to about 3 mol phosphate/mol C-protein. Incubation of [ 32 P]C-protein with the catalytic subunit of protein phosphatase 1 or 2A rapidly removed 30-40% of 32 [P]. Phosphopeptide maps and phosphoamino acid analysis revealed that the major site(s) dephosphorylated by either phosphatase was a phosphothreonine residue(s) located on the same tryptic peptide and on the same CNBr fragment. Increasing the incubation period or the phosphatase concentration did not result in any further dephosphorylation of C-protein by phosphatase 1, but phosphatase 2A completely dephosphorylated C-protein. Preliminary studies showed that the major protein phosphatase associated with the myofibril was phosphatase 2A. These results indicate the phosphatase 2A may be important in the regulation of the phosphorylation state of C-protein

  5. Glycerol production by Oenococcus oeni during sequential and simultaneous cultures with wine yeast strains.

    Science.gov (United States)

    Ale, Cesar E; Farías, Marta E; Strasser de Saad, Ana M; Pasteris, Sergio E

    2014-07-01

    Growth and fermentation patterns of Saccharomyces cerevisiae, Kloeckera apiculata, and Oenococcus oeni strains cultured in grape juice medium were studied. In pure, sequential and simultaneous cultures, the strains reached the stationary growth phase between 2 and 3 days. Pure and mixed K. apiculata and S. cerevisiae cultures used mainly glucose, producing ethanol, organic acids, and 4.0 and 0.1 mM glycerol, respectively. In sequential cultures, O. oeni achieved about 1 log unit at 3 days using mainly fructose and L-malic acid. Highest sugars consumption was detected in K. apiculata supernatants, lactic acid being the major end-product. 8.0 mM glycerol was found in 6-day culture supernatants. In simultaneous cultures, total sugars and L-malic acid were used at 3 days and 98% of ethanol and glycerol were detected. This study represents the first report of the population dynamics and metabolic behavior of yeasts and O. oeni in sequential and simultaneous cultures and contributes to the selection of indigenous strains to design starter cultures for winemaking, also considering the inclusion of K. apiculata. The sequential inoculation of yeasts and O. oeni would enhance glycerol production, which confers desirable organoleptic characteristics to wines, while organic acids levels would not affect their sensory profile. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  6. Purification of crude glycerol from transesterification reaction of palm oil using direct method and multistep method

    Science.gov (United States)

    Nasir, N. F.; Mirus, M. F.; Ismail, M.

    2017-09-01

    Crude glycerol which produced from transesterification reaction has limited usage if it does not undergo purification process. It also contains excess methanol, catalyst and soap. Conventionally, purification method of the crude glycerol involves high cost and complex processes. This study aimed to determine the effects of using different purification methods which are direct method (comprises of ion exchange and methanol removal steps) and multistep method (comprises of neutralization, filtration, ion exchange and methanol removal steps). Two crude glycerol samples were investigated; the self-produced sample through the transesterification process of palm oil and the sample obtained from biodiesel plant. Samples were analysed using Fourier Transform Infrared Spectroscopy, Gas Chromatography and High Performance Liquid Chromatography. The results of this study for both samples after purification have showed that the pure glycerol was successfully produced and fatty acid salts were eliminated. Also, the results indicated the absence of methanol in both samples after purification process. In short, the combination of 4 purification steps has contributed to a higher quality of glycerol. Multistep purification method gave a better result compared to the direct method as neutralization and filtration steps helped in removing most excess salt, fatty acid and catalyst.

  7. Impact of ionic aluminium on extracellular phosphatases in acidified lakes

    Czech Academy of Sciences Publication Activity Database

    Bittl, T.; Vrba, Jaroslav; Nedoma, Jiří; Kopáček, Jiří

    2001-01-01

    Roč. 3, č. 9 (2001), s. 578-587 ISSN 1462-2912 R&D Projects: GA ČR GA206/97/0072; GA ČR GA206/00/0063 Keywords : acid phosphatases * pH effect * inhibition Subject RIV: DA - Hydrology ; Limnology Impact factor: 3.276, year: 2001

  8. Bio-Propane from glycerol for biogas addition

    Energy Technology Data Exchange (ETDEWEB)

    Brandin, Jan; Hulteberg, Christian; Liljegren Nilsson, Andreas (Biofuel-Solution AB, Malmoe (Sweden))

    2008-11-15

    In this report, the technical and economical feasibility to produce higher alkanes from bioglycerol has been investigated. The main purpose of producing this kind of chemicals would be to replace the fossil LPG used in upgraded biogas production. When producing biogas and exporting it to the natural gas grid, the Wobbe index and heating value does not match the existing natural gas. Therefore, the upgraded biogas that is put into the natural gas grid in Sweden today contains 8-10 vol-% of LPG. The experimental work performed in association to this report has shown that it is possible to produce propane from glycerol. However, the production of ethane from glycerol may be even more advantageous. The experimental work has included developing and testing catalysts for several intermediate reactions. The work was performed using different micro-scale reactors with a liquid feed rate of 18 g/h. The first reaction, independent on if propane or ethane is to be produced, is dehydration of glycerol to acrolein. This was showed during 60 h on an acidic catalyst with a yield of 90%. The production of propanol, the second intermediate to producing propane, was shown as well. Propanol was produced both using acrolein as the starting material as well as glycerol (combining the first and second step) with yields of 70-80% in the first case and 65-70% in the second case. The propanol produced was investigated for its dehydration to propene, with a yield of 70-75%. By using a proprietary, purposely developed catalyst the propene was hydrogenated to propane, with a yield of 85% from propanol. The formation of propane from glycerol was finally investigated, with an overall yield of 55%. The second part of the experimental work performed investigated the possibilities of decarbonylating acrolein to form ethane. This was made possible by the development of a proprietary catalyst which combines decarbonylation and water-gas shift functionality. By combining these two functionalities, no

  9. Catalytic glycerol steam reforming for hydrogen production

    International Nuclear Information System (INIS)

    Dan, Monica; Mihet, Maria; Lazar, Mihaela D.

    2015-01-01

    Hydrogen production from glycerol by steam reforming combine two major advantages: (i) using glycerol as raw material add value to this by product of bio-diesel production which is obtained in large quantities around the world and have a very limited utilization now, and (ii) by implication of water molecules in the reaction the efficiency of hydrogen generation is increased as each mol of glycerol produces 7 mol of H 2 . In this work we present the results obtained in the process of steam reforming of glycerol on Ni/Al 2 O 3 . The catalyst was prepared by wet impregnation method and characterized through different methods: N 2 adsorption-desorption, XRD, TPR. The catalytic study was performed in a stainless steel tubular reactor at atmospheric pressure by varying the reaction conditions: steam/carbon ratio (1-9), gas flow (35 ml/min -133 ml/min), temperature (450-650°C). The gaseous fraction of the reaction products contain: H 2 , CH 4 , CO, CO 2 . The optimum reaction conditions as resulted from this study are: temperature 550°C, Gly:H 2 O ratio 9:1 and Ar flow 133 ml/min. In these conditions the glycerol conversion to gaseous products was 43% and the hydrogen yield was 30%

  10. Catalytic glycerol steam reforming for hydrogen production

    Energy Technology Data Exchange (ETDEWEB)

    Dan, Monica, E-mail: monica.dan@itim-cj.ro; Mihet, Maria, E-mail: maria.mihet@itim-cj.ro; Lazar, Mihaela D., E-mail: diana.lazar@itim-cj.ro [National Institute for Research and Development of Isotopic and Molecular Technologies, 67-103 Donat Street, 400293 Cluj Napoca (Romania)

    2015-12-23

    Hydrogen production from glycerol by steam reforming combine two major advantages: (i) using glycerol as raw material add value to this by product of bio-diesel production which is obtained in large quantities around the world and have a very limited utilization now, and (ii) by implication of water molecules in the reaction the efficiency of hydrogen generation is increased as each mol of glycerol produces 7 mol of H{sub 2}. In this work we present the results obtained in the process of steam reforming of glycerol on Ni/Al{sub 2}O{sub 3}. The catalyst was prepared by wet impregnation method and characterized through different methods: N{sub 2} adsorption-desorption, XRD, TPR. The catalytic study was performed in a stainless steel tubular reactor at atmospheric pressure by varying the reaction conditions: steam/carbon ratio (1-9), gas flow (35 ml/min -133 ml/min), temperature (450-650°C). The gaseous fraction of the reaction products contain: H{sub 2}, CH{sub 4}, CO, CO{sub 2}. The optimum reaction conditions as resulted from this study are: temperature 550°C, Gly:H{sub 2}O ratio 9:1 and Ar flow 133 ml/min. In these conditions the glycerol conversion to gaseous products was 43% and the hydrogen yield was 30%.

  11. Determination of trace alkaline phosphatase by affinity adsorption solid substrate room temperature phosphorimetry based on wheat germ agglutinin labeled with 8-quinolineboronic acid phosphorescent molecular switch and prediction of diseases

    Science.gov (United States)

    Liu, Jia-Ming; Gao, Hui; Li, Fei-Ming; Shi, Xiu-Mei; Lin, Chang-Qing; Lin, Li-Ping; Wang, Xin-Xing; Li, Zhi-Ming

    2010-09-01

    The 8-quinolineboronic acid phosphorescent molecular switch (abbreviated as PMS-8-QBA. Thereinto, 8-QBA is 8-quinolineboronic acid, and PMS is phosphorescent molecular switch) was found for the first time. PMS-8-QBA, which was in the "off" state, could only emit weak room temperature phosphorescence (RTP) on the acetyl cellulose membrane (ACM). However, PMS-8-QBA turned "on" automatically for its changed structure, causing that the RTP of 8-QBA in the system increased, after PMS-8-QBA-WGA (WGA is wheat germ agglutinin) was formed by reaction between -OH of PMS-8-QBA and -COOH of WGA. More interesting is that the -NH 2 of PMS-8-QBA-WGA could react with the -COOH of alkaline phosphatase (AP) to form the affinity adsorption (AA) product WGA-AP-WGA-8-QBA-PMS (containing -NH-CO- bond), which caused RTP of the system to greatly increase. Thus, affinity adsorption solid substrate room temperature phosphorimetry using PMS-8-QBA as labelling reagent (PMS-8-QBA-AA-SSRTP) for the determination of trace AP was established. The method had many advantages, such as high sensitivity (the detection limit (LD) was 2.5 zg spot -1. For sample volume of 0.40 μl spot -1, corresponding concentration was 6.2 × 10 -18 g ml -1), good selectivity (the allowed concentration of coexisting material was higher, when the relative error was ±5%), high accuracy (applied to detection of AP content in serum samples, the result was coincided with those obtained by enzyme-linked immunoassay), which was suitable for the detection of trace AP content in serum samples and the forecast of human diseases. Meanwhile, the mechanism of PMS-8-QBA-AASSRTP was discussed. The new field of analytical application and clinic diagnosis technique of molecule switch are exploited, based on the phosphorescence characteristic of PMS-8-QBA, the AA reaction between WGA and AP, as well as the relation between AP content and human diseases. The research results promote the development and interpenetrate among molecule

  12. Preparative resolution of D,L-threonine catalyzed by immobilized phosphatase.

    Science.gov (United States)

    Scollar, M P; Sigal, G; Klibanov, A M

    1985-03-01

    Hydrolysis of L- and D-O-phosphothreonines catalyzed by four different phosphatases, alkaline phosphatases from calf intestine and E. coli and acid phosphatases from wheat germ and potato, has been kinetically studied. Alkaline phosphatases were found to have comparable reactivities towards the optical isomers. On the other hand, both acid phosphatases displayed a marked stereoselectivity, hydrolyzing the L-ester much faster than its D counterpart. Wheat germ acid phosphatase was the most stereoselective enzyme: V(L)/V(D) = 24 and K(m,L)/K(m,D) = 0.17. This enzyme was immobilized (in k-carrageenan gel, followed by crosslinking with glutaraldehyde) and used for the preparative resolution of D,L-threonine: the latter was first chemically O-phosphorylated and then asymmetrically hydrolyzed by the immobilized phosphatase. As a result, gram quantities of L-threonine of high optical purity and O-phospho-D-threonine were prepared. Immobilized wheat germ phosphatase has been tested for the resolution of other racemic alcohols: serine, 2-amino-1-butanol, 1-amino-2-propanol, 2-octanol, and menthol. In all those cases, the enzyme was either not sufficiently stereoselective or too slow for preparative resolutions.

  13. Aquaglyceroporin-null trypanosomes display glycerol transport defects and respiratory-inhibitor sensitivity.

    Directory of Open Access Journals (Sweden)

    Laura Jeacock

    2017-03-01

    Full Text Available Aquaglyceroporins (AQPs transport water and glycerol and play important roles in drug-uptake in pathogenic trypanosomatids. For example, AQP2 in the human-infectious African trypanosome, Trypanosoma brucei gambiense, is responsible for melarsoprol and pentamidine-uptake, and melarsoprol treatment-failure has been found to be due to AQP2-defects in these parasites. To further probe the roles of these transporters, we assembled a T. b. brucei strain lacking all three AQP-genes. Triple-null aqp1-2-3 T. b. brucei displayed only a very moderate growth defect in vitro, established infections in mice and recovered effectively from hypotonic-shock. The aqp1-2-3 trypanosomes did, however, display glycerol uptake and efflux defects. They failed to accumulate glycerol or to utilise glycerol as a carbon-source and displayed increased sensitivity to salicylhydroxamic acid (SHAM, octyl gallate or propyl gallate; these inhibitors of trypanosome alternative oxidase (TAO can increase intracellular glycerol to toxic levels. Notably, disruption of AQP2 alone generated cells with glycerol transport defects. Consistent with these findings, AQP2-defective, melarsoprol-resistant clinical isolates were sensitive to the TAO inhibitors, SHAM, propyl gallate and ascofuranone, relative to melarsoprol-sensitive reference strains. We conclude that African trypanosome AQPs are dispensable for viability and osmoregulation but they make important contributions to drug-uptake, glycerol-transport and respiratory-inhibitor sensitivity. We also discuss how the AQP-dependent inverse sensitivity to melarsoprol and respiratory inhibitors described here might be exploited.

  14. Integrated multienzyme electrochemical biosensors for the determination of glycerol in wines.

    Science.gov (United States)

    Gamella, M; Campuzano, S; Reviejo, A J; Pingarrón, J M

    2008-02-25

    The construction and performance of integrated amperometric biosensors for the determination of glycerol are reported. Two different biosensor configurations have been evaluated: one based on the glycerol dehydrogenase/diaphorase (GDH/DP) bienzyme system, and another using glycerol kinase/glycerol-3-phosphate oxidase/peroxidase (GK/GPOx/HRP). Both enzyme systems were immobilized together with the mediator tetrathiafulvalene (TTF) on a 3-mercaptopropionic acid (MPA) self-assembled monolayer (SAM)-modified gold electrode by using a dialysis membrane. The electrochemical oxidation of TTF at +150mV (vs. Ag/AgCl), and the reduction of TTF(+) at 0mV were used for the monitoring of the enzyme reactions for the bienzyme and trienzyme configurations, respectively. Experimental variables concerning both the biosensors composition and the working conditions were optimized for each configuration. A good repeatability of the measurements with no need of cleaning or pretreatment of the biosensors was obtained in both cases. After 51 days of use, the GDH/DP biosensor still exhibited 87% of the original sensitivity, while the GK/GPOx/HRP biosensor yielded a 46% of the original response after 8 days. Calibration graphs for glycerol with linear ranges of 1.0x10(-6) to 2.0x10(-5) or 1.0x10(-6) to 1.0x10(-5)M glycerol and sensitivities of 1214+/-21 or 1460+/-34microAM(-1) were obtained with GDH/DP and GK/GPOx/HRP biosensors, respectively. The calculated detection limits were 4.0x10(-7) and 3.1x10(-7)M, respectively. The biosensors exhibited a great sensitivity with no significant interferences in the analysis of wines. The biosensors were applied to the determination of glycerol in 12 different wines and the results advantageously compared with those provided by a commercial enzyme kit.

  15. Using crude glycerol and thin stillage for the production of microbial lipids through the cultivation of Rhodotorula glutinis.

    Science.gov (United States)

    Yen, Hong-Wei; Yang, Ya-Chun; Yu, Yi-Huan

    2012-10-01

    Single cell oils (SCO) produced from oleaginous microorganisms are a potential alternative oil feedstock for biodiesel production. The worldwide production of glycerol, a 10% (w/w) byproduct produced in the transesterfication process of oils converted to biodiesel, is increasing as more biodiesel is being produced. For the purposes of cost reduction, crude glycerol was regarded as a suitable carbon source for the cultivation of Rhodotorula glutinis. In addition to using renewable crude glycerol, waste solution collected from the brewing company (called thin stillage) was adopted as a substitute to replace a costly nitrogen source used in the medium. The results of using mixture of crude glycerol and thin stillage indicated about a 27% increase in total biomass as compared to that of using crude glycerol with a standard medium. Using glycerol instead of glucose as the carbon source could also alter the lipid profile, resulting in an increase in linolenic acid (C18:2) to comprise over 20% of the total lipid. Successfully using renewable crude glycerol and thin stillage for the cultivation of oleaginous microorganisms could greatly enhance the economic competition of biodiesel produced from SCO. Copyright © 2012 The Society for Biotechnology, Japan. Published by Elsevier B.V. All rights reserved.

  16. From Symmetric Glycerol Derivatives to Dissymmetric Chlorohydrins

    Directory of Open Access Journals (Sweden)

    Gemma Villorbina

    2011-03-01

    Full Text Available The anticipated worldwide increase in biodiesel production will result in an accumulation of glycerol for which there are insufficient conventional uses. The surplus of this by-product has increased rapidly during the last decade, prompting a search for new glycerol applications. We describe here the synthesis of dissymmetric chlorohydrin esters from symmetric 1,3-dichloro-2-propyl esters obtained from glycerol. We studied the influence of two solvents: 1,4-dioxane and 1-butanol and two bases: sodium carbonate and 1-butylimidazole, on the synthesis of dissymmetric chlorohydrin esters. In addition, we studied the influence of other bases (potassium and lithium carbonates in the reaction using 1,4-dioxane as the solvent. The highest yield was obtained using 1,4-dioxane and sodium carbonate.

  17. Chemoselective Oxidation of Bio-Glycerol with Nano-Sized Metal Catalysts

    DEFF Research Database (Denmark)

    Li, Hu; Kotni, Ramakrishna; Zhang, Qiuyun

    2015-01-01

    to selectively oxidize glycerol and yield products with good selectivity is the use of nano-sized metal particles as heterogeneous catalysts. In this short review, recent developments in chemoselective oxidation of glycerol to specific products over nano-sized metal catalysts are described. Attention is drawn...... to various reaction parameters such as the type of the support, the size of the metal particles, and the acid/base properties of the reaction medium which were illustrated to largely influence the activity of the nanocatalyst and selectivity to the target product. - See more at: http...

  18. Design and analysis of fuel ethanol production from raw glycerol

    International Nuclear Information System (INIS)

    Posada, J.A.; Cardona, C.A.

    2010-01-01

    Three configurations for fuel ethanol production from raw glycerol using Escherichia coli were simulated and economically assessed using Aspen Plus and Aspen Icarus, respectively. These assessments considered raw glycerol (60 wt%) purification to both crude glycerol (88 wt%) and pure glycerol (98 wt%). The highest purification cost (PC) was obtained using pure glycerol due to its higher energy consumption in the distillation stage. In addition, the remaining methanol in the raw glycerol stream was recovered and recycled, decreasing the purification costs. The E. coli strain is able to convert crude glycerol (at 10 g/L or 20 g/L), or pure glycerol (at 10 g/L) to ethanol. Among these three glycerol concentrations, the lowest bioconversion cost was obtained when crude glycerol was diluted at 20 g/L. Purification and global production costs were compared with the commercial prices of glycerol and fuel ethanol from corn and sugarcane. Purification costs of raw glycerol were lower than previously reported values due to the methanol recovery. Global production costs for fuel ethanol from glycerol were lower than the reported values for corn-based production and higher than those for cane-based production. (author)

  19. Effects of feeding dry glycerol on milk production, nutrients digestibility and blood components in primiparous Holstein dairy cows during the early postpartum period

    Energy Technology Data Exchange (ETDEWEB)

    Kafilzadeh, F.; Piri, V.; Karami-Shabankareh, H.

    2015-07-01

    The aim of this study was to evaluate the glucogenic property of glycerol supplementation in the dairy cow’s diet. Sixty primiparous cows (control, n=30, and glycerol supplemented, n=30) were used to measure milk yield and components, blood hormone and metabolite profiles, and body condition score. Feed intake and apparent total-tract digestibility were also measured using 10 primiparous cows (control, n=5, and glycerol supplemented, n=5). Dry glycerol was top dressed at 250 g/day/cow from parturition to 21 days postpartum. Average feed intake, milk yield and components were not affected by glycerol supplementation. Apparent total–tract digestibility of organic matter and neutral detergent fibre were not influenced by dry glycerol supplementation, but lipid digestibility was greater (p=0.01) in cows fed glycerol. The serum concentration of glucose and insulin tended to be higher in dry glycerol-supplemented cows (p=0.1; p=0.06, respectively). While, serum concentrations of nonesterified fatty acids and β-hydroxybutyrate were not affected. Supplemented cows had lower body condition loss during weeks 1 to 5 after calving (p=0.09). The glucogenic effect of glycerol did not affect milk yield during the first 3 weeks of lactation. However, daily milk yield during the 13 weeks recording period was higher in the glycerol-supplemented cows (28.5 vs. 30.3 kg, p<0.001). Percentages of cows cycling at the planned breeding date was greater (p=0.01) for cows fed dry glycerol. The results demonstrated that feeding dry glycerol as a glucogenic supply could be useful in saving body reserves and improving energy balance of primiparous Holstein dairy cows during the early postpartum period. (Author)

  20. Effects of feeding dry glycerol on milk production, nutrients digestibility and blood components in primiparous Holstein dairy cows during the early postpartum period

    Directory of Open Access Journals (Sweden)

    Farokh Kafilzadeh

    2015-12-01

    Full Text Available The aim of this study was to evaluate the glucogenic property of glycerol supplementation in the dairy cow’s diet. Sixty primiparous cows (control, n=30, and glycerol supplemented, n=30 were used to measure milk yield and components, blood hormone and metabolite profiles, and body condition score. Feed intake and apparent total-tract digestibility were also measured using 10 primiparous cows (control, n=5, and glycerol supplemented, n=5. Dry glycerol was top dressed at 250 g/day/cow from parturition to 21 days postpartum. Average feed intake, milk yield and components were not affected by glycerol supplementation. Apparent total–tract digestibility of organic matter and neutral detergent fibre were not influenced by dry glycerol supplementation, but lipid digestibility was greater (p=0.01 in cows fed glycerol. The serum concentration of glucose and insulin tended to be higher in dry glycerol-supplemented cows (p=0.1; p=0.06, respectively. While, serum concentrations of nonesterified fatty acids and β-hydroxybutyrate were not affected. Supplemented cows had lower body condition loss during weeks 1 to 5 after calving (p=0.09. The glucogenic effect of glycerol did not affect milk yield during the first 3 weeks of lactation. However, daily milk yield during the 13 weeks recording period was higher in the glycerol-supplemented cows (28.5 vs. 30.3 kg, p<0.001. Percentages of cows cycling at the planned breeding date was greater (p=0.01 for cows fed dry glycerol. The results demonstrated that feeding dry glycerol as a glucogenic supply could be useful in saving body reserves and improving energy balance of primiparous Holstein dairy cows during the early postpartum period.

  1. Conversion of Crude Glycerol to 1, 3-Propanediol by Newly Isolated Kluyvera Cryocrescens

    International Nuclear Information System (INIS)

    Loh, S.K.; Stasha Eleanor Rosland Abel

    2016-01-01

    Bio diesel, an environmental-friendly and renewable fuel, has gained market share and popularity as an alternative to fossil fuel. While expanding its production globally to meet the demand, the production of its principal co-product, crude glycerol which is surplus and under utilised, has affected both the economic and environment. Crude glycerol has limited usage due to the impurities present. It cannot be disposed naturally in the environment and its storage and processing are very costly. Glycerol with its triglyceride backbone serves as a natural metabolite susceptible to microbial degradation into high value-added compounds. In this study, a novel 1,3-PD producing bacterial strain isolated from palm oil mill effluent was used in microbial fermentation of crude glycerol. The strain, identified as Kluyvera cryocrescens NBRC 102467 based on its 16S ribosomal ribonucleic acid sequences, was capable of producing 1,3-PD (5.28 g litre -1 ) along with by-products, butanol (0.34 g litre -1 ) and acetone (0.31 g litre -1 ) after an optimum 48 hour of incubation at 30 degree Celsius in agitated medium enriched with crude glycerol at 150 revolutions per minute. Interestingly, its productivity peaked at the 6 hour reaching 0.28 g litre -1 hour -1 and declined thereafter. In future, this strain has potential to be used in the bioprocess of interest. (author)

  2. Characterization and site-directed mutagenesis of Wzb, an O-phosphatase from Lactobacillus rhamnosus

    Directory of Open Access Journals (Sweden)

    Gilbert Christophe

    2008-04-01

    Full Text Available Abstract Background Reversible phosphorylation events within a polymerisation complex have been proposed to modulate capsular polysaccharide synthesis in Streptococcus pneumoniae. Similar phosphatase and kinase genes are present in the exopolysaccharide (EPS biosynthesis loci of numerous lactic acid bacteria genomes. Results The protein sequence deduced from the wzb gene in Lactobacillus rhamnosus ATCC 9595 reveals four motifs of the polymerase and histidinol phosphatase (PHP superfamily of prokaryotic O-phosphatases. Native and modified His-tag fusion Wzb proteins were purified from Escherichia coli cultures. Extracts showed phosphatase activity towards tyrosine-containing peptides. The purified fusion protein Wzb was active on p-nitrophenyl-phosphate (pNPP, with an optimal activity in presence of bovine serum albumin (BSA 1% at pH 7.3 and a temperature of 75°C. At 50°C, residual activity decreased to 10 %. Copper ions were essential for phosphatase activity, which was significantly increased by addition of cobalt. Mutated fusion Wzb proteins exhibited reduced phosphatase activity on p-nitrophenyl-phosphate. However, one variant (C6S showed close to 20% increase in phosphatase activity. Conclusion These characteristics reveal significant differences with the manganese-dependent CpsB protein tyrosine phosphatase described for Streptococcus pneumoniae as well as with the polysaccharide-related phosphatases of Gram negative bacteria.

  3. Okadaic Acid, a Bioactive Fatty Acid from Halichondria okadai, Stimulates Lipolysis in Rat Adipocytes: The Pivotal Role of Perilipin Translocation

    Directory of Open Access Journals (Sweden)

    Nen-Chung Chang

    2013-01-01

    Full Text Available Lipid metabolism in visceral fat cells is correlated with metabolic syndrome and cardiovascular diseases. Okadaic-acid, a 38-carbon fatty acid isolated from the black sponge Halichondria okadai, can stimulate lipolysis by promoting the phosphorylation of several proteins in adipocytes. However, the mechanism of okadaic acid-induced lipolysis and the effects of okadaic acid on lipid-droplet-associated proteins (perilipins and beta-actin remain unclear. We isolated adipocytes from rat epididymal fat pads and treated them with isoproterenol and/or okadaic acid to estimate lipolysis by measuring glycerol release. Incubating adipocytes with okadaic acid stimulated time-dependent lipolysis. Lipid-droplet-associated perilipins and beta-actin were analyzed by immunoblotting and immunofluorescence, and the association of perilipin A and B was found to be decreased in response to isoproterenol or okadaic acid treatment. Moreover, okadaic-acid treatment could enhance isoproterenol-mediated lipolysis, whereas treatment of several inhibitors such as KT-5720 (PKA inhibitor, calphostin C (PKC inhibitor, or KT-5823 (PKG inhibitor did not attenuate okadaic-acid-induced lipolysis. By contrast, vanadyl acetylacetonate (tyrosine phosphatase inhibitor blocked okadaic-acid-dependent lipolysis. These results suggest that okadaic acid induces the phosphorylation and detachment of lipid-droplet-associated perilipin A and B from the lipid droplet surface and thereby leads to accelerated lipolysis.

  4. Trehalose 6-phosphate phosphatases of Pseudomonas aeruginosa.

    Science.gov (United States)

    Cross, Megan; Biberacher, Sonja; Park, Suk-Youl; Rajan, Siji; Korhonen, Pasi; Gasser, Robin B; Kim, Jeong-Sun; Coster, Mark J; Hofmann, Andreas

    2018-04-24

    The opportunistic bacterium Pseudomonas aeruginosa has been recognized as an important pathogen of clinical relevance and is a leading cause of hospital-acquired infections. The presence of a glycolytic enzyme in Pseudomonas, which is known to be inhibited by trehalose 6-phosphate (T6P) in other organisms, suggests that these bacteria may be vulnerable to the detrimental effects of intracellular T6P accumulation. In the present study, we explored the structural and functional properties of trehalose 6-phosphate phosphatase (TPP) in P. aeruginosa in support of future target-based drug discovery. A survey of genomes revealed the existence of 2 TPP genes with either chromosomal or extrachromosomal location. Both TPPs were produced as recombinant proteins, and characterization of their enzymatic properties confirmed specific, magnesium-dependent catalytic hydrolysis of T6P. The 3-dimensional crystal structure of the chromosomal TPP revealed a protein dimer arising through β-sheet expansion of the individual monomers, which possess the overall fold of halo-acid dehydrogenases.-Cross, M., Biberacher, S., Park, S.-Y., Rajan, S., Korhonen, P., Gasser, R. B., Kim, J.-S., Coster, M. J., Hofmann, A. Trehalose 6-phosphate phosphatases of Pseudomonas aeruginosa.

  5. Prebiotic Peptide (Amide) Bond Synthesis Accelerated by Glycerol and Bicarbonate Under Neutral to Alkaline Dry-Down Conditions

    Science.gov (United States)

    Forsythe, J. G.; Weber, A. L.

    2017-01-01

    Past studies of prebiotic peptide bond synthesis have generally been carried out in the acidic to neutral pH range [1, 2]. Here we report a new process for peptide bond (amide) synthesis in the neutral to alkaline pH range that involves simple dry-down heating of amino acids in the presence of glycerol and bicarbonate. Glycerol was included in the reaction mixture as a solvent and to provide hydroxyl groups for possible formation of ester intermediates previously implicated in peptide bond synthesis under acidic to neutral conditions [1]. Bicarbonate was added to raise the reaction pH to 8-9.

  6. Synthesis of substituted 1,3-diesters of glycerol using wittig chemistry.

    Science.gov (United States)

    Lowe, Henry I C; Toyang, Ngeh J; Watson, Charah T; Bryant, Joseph

    2014-05-01

    1,3-di-O-Cinnamoyl-glycerol is a natural compound isolated from a Jamaican medicinal plant commonly referred to as Ball moss (Tillandsia recurvata). The synthesis of this compound was achieved via a Wittig chemistry process. The synthetic approach started with acylation of a di-protected glycerol with cinnamoyl chloride, deprotection of the glycerol moiety, reaction of the primary alcohol with bromo acetylbromide followed by treatment with triphenyl phosphine to give the corresponding phosphonium bromide. The phosphonium bromide was then converted in situ to the Wittig reagent which is the basis for a novel route to 1,3-di-O-cinnamoyl glycerol. Four analogs were also synthesized, three of which are new and are being reported in this article for the first time. The new compounds include 3-(3,4-diemthoxy-phenyl)-acrylic acid 2-hydroxy-3-(3-ptolyl-acryloyloxy)-propyl ester (3), 2-acetoxy-5-((E)-3-(3-((E)-3-(3,4-dimethoxyphenyl)acryloyloxy)-2-hydropropoxy)-3-oxoprop- 1-enyl)benzoic acid (4) and 4-((E)-3-(3-((E)-3-(3,4-dimethoxyphenyl)acryloyloxy)-2-hydropropoxy)-3-oxoprop-1-enyl)benzoic acid (5). The compounds showed no activity in our anticancer assay.

  7. Synthesis of FAEEs from glycerol in engineered Saccharomyces cerevisiae using endogenously produced ethanol by heterologous expression of an unspecific bacterial acyltransferase.

    Science.gov (United States)

    Yu, Kyung Ok; Jung, Ju; Kim, Seung Wook; Park, Chul Hwan; Han, Sung Ok

    2012-01-01

    The high price of petroleum-based diesel fuel has led to the development of alternative fuels, such as ethanol. Saccharomyces cerevisiae was metabolically engineered to utilize glycerol as a substrate for ethanol production. For the synthesis of fatty acid ethyl esters (FAEEs) by engineered S. cerevisiae that utilize glycerol as substrate, heterologous expression of an unspecific acyltransferase from Acinetobacter baylyi with glycerol utilizing genes was established. As a result, the engineered YPH499 (pGcyaDak, pGupWs-DgaTCas) strain produced 0.24 g/L FAEEs using endogenous ethanol produced from glycerol. And this study also demonstrated the possibility of increasing FAEE production by enhancing ethanol production by minimizing the synthesis of glycerol. The overall FAEE production in strain YPH499 fps1Δ gpd2Δ (pGcyaDak, pGupWs-DgaTCas) was 2.1-fold more than in YPH499 (pGcyaDak, pGupWs-DgaTCas), with approximately 0.52 g/L FAEEs produced, while nearly 17 g/L of glycerol was consumed. These results clearly indicated that FAEEs were synthesized in engineered S. cerevisiae by esterifying exogenous fatty acids with endogenously produced ethanol from glycerol. This microbial system acts as a platform in applying metabolic engineering that allows the production of FAEEs from cheap and abundant substrates specifically glycerol through the use of endogenous bioethanol. Copyright © 2011 Wiley Periodicals, Inc.

  8. Phosphatases in Cancer : Shifting the balance

    NARCIS (Netherlands)

    E. Hoekstra (Elmer)

    2015-01-01

    markdownabstractAbstract The role of phosphatases in cancer is an ignored research field, mostly based on the dogma that phosphatases function as tumor suppressor genes. However, in our opinion dephosphorylation events by phosphatases can also enhance signaling in cancer. The current research

  9. Determining Atmospheric Pressure with a Eudiometer and Glycerol

    Science.gov (United States)

    Brody, Jed; Rohald, Kate; Sutton, Atasha

    2010-01-01

    We consider a volume of air trapped over a glycerol column in a eudiometer. We demonstrate that there is an approximately linear relationship between the volume of trapped air and the height of the glycerol column. Simply by moving the eudiometer up and down, we cause the glycerol-column height and trapped-air volume to vary. The plot of volume…

  10. Prebiotic Peptide (Amide) Bond Synthesis Accelerated by Glycerol and Bicarbonate Under Neutral to Alkaline Dry-Down Conditions

    Science.gov (United States)

    Forsythe, J. G.; Weber, A. L.

    2017-07-01

    We report a new process for robust peptide bond synthesis in the pH 6–10 range that involves dry-down heating of amino acids in the presence of glycerol and bicarbonate (substrates: L-alanine, L-2-aminobutyric acid, β-alanine, isoserine).

  11. Influencia de especies forestales sobre la actividad de las enzimas fosfatasa ácida y proteasas en un suelo de bosque Influence of tree species on the activity of acid phosphatase and protease in a forest soil

    Directory of Open Access Journals (Sweden)

    Rl Defrieri

    2008-12-01

    reflejaron mejor los cambios debidos a la influencia de las diferentes especies y de la época del año que otros parámetros químicos del suelo.Plant cover and especially the dominant tree species affect biological and chemical properties of the soil. Litter decomposition rate is affected by its N and P concentration. The aim of this work was to determine the different effects of forest tree species on some biochemical properties of the soil. The study site was located at the Reserva Natural Estricta Colonia Benítez, Chaco, Argentina. Soil samples were taken under trees of the four dominant species in the area and at two depths (0-10 cm and 10-20cm and moments: in summer and in winter. Activities of acid phosphatase and protease enzymes and some edaphic parameters were determined. The results obtained for all studied variables were significantly lower at the 10-20 cm depth, for all forest species and in both seasons. Values of enzyme activities showed significant differences between species only in surface samples where the incorporation of organic matter is greater and in summer. In these conditions, the values of enzymatic activities obtained in soils under each species ranged between 1,600 and 900 μg p-nitrophenol g-1 h-1 for acid phosphatase and between 850 y 450 g tyrosine g-1h-1 for protease. For two of the studied species, a relationship was found between the amount of litter produced, the different decomposition rates and the N and P concentrations in senescent leaves with the enzyme activities in soils. Inorganic N and available P concentrations in soils did not show significant differences between species. In this study, soil enzyme activities were more related to the overlying species than some measured soil parameters.

  12. Monitoring the process of purification of crude glycerol derived from biodiesel production: a method based on fluorescence spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Magalhaes, Keurison F.; Caires, Anderson R.L. [Universidade Federal da Grande Dourados, MS (Brazil). Grupo de Optica Aplicada; Oliveira, Samuel L. [Universidade Federal de Mato Grosso do Sul (UFMS), MS (Brazil). Grupo de Optica e Fotonica

    2011-07-01

    Full text. The use of biodiesel has increased worldwide. The biodiesel production on an industrial scale has been based on the transesterification of vegetable oils and fats with methanol in the presence of an alkaline catalyst. During the transesterification, one molecule of triglyceride reacts with three molecules of alcohol to produce glycerol and molecules of alkyl esters (biodiesel). As a result, an increase in biodiesel production also enhances the availability of glycerol on the market. However, crude glycerin has about 30% of impurities which are inherent to biodiesel production such as catalyst, alcohol and fatty acids. The present study evaluated the usefulness of the fluorescence spectroscopy as a tool to monitor the glycerol purification process. Glycerol samples were obtained from transesterification of soybean, canola, and sunflower oils in the presence of NaOH. After stirring time, the solutions were let to stand in separating funnels, then two phases were observed: one containing mainly biodiesel and other consisting of glycol. Then, the respective glycerol samples were collected, henceforth called G1. After that, it was added H2SO4 (20%) in the crude glycerol samples to reduce their pH to 4 in order to remove fatty acids. The solutions were stored for 24 hours in separating funnels. The glycerol (heavy phase), hereafter named G2, was then separated and filtered. To remove other impurities from G2 samples by means of ionic exchange columns, the samples were neutralized and diluted using Milli-Q water (G3 samples). Aliquots of 20 mL were then passed through cationic and anionic resins (G4 and G5 samples, respectively). Emission and excitation spectra of the G1-G5 samples as well as of the glycerol PA-ACS (reference) were recorded at room temperature using a spectrofluorimeter. The emission spectra were obtained setting the excitation at 325nm and monitoring the emission in the 330-800nm range. Fluorimetric maps were also achieved by pumping the

  13. Immunocytochemical detection of the microsomal glucose-6-phosphatase in human brain astrocytes.

    Science.gov (United States)

    Bell, J E; Hume, R; Busuttil, A; Burchell, A

    1993-10-01

    Using an antibody raised against the catalytic subunit of glucose-6-phosphatase, this enzyme was immunolocalized in many astrocytes in 20 normal human brains. Double immunofluorescence studies showed co-localization of glial fibrillary acidic protein (GFAP) with glucose-6-phosphatase in astrocytes. However, not all GFAP-positive cells were also glucose-6-phosphatase positive, indicating that some astrocytes do not contain demonstrable expression of this enzyme. Reactive astrocytes in a variety of abnormal brains were strongly glucose-6-phosphatase positive, but neoplastic astrocytes were often only weakly positive. Expression of the enzyme could not be demonstrated in radial glia, neurons or oligodendroglia. Astrocytes normally contain glycogen and the demonstration that some astrocytes also contain glucose-6-phosphatase indicates that they are competent for both glycogenolysis and gluconeogenesis, which may be critical for neuronal welfare.

  14. Biodiesel biorefinery: opportunities and challenges for microbial production of fuels and chemicals from glycerol waste

    Directory of Open Access Journals (Sweden)

    Almeida João R M

    2012-07-01

    Full Text Available Abstract The considerable increase in biodiesel production worldwide in the last 5 years resulted in a stoichiometric increased coproduction of crude glycerol. As an excess of crude glycerol has been produced, its value on market was reduced and it is becoming a “waste-stream” instead of a valuable “coproduct”. The development of biorefineries, i.e. production of chemicals and power integrated with conversion processes of biomass into biofuels, has been singled out as a way to achieve economically viable production chains, valorize residues and coproducts, and reduce industrial waste disposal. In this sense, several alternatives aimed at the use of crude glycerol to produce fuels and chemicals by microbial fermentation have been evaluated. This review summarizes different strategies employed to produce biofuels and chemicals (1,3-propanediol, 2,3-butanediol, ethanol, n-butanol, organic acids, polyols and others by microbial fermentation of glycerol. Initially, the industrial use of each chemical is briefly presented; then we systematically summarize and discuss the different strategies to produce each chemical, including selection and genetic engineering of producers, and optimization of process conditions to improve yield and productivity. Finally, the impact of the developments obtained until now are placed in perspective and opportunities and challenges for using crude glycerol to the development of biodiesel-based biorefineries are considered. In conclusion, the microbial fermentation of glycerol represents a remarkable alternative to add value to the biodiesel production chain helping the development of biorefineries, which will allow this biofuel to be more competitive.

  15. Temperature-Dependent Alkyl Glycerol Ether Lipid Composition of Mesophilic and Thermophilic Sulfate-Reducing Bacteria

    Directory of Open Access Journals (Sweden)

    Arnauld Vinçon-Laugier

    2017-08-01

    Full Text Available The occurrence of non-isoprenoid alkyl glycerol ether lipids in Bacteria and natural environments is increasingly being reported and the specificity and diagenetic stability of these lipids make them powerful biomarkers for biogeochemical and environmental studies. Yet the environmental controls on the biosynthesis of these peculiar membrane lipids remain poorly documented. Here, the lipid content of two mesophilic (Desulfatibacillum aliphaticivorans and Desulfatibacillum alkenivorans and one thermophilic (Thermodesulfobacterium commune sulfate-reducing bacteria—whose membranes are mostly composed of ether lipids—was investigated as a function of growth temperature (20–40°C and 54–84°C, respectively. For all strains, the cellular lipid content was lower at sub- or supra-optimal growth temperature, but the relative proportions of dialkyl glycerols, monoalkyl glycerols and fatty acids remained remarkably stable whatever the growth temperature. Rather than changing the proportions of the different lipid classes, the three strains responded to temperature changes by modifying the average structural composition of the alkyl and acyl chains constitutive of their membrane lipids. Major adaptive mechanisms concerned modifications of the level of branching and of the proportions of the different methyl branched lipids. Specifically, an increase in temperature induced mesophilic strains to produce less dimethyl branched dialkyl glycerols and 10-methyl branched lipids relative to linear structures, and the thermophilic strain to decrease the proportion of anteiso relative to iso methyl branched compounds. These modifications were in agreement with a regulation of the membrane fluidity. In one mesophilic and the thermophilic strains, a modification of the growth temperature further induced changes in the relative proportions of sn-2 vs sn-1 monoalkyl glycerols, suggesting an unprecedented mechanism of homeoviscous adaptation in Bacteria. Strong

  16. Study of Catalyst Variation Effect in Glycerol Conversion Process to Hydrogen Gas by Steam Reforming

    Science.gov (United States)

    Widayat; Hartono, R.; Elizabeth, E.; Annisa, A. N.

    2018-04-01

    Along with the economic development, needs of energy being increase too. Hydrogen as alternative energy has many usages. Besides that, hydrogen is one source of energy that is a clean fuel, but process production of hydrogen from natural gas as a raw material has been used for a long time. Therefore, there is need new invention to produce hydrogen from the others raw material. Glycerol, a byproduct of biodiesel production, is a compound which can be used as a raw material for hydrogen production. By using glycerol as a raw material of hydrogen production, we can get added value of glycerol as well as an energy source solution. The process production of hydrogen by steam reforming is a thermochemical process with efficiency 70%. This process needs contribution of catalyst to improve its efficiency and selectivity of the process. In this study will be examined the effect variation of catalyst for glycerol conversion process to hydrogen by steam reforming. The method for catalyst preparation was variation of catalyst impregnation composition, catalyst calcined with difference concentration of hydrochloric acid and calcined with difference hydrochloric acid ratio. After that, all of catalyst which have been prepared, used for steam reforming process for hydrogen production from glycerol as a raw material. From the study, the highest yield of hydrogen gas showed in the process production by natural zeolite catalyst with 1:15 Hydrochloric acid ratio was 42.28%. Hydrogen yield for 2M calcined natural zeolite catalyst was 38.37%, for ZSM-5 catalyst was 15.83%, for 0.5M calcined natural zeolite was 13.09% and for ultrasonic natural zeolite was 11.43%. The lowest yield of hydrogen gas showed in catalyst 2Zn/ZSM-5 with 11.22%. This result showed that hydrogen yield product was affected by catalyst variation because of the catalyst has difference characteristic and difference catalytic activity after the catalyst preparation process.

  17. Investigation of the kinetics and mechanism of the glycerol chlorination reaction using gas chromatography–mass spectrometry

    Directory of Open Access Journals (Sweden)

    JUN WANG

    2010-01-01

    Full Text Available As a primary by-product in biodiesel production, glycerol can be used to prepare an important fine chemical, epichlorohydrin, by the glycerol chlorination reaction. Although this process has been applied in industrial production, unfortunately, less attention has been paid to the analysis and separation of the compounds in the glycerol chlorination products. In this study, a convenient and accurate method to determine the products in glycerol chlorination reaction was established and based on the results the kinetic mechanism of the reaction was investigated. The structure of main products, including 1,3--dichloropropan-2-ol, 2,3-dichloropropan-1-ol, 3-chloro-1,2-propanediol, 2-chloro-1,3-propanediol and glycerol was ascertained by gas chromatography–mass spectrometry and the isomers of the products were distinguished. Apidic acid was considered as the best catalyst because of its excellent catalytic effect and high boiling point. The mechanism of the glycerol chlorination reaction was proposed and a new kinetic model was developed. Kinetic equations of the process in the experimental range were obtained by data fitting and the activation energies of each tandem reaction were 30.7, 41.8, 29.4 and 49.5 kJ mol-1, respectively. This study revealed the process and mechanism of the kinetics and provides the theoretical basis for engineering problems.

  18. Glycerol as Precursor of Organoselanyl and Organotellanyl Alkynes.

    Science.gov (United States)

    Lenardão, Eder J; Borges, Elton L; Stach, Guilherme; Soares, Liane K; Alves, Diego; Schumacher, Ricardo F; Bagnoli, Luana; Marini, Francesca; Perin, Gelson

    2017-03-02

    Herein we describe the synthesis of organoselanyl and organotellanyl alkynes by the addition of lithium alkynylchalcogenolate (Se and Te) to tosyl solketal, easily obtained from glycerol. The alkynylchalcogenolate anions were generated in situ and added to tosyl solketal in short reaction times, furnishing in all cases the respective products of substitution in good yields. Some of the prepared compounds were deprotected using an acidic resin to afford new water-soluble 3-organotellanylpropane-1,2-diols. The synthetic versatility of the new chalcogenyl alkynes was demonstrated in the iodocyclization of 2,2-dimethyl-1,3-dioxolanylmethyl(2-methoxyphenylethynyl)selane 3f , which afforded 3-iodo-2-(2,2-dimethyl-1,3-dioxolanylmethyl) selenanylbenzo[ b ]furan in 85% yield, opening a new way to access water-soluble Se-functionalized benzo[ b ]furanes.

  19. Characterization of protein phosphatase 5 from three lepidopteran insects: Helicoverpa armigera, Mythimna separata and Plutella xylostella.

    Directory of Open Access Journals (Sweden)

    Xi'en Chen

    Full Text Available Protein phosphatase 5 (PP5, a unique member of serine/threonine phosphatases, regulates a variety of biological processes. We obtained full-length PP5 cDNAs from three lepidopteran insects, Helicoverpa armigera, Mythimna separata and Plutella xylostella, encoding predicted proteins of 490 (55.98 kDa, 490 (55.82 kDa and 491 (56.07 kDa amino acids, respectively. These sequences shared a high identity with other insect PP5s and contained the TPR (tetratricopeptide repeat domains at N-terminal regions and highly conserved C-terminal catalytic domains. Tissue- and stage-specific expression pattern analyses revealed these three PP5 genes were constitutively expressed in all stages and in tested tissues with predominant transcription occurring at the egg and adult stages. Activities of Escherichia coli-produced recombinant PP5 proteins could be enhanced by almost 2-fold by a known PP5 activator: arachidonic acid. Kinetic parameters of three recombinant proteins against substrate pNPP were similar both in the absence or presence of arachidonic acid. Protein phosphatases inhibitors, okadaic acid, cantharidin, and endothall strongly impeded the activities of the three recombinant PP5 proteins, as well as exerted an inhibitory effect on crude protein phosphatases extractions from these three insects. In summary, lepidopteran PP5s share similar characteristics and are all sensitive to the protein phosphatases inhibitors. Our results also imply protein phosphatase inhibitors might be used in the management of lepidopteran pests.

  20. Biological Conversion of Glycerol to Ethanol by Enterobacter aerogenes

    Science.gov (United States)

    Nwachukwu, Raymond E. S.

    In a search to turn the economically and environmentally non-valuable "waste" streams of biodiesel production into a profitable byproduct, a mutant strain of Enterobacter aerogenes ATCC 13048 was developed by six-tube subculturing technique. This technique is based on the principle of adaptive evolution, and involved subculturing the bacterium in a tryptic soy broth without dextrose (TSB) containing specific glycerol and ethanol concentration for six consecutive times. Then, the six consecutive subculturing was repeated in a fresh TSB of higher glycerol and ethanol concentrations. A new mutant strain, E. aerogenes S012, which could withstand a combination of 200 g/l glycerol and 30 g/l ethanol concentrations, was developed. The wild and mutant strains were used for the fermentation of pure (P-) and recovered (R-) glycerol. Taguchi and full factorial methods of design of experiments were used to screen and optimize the important process factors that influence the microbial production of ethanol. A statistically sound regression model was used to establish the mathematical relationship between the process variables and ethanol production. Temperature of 38°C, agitation speed of 200 rpm, pH of 6.3-6.6, and microaerobic condition were the optimum process conditions. Different pretreatment methods to recover glycerol from the crude glycerol and the subsequent fermentation method showed that direct acidification using 85% H3PO4 was the best. The R-glycerol contained 51% pure glycerol and 21% methanol. The wild strain, E. aerogenes ATCC 13048, produced only 12 g/l and 12.8 g/l ethanol from 20 g/l P- and R-glycerol respectively, and could not utilize higher glycerol concentrations. The mutant, E. aerogenes S012, produced ethanol amount and yield of 43 g/l and 1.12 mol/mol-glycerol from P-glycerol, respectively within 96 h. It also produced ethanol amount and yield of 26.8 g/l and 1.07 mol/mol-glycerol, respectively, from R-glycerol within the same duration. In a

  1. Molecular cloning and chromosome mapping of the human gene encoding protein phosphotyrosyl phosphatase 1B

    International Nuclear Information System (INIS)

    Brown-Shimer, S.; Johnson, K.A.; Bruskin, A.; Green, N.R.; Hill, D.E.; Lawrence, J.B.; Johnson, C.

    1990-01-01

    The inactivation of growth suppressor genes appears to play a major role in the malignant process. To assess whether protein phosphotyrosyl phosphatases function as growth suppressors, the authors have isolated a cDNA clone encoding human protein phosphotyrosyl phosphatase 1B for structural and functional characterization. The translation product deduced from the 1,305-nucleotide open reading frame predicts a protein containing 435 amino acids and having a molecular mass of 49,966 Da. The amino-terminal 321 amino acids deduced from the cDNA sequence are identical to the empirically determined sequence of protein phosphotyrosyl phosphatase 1B. A genomic clone has been isolated and used in an in situ hybridization to banded metaphase chromosomes to determine that the gene encoding protein phosphotyrosyl phosphatase 1B maps as a single-copy gene to the long arm of chromosome 20 in the region q13.1-q13.2

  2. Ivermectin resistant and susceptible third-stage larvae of Haemonchus contortus: cholinesterase and phosphatase activities

    Directory of Open Access Journals (Sweden)

    Consuelo Giménez-Pardo

    2004-03-01

    Full Text Available Cholinesterase and acid phosphatase (AP, but not alkaline phosphatase activities, were detected in cytosolic and membrane-bound fractions of ivermectin resistant and susceptible Haemonchus contortus infective-stage larvae. Some differences in acetylcholinesterase activity of cytosolic fractions and in the AP activity of these fractions as well as in the response to AP inhibitors by membrane-bound fractions were detected. Data are discussed.

  3. Investigation of glycerol assimilation and cofactor metabolism in Lactococcus lactis

    DEFF Research Database (Denmark)

    Holm, Anders Koefoed

    of glycerol kinase from L. lactis, introduction of a heterologous glycerol assimilation pathway and construction of a library of NADH oxidase activity. Based on a preliminary analysis of transcription level data, an attempt was made to stimulate glycerol assimilation by overexpressing the glycerol kinase...... already present in L. lactis. The construction and verification of a strain with increased glycerol kinase activity was not fully completed and is still ongoing. Similarly the construction of mutants expressing a heterologous pathway for glycerol dissimilation is also an ongoing task. An artificial...... effects and improve the growth rate, though not completely to the level of the reference strain. The fact that this effect was predominantly observed while utilizing xylose implicates the involvement of the pentose phosphate pathway. A possible mechanism underlying the observed growth characteristics...

  4. Intercalation compounds of vanadium(5) phosphates with glycerol

    International Nuclear Information System (INIS)

    Yakovleva, T.N.; Vykhodtseva, K.I.; Tarasova, D.V.; Soderzhinova, M.M.

    1997-01-01

    Interaction products of glycerol aqueous solutions with vanadium(5) phosphates were investigated by the methods of ESR, X-ray phase and thermal analyses. It is shown that glycerol molecules enter the interlayer space of VOPO 4 · 2H 2 O lattice with formation of disordered intercalated compounds with glycerol on the basis of partially reduced vanadium phosphate form when using α-VOPO 4 . 16 refs., 4 figs., 1 tab

  5. Functional Analysis of Mouse G6pc1 Mutations Using a Novel In Situ Assay for Glucose-6-Phosphatase Activity and the Effect of Mutations in Conserved Human G6PC1/G6PC2 Amino Acids on G6PC2 Protein Expression.

    Directory of Open Access Journals (Sweden)

    Kayla A Boortz

    Full Text Available Elevated fasting blood glucose (FBG has been associated with increased risk for development of type 2 diabetes. Single nucleotide polymorphisms (SNPs in G6PC2 are the most important common determinants of variations in FBG in humans. Studies using G6pc2 knockout mice suggest that G6pc2 regulates the glucose sensitivity of insulin secretion. G6PC2 and the related G6PC1 and G6PC3 genes encode glucose-6-phosphatase catalytic subunits. This study describes a functional analysis of 22 non-synonymous G6PC2 SNPs, that alter amino acids that are conserved in human G6PC1, mouse G6pc1 and mouse G6pc2, with the goal of identifying variants that potentially affect G6PC2 activity/expression. Published data suggest strong conservation of catalytically important amino acids between all four proteins and the related G6PC3 isoform. Because human G6PC2 has very low glucose-6-phosphatase activity we used an indirect approach, examining the effect of these SNPs on mouse G6pc1 activity. Using a novel in situ functional assay for glucose-6-phosphatase activity we demonstrate that the amino acid changes associated with the human G6PC2 rs144254880 (Arg79Gln, rs149663725 (Gly114Arg and rs2232326 (Ser324Pro SNPs reduce mouse G6pc1 enzyme activity without affecting protein expression. The Arg79Gln variant alters an amino acid mutation of which, in G6PC1, has previously been shown to cause glycogen storage disease type 1a. We also demonstrate that the rs368382511 (Gly8Glu, rs138726309 (His177Tyr, rs2232323 (Tyr207Ser rs374055555 (Arg293Trp, rs2232326 (Ser324Pro, rs137857125 (Pro313Leu and rs2232327 (Pro340Leu SNPs confer decreased G6PC2 protein expression. In summary, these studies identify multiple G6PC2 variants that have the potential to be associated with altered FBG in humans.

  6. Lipid and carotenoid synthesis by Rhodosporidium diobovatum, grown on glucose versus glycerol, and its biodiesel properties.

    Science.gov (United States)

    Nasirian, Nima; Mirzaie, Maryam; Cicek, Nazim; Levin, David B

    2018-04-01

    Relationships between lipid and carotenoid synthesis by Rhodosporidium diobovatum were investigated for cell cultures in nitrogen-limited medium (GMY) containing equimolar amounts of carbon of glucose or glycerol. The cultures were also supplemented with additional substrate at 120 h postinoculation (pi) and during a fed-batch experiment. Growth of R. diobovatum on glucose resulted in higher yields of triacyglycerides (TAGs) and carotenoid than when grown on glycerol, even though the cultures contained equimolar amounts of carbon. After the addition of fresh substrate at 120 h pi, total carotenoid concentrations were significantly different from the concentrations measured at 120 h pi in both glucose and glycerol cultures, with no concomitant increase in lipid concentrations, suggesting that carotenoid synthesis is linked to exponential-phase growth, while lipid synthesis is linked to stationary phase. We also compared the calculated properties of biodiesel that could be made with TAGs derived from R. diobovatum with properties of biodiesel made from TAGs of other oleaginous yeasts, microalgae, vegetable oils, and animal fats. This study shows that R. diobovatum can be an effective strain for production of neutral lipids containing high percentages of oleic acid, palmitic acid, and linoleic acid, as well as carotenoids.

  7. Apposite of pig skin preserved in glycerol

    International Nuclear Information System (INIS)

    Reyes F, M.L.; Gonzalez V, C.; Salinas A, M.

    2007-01-01

    In the Radio sterilized Tissue Bank (BTR) of the ININ apposite of pig skin are processed and preserved to low temperature (-80 C), which are sterilized by irradiation and transported to the hospitals in dry ice to avoid its unfreezing. With the purpose of making more simple the manipulation of the apposite it was carried out this work that consisted on developing the processing of the pig skin using glycerol like preservation medium, since this way the irradiation, the storage and transport of the apposite is carried out at refrigeration temperature, that makes its manage more simple. (Author)

  8. Rapid monitoring of glycerol in fermentation growth media: Facilitating crude glycerol bioprocess development.

    Science.gov (United States)

    Abad, Sergi; Pérez, Xavier; Planas, Antoni; Turon, Xavier

    2014-04-01

    Recently, the need for crude glycerol valorisation from the biodiesel industry has generated many studies for practical and economic applications. Amongst them, fermentations based on glycerol media for the production of high value metabolites are prominent applications. This has generated a need to develop analytical techniques which allow fast and simple glycerol monitoring during fermentation. The methodology should be fast and inexpensive to be adopted in research, as well as in industrial applications. In this study three different methods were analysed and compared: two common methodologies based on liquid chromatography and enzymatic kits, and the new method based on a DotBlot assay coupled with image analysis. The new methodology is faster and cheaper than the other conventional methods, with comparable performance. Good linearity, precision and accuracy were achieved in the lower range (10 or 15 g/L to depletion), the most common range of glycerol concentrations to monitor fermentations in terms of growth kinetics. Copyright © 2014 Elsevier B.V. All rights reserved.

  9. Increased liver alkaline phosphatase and aminotransferase ...

    African Journals Online (AJOL)

    The effect of daily, oral administration of ethanolic extract of Khaya senegalensis stem bark (2mg/kg body weight) for 18days on the alkaline phosphatase, aspartate and alanine aminotransferase activities of rat liver and serum were investigated. Compared with the control, the activities of liver alkaline phosphatase (ALP), ...

  10. Identification and characterization of a pyridoxal 5'-phosphate phosphatase in the silkworm (Bombyx mori).

    Science.gov (United States)

    Huang, ShuoHao; Han, CaiYun; Ma, ZhenQiao; Zhou, Jie; Zhang, JianYun; Huang, LongQuan

    2017-03-01

    Vitamin B 6 comprises six interconvertible pyridine compounds, among which pyridoxal 5'-phosphate (PLP) is a coenzyme for over 140 enzymes. PLP is also a very reactive aldehyde. The most well established mechanism for maintaining low levels of free PLP is its dephosphorylation by phosphatases. A human PLP-specific phosphatase has been identified and characterized. However, very little is known about the phosphatase in other living organisms. In this study, a cDNA clone of putative PLP phosphatase was identified from B. mori and characterized. The cDNA encodes a polypeptide of 343 amino acid residues, and the recombinant enzyme purified from E. coli exhibited properties similar to that of human PLP phosphatase. B. mori has a single copy of the PLPP gene, which is located on 11th chromosome, spans a 5.7kb region and contains five exons and four introns. PLP phosphatase transcript was detected in every larva tissue except hemolymph, and was most highly represented in Malpighian tube. We further down-regulated the gene expression of the PLP phosphatase in 5th instar larvae with the RNA interference. However, no significant changes in the gene expression of PLP biosynthetic enzymes and composition of B 6 vitamers were detected as compared with the control. Copyright © 2017 Elsevier Inc. All rights reserved.

  11. Criteria for Quick and Consistent Synthesis of Poly(glycerol sebacate) for Tailored Mechanical Properties.

    Science.gov (United States)

    Li, Xinda; Hong, Albert T-L; Naskar, Nilanjon; Chung, Hyun-Joong

    2015-05-11

    Poly(glycerol sebacate) (PGS) and its derivatives make up an attractive class of biomaterial owing to their tunable mechanical properties with programmable biodegradability. In practice, however, the application of PGS is often hampered by frequent inconsistency in reproducing process conditions. The inconsistency stems from the volatile nature of glycerol during the esterification process. In this study, we suggest that the degree of esterification (DE) can be used to predict precisely the physical status, the mechanical properties, and the degradation of the PGS materials. Young's modulus is shown to linearly increase with DE, which is in agreement with an entropic spring theory of rubbers. To provide a processing guideline for researchers, we also provide a physical status map as a function of curing temperature and time. The amount of glycerol loss, obtainable by monitoring the evolution of the total mass loss and the DE during synthesis, is shown to make the predictions even more precise. We expect that these strategies can be applicable to different categories of polymers that involve condensation polymerization with the volatility of the reactants. In addition, we demonstrate that microwave-assisted prepolymerization is a time- and energy-efficient pathway to obtain PGS. For example, 15 min of microwave time is shown to be as efficient as prepolymerization in nitrogen atmosphere for 6 h at 130 °C. The quick synthesis method, however, causes a severe evaporation of glycerol, resulting in a large distortion in the monomer ratio between glycerol and sebacic acid. Consequently, more rigid PGS is produced under a similar curing condition compared to the conventional prepolymerization method. Finally, we demonstrate that the addition of molecularly rigid cross-linking agents and network-structured inorganic nanoparticles are also effective in enhancing the mechanical properties of the PGS-derived materials.

  12. Structure of glycerol-3-phosphate dehydrogenase, an essential monotopic membrane enzyme involved in respiration and metabolism

    International Nuclear Information System (INIS)

    Yeh, Joanne I.; Chinte, Unmesh; Du, Shoucheng

    2008-01-01

    Sn-glycerol-3-phosphate dehydrogenase (GlpD) is an essential membrane enzyme, functioning at the central junction of respiration, glycolysis, and phospholipid biosynthesis. Its critical role is indicated by the multitiered regulatory mechanisms that stringently controls its expression and function. Once expressed, GlpD activity is regulated through lipid-enzyme interactions in Escherichia coli. Here, we report seven previously undescribed structures of the fully active E. coli GlpD, up to 1.75 (angstrom) resolution. In addition to elucidating the structure of the native enzyme, we have determined the structures of GlpD complexed with substrate analogues phosphoenolpyruvate, glyceric acid 2-phosphate, glyceraldehyde-3-phosphate, and product, dihydroxyacetone phosphate. These structural results reveal conformational states of the enzyme, delineating the residues involved in substrate binding and catalysis at the glycerol-3-phosphate site. Two probable mechanisms for catalyzing the dehydrogenation of glycerol-3-phosphate are envisioned, based on the conformational states of the complexes. To further correlate catalytic dehydrogenation to respiration, we have additionally determined the structures of GlpD bound with ubiquinone analogues menadione and 2-n-heptyl-4-hydroxyquinoline N-oxide, identifying a hydrophobic plateau that is likely the ubiquinone-binding site. These structures illuminate probable mechanisms of catalysis and suggest how GlpD shuttles electrons into the respiratory pathway. Glycerol metabolism has been implicated in insulin signaling and perturbations in glycerol uptake and catabolism are linked to obesity in humans. Homologs of GlpD are found in practically all organisms, from prokaryotes to humans, with >45% consensus protein sequences, signifying that these structural results on the prokaryotic enzyme may be readily applied to the eukaryotic GlpD enzymes.

  13. Production of gaseous and liquid chemicals by aqueous phase reforming of crude glycerol: Influence of operating conditions on the process

    International Nuclear Information System (INIS)

    Remón, J.; Giménez, J.R.; Valiente, A.; García, L.; Arauzo, J.

    2016-01-01

    Highlights: • Aqueous phase reforming: a tailor-made process for the valorisation of crude glycerol. • In-depth understanding of the effect of the operating conditions on the process. • Process optimisation for the selective production of valuable gas and liquid products. • Low pressure and high temperature and spatial time favour gas production. • High pressure and medium temperature maximise the production of valuable liquids. - Abstract: The present work studies the influence of the temperature (200–240 °C), pressure (38–50 bar), glycerol concentration (10–50 wt.%) and mass of catalyst/ glycerol mass flow rate ratio (W/m_g_l_y_c_e_r_o_l = 10–40 g catalyst min/g glycerol) during the aqueous phase reforming (APR) of a glycerol solution obtained from the production of biodiesel. The operating conditions exerted a statistically significant influence on the reforming results. Specifically, the global glycerol conversion and the carbon converted into gas and liquid products varied as follows: 4–100%, 1–80% and 16–93%, respectively. The gas phase was made up of H_2 (8–55 vol.%), CO_2 (34–66 vol.%), CO (0–4 vol.%) and CH_4 (6–45 vol.%). The liquid phase consisted of a mixture of alcohols (monohydric: methanol and ethanol; and polyhydric: 1,2-propanediol, 1,2-ethanediol, 2,3-butanediol), aldehydes (acetaldehyde), ketones (C3-ketones: acetone and 2-propanone-1-hydroxy; C4-ketones: 2-butanone-3-hydroxy and 2-butanone-1-hydroxy; and cyclic ketones), carboxylic acids (acetic and propionic acids) and esters (1,2,3-propanetriol-monoacetate), together with unreacted glycerol and water. The relative amount (free of water and un-reacted glycerol) of these compounds in the liquid phase was as follows: monohydric alcohols: 4–47%, polyhydric-alcohols: 14–68%, aldehydes: 0–5%, C3-ketones: 2–33%, C4-ketones: 0–10%, ciclo-ketones: 0–6%, carboxylic acids: 2–43%, and esters: 0–46%. This process turned out to be highly customisable for the

  14. The effect of concentration of glycerol and electric current on the morphology and particle size of electrodeposited cadmium powder

    Directory of Open Access Journals (Sweden)

    S. G. Viswanath

    2013-06-01

    Full Text Available Cadmium powder was obtained by electrodeposition of cadmium from glycerol and sulphuric acid. The morphology and particle size of these powders were studied. Broken dendrites, intermingled with spongy and irregular particles were observed in the powder. Around 60% of particles were below 100 µm. XRD studies showed that particles with sizes between 212.2 and 303.2 nm were present in the powder. The apparent density of cadmium powder decreased with increase in concentration of glycerol. The stability of the powder and current efficiency were also studied

  15. 130 kDa phosphatase from the liver of labeo rohita: isolation: purification and some kinetic properties

    International Nuclear Information System (INIS)

    Siddiqua, A.; Sherazi, M.; Shah, A.H.; Khan, A.R.; Khan, H.U.

    2009-01-01

    An isoenzyme of high molecular weight acid phosphatase (HM-ACP) from the live of fish rohu (Labeo Rohita) was isolated and purified to homogeneity. The enzyme had specific activity of 14.96 U/mg and a recovery of about 4%. The purification procedure included ammonium sulphate precipitation and series of chromatographic separations on SP-Sephadex C-50, CM-Cellulose and Sephacryl HR-200 columns. Nealry 500-folds purification was achieved. The molecular weight was estimated to be 120-130 kDa by polyacrylamide gel electrophoresis (PAGE) of native enzyme and 130 kDa by gel filtration on calibrated Sephadex G-100 column. sodium dodecyl sulphate polyacrylamide gel electrophoresis (SDS-PAGE) under reduced and non-reduced condition showed a band corresponding to 66 kDa confirming the dimeric nature of enzyme. para nitrophenyl phosphate and flavin mononucleotide were hydrolyzed effectively by the enzyme and found to be good substrates. Optimum temperature for the enzyme was 50 degree C and temperature stability was 0 degree-50 degree C. Similarly optimum ph for the enzyme was 5.4 and ph stability was 4.8-6.0. The K/sub m/ for the p-nitrophenyl phosphate was estimated to be 0.15 mM. The enzyme was competitively inhibited by the phosphate, vanadate, molybdate, tartrate, fluoride and pyridoxal-5-PO/sub 4/ while pyridoxamine-5-PO/sub 4/ showed poor inhibition. Metal ions such as Ag/sup +/, Cu/sup ++/ Zn/sup ++/ showed strong inhibition on the enzyme activity while other divalent ions like Mg/sup ++/, Mn/sup ++/ and Co/sup ++/ were found to be poor inhibitors. Modifiers like EDTA, methanol, ethanol, acetone and glycerol had no effect on the enzyme's activity. (author)

  16. Purification and characterization of a phosphotyrosyl-protein phosphatase from wheat seedlings.

    Science.gov (United States)

    Cheng, H F; Tao, M

    1989-10-19

    A neutral phosphatase which catalyzes the hydrolysis of p-nitrophenylphosphate has been purified to homogeneity from wheat seedlings. The enzyme is a monomeric glycoprotein exhibiting a molecular weight of 35,000, frictional ratio of 1.22, Stokes' radius of 260 nm, and sedimentation coefficient of 3.2 S. That the enzyme is a glycoprotein is surmised from its chromatographic property on Concanavalin A-Sepharose column. An examination of the substrate specificity indicates that the enzyme exhibits a preference for phosphotyrosine over a number of phosphocompounds, including p-nitrophenylphosphate and several glycolytic intermediates. Both phosphoserine and phosphothreonine are not hydrolyzed by the enzyme. The phosphatase activity is not affected by high concentrations of chelating agents and does not require metal ions. Molybdate, orthovanadate, Zn2+, and Hg2+ are all potent inhibitors of the phosphatase activity. The ability of the phosphatase to dephosphorylate protein phosphotyrosine has been investigated. [32P-Tyr]poly(Glu,Tyr)n, [32P-Tyr]alkylated bovine serum albumin, [32P-Tyr]angiotensin-I, and [32P-Tyr]band 3 (from human erythrocyte) are all substrates of the phosphatase. On the other hand, the enzyme has no activity toward protein phosphoserine and phosphothreonine. Our result further indicates that the neutral phosphatase is distinct from the wheat germ acid phosphatase. The latter enzyme is found to dephosphorylate phosphotyrosyl as well as phosphoseryl and phosphothreonyl groups in proteins. In light of the many similarities in properties to phosphotyrosyl protein phosphatases isolated from several sources, it is suggested that the wheat seedling phosphatase may participate in cellular regulation involving protein tyrosine phosphorylation.

  17. Protein phosphatases decrease their activity during capacitation: a new requirement for this event.

    Directory of Open Access Journals (Sweden)

    Janetti R Signorelli

    Full Text Available There are few reports on the role of protein phosphatases during capacitation. Here, we report on the role of PP2B, PP1, and PP2A during human sperm capacitation. Motile sperm were resuspended in non-capacitating medium (NCM, Tyrode's medium, albumin- and bicarbonate-free or in reconstituted medium (RCM, NCM plus 2.6% albumin/25 mM bicarbonate. The presence of the phosphatases was evaluated by western blotting and the subcellular localization by indirect immunofluorescence. The function of these phosphatases was analyzed by incubating the sperm with specific inhibitors: okadaic acid, I2, endothall, and deltamethrin. Different aliquots were incubated in the following media: 1 NCM; 2 NCM plus inhibitors; 3 RCM; and 4 RCM plus inhibitors. The percent capacitated sperm and phosphatase activities were evaluated using the chlortetracycline assay and a phosphatase assay kit, respectively. The results confirm the presence of PP2B and PP1 in human sperm. We also report the presence of PP2A, specifically, the catalytic subunit and the regulatory subunits PR65 and B. PP2B and PP2A were present in the tail, neck, and postacrosomal region, and PP1 was present in the postacrosomal region, neck, middle, and principal piece of human sperm. Treatment with phosphatase inhibitors rapidly (≤1 min increased the percent of sperm depicting the pattern B, reaching a maximum of ∼40% that was maintained throughout incubation; after 3 h, the percent of capacitated sperm was similar to that of the control. The enzymatic activity of the phosphatases decreased during capacitation without changes in their expression. The pattern of phosphorylation on threonine residues showed a sharp increase upon treatment with the inhibitors. In conclusion, human sperm express PP1, PP2B, and PP2A, and the activity of these phosphatases decreases during capacitation. This decline in phosphatase activities and the subsequent increase in threonine phosphorylation may be an important

  18. Identification of human pulmonary alkaline phosphatase isoenzymes.

    Science.gov (United States)

    Capelli, A; Cerutti, C G; Lusuardi, M; Donner, C F

    1997-04-01

    An increase of alkaline phosphatase (ALP) activity has been observed in the bronchoalveolar lavage fluid (BALF) of patients affected by pulmonary fibrosis in chronic interstitial lung disorders. To characterize the ALP isoenzymes in such cases, we used gel filtration, agarose gel electrophoresis, heat and amino acid inhibition assays, wheat-germ agglutinin (WGA) precipitation, and an immunoassay specific for the bone-isoform of ALP. Only one anodic band representing a high-molecular-weight isoform of ALP (Mr approximately 2,000 kDa) was observed on electrophoresis of BALF. The inhibition assay results were consistent for a tissue-nonspecific isoenzyme sensitive to a temperature of 56 degrees C (71.9 +/- 2.5% inhibition) and to homoarginine (65.7 +/- 1.9%), and resistant to L-phenylalanine and L-leucine. Less than 13% of ALP activity was heat-stable. After incubation of BALF specimens with glycosyl-phosphatidylinositol-phospholipase D plus Nonidet P-40, or with phosphatidylinositol-phospholipase C alone, an electrophoretic cathodic band (Mr approximately 220 kDa) appeared near the bone band of a standard serum. With the WGA assay, 84.4 +/- 3.3% of ALP precipitated and the band disappeared. After immunoassay for the bone isoform, a mean of less than 5% enzyme activity was measured. We conclude that the ALP found in BALF is a pulmonary isoform of a tissue nonspecific isoenzyme.

  19. Alkaline Phosphatase, an Unconventional Immune Protein

    Directory of Open Access Journals (Sweden)

    Bethany A. Rader

    2017-08-01

    Full Text Available Recent years have seen an increase in the number of studies focusing on alkaline phosphatases (APs, revealing an expanding complexity of function of these enzymes. Of the four human AP (hAP proteins, most is known about tissue non-specific AP (TNAP and intestinal AP (IAP. This review highlights current understanding of TNAP and IAP in relation to human health and disease. TNAP plays a role in multiple processes, including bone mineralization, vitamin B6 metabolism, and neurogenesis, is the genetic cause of hypophosphatasia, influences inflammation through regulation of purinergic signaling, and has been implicated in Alzheimer’s disease. IAP regulates fatty acid absorption and has been implicated in the regulation of diet-induced obesity and metabolic syndrome. IAP and TNAP can dephosphorylate bacterial-derived lipopolysaccharide, and IAP has been identified as a potential regulator of the composition of the intestinal microbiome, an evolutionarily conserved function. Endogenous and recombinant bovine APs and recombinant hAPs are currently being explored for their potential as pharmacological agents to treat AP-associated diseases and mitigate multiple sources of inflammation. Continued research on these versatile proteins will undoubtedly provide insight into human pathophysiology, biochemistry, and the human holobiont.

  20. Glycerol reforming in supercritical water : a short review

    NARCIS (Netherlands)

    Markocic, Elena; Kramberger, Boris; van Bennekom, Joost G.; Heeres, Hero Jan; Vos, John; Knez, Zeljko; Markočič, Elena; Knez, Željko

    Due to the rise in global biodiesel production, the amount of crude glycerol, the main byproduct, has increased steadily. Identification of high value added outlets for crude glycerol has been explored in detail to increase the overall economics of the biodiesel process. Examples are the use of

  1. Vanadium-Catalyzed Deoxydehydration of Glycerol Without an External Reductant

    DEFF Research Database (Denmark)

    Petersen, Allan Robertson; Nielsen, Lasse Bo; Dethlefsen, Johannes Rytter

    2018-01-01

    A vanadium‐catalysed deoxydehydration (DODH) of neat glycerol has been developed. Cheap and readily available ammonium metavanadate (NH4VO3) affords higher yields of allyl alcohol than the well‐established catalyst methyltrioxorhenium. A study in which deuterium‐labelled glycerol was used...

  2. The effect of mixing on fermentation of primary solids, glycerol, and biodiesel waste.

    Science.gov (United States)

    Ghasemi, Marzieh; Randall, Andrew A

    2018-03-01

    In this study, the effect of mixing on volatile fatty acid (VFA) production and composition was investigated through running five identical bench-scale reactors that were filled with primary solid and dosed with either pure glycerol or biodiesel waste. Experimental results revealed that there was an inverse correlation between the mixing intensity and the VFA production. The total VFA production in the un-mixed reactor was 9,787 ± 3,601 mg COD/L, whereas in the reactor mixed at 100 rpm this dropped to 3,927 ± 1,175 mg COD/L, while both types of reactor were dosed with pure glycerol at the beginning of each cycle to reach the initial concentration of 1,000 mg/L (1,217 mg COD/L). Propionic acid was the dominant VFA in all the reactors except the reactor mixed at 30 rpm. It is hypothesized that low mixing facilitated hydrogen transfer between obligate hydrogen producing acetogens (OHPA) and hydrogen consuming acidogens in these non-methanogenic reactors. Also, in a narrower range of mixing (0 or 7 rpm), the total VFA production in biodiesel waste-fed reactors was considerably higher than that of pure glycerol-fed reactors.

  3. Peculiarities of glucose and glycerol metabolism in Nocardia vaccinii IMB B-7405

    Directory of Open Access Journals (Sweden)

    T. P. Pirog

    2015-04-01

    Full Text Available It has been established that in cells of Nocardia vaccinii IMB B-7405 (surfactant producer glucose catabolism is performed through pentose phosphate cycle as well as through gluconate (activi­ty of NAD+-dependent glucose-6- phosphate dehydrogenase and FAD+-dependent glucose dehydrogenase 835 ± 41 and 698 ± 35 nmol∙min-1∙mg-1 of protein respectively. 6-Phosphogluconate formed in the gluconokinase reaction is involved in the pentose phosphate cycle (activity of constitutive NADP+-dependent 6-phosphogluconate dehydrogenase 357 ± 17 nmol∙min-1∙mg-1 of protein. Glyce­rol catabolism to dihydroxyacetonephosphate (the intermediate of glycolysis may be performed in two ways: through glycerol-3-phosphate (glycerol kinase activity 244 ± 12 nmol∙min-1∙mg-1 of protein and through dihydroxyacetone. Replenishment of the C4-dicarboxylic acids pool in N. vaccinii IMV B-7405 grown on glucose and glycerol occurs in the phosphoenolpyruvate(PEPcarboxylase reaction (714–803 nmol∙min-1∙mg-1 of protein. 2-Oxoglutara­te was involved in tricarboxylic acid cycle by alternate pathway with the participation of 2-oxoglutarate synthase. The observed activity of both key enzymes of gluconeogenesis (PEP- carboxykinase and PEP-synthase, trehalose phosphate synthase and NADP+-dependent glutamate dehydrogenase confirmed the ability of IMV B-7405 strain to the synthesis of surface active glyco- and aminolipids, respectively.

  4. Bioconversion of crude glycerol feedstocks into ethanol by Pachysolen tannophilus

    DEFF Research Database (Denmark)

    Liu, Xiaoying; Jensen, Peter Ruhdal; Workman, Mhairi

    2012-01-01

    Glycerol, the by-product of biodiesel production, is considered as a waste by biodiesel producers. This study demonstrated the potential of utilising the glycerol surplus through conversion to ethanol by the yeast Pachysolen tannophilus (CBS4044). This study demonstrates a robust bioprocess which...... was not sensitive to the batch variability in crude glycerol dependent on raw materials used for biodiesel production. The oxygen transfer rate (OTR) was a key factor for ethanol production, with lower OTR having a positive effect on ethanol production. The highest ethanol production was 17.5 g/L on 5% (v/v) crude...... glycerol, corresponding to 56% of the theoretical yield. A staged batch process achieved 28.1 g/L ethanol, the maximum achieved so far for conversion of glycerol to ethanol in a microbial bioprocess. The fermentation physiology has been investigated as a means to designing a competitive bioethanol...

  5. Conserved family of glycerol kinase loci in Drosophila melanogaster

    Science.gov (United States)

    Martinez Agosto, Julian A.; McCabe, Edward R.B.

    2009-01-01

    Glycerol kinase (GK) is an enzyme that catalyzes the formation of glycerol 3-phosphate from ATP and glycerol, the rate-limiting step in glycerol utilization. We analyzed the genome of the model organism Drosophila melanogaster and identified five GK orthologs, including two loci with sequence homology to the mammalian Xp21 GK protein. Using a combination of sequence analysis and evolutionary comparisons of orthologs between species, we characterized functional domains in the protein required for GK activity. Our findings include additional conserved domains that suggest novel nuclear and mitochondrial functions for glycerol kinase in apoptosis and transcriptional regulation. Investigation of GK function in Drosophila will inform us about the role of this enzyme in development and will provide us with a tool to examine genetic modifiers of human metabolic disorders. PMID:16545593

  6. THE DEPENDENCE OF GLYCEROL ACCUMULATION AND STARCH HYDROLYZATES FERMENTATION FROM WORT CONCENTRATION

    Directory of Open Access Journals (Sweden)

    Оliynichuk S. Т.

    2015-08-01

    Full Text Available The purpose of this work is to study the dependence of ethanol accumulation by-products and secondary products (glycerol and propionic acid during the fermentation in the case of increasing the wort concentration from 12 to 21% by weight of sugar as an example of commonly used in the alcohol industry the commercial dry yeast company “Danisco” and experimental osmophilic strain Saccharomyces cerevisiae DS-02-E, isolated from a concentrated (80% DM of rye malt wort which spontaneously fermented. The enzyme preparations “AMYLEX 4T”, “ALPHALASE AFP” and “DIAZYME SSF” were used for the liquefaction and saccharification of starch wort. The finished industrial of both yeast strains were added to the fermentation flasks in an amount of 10% by volume of the primary wort. In the mature brew the unfermented carbohydrates content was determined by colorimetric method with anthrone reagent, alcohol — by glass areometer-alcoholometer, acidity — potentiometrically, the concentration of dry matter — by areometer, glycerol content — by photocolorimetry method. In the brew distillate a volatile impurities content, namely propionic acid, was determined using gas chromatography. Statistical processing of the results of three series of experiments were carried out by calculating the arithmetical mean value of 5 measurements, their standard deviations and errors. To determine the probable differences between the mean values were used Student’s t test. Differences were considered statistically significant at P < 0.05. Reduction for accumulation of glycerol (between 38 till 53% at higher concentrations of nutrient medium in the case of the yeast Saccharomyces cerevisiae DS-02-E as compared with commercial dry yeast, reduction the formation of unwanted by-product of fermentation — propionic acid (up to 34%, a better ability of the experimental strain to accumulate sugar of wort and to accumulate ethanol (up to 0.1–0.25% vol. were shown. It

  7. Microemulsion based hybrid biofuels using glycerol monooleate

    International Nuclear Information System (INIS)

    Bora, Plaban; Konwar, Lakhya Jyoti; Deka, Dhanapati

    2016-01-01

    Highlights: • Fuel quality of GMO based MHBFs. • Effect of externally added monoglyceride surfactant (GMO) on fuel characteristics of MHBF. • Structural and dynamic behaviors of GMO based MHBFs. • Can offer strong candidature for future biofuel industry. - Abstract: The present investigation aims to highlighten the effect of monoglyceride surfactant (GMO) on structure and dynamic behavior and other fuel characteristics of microemulsion based hybrid biofuels (MHBFs). Fuel quality of MHBFs formulated using purified GMO (>90%), which was prepared by esterification of glycerol, was investigated in the study. Phase behaviors, droplet size distribution, number of droplets present in the system, average droplet size and average length of surface active agents were studied as a part of structural investigations of the GMO based MHBFs. Diffusion coefficient, energy barrier to droplet coalescence and rate of coalescence of droplets were also investigated for the formulated MHBFs. The number of droplets, length of surface active agent and the diffusion co-efficient were in the ranges of 1.87 × 10"2"1–5.66 × 10"2"1/m"3, 0.92–1.07 nm and 1.00 × 10"−"1"1–1.79 × 10"−"1"1 m"2/s, respectively. The rate of droplet coalescence was obtained in the range 2.77 × 10"−"4–8.78 × 10"−"4 times the collision factor. MHBFs incorporating the glycerol derived bio-based nonionic surfactant GMO exhibited viscosity of 4.12 mm"2/s (at 40 °C), gross calorific value (GCV) of 39.17 MJ/kg and pour point of −7 °C.

  8. Phosphatase Activity of Microbial Populations in Different Milk Samples in Relation to Protein and Carbohydrate Content

    Directory of Open Access Journals (Sweden)

    Sosanka Protim SANDILYA

    2014-12-01

    Full Text Available Cattle milk is a rich source of protein, carbohydrate, vitamins, minerals and all other major and micro nutrients. At a moderate pH, milk is an excellent media for the growth of microbes and thus, intake of raw milk is precarious. In this study, attempt was made for a qualitative study of eight raw milk samples of different varieties of cow and goat milk, collected from Jorhat district of Assam, India, on the basis of nutritional value and microbial population. The highest microbial population was found in the milk collected from cross hybrid variety of cow, whereas microbial contamination was the least in Jersey cow milk. Samples of C1 (Jersey cow variety showed presence of the highest amount of protein and carbohydrate content as compared to the others. Almost all the milk samples showed positive acid and alkaline phosphatase activity. Maximum acid phosphatase activity was observed in cross hybrid cow milk, whereas local cow milk exhibited the highest alkaline phosphatase activity. Phosphatase activity did not show any co-relationship with microbial population of the milk samples. Similarly, the protein and carbohydrate content of the samples did not have any significant impact on both acid and alkaline phosphatase activity.

  9. A tailored catalyst for the sustainable conversion of glycerol to acrolein: mechanistic aspect of sequential dehydration.

    Science.gov (United States)

    Yun, Danim; Kim, Tae Yong; Park, Dae Sung; Yun, Yang Sik; Han, Jeong Woo; Yi, Jongheop

    2014-08-01

    Developing a catalyst to resolve deactivation caused from coke is a primary challenge in the dehydration of glycerol to acrolein. An open-macropore-structured and Brønsted-acidic catalyst (Marigold-like silica functionalized with sulfonic acid groups, MS-FS) was synthesized for the stable and selective production of acrolein from glycerol. A high acrolein yield of 73% was achieved and maintained for 50 h in the presence of the MS-FS catalyst. The hierarchical structure of the catalyst with macropores was found to have an important effect on the stability of the catalyst because coke polymerization and pore blocking caused by coke deposition were inhibited. In addition, the behavior of 3-hydroxypropionaldehyde (3-HPA) during the sequential dehydration was studied using density functional theory (DFT) calculations because 3-HPA conversion is one of the main causes for coke formation. We found that the easily reproducible Brønsted acid sites in MS-FS permit the selective and stable production of acrolein. This is because the reactive intermediate (3-HPA) is readily adsorbed on the regenerated acid sites, which is essential for the selective production of acrolein during the sequential dehydration. The regeneration ability of the acid sites is related not only to the selective production of acrolein but also to the retardation of catalyst deactivation by suppressing the formation of coke precursors originating from 3-HPA degradation. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  10. Autophagy Signaling in Prostate Cancer: Identification of a Novel Phosphatase

    Science.gov (United States)

    2013-01-01

    chloroquine treatment] and LC3 accumulation used as a measure of autophagic flux (Tanida et al., 2005). We found that both knockdown of PTPs and amino acid...6 Jeffrey P. MacKeigan,3 Kyle A. Furge,2 H. Eric Xu1,7†D ow nloaded The antimalaria drug chloroquine has been used as an anti-inflammatory agent for...verified and characterized for phosphatase activity in vitro (task 2). In addition to inserting these constructs into mammalian expression vectors, used

  11. Chromatographic separation of alkaline phosphatase from dental enamel

    DEFF Research Database (Denmark)

    Moe, D; Kirkeby, S; Salling, E

    1989-01-01

    Alkaline phosphatase (AP) was prepared from partly mineralized bovine enamel by extraction in phosphate buffer, centrifugation and various chromatographic techniques. Chromatofocusing showed that the enamel enzyme possessed five isoelectric points at the acid pH level ranging from pH 5.7 to pH 4.......4. Three enzyme peaks were eluted using low pressure chromatography with a Bio-gel column. With a HPLC gel filtration column the separation of the enamel extract resulted in only one peak with AP activity. The fractions of this peak were used to produce an antibody against bovine AP....

  12. A novel route to synthesis of glycerol dimethyl ether from epichlorohydrin with high selectivity

    International Nuclear Information System (INIS)

    Ding, Xiaoshu; Liu, Hao; Yang, Qiusheng; Li, Naihua; Dong, Xiangmo; Wang, Shufang; Zhao, Xinqiang; Wang, Yanji

    2014-01-01

    The effective utilization of glycerol, a by-product in the production of biodiesel, into useful chemicals is desirable from the viewpoint of green chemistry. With this in mind, a novel and highly selective route to synthesizing glycerol dimethyl ether (2,3-dimethoxy-1-propanol), a potential fuel additive, from glycerol was proposed. This route uses both glycerol and methanol as starting materials, takes epichlorohydrin as an intermediate product, and utilizes HCl as a recycling agent. Hereinto, the key step of this route is the reaction between epichlorohydrin and methanol to produce 2,3-dimethoxy-1-propanol which is identified by GC–MS, ESI-MS, IR and NMR. The thermodynamics of this reaction was analyzed and the result showed that the thermodynamics of a reaction was favorable and a high product yield was expected. The effect of various parameters such as kind of acid catalyst, molar ratio of epichlorohydrin to methanol, reaction temperature and reaction time was studied. Among various acid catalysts investigated, the acidic ionic liquid [HSO 3 -b-N(CH 3 ) 3 ]HSO 4 exhibited the highest activity and selectivity: conversion of epichlorohydrin of 100% and selectivity of 2,3-dimethoxy-1-propanol of 99% at 393 K, 10 h, an initial pressure of 0.1 MPa and a molar ratio of catalyst:ECH:CH 3 OH of 0.01:1:5. After the reaction, [HSO 3 -b-N(CH 3 ) 3 ]HSO 4 was separated by vacuum distillation and then reused for the next cycle directly. The results showed that the product selectivity remained at about 94% but the conversion of epichlorohydrin dropped to 75% after being used five times. Subsequently, a reaction mechanism for the synthesis of 2,3-dimethoxy-1-propanol from epichlorohydrin and methanol was proposed. - Highlights: • Epichlorohydrin was converted effectively into glycerol dimethyl ether used as potential fuel additive. • The selectivity of 99% and the conversion of 100% under the mild reaction condition. • The reaction was high product selectivity and

  13. Damage of guinea pig heart and arteries by a trioleate-enriched diet and of cultured cardiomyocytes by oleic acid.

    Directory of Open Access Journals (Sweden)

    Josef Krieglstein

    2010-03-01

    Full Text Available Mono-unsaturated fatty acids (MUFAs like oleic acid have been shown to cause apoptosis of cultured endothelial cells by activating protein phosphatase type 2C alpha and beta (PP2C. The question arises whether damage of endothelial or other cells could be observed in intact animals fed with a trioleate-enriched diet.Dunkin-Hartley guinea pigs were fed with a trioleate-enriched diet for 5 months. Advanced atherosclerotic changes of the aorta and the coronary arteries could not be seen but the arteries appeared in a pre-atherosclerotic stage of vascular remodelling. However, the weight and size of the hearts were lower than in controls and the number of apoptotic myocytes increased in the hearts of trioleate-fed animals. To confirm the idea that oleic acid may have caused this apoptosis by activation of PP2C, cultured cardiomyocytes from guinea pigs and mice were treated with various lipids. It was demonstrable that oleic acid dose-dependently caused apoptosis of cardiomyocytes from both species, yet, similar to previous experiments with cultured neurons and endothelial cells, stearic acid, elaidic acid and oleic acid methylester did not. The apoptotic effect caused by oleic acid was diminished when PP2C alpha and beta were downregulated by siRNA showing that PP2C was causally involved in apoptosis caused by oleic acid.The glycerol trioleate diet given to guinea pigs for 5 months did not cause marked atherosclerosis but clearly damaged the hearts by activating PP2C alpha and beta. The diet used with 24% (wt/wt glycerol trioleate is not comparable to human diets. The detrimental role of MUFAs for guinea pig heart tissue in vivo is shown for the first time. Whether it is true for humans remains to be shown.

  14. Glycerol and environmental factors: effects on 1,3-propanediol production and NAD(+) regeneration in Lactobacillus panis PM1.

    Science.gov (United States)

    Kang, T S; Korber, D R; Tanaka, T

    2013-10-01

    This study was conducted to understand the influences of fermentation factors in NADH recycling and mechanisms of 1,3-propanediol (1,3-PDO) production in Lactobacillus panis PM1. We conducted metabolite analyses, qRT-PCR of the glycerol reductive pathway [glycerol dehydratase (DhaB) and 1,3-PDO dehydrogenase (DhaT)] and DhaT activity assays at different pH, temperature and initial glycerol concentrations. The supplementation of 150 mmol l(-1) glycerol caused a shift in NADH flux from ethanol to 1,3-PDO production, whereas 300 mol l(-1) glycerol negatively affected the regeneration of NAD(+) via 1,3-PDO production. This retardation decreased transcription levels and specific activities of DhaT. The decreased DhaT activity eventually caused the shutdown of 1,3-PDO production. Temperature and pH did not significantly affect the specific activity of DhaT, whereas expression of genes for DhaB and DhaT was activated under acidic conditions. Moreover, fresh glucose addition after its depletion could not restart the glycerol reduction, but increased ethanol production. Those environmental factors affect 1,3-PDO production in different ways through changing the expression level of enzymes and shifting the NAD(+) regeneration pathways. Our findings elucidated a key element to optimize 1,3-PDO production by Lact. panis PM1, which potentially improves 1,3-PDO manufacturing efficiencies. © 2013 The Society for Applied Microbiology.

  15. The metabolic costs of improving ethanol yield by reducing glycerol formation capacity under anaerobic conditions in Saccharomyces cerevisiae.

    Science.gov (United States)

    Pagliardini, Julien; Hubmann, Georg; Alfenore, Sandrine; Nevoigt, Elke; Bideaux, Carine; Guillouet, Stephane E

    2013-03-28

    Finely regulating the carbon flux through the glycerol pathway by regulating the expression of the rate controlling enzyme, glycerol-3-phosphate dehydrogenase (GPDH), has been a promising approach to redirect carbon from glycerol to ethanol and thereby increasing the ethanol yield in ethanol production. Here, strains engineered in the promoter of GPD1 and deleted in GPD2 were used to investigate the possibility of reducing glycerol production of Saccharomyces cerevisiae without jeopardising its ability to cope with process stress during ethanol production. For this purpose, the mutant strains TEFmut7 and TEFmut2 with different GPD1 residual expression were studied in Very High Ethanol Performance (VHEP) fed-batch process under anaerobic conditions. Both strains showed a drastic reduction of the glycerol yield by 44 and 61% while the ethanol yield improved by 2 and 7% respectively. TEFmut2 strain showing the highest ethanol yield was accompanied by a 28% reduction of the biomass yield. The modulation of the glycerol formation led to profound redox and energetic changes resulting in a reduction of the ATP yield (YATP) and a modulation of the production of organic acids (acetate, pyruvate and succinate). Those metabolic rearrangements resulted in a loss of ethanol and stress tolerance of the mutants, contrarily to what was previously observed under aerobiosis. This work demonstrates the potential of fine-tuned pathway engineering, particularly when a compromise has to be found between high product yield on one hand and acceptable growth, productivity and stress resistance on the other hand. Previous study showed that, contrarily to anaerobiosis, the resulting gain in ethanol yield was accompanied with no loss of ethanol tolerance under aerobiosis. Moreover those mutants were still able to produce up to 90 gl-1 ethanol in an anaerobic SSF process. Fine tuning metabolic strategy may then open encouraging possibilities for further developing robust strains with improved

  16. Radioprotective effect of Panax ginseng on the phosphatases and lipid peroxidation level in testes of Swiss albino mice

    Energy Technology Data Exchange (ETDEWEB)

    Kumar M.; Sharma M.K.; Saxena P.S.; Kumar A. [Rajasthan Univ., Jaipur (India)

    2003-03-01

    The Panax ginseng has been used as traditional medicine for past several years among oriental people. The present investigation has been made to assess the radioprotective efficacy of ginseng root extract in the testicular enzymes of Swiss albino mice. The Swiss albino mice were divided into different groups. Ginseng treated group: The animals were administered 10 mg/kg body weight ginseng root extract intraperitoneal (i.p.). Radiation treated group: The animals were exposed to 8 Gy gamma radiation at the dose rate of 1.69 Gy/min at the distance of 80 cm. Combination group: Animals were administered ginseng extract continuously for 4 d and on 4th day they were irradiated to 8 Gy gamma radiation after 30 min of extract administration. The animals from above groups were autopsied on day 1, 3, 7, 14 and 30. Biochemical estimations of acid and alkaline phosphatases and Lipid peroxidation (LPO) in testes were done. In ginseng treated group acid and alkaline phosphatases activity and LPO level did not show any significant alteration. In irradiated animals there was a significant increase in acid phosphatase activity and LPO level. However, significant decline in alkaline phosphatase activity was observed. The treatment of ginseng before irradiation causes significant decrease in acid phosphatase and LPO level and significant increase in alkaline phosphatase activity. One of the cause of radiation damage is lipid peroxidation. Due to lipid peroxidation, lysosomal membrane permeability alters and thus results in release of hydrolytic enzymes. So, an increase in acid phosphatase was noticed after radiation treatment. The alkaline phosphatase activity is associated with membrane permeability and different stages of spermatogenesis. Due to membrane damage and depletion of germ cells of testes after irradiation the enzyme activity was decreased. Ginseng markedly inhibits lipid peroxidation. It acts in indirect fashion to protect radical processes by inhibition of initiation of

  17. Radioprotective effect of Panax ginseng on the phosphatases and lipid peroxidation level in testes of Swiss albino mice

    International Nuclear Information System (INIS)

    Kumar, M.; Sharma, M.K.; Saxena, P.S.; Kumar, A.

    2003-01-01

    The Panax ginseng has been used as traditional medicine for past several years among oriental people. The present investigation has been made to assess the radioprotective efficacy of ginseng root extract in the testicular enzymes of Swiss albino mice. The Swiss albino mice were divided into different groups. Ginseng treated group: The animals were administered 10 mg/kg body weight ginseng root extract intraperitoneal (i.p.). Radiation treated group: The animals were exposed to 8 Gy gamma radiation at the dose rate of 1.69 Gy/min at the distance of 80 cm. Combination group: Animals were administered ginseng extract continuously for 4 d and on 4th day they were irradiated to 8 Gy gamma radiation after 30 min of extract administration. The animals from above groups were autopsied on day 1, 3, 7, 14 and 30. Biochemical estimations of acid and alkaline phosphatases and Lipid peroxidation (LPO) in testes were done. In ginseng treated group acid and alkaline phosphatases activity and LPO level did not show any significant alteration. In irradiated animals there was a significant increase in acid phosphatase activity and LPO level. However, significant decline in alkaline phosphatase activity was observed. The treatment of ginseng before irradiation causes significant decrease in acid phosphatase and LPO level and significant increase in alkaline phosphatase activity. One of the cause of radiation damage is lipid peroxidation. Due to lipid peroxidation, lysosomal membrane permeability alters and thus results in release of hydrolytic enzymes. So, an increase in acid phosphatase was noticed after radiation treatment. The alkaline phosphatase activity is associated with membrane permeability and different stages of spermatogenesis. Due to membrane damage and depletion of germ cells of testes after irradiation the enzyme activity was decreased. Ginseng markedly inhibits lipid peroxidation. It acts in indirect fashion to protect radical processes by inhibition of initiation of

  18. Diversity and Gene Expression of Phosphatase Genes Provide Insight into Soil Phosphorus Dynamics in a New Zealand Managed Grassland

    Science.gov (United States)

    Dunfield, K. E.; Gaiero, J. R.; Condron, L.

    2017-12-01

    Healthy and diverse communities of soil organisms influence key soil ecosystem services such as carbon sequestration, water quality protection, climate regulation and nutrient cycling. Microbially driven mineralization of organic phosphorus is an important contributor to plant available inorganic orthophosphates. In acidic soils, microbes produce non-specific acid phosphatases (NSAPs) which act on common forms of organic phosphorus (P). Our current understanding of P turnover in soils has been limited by lack of research tools capable of targeting these genes. Thus, we developed a set of oligonucleotide PCR primers that targeted bacteria with the genetic potential for acid phosphatase production. A long term randomized-block pasture trial was sampled following 22 years of continued aerial biomass removal and retention. Primers were used to target genes encoding alkaline phosphatase (phoD) and the three classes (CAAP, CBAP, CCAP) of non-specific acid phosphatases. PCR amplicons targeting total genes and gene transcripts were sequenced using Illumina MiSeq to understand the diversity of the bacterial phosphatase producing communities. In general, the majority of operational taxonomic units (OTUs) were shared across both treatments and across metagenomes and transcriptomes. However, analysis of DNA OTUs revealed significantly different communities driven by treatment differences (P reduced Olsen P levels (15 vs. 36 mg kg-1 in retained treatment). Acid phosphatase activity was measured in all samples, and found to be highest in the biomass retained treatment (16.8 vs. 11.4 µmol g-1 dry soil h-1), likely elevated due to plant-derived enzymes; however, was still correlated to bacterial gene abundances. Overall, the phosphatase producing microbial communities responded to the effect of consistent P limitation as expected, through alteration in the composition of the community structure and through increased levels of gene expression of the phosphatase genes.

  19. Industrial-scale application of Lactobacillus reuteri coupled with glycerol as a biopreservation system for inhibiting Clostridium tyrobutyricum in semi-hard ewe milk cheese.

    Science.gov (United States)

    Ávila, Marta; Gómez-Torres, Natalia; Delgado, David; Gaya, Pilar; Garde, Sonia

    2017-09-01

    The suitability of the biopreservation system formed by reuterin-producing L. reuteri INIA P572 and glycerol (required for reuterin production) to prevent late blowing defect (LBD) was evaluated in industrial sized semi-hard ewe milk cheese contaminated with Clostridium tyrobutyricum INIA 68, a wild strain isolated from a LBD cheese. For this purpose, six batches of cheese were made (three with and three without clostridial spores): control cheeses with lactococci starter, cheeses with L. reuteri as adjunct, and cheeses with L. reuteri and 30 mM glycerol. Spores of C. tyrobutyricum INIA 68 germinated during pressing of cheese curd, causing butyric acid fermentation in cheese after 30 d of ripening. The addition of L. reuteri, without glycerol, enhanced the symptoms and the formation of volatile compounds associated with LBD. When glycerol was added to cheese milk contaminated with C. tyrobutyricum, L. reuteri was able to produce reuterin in cheese resulting in cheeses with a uniform cheese matrix and a volatile profile similar to cheese made with L. reuteri and glycerol (without spores). Accordingly, L. reuteri INIA P572 coupled with glycerol seems a novel biopreservation system to inhibit Clostridium growth and prevent LBD by means of in situ reuterin production. Copyright © 2017 Elsevier Ltd. All rights reserved.

  20. Phosphoprotein phosphatase of bovine spleen cell nuclei: physicochemical properties

    International Nuclear Information System (INIS)

    Rezyapkin, V.I.; Leonova, L.E.; Komkova, A.I.

    1986-01-01

    The physicochemical properties of phosphoprotein phosphatase (EC 1.3.1.16) from bovine spleen cell nuclei were studied. The enzyme possesses broad substrate specificity and catalyzes the dephosphorylation of phosphocasein, ATP, ADP, and p-nitrophenyl phosphate (pNPP). K/sub m/ for ATP, ADP, and pNPP are equal to 0.44, 0.43, and 1.25 mM, respectively. M/sub r/ of the enzyme, according to the data of gel filtraction of Sephadex G-75 and electrophoresis in polyacrylamide gel of various concentrations is ∼ 33,000. In electrophoresis in the presence of SDS, two protein bands with M/sub r/ 12,000 and 18,000 are detected. In the enzyme molecule, acid amino acid residues predominate; two free SH groups and two disulfide bridges are detected. Phosphoprotein phosphatase is a glycoprotein, containing ∼ 22% carbonhydrates. The protein possesses a supplementary absorption maximum at 560 nm. Ammonium molybdate is a competitive inhibitor with K/sub i/ 0.37 μM, while sodium fluoride is a noncompetitive inhibitor with K/sub i/ 1.3 mM. Incubation in the presence of 2 mM phenylmethylsulfonyl fluoride for 25 h leads to a loss of ∼ 46% of the enzymatic activity. Ammonium molybdate, sodium fluoride, and PMSF are reversible inhibitors. Modifications of the SH groups, NH 2 groups, and histidine leads to a decrease in the enzymatic activity. Incubation of phosphoprotein phosphatase with [γ- 32 P]ATP leads to the incorporation of 0.33 mole 33 P per mole of the enzyme. The mechanism of hydrolysis of the phosphodiester bond, catalyzed by the enzyme, is discussed

  1. Development of ethanol production from cooking oil glycerol waste ...

    African Journals Online (AJOL)

    Tuoyo Aghomotsegin

    2016-10-12

    Oct 12, 2016 ... glycerol waste by mutant Enterobacter aerogenes ... wild type strain was altered for enhancing ethanol production using UV irradiation and chemical method. .... microbial medium analytical methods were of laboratory and.

  2. Glycerol extracting dealcoholization for the biodiesel separation process.

    Science.gov (United States)

    Ye, Jianchu; Sha, Yong; Zhang, Yun; Yuan, Yunlong; Wu, Housheng

    2011-04-01

    By means of utilizing sunflower oil and Jatropha oil as raw oil respectively, the biodiesel transesterification production and the multi-stage extracting separation were carried out experimentally. Results indicate that dealcoholized crude glycerol can be utilized as the extracting agent to achieve effective separation of methanol from the methyl ester phase, and the glycerol content in the dealcoholized methyl esters is as low as 0.02 wt.%. For the biodiesel separation process utilizing glycerol extracting dealcoholization, its technical and equipment information were acquired through the rigorous process simulation in contrast to the traditional biodiesel distillation separation process, and results show that its energy consumption decrease about 35% in contrast to that of the distillation separation process. The glycerol extracting dealcoholization has sufficient feasibility and superiority for the biodiesel separation process. Copyright © 2011 Elsevier Ltd. All rights reserved.

  3. Enhancement of glycerol production by zygosaccharomyces ruxii using strawberry wastes

    International Nuclear Information System (INIS)

    Meleigy, S.A; Taha, S.M.A.

    2010-01-01

    Glycerol is important industrial product that can be produced using osmophilic yeasts. In this study a local isolate of osmophilic yeast, zygosaccharomyces ruxii, was used for glycerol production from strawberry waste. The effects of some important parameters including glucose and urea concentrations, incubation temperature, initial ph and gamma irradiation were investigated. The optimum conditions for maximum glycerol production (126.8 g/l)by z. ruxii were occurred at 31 degree C and initial ph 5 in the presence of 250 g/l glucose and 3 g/l urea in the production medium . Under these optimizing fermentation parameters, enhancement of glycerol production (130 g/l) were recorded when the inoculum of z. ruxii was exposed to 0.25 kGy. also, the present results showed reduction in BOD 5 levels of fermented strawberry waste.

  4. Crude glycerol combustion: Particulate, acrolein, and other volatile organic emissions

    KAUST Repository

    Steinmetz, Scott; Herrington, Jason S.; Winterrowd, Chris K.; Roberts, William L.; Wendt, Jost O L; Linak, William P.

    2013-01-01

    to be formed from the low temperature thermal decomposition of glycerol. Currently, there is no known reliable method for measuring acrolein in sources. Acrolein and emissions of other volatile organic compounds were characterized through the use of a SUMMA

  5. Recent Advances in Glycerol Polymers: Chemistry and Biomedical Applications

    Science.gov (United States)

    Zhang, Heng

    2015-01-01

    Glycerol polymers are attracting increased attention due to the diversity of polymer compositions and architectures available. This article provides a brief chronological review on the current status of these polymers along with representative examples of their use for biomedical applications. First, we describe the underlying chemistry of glycerol, which provides access to a range of monomers for subsequent polymerizations. We then review the various synthetic methodologies to prepare glycerol-based polymers including polyethers, polycarbonates, polyesters, and so forth. Next, we describe several biomedical applications where glycerol polymers are being investigated including carriers for drug delivery, sealants or coatings for tissue repair, and agents possessing antibacterial activity. Fourth, we describe the growing market opportunity for the use of polymers in medicine. Finally we conclude and summarize the findings, as well as discuss potential opportunities for continued research efforts. PMID:25308354

  6. Supercritical water reformation of crude glycerol solution for hydrogen production.

    Science.gov (United States)

    2009-12-01

    Glycerol, also known as glycerin, is a less desirable byproduct formed in the production of biodiesel via the transesterification otriglycerides and presents a nontrivial issue in terms of developing other beneficial end uses. With an inflated glycer...

  7. Phosphate-solubility and phosphatase activity in Gangetic alluvial soil as influenced by organophosphate insecticide residues.

    Science.gov (United States)

    Majumder, Shyam Prasad; Das, Amal Chandra

    2016-04-01

    An experiment was conducted under laboratory conditions to investigate the effect of four organophosphate insecticides, viz. monocrotophos, profenophos, quinalphos and triazophos at their field application rates (0.75, 1.0, 0.5 and 0.6 kg a.i.ha(-1), respectively), on the growth and activities of phosphate solubilizing microorganisms in relation to availability of insoluble phosphates in the Gangetic alluvial soil of West Bengal, India. The proliferation of phosphate solubilizing microorganisms was highly induced with profenophos (38.3%), while monocrotophos exerted maximum stimulation (20.8%) towards the solubility of insoluble phosphates in soil. The phosphatase activities of the soil (both acid phosphatase and alkaline phosphatase) were significantly increased due to the incorporation of the insecticides in general, and the augmentation was more pronounced with quinalphos (43.1%) followed by profenophos (27.6%) for acid phosphatase, and with monocrotophos (25.2%) followed by profenophos (16.1%) for alkaline phosphatase activity in soil. The total phosphorus was highly retained by triazophos (19.9%) followed by monocrotophos (16.5%), while incorporation of triazophos and quinalphos manifested greater availability of water soluble phosphorus in soil. Copyright © 2015 Elsevier Inc. All rights reserved.

  8. Effects of increasing crude glycerol and dried distillers grains with solubles on growth performance, carcass characteristics, and carcass fat quality of finishing pigs.

    Science.gov (United States)

    Duttlinger, A J; Derouchey, J M; Tokach, M D; Dritz, S S; Goodband, R D; Nelssen, J L; Houser, T A; Sulabo, R C

    2012-03-01

    This study was conducted to determine the effects of dietary crude glycerol and dried distillers grains with solubles (DDGS) on growing-finishing pig performance, carcass characteristics, and carcass fat quality. We hypothesized that because dietary crude glycerol has been observed to increase carcass SFA, it might ameliorate the negative effects of DDGS on fat quality. The 97-d study was conducted at a commercial swine research facility in southwestern Minnesota with 1,160 barrows (initial BW = 31.0 ± 1.1 kg). Pigs were blocked by initial BW, and pens were randomly allotted to 1 of 6 dietary treatments with 7 replications per treatment. Treatments were arranged in a 2 × 3 factorial with main effects of crude glycerol (0, 2.5, or 5%) and DDGS (0 or 20%). All corn-soybean meal-based diets contained 3% added fat (choice white grease). There were no glycerol × DDGS interactions for any response criteria evaluated. Increasing dietary glycerol did not affect finishing pig growth performance. Adding 20% DDGS to the diet did not affect ADG; however, finishing pigs fed diets with added DDGS had greater (2.47 vs. 2.41 kg/d; P = 0.02) ADFI and poorer (0.39 vs. 0.40; P = 0.01) G:F than pigs not fed DDGS. Feeding increasing dietary glycerol or 20% DDGS did not affect carcass characteristics. For carcass fat quality, feeding 20% DDGS resulted in decreased (P carcass fat iodine value, whereas feeding crude glycerol did not influence growth performance, carcass characteristics, and had a minor influence on fatty acids of carcass fat. Both of these biofuel coproducts can be used in combination without affecting finishing pig performance or carcass traits; however, feeding crude glycerol did not fully mitigate the increased unsaturation of carcass fat observed when feeding DDGS.

  9. Economic Risk Assessment of Early Stage Designs for Glycerol2Valorization in Biorefinery Concepts

    DEFF Research Database (Denmark)

    Loureiro da Costa Lira Gargalo, Carina; Cheali, Peam; Posada, John A.

    2016-01-01

    , and discount rate, among others, have high impact on the project’s profitability analysis. Therefore, the profitability was tested under uncertainties by using NPV and MSP as economic metrics. The robust ranking of solutions is presented with respect to minimum economic risk of the project being nonprofitable...... (failure to achieve a positive NPV times the consequential profit loss). It was found that the best potential options for glycerol valorization is through the production of either (i) lactic acid (9 MM$ with 63% probability of failure to achieve a positive NPV); (ii) succinic acid (14 MM$ with 76......%); or finally, (iii) 1,2-propanediol (16 MM$ with 68%). As a risk reduction strategy, a multiproduct biorefinery is suggested which is capable of switching between the production of lactic acid and succinic acid. This solution comes with increased capital investment; however, it leads to more robust NPV...

  10. Efficient synthetic protocols in glycerol under heterogeneous catalysis.

    Science.gov (United States)

    Cravotto, Giancarlo; Orio, Laura; Gaudino, Emanuela Calcio; Martina, Katia; Tavor, Dorith; Wolfson, Adi

    2011-08-22

    The massive increase in glycerol production from the transesterification of vegetable oils has stimulated a large effort to find novel uses for this compound. Hence, the use of glycerol as a solvent for organic synthesis has drawn particular interest. Drawbacks of this green and renewable solvent are a low solubility of highly hydrophobic molecules and a high viscosity, which often requires the use of a fluidifying co-solvent. These limitations can be easily overcome by performing reactions under high-intensity ultrasound and microwaves in a stand-alone or combined manner. These non-conventional techniques facilitate and widen the use of glycerol as a solvent in organic synthesis. Glycerol allows excellent acoustic cavitation even at high temperatures (70-100 °C), which is otherwise negligible in water. Herein, we describe three different types of applications: 1) the catalytic transfer hydrogenation of benzaldehyde to benzyl alcohol in which glycerol plays the dual role of the solvent and hydrogen donor; 2) the palladium-catalyzed Suzuki cross-coupling; and (3) the Barbier reaction. In all cases glycerol proved to be a greener, less expensive, and safer alternative to the classic volatile organic solvents. Copyright © 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  11. Multiple forms of the human tyrosine phosphatase RPTP alpha. Isozymes and differences in glycosylation

    DEFF Research Database (Denmark)

    Daum, G; Regenass, S; Sap, J

    1994-01-01

    Among all the receptor-linked protein-tyrosine-phosphatase RPTP alpha clones described from mammalian tissues, one differed in that it encoded a 9-amino-acid insert 3 residues upstream from the transmembrane segment (Kaplan, R., Morse, B., Huebner, K., Croce, C., Howk, R. Ravera, M., Ricca, G...

  12. Utilization of Crude Glycerol as a Substrate for the Production of Rhamnolipid by Pseudomonas aeruginosa

    OpenAIRE

    Eraqi, Walaa A.; Yassin, Aymen S.; Ali, Amal E.; Amin, Magdy A.

    2016-01-01

    Biosurfactants are produced by bacteria or yeast utilizing different substrates as sugars, glycerol, or oils. They have important applications in the detergent, oil, and pharmaceutical industries. Glycerol is the product of biodiesel industry and the existing glycerol market cannot accommodate the excess amounts generated; consequently, new markets for refined glycerol need to be developed. The aim of present work is to optimize the production of microbial rhamnolipid using waste glycerol. We...

  13. Production of polyhydroxybutyrate and alginate from glycerol by Azotobacter vinelandii under nitrogen-free conditions

    OpenAIRE

    Yoneyama, Fuminori; Yamamoto, Mayumi; Hashimoto, Wataru; Murata, Kousaku

    2015-01-01

    Glycerol is an interesting feedstock for biomaterials such as biofuels and bioplastics because of its abundance as a by-product during biodiesel production. Here we demonstrate glycerol metabolism in the nitrogen-fixing species Azotobacter vinelandii through metabolomics and nitrogen-free bacterial production of biopolymers, such as poly-d-3-hydroxybutyrate (PHB) and alginate, from glycerol. Glycerol-3-phosphate was accumulated in A. vinelandii cells grown on glycerol to the exponential phase...

  14. Loss of SYNJ1 dual phosphatase activity leads to early onset refractory seizures and progressive neurological decline

    DEFF Research Database (Denmark)

    Hardies, Katia; Cai, Yiying; Jardel, Claude

    2016-01-01

    SYNJ1 encodes a polyphosphoinositide phosphatase, synaptojanin 1, which contains two consecutive phosphatase domains and plays a prominent role in synaptic vesicle dynamics. Autosomal recessive inherited variants in SYNJ1 have previously been associated with two different neurological diseases...... with intractable epilepsy and tau pathology. We performed whole exome or genome sequencing in three independent sib pairs with early onset refractory seizures and progressive neurological decline, and identified novel segregating recessive SYNJ1 defects. A homozygous missense variant resulting in an amino acid...

  15. Posttranslational heterogeneity of bone alkaline phosphatase in metabolic bone disease.

    Science.gov (United States)

    Langlois, M R; Delanghe, J R; Kaufman, J M; De Buyzere, M L; Van Hoecke, M J; Leroux-Roels, G G

    1994-09-01

    Bone alkaline phosphatase is a marker of osteoblast activity. In order to study the posttranscriptional modification (glycosylation) of bone alkaline phosphatase in bone disease, we investigated the relationship between mass and catalytic activity of bone alkaline phosphatase in patients with osteoporosis and hyperthyroidism. Serum bone alkaline phosphatase activity was measured after lectin precipitation using the Iso-ALP test kit. Mass concentration of bone alkaline phosphatase was determined with an immunoradiometric assay (Tandem-R Ostase). In general, serum bone alkaline phosphatase mass and activity concentration correlated well. The activity : mass ratio of bone alkaline phosphatase was low in hyperthyroidism. Activation energy of the reaction catalysed by bone alkaline phosphatase was high in osteoporosis and in hyperthyroidism. Experiments with neuraminidase digestion further demonstrated that the thermodynamic heterogeneity of bone alkaline phosphatase can be explained by a different glycosylation of the enzyme.

  16. Promoting Uranium Immobilization by the Activities of Microbial Phosphatases

    Energy Technology Data Exchange (ETDEWEB)

    Martinez, Robert J.; Beazley, Melanie J.; Wilson, Jarad J.; Taillefert, Martial; Sobecky, Patricia A.

    2005-04-05

    The overall goal of this project is to examine the role of nonspecific phosphohydrolases present in naturally occurring subsurface microorganisms for the purpose of promoting the immobilization of radionuclides through the production of uranium [U(VI)] phosphate precipitates. Specifically, we hypothesize that the precipitation of U(VI) phosphate minerals may be promoted through the microbial release and/or accumulation of PO{sub 4}{sup 3-}. During this phase of the project we have been conducting assays to determine the effects of pH, inorganic anions and organic ligands on U(VI) mineral formation and precipitation when FRC bacterial isolates were grown in simulated groundwater medium. The molecular characterization of FRC isolates has also been undertaken during this phase of the project. Analysis of a subset of gram-positive FRC isolates cultured from FRC soils (Areas 1, 2 and 3) and background sediments have indicated a higher percentage of isolates exhibiting phosphatase phenotypes (i.e., in particular those surmised to be PO{sub 4}{sup 3-}-irrepressible) relative to isolates from the reference site. A high percentage of strains that exhibited such putatively PO{sub 4}{sup 3-}-irrepressible phosphatase phenotypes were also resistant to the heavy metals lead and cadmium. Previous work on FRC strains, including Arthrobacter, Bacillus and Rahnella spp., has demonstrated differences in tolerance to U(VI) toxicity (200 {micro}M) in the absence of organophosphate substrates. For example, Arthrobacter spp. exhibited the greatest tolerance to U(VI) while the Rahnella spp. have been shown to facilitate the precipitation of U(VI) from solution and the Bacillus spp. demonstrate the greatest sensitivity to acidic conditions and high concentrations of U(VI). PCR-based detection of FRC strains are being conducted to determine if non-specific acid phosphatases of the known molecular classes [i.e., classes A, B and C] are present in these FRC isolates. Additionally, these

  17. Combinations of glycerol percent, glycerol equilibration time, and thawing rate upon freezability of bull spermatozoa in plastic straws.

    Science.gov (United States)

    Wiggin, H B; Almquist, J O

    1975-03-01

    Twelve ejaculates were used in a central composite experiment to test 15 combinations of glycerol (7, 9, 11, 13, or 15%), glycerol equilibration times (1, 2, 4, 8, or 16 h) and thawing rates (water at 35 C for 15 s, 50 C for 13 s, 65 C for 11 s, 80 C for 9 s, or 95 C for 7 s). Semen was diluted in heated skim milk-glycerol, packaged in .3-ml. Continental U.S. straws and frozen in liquid nitrogen vapor. Based on post-thaw progressive sperm motility after storage at -196 C for 9 to 11 days, estimated optima from multiple regression were 10.7% for glycerol, 2.0 h for glycerol equilibration time, and 76 C for thawing bath temperature. Only the linear effect for each variable was significant. Much faster thawing rates and shorter glycerol equilibration times than those for freezing bull spermatozoa in glass ampules should be used for maximum post-thaw sperm motility in straws.

  18. Changes in the microbial community during the acclimation stages of the methane fermentation for the treatment of glycerol

    International Nuclear Information System (INIS)

    Dinh, Nga Thi; Hatta, Kohei; Kwon, Sang Hagk; Rollon, Analiza P.; Nakasaki, Kiyohiko

    2014-01-01

    Granular sludge from a full-scale methane reactor treating brewery wastewater was used as a seed for the treatment of glycerol in a laboratory-scale repeated-batch methane reactor, and the change in the microbial community during the acclimation stages was examined. Two types of substrate solutions, a glucose, sodium acetate, and lactic acid mixture, as well as glycerol, were prepared and fed by mixing the two solutions to increase the ratio, in a stepwise manner, of glycerol from 0% to 100%, while keeping a loading of COD at 2.5 kg m −3  d −1 throughout the fermentation process. Vigorous methane gas production, approximately 580 dm 3  m −3  d −1 , was observed during the acclimation stages. Microbial analysis revealed that both bacterial and archaeal communities changed significantly; bacteria (genus Trichococcus and family Syntrophomonadaceae) became dominant rapidly after the start of acclimation, and archaea belonging to the hydrogenotrophic methanogens (genera Methanobacterium and Methanospirillum), increased gradually with the progress of acclimation. - Highlights: • Acclimation stages to the methane fermentation of glycerol were examined. • Vigorous methane gas production, approximately 580 dm 3  m −3  d −1 , was observed. • Both bacteria and archaea, changed significantly during the acclimation stages. • Bacteria belonging to genus Trichococcus and Syntrophomonadaceae became dominant. • Archaea belonging to the hydrogenotrophic methanogens increased gradually

  19. Defining Starch Binding by Glucan Phosphatases

    DEFF Research Database (Denmark)

    Auger, Kyle; Raththagala, Madushi; Wilkens, Casper

    2015-01-01

    Starch is a vital energy molecule in plants that has a wide variety of uses in industry, such as feedstock for biomaterial processing and biofuel production. Plants employ a three enzyme cyclic process utilizing kinases, amylases, and phosphatases to degrade starch in a diurnal manner. Starch...... is comprised of the branched glucan amylopectin and the more linear glucan amylose. Our lab has determined the first structures of these glucan phosphatases and we have defined their enzymatic action. Despite this progress, we lacked a means to quickly and efficiently quantify starch binding to glucan...

  20. Vapour phase dehydration of glycerol to acrolein over tungstated zirconia catalysts

    Energy Technology Data Exchange (ETDEWEB)

    Rao Ginjupalli, Srinivasa; Mugawar, Sowmya; Rajan, Pethan N.; Kumar Balla, Putra; Chary Komandur, V.R., E-mail: kvrchary@iict.res.in

    2014-08-01

    Tetragonal (TZ) and monoclinic (MZ) polymorphs of zirconia supports were synthesised by sol–gel method followed by variation of the calcination temperature. Tungstated (10 wt% WO{sub 3}) supported on the zirconia polymorphs were prepared by impregnation method by using ammonium metatungstate precursor. The physico-chemical properties of the calcined catalysts were characterised by X-ray diffraction, UV–vis diffused reflectance spectroscopy, X-ray photoelectron spectroscopy (XPS), surface area and pore size distribution measurements to gain insight into the effect of morphology of the catalyst textural properties, and structure. The surface acidic properties have been determined by NH{sub 3} TPD method and also with FT-IR spectra of pyridine adsorption. Vapour phase dehydration of glycerol to acrolein was employed to investigate the catalytic functionalities. Glycerol conversion and acrolein selectivity was mainly dependent on the fraction of moderate acid sites with majority of them are due to Brønsted acidic sites. Monoclinic zirconia based catalysts have shown the highest activity and acrolein selectivity compared to the corresponding tetragonal zirconia catalysts.

  1. Vapour phase dehydration of glycerol to acrolein over tungstated zirconia catalysts

    Science.gov (United States)

    Rao Ginjupalli, Srinivasa; Mugawar, Sowmya; Rajan N., Pethan; Kumar Balla, Putra; Chary Komandur, V. R.

    2014-08-01

    Tetragonal (TZ) and monoclinic (MZ) polymorphs of zirconia supports were synthesised by sol-gel method followed by variation of the calcination temperature. Tungstated (10 wt% WO3) supported on the zirconia polymorphs were prepared by impregnation method by using ammonium metatungstate precursor. The physico-chemical properties of the calcined catalysts were characterised by X-ray diffraction, UV-vis diffused reflectance spectroscopy, X-ray photoelectron spectroscopy (XPS), surface area and pore size distribution measurements to gain insight into the effect of morphology of the catalyst textural properties, and structure. The surface acidic properties have been determined by NH3 TPD method and also with FT-IR spectra of pyridine adsorption. Vapour phase dehydration of glycerol to acrolein was employed to investigate the catalytic functionalities. Glycerol conversion and acrolein selectivity was mainly dependent on the fraction of moderate acid sites with majority of them are due to Brønsted acidic sites. Monoclinic zirconia based catalysts have shown the highest activity and acrolein selectivity compared to the corresponding tetragonal zirconia catalysts.

  2. Vapour phase dehydration of glycerol to acrolein over tungstated zirconia catalysts

    International Nuclear Information System (INIS)

    Rao Ginjupalli, Srinivasa; Mugawar, Sowmya; Rajan, Pethan N.; Kumar Balla, Putra; Chary Komandur, V.R.

    2014-01-01

    Tetragonal (TZ) and monoclinic (MZ) polymorphs of zirconia supports were synthesised by sol–gel method followed by variation of the calcination temperature. Tungstated (10 wt% WO 3 ) supported on the zirconia polymorphs were prepared by impregnation method by using ammonium metatungstate precursor. The physico-chemical properties of the calcined catalysts were characterised by X-ray diffraction, UV–vis diffused reflectance spectroscopy, X-ray photoelectron spectroscopy (XPS), surface area and pore size distribution measurements to gain insight into the effect of morphology of the catalyst textural properties, and structure. The surface acidic properties have been determined by NH 3 TPD method and also with FT-IR spectra of pyridine adsorption. Vapour phase dehydration of glycerol to acrolein was employed to investigate the catalytic functionalities. Glycerol conversion and acrolein selectivity was mainly dependent on the fraction of moderate acid sites with majority of them are due to Brønsted acidic sites. Monoclinic zirconia based catalysts have shown the highest activity and acrolein selectivity compared to the corresponding tetragonal zirconia catalysts.

  3. Biodiesel production using heterogeneous catalysts including wood ash and the importance of enhancing byproduct glycerol purity

    International Nuclear Information System (INIS)

    Uprety, Bijaya K.; Chaiwong, Wittavat; Ewelike, Chinomnso; Rakshit, Sudip K.

    2016-01-01

    Highlights: • Comparison of biodiesel production using homogeneous and heterogeneous catalysts. • Comparative study of CaO and CaO supported on alumina for biodiesel production. • Tradeoff between biodiesel conversion rate and purity. • Ash from birch bark and wood pellet industry explored as a potential catalyst. - Abstract: Transesterification of vegetable oils or animal fats with methanol in the presence of catalysts produces fatty acid methyl esters (FAME) and glycerol as a co-product. This study was focused on a comparative study of the transesterification of refined, bleached and deodorized palm oil (RBD palm oil) using a heterogeneous catalysts CaO with and without γ-alumina (γ-Al_2O_3) as a support. The results were also compared to that using sodium hydroxide (NaOH), which is a homogenous catalyst. Parameters like the amount of catalyst, the molar ratio of methanol to oil, reaction time and reaction temperature that affect methyl ester and glycerol formation were analyzed and the optimum conditions were determined. The FAME and glycerol content (96.75% and 92.73% respectively) obtained using CaO were lower in purity compared to that using CaO/Al_2O_3 (97.66% and 96.36% respectively). In the second phase of our work, wood ash from two different sources (birch bark & flyash from a biomass based power plant), which were calcined at 800 °C were studied for their potential use as a cheap renewable alternative heterogeneous catalyst. Both the wood ash samples were found to have good potential for use in such production process, but needs to be optimized further to obtain biodiesel which meets fuel biodiesel specifications. Both CaO and CaO supported on alumina produces FAME to levels that meet the fuel specifications required for blending with diesel. However, the latter produces a purer form of byproduct glycerol that can be easily converted to value added products, without the need for purification. On this basis the supported catalyst is

  4. Switch from Sodium Phenylbutyrate to Glycerol Phenylbutyrate Improved Metabolic Stability in an Adolescent with Ornithine Transcarbamylase Deficiency.

    OpenAIRE

    Laemmle Alexander; Stricker Tamar; Häberle Johannes

    2016-01-01

    A male patient, born in 1999, was diagnosed with ornithine transcarbamylase deficiency as neonate and was managed with a strict low-protein diet supplemented with essential amino acids, l-citrulline, and l-arginine as well as sodium benzoate. He had an extensive history of hospitalizations for hyperammonemic crises throughout childhood and early adolescence, which continued after the addition of sodium phenylbutyrate in 2009. In December 2013 he was switched to glycerol phenylbutyrate, and hi...

  5. Synthesis and characterization of sulfonated polyesters derived from glycerol; Sintese e caracterizacao de poliesteres sulfonados obtidos a partir do glicerol

    Energy Technology Data Exchange (ETDEWEB)

    Fiuza, R.A.; Jose, N.M.; Boaventura, J.S. [Universidade Federal da Bahia (IQ/UFBA), Salvador, BA (Brazil). Inst. de Quimica; Fiuza, R.P. [Universidade Federal da Bahia (EP/UFBA), Salvador, BA (Brazil). Escola Politecnica. Curso de Mestrado em Engenharia Quimica

    2010-07-01

    In this work were synthesized polyesters from glycerol and acid sulfonated phthalic previously. The materials were characterized by DSC, TGA, FTIR, SEM, XRD and XRF. The results showed effective sulfonation of phthalic acid. The presence of sulfonic groups promoted strong changes in the crystallinity of the new material makes the lens. The polyesters made from phthalic acid sulfonated combine characteristics such as heat resistance and groups that drivers potentiate the electrolyte for application in fuel cells proton exchange membrane and also for gas separation. (author)

  6. Evidence for phosphoprotein phosphatase in Streptomyces granaticolor

    Czech Academy of Sciences Publication Activity Database

    Bobek, J.; Hercík, K.; Dobrová, Zuzana; Branny, Pavel; Nádvorník, Richard; Janeček, Jiří

    2000-01-01

    Roč. 45, č. 4 (2000), s. 310-312 ISSN 0015-5632 R&D Projects: GA ČR GA204/99/1534 Institutional research plan: CEZ:AV0Z5020903 Keywords : streptomycetes * phosphoprotein phosphatase Subject RIV: EE - Microbiology, Virology Impact factor: 0.752, year: 2000

  7. Enzyme kinetic characterization of protein tyrosine phosphatases

    DEFF Research Database (Denmark)

    Peters, Günther H.J.; Branner, S.; Møller, K. B.

    2003-01-01

    Protein tyrosine phosphatases (PTPs) play a central role in cellular signaling processes, resulting in an increased interest in modulating the activities of PTPs. We therefore decided to undertake a detailed enzyme kinetic evaluation of various transmembrane and cytosolic PTPs (PTPalpha, PTPbeta...

  8. Deuterium nuclear magnetic resonance studies on the plasmalogens and the glycerol acetals of plasmalogens of Clostridium butyricum and Clostridium beijerinckii

    International Nuclear Information System (INIS)

    Malthaner, M.; Seelig, J.; Johnston, N.C.; Goldfine, H.

    1987-01-01

    Deuterium nuclear magnetic resonance was used to investigate the structure of different lipid fractions isolated from the anaerobic bacteria Clostridium butyricum and Clostridium beijerinckii. The fractions isolated from C. butyricum were (1) phosphatidylethanolamine/plasmenylethanolamine and (2) the glycerol acetal of plasmenylethanolamine, and from C. beijerinckii similar fractions containing principally (1) phosphatidyl-N-monomethylethanolamine, along with its plasmalogen, and (2) the glycerol acetal of this plasmalogen were isolated. The third fraction from both species consisted largely of the acidic lipids phosphatidylglycerol and cardiolipin along with plasmalogen forms of these lipids. Palmitic acid with deuterium labels at C-2, C-3, or C-4 or oleic acid with deuterium labels at C-2 and C-9,10 was added to the growth medium and incorporated to various extents in the lipid fractions. Biochemical analysis showed that palmitic acid and oleic acid were preferentially bound to the sn-2 and sn-1 positions, respectively, of the glycerol backbone when both fatty acids were added to the medium. From the 2 H NMR spectra, the hydrocarbon chain ordering near the lipid-water interface could be determined and appeared to be similar for all three lipid fractions. The deuterium quadrupole splitting and order parameter were low at the C-2 segment and increased by almost a factor of 2 at positions C-3 and C-4 for cells fed with deuteriated palmitic acid along with unlabeled oleic acid. These results agree with previous findings on pure diacyl lipids in which the sn-2 chain was found to adopt a bent conformation at the carbon segment C-2. However, two unusual quadrupole splittings could be detected for the plasmalogens. By comparison with other model systems it could be concluded that the double bond is aligned essentially parallel with the long axis of the hydrocarbon chains

  9. Digestible energy of crude glycerol for pacu and silver catfish

    Directory of Open Access Journals (Sweden)

    Rafael Ernesto Balen

    2014-01-01

    Full Text Available The increase in global biodiesel production is originating a glycerol surplus, which has no defined destination. An alternative to overcome this problem is its use as energy source in animal feeding. In Brazil, Pacu (Piaractus mesopotamicus is one of the most farmed native fish species, whereas Silver catfish (Rhamdia quelen is suitable for production in subtropical region. Considering little knowledge about crude glycerol utilization in feeds for Neotropical fish species, it was evaluated the apparent digestibility coefficients (ADCs for energy of crude glycerol for P. mesopotamicus and R. quelen. The digestibility and digestible energy content of crude glycerol can be considered excellent even when compared to energy of common ingredients such as maize and wheat, presenting 0.97 and 0.89 of energy ADCs, and 15.2 and 13.95MJ kg-1 of digestible energy for Pacu and Silver catfish, respectively. In conclusion, crude glycerol is an energetic ingredient with good potential in Brazilian native fish diets.

  10. An experimental and kinetic modeling study of glycerol pyrolysis

    International Nuclear Information System (INIS)

    Fantozzi, F.; Frassoldati, A.; Bartocci, P.; Cinti, G.; Quagliarini, F.; Bidini, G.; Ranzi, E.M.

    2016-01-01

    Highlights: • Glycerol pyrolysis can produce about 44–48%v hydrogen at 750–800 °C. • A simplified 452 reactions kinetic model of glycerol pyrolysis has been developed. • The model has good agreement with experimental data. • Non condensable gas yields can reach 70%. - Abstract: Pyrolysis of glycerol, a by-product of the biodiesel industry, is an important potential source of hydrogen. The obtained high calorific value gas can be used either as a fuel for combined heat and power (CHP) generation or as a transportation fuel (for example hydrogen to be used in fuel cells). Optimal process conditions can improve glycerol pyrolysis by increasing gas yield and hydrogen concentration. A detailed kinetic mechanism of glycerol pyrolysis, which involves 137 species and more than 4500 reactions, was drastically simplified and reduced to a new skeletal kinetic scheme of 44 species, involved in 452 reactions. An experimental campaign with a batch pyrolysis reactor was properly designed to further validate the original and the skeletal mechanisms. The comparisons between model predictions and experimental data strongly suggest the presence of a catalytic process promoting steam reforming of methane. High pyrolysis temperatures (750–800 °C) improve process performances and non-condensable gas yields of 70%w can be achieved. Hydrogen mole fraction in pyrolysis gas is about 44–48%v. The skeletal mechanism developed can be easily used in Computational Fluid Dynamic software, reducing the simulation time.

  11. Insights into the biological source and environmental gradients shaping the distribution of H-shaped glycerol dialkyl glycerol tetraethers in Yellowstone National Park geothermal springs

    Science.gov (United States)

    Jia, C.; Xie, W.; Wang, J.; Boyd, E. S.; Zhang, C.

    2013-12-01

    Archaea are ubiquitous in natural environments. The unique tetraether lipids in archaeal membranes enable the maintenance of ion permeability across broad environmental gradients. H-shaped isoprenoid glycerol dialkyl glycerol tetraethers (H-GDGTs), in which the two biphytanyl carbon skeletons are covalently bound by a carbon-carbon bond, have been recently identified in both marine and geothermal environments. Here we report the core H-GDGTs (C-H-GDGTs) and polar H-GDGTs (P-H-GDGTs) associated with sediments sampled from geothermal springs in Yellowstone National Park and investigate their abundance in relation to environmental gradients. The abundance of C- and P-H-GDGTs exhibit strong and negative correlation with pH (P = 0.007), suggesting that H-shaped GDGTs help to maintain cell membrane fluidity in acidic environments. Reanalysis of archaeal 16S rRNA gene pyrotags published previously from (Boyd E. Hamilton T. L., Wang J., He L., Zhang C. L. 2013. The role of tetraether lipid composition in the adaptation of thermophilic archaea to acidity. Frontiers in Terrestrial Microbiology. 4: doi: 10.3389/fmicb.2013.00062) indicates that these H-GDGTs are associated with environments dominanted by Thermoplasmatales, which are thermoacidiphiles. Two equations were established to define the relationships between the abundance of H-GDGTs, the abundance of archaeal taxa based on 16S rRNA gene phylogenetic affiliations, and pH. Both equations have high predictive capacity in predicting the distribution of archaeal lipids in the geothermal system. These observations provide new insight into the biological source of H-GDGTs and suggest a prominent role for these lipids in the diversification of archaea into or out of acidic high temperature environments.

  12. Osteocalcin and bone-specific alkaline phosphatase in Sickle cell ...

    African Journals Online (AJOL)

    specific alkaline phosphatase (b-AP) total protein levels were evaluated as indicators of bone turnover in twenty patients with sickle cell haemoglobinopathies and in twenty normal healthy individuals. The serum bonespecific alkaline phosphatase ...

  13. Effects of addition glycerol co-product of biodiesel in the thermophysical properties of water-glycerol solution applied as secondary coolant

    Energy Technology Data Exchange (ETDEWEB)

    Medeiros, Pedro Samuel Gomes; Barbosa, Cleiton Rubens Formiga; Fontes, Francisco de Assis Oliveira [Federal University of Rio Grande do Norte, Natal, RN (Brazil). Energy Laboratory. Thermal Systems Studies Group], e-mail: cleiton@ufrnet.br

    2010-07-01

    This paper evaluates the effects of glycerol concentration on thermophysical properties of water-glycerol solution applied as a secondary coolant in refrigeration systems by expansion-indirect. The processing of triglycerides for biodiesel production generates glycerol as co-product and there are concerns of environmental and economic order on the surplus of glycerol. The addition of glycerol in water alters the colligative and thermophysical properties (melting point, mass, specific heat, thermal conductivity and dynamic viscosity). There are studies that prove the feasibility of using glycerol as an additive and this paper has the goal to verify the changes on properties compared with pure water. This comparison was made from data obtained by the software simulation and they analyzed using graphs and tables. It was shown that glycerol increases the density and dynamic viscosity, and reduces the specific heat and thermal conductivity. This behavior of water-glycerol solution is proportional to the mass concentration of glycerol and it is justified because the glycerol has low values of specific heat, thermal conductivity and high viscosity when compared with water. Despite the losses in the thermophysical properties, glycerol shows its potential application, because of the cryoscopic effect and it is a non-toxic substance at low cost. (author)

  14. Effect of substituting barley with glycerol as energy feed on feed intake, milk production and milk quality in dairy cows in mid or late lactation

    DEFF Research Database (Denmark)

    Gaillard, Charlotte; Sørensen, Martin Tang; Vestergaard, Mogens

    2018-01-01

    The experiment reported in this research paper aimed to determine the level at which glycerol can substitute barley in grass-clover silage-based ration for dairy cows in mid or late lactation, without affecting milk production, milk composition, milk free fatty acid (FFA) profile, and milk sensor...

  15. SUPPLEMENTATION OF GLYCEROL OR LECITHIN IN DIFFERENT LEVELS OF FREE FAT ACIDS IN BROILER DIETS SUPLEMENTAÇÃO DE GLICEROL OU DE LECITINA EM DIFERENTES NÍVEIS DE ÁCIDOS GRAXOS LIVRES EM DIETAS PARA FRANGOS DE CORTE

    Directory of Open Access Journals (Sweden)

    Alexandre de Mello Kessler

    2009-09-01

    Full Text Available A metabolism trial was carried out with 95 male broilers, 24 day-old, of commercial line, subjected to 18+1 treatments with 5 replications. Three levels of free fat acid (FFA inclusion by the usage of soybean oil (SO, acidulated soybean soapstock (ASS, and the mixture between the two oils (50:50%, in two levels of inclusion (4 and 8% in the basal diet (BD and the supplementation of glycerol or emulsifier (0.5%, in substitution to starch were tested. The trial was conducted for 8 days. Birds performance, metabolizability coefficient of dry matter (MCDM, fat (MCCF and energy (MCCE were evaluated and the comparison among oils and supplements. The performance and the metabolism were not affected (P>0.05 by FFA levels or supplements tested.  It was observed that the use of lecithin improved added crude fat metabolism (P<0.01 and that birds used equally SO and ASS. Both SO and ASS are good sources of fat for broilers.

    KEY WORDS: Acidulated soybean soapstock, emulsification, lecithin, metabolism, performance.
    Realizou-se um experimento com 95 frangos de corte machos de 24 dias de idade, de linhagem comercial, submetidos a 18+1 tratamentos e cinco repetições. Testaram-se três níveis de inclusão de ácidos graxos livres (AGL,  pelo uso de óleo degomado de soja (ODS, óleo ácido de soja (OAS e a mistura entre os dois óleos (50:50%, em dois níveis de inclusão de óleo (4 e 8% na dieta basal e a suplementação glicerol ou lecitina (0,5% em substituição ao amido. Desenvolveu-se o ensaio em oito dias, com avaliação do desempenho das aves, do coeficiente de metabolizabilidade da matéria seca (CMMS, da gordura bruta (CMGB e da energia bruta (CMEB das dietas e comparação dos óleos e suplementos. O desempenho e o metabolismo não foram afetados (P>0,05 pelos níveis de AGL ou suplementos testados. Observou-se que o uso de lecitina proporcionou melhor aproveitamento da gordura bruta adicionada às dietas (P<0

  16. Effect of laser peening with glycerol as plasma confinement layer

    Science.gov (United States)

    Tsuyama, Miho; Ehara, Naoya; Yamashita, Kazuma; Heya, Manabu; Nakano, Hitoshi

    2018-03-01

    The effects of controlling the plasma confinement layer on laser peening were investigated by measuring the hardness and residual stress of laser-peened stainless steels. The plasma confinement layer contributes to increasing the pressure of shock waves by suppressing the expansion of the laser-produced plasma. Most previous studies on laser peening have employed water as the plasma confinement layer. In this study, a glycerol solution is used in the context of a large acoustic impedance. It is found that this glycerol solution is superior to water in its ability to confine plasma and that suitable conditions exist for the glycerol solution to act as a plasma confinement layer to achieve efficient laser peening.

  17. Phosphatase activity and culture conditions of the yeast Candida mycoderma sp. and analysis of organic phosphorus hydrolysis ability.

    Science.gov (United States)

    Yan, Mang; Yu, Liufang; Zhang, Liang; Guo, Yuexia; Dai, Kewei; Chen, Yuru

    2014-11-01

    Orthophosphate is an essential but limiting macronutrient for plant growth. About 67% cropland in China lacks sufficient phosphorus, especially that with red soil. Extensive soil phosphorus reserves exist in the form of organic phosphorus, which is unavailable for root uptake unless hydrolyzed by secretory acid phosphatases. Thus, many microorganisms with the ability to produce phosphatase have been exploited. In this work, the activity of an extracellular acid phosphatase and yeast biomass from Candida mycoderma was measured under different culture conditions, such as pH, temperature, and carbon source. A maximal phosphatase activity of 8.47×10(5)±0.11×10(5)U/g was achieved by C. Mycoderma in 36 hr under the optimal conditions. The extracellular acid phosphatase has high activity over a wide pH tolerance range from 2.5 to 5.0 (optimum pH3.5). The effects of different phosphorus compounds on the acid phosphatase production were also studied. The presence of phytin, lecithin or calcium phosphate reduced the phosphatase activity and biomass yield significantly. In addition, the pH of the culture medium was reduced significantly by lecithin. The efficiency of the strain in releasing orthophosphate from organic phosphorus was studied in red soil (used in planting trees) and rice soil (originating as red soil). The available phosphorus content was increased by 230% after inoculating 20 days in rice soil and decreased by 50% after inoculating 10 days in red soil. This work indicates that the yeast strain C. mycoderma has potential application for enhancing phosphorus utilization in plants that grow in rice soil. Copyright © 2014. Published by Elsevier B.V.

  18. Crude glycerol combustion: Particulate, acrolein, and other volatile organic emissions

    KAUST Repository

    Steinmetz, Scott

    2013-01-01

    Crude glycerol is an abundant by-product of biodiesel production. As volumes of this potential waste grow, there is increasing interest in developing new value added uses. One possible use, as a boiler fuel for process heating, offers added advantages of energy integration and fossil fuel substitution. However, challenges to the use of crude glycerol as a boiler fuel include its low energy density, high viscosity, and high autoignition temperature. We have previously shown that a refractory-lined, high swirl burner can overcome challenges related to flame ignition and stability. However, critical issues related to ash behavior and the possible formation of acrolein remained. The work presented here indicates that the presence of dissolved catalysts used during the esterification and transesterification processes results in extremely large amounts of inorganic species in the crude glycerol. For the fuels examined here, the result is a submicron fly ash comprised primarily of sodium carbonates, phosphates, and sulfates. These particles report to a well-developed accumulation mode (0.3-0.7 μm diameter), indicating extensive ash vaporization and particle formation via nucleation, condensation, and coagulation. Particle mass emissions were between 2 and 4 g/m3. These results indicate that glycerol containing soluble catalyst is not suitable as a boiler fuel. Fortunately, process improvements are currently addressing this issue. Additionally, acrolein is of concern due to its toxicity, and is known to be formed from the low temperature thermal decomposition of glycerol. Currently, there is no known reliable method for measuring acrolein in sources. Acrolein and emissions of other volatile organic compounds were characterized through the use of a SUMMA canister-based sampling method followed by GC-MS analysis designed for ambient measurements. Results indicate crude glycerol combustion produces relatively small amounts of acrolein (∼15 ppbv) and other volatile organic

  19. TORC1 regulates Pah1 phosphatidate phosphatase activity via the Nem1/Spo7 protein phosphatase complex.

    Directory of Open Access Journals (Sweden)

    Emmanuelle Dubots

    Full Text Available The evolutionarily conserved target of rapamycin complex 1 (TORC1 controls growth-related processes such as protein, nucleotide, and lipid metabolism in response to growth hormones, energy/ATP levels, and amino acids. Its deregulation is associated with cancer, type 2 diabetes, and obesity. Among other substrates, mammalian TORC1 directly phosphorylates and inhibits the phosphatidate phosphatase lipin-1, a central enzyme in lipid metabolism that provides diacylglycerol for the synthesis of membrane phospholipids and/or triacylglycerol as neutral lipid reserve. Here, we show that yeast TORC1 inhibits the function of the respective lipin, Pah1, to prevent the accumulation of triacylglycerol. Surprisingly, TORC1 regulates Pah1 in part indirectly by controlling the phosphorylation status of Nem1 within the Pah1-activating, heterodimeric Nem1-Spo7 protein phosphatase module. Our results delineate a hitherto unknown TORC1 effector branch that controls lipin function in yeast, which, given the recent discovery of Nem1-Spo7 orthologous proteins in humans, may be conserved.

  20. A review on the performance of glycerol carbonate production via catalytic transesterification: Effects of influencing parameters

    International Nuclear Information System (INIS)

    Teng, Wai Keng; Ngoh, Gek Cheng; Yusoff, Rozita; Aroua, Mohamed Kheireddine

    2014-01-01

    Highlights: • Utilization of glycerol to synthesize glycerol carbonate through various routes. • Different types of carbonates and catalysts used for glycerol carbonate production via transesterification are elucidated. • Important factors influencing glycerol carbonate production performances are detailed. • Future research needs of glycerol carbonate production are proposed. - Abstract: Driven by high energy demand and environmental concerns, biodiesel as a substitute for fossil fuels is recognized to be promising renewable and clean energy. The increase in the biodiesel plant dramatically leads to the oversupply of its by-product glycerol in the biodiesel industries. Developing new industrial uses for glycerol is essential to increase the net energy and sustainability of biodiesel. Moreover, glycerol has great potential to be converted into marketable and valuable chemicals. The conversion of glycerol to glycerol carbonate (GC) has been extensively studied and transesterification of glycerol to GC has been proven to be the most promising route. Aimed to reveal the underlying mechanism of this successful conversion path, this paper reviews the chemo- and biocatalytic transesterification of glycerol with different carbonates sources. Also, a detail elucidation of the influence of the catalysts and operating conditions on the GC yield is included to provide an insight into the process. In addition, the future direction of glycerol carbonate production via catalytic transesterification is provided in this review

  1. Propylene from renewable resources: catalytic conversion of glycerol into propylene.

    Science.gov (United States)

    Yu, Lei; Yuan, Jing; Zhang, Qi; Liu, Yong-Mei; He, He-Yong; Fan, Kang-Nian; Cao, Yong

    2014-03-01

    Propylene, one of the most demanded commodity chemicals, is obtained overwhelmingly from fossil resources. In view of the diminishing fossil resources and the ongoing climate change, the identification of new efficient and alternative routes for the large-scale production of propylene from biorenewable resources has become essential. Herein, a new selective route for the synthesis of propylene from bio-derived glycerol is demonstrated. The route consists of the formation of 1-propanol (a versatile bulk chemical) as intermediate through hydrogenolysis of glycerol at a high selectivity. A subsequent dehydration produces propylene. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  2. On the pressure dependence of the fragility of glycerol

    Energy Technology Data Exchange (ETDEWEB)

    Pawlus, S; Paluch, M; Ziolo, J [Institute of Physics, University of Silesia, Uniwersytecka 4, 40-007 Katowice (Poland); Roland, C M [Naval Research Laboratory, Chemistry Division, Code 6120, Washington, DC 20375-5342 (United States)

    2009-08-19

    This work was motivated by ostensibly contradictory results from different groups regarding the effect of pressure on the fragility of glycerol. We present new experimental data for an intermediate pressure regime showing that the fragility increases with pressure up to about 1.8 GPa, becoming invariant at higher pressures. There is no discrepancy among the various literature data taken in toto. The behavior of glycerol is quite distinct from that of normal liquids, a result of its substantial hydrogen bonding. (fast track communication)

  3. Structural stability of human protein tyrosine phosphatase ρ catalytic domain: effect of point mutations.

    Directory of Open Access Journals (Sweden)

    Alessandra Pasquo

    Full Text Available Protein tyrosine phosphatase ρ (PTPρ belongs to the classical receptor type IIB family of protein tyrosine phosphatase, the most frequently mutated tyrosine phosphatase in human cancer. There are evidences to suggest that PTPρ may act as a tumor suppressor gene and dysregulation of Tyr phosphorylation can be observed in diverse diseases, such as diabetes, immune deficiencies and cancer. PTPρ variants in the catalytic domain have been identified in cancer tissues. These natural variants are nonsynonymous single nucleotide polymorphisms, variations of a single nucleotide occurring in the coding region and leading to amino acid substitutions. In this study we investigated the effect of amino acid substitution on the structural stability and on the activity of the membrane-proximal catalytic domain of PTPρ. We expressed and purified as soluble recombinant proteins some of the mutants of the membrane-proximal catalytic domain of PTPρ identified in colorectal cancer and in the single nucleotide polymorphisms database. The mutants show a decreased thermal and thermodynamic stability and decreased activation energy relative to phosphatase activity, when compared to wild- type. All the variants show three-state equilibrium unfolding transitions similar to that of the wild- type, with the accumulation of a folding intermediate populated at ~4.0 M urea.

  4. Intercropping Acacia mangium stimulates AMF colonization and soil phosphatase activity in Eucalyptus grandis

    Directory of Open Access Journals (Sweden)

    Daniel Bini

    Full Text Available ABSTRACT: Arbuscular mycorrhizal fungi (AMF are very important to plant nutrition, mostly in terms of acquisition of P and micronutrients. While Acacia mangium is closely associated with AMF throughout the whole cycle, Eucalyptus grandis presents this symbiosis primarily at the seedling stage. The aim of this study was to evaluate the dynamics of AMF in these two tree species in both pure and mixed plantations during the first 20 months after planting. We evaluated the abundance, richness and diversity of AMF spores, the rate of AMF mycorrhizal root colonization, enzymatic activity and soil and litter C, N and P. There was an increase in AMF root colonization of E. grandis when intercropped with A. mangium as well as an increase in the activity of acid and alkaline phosphatase in the presence of leguminous trees. AMF colonization and phosphatase activities were both involved in improvements in P cycling and P nutrition in soil. In addition, P cycling was favored in the intercropped plantation, which showed negative correlation with litter C/N and C/P ratios and positive correlation with soil acid phosphatase activity and soil N and P concentrations. Intercropping A. mangium and E. grandis maximized AMF root colonization of E. grandis and phosphatase activity in the soil, both of which accelerate P cycling and forest performance.

  5. Investigation of the promoting effect of Mn on a Pt/C catalyst for the steam and aqueous phase reforming of glycerol

    Energy Technology Data Exchange (ETDEWEB)

    Bossola, Filippo; Pereira-Hernández, Xavier Isidro; Evangelisti, Claudio; Wang, Yong; Dal Santo, Vladimiro

    2017-05-01

    The catalytic performances in steam reforming (SR) and aqueous phase reforming (APR) of glycerol of a bimetallic Pt-Mn catalyst supported on activated carbon are investigated and correlated with the surface properties of the catalyst. Under SR conditions, Mn showed a significant promoting effect over Pt/C, both in terms of hydrogen production rate and conversion, with a higher selectivity toward the glycerol dehydration products. Upon addition of Mn the amount of strong Lewis acid sites increased, promoting the dehydration of glycerol and favoring the CAO over CAC cleavage at expenses of hydrogen selectivity. Conversely, under APR conditions, a slightly higher hydrogen selectivity and only minimal enhancement in hydrogen production were found, while the products selectivity was comparable to Pt/C. Most of Mn leached into the aqueous media, but the remaining (<5% of the fresh parent sample) might be alloyed with Pt and promote the CO desorption from neighbor Pt sites.

  6. Production of bioplastic from jackfruit seed starch (Artocarpus heterophyllus) reinforced with microcrystalline cellulose from cocoa pod husk (Theobroma cacao L.) using glycerol as plasticizer

    Science.gov (United States)

    Lubis, M.; Gana, A.; Maysarah, S.; Ginting, M. H. S.; Harahap, M. B.

    2018-02-01

    The production of bioplastic from jackfruit seed starch reinforced with microcrystalline cellulose (MCC) cocoa pod husk using glycerol as plasticizer was investigated to determine the most optimum mass and volume of MCC and glycerol in producing bioplastics. To produce MCC, Cocoa pod husk was subjected to alkali treatment, bleaching, and hydrochloric acid hydrolysis. The degree of crystallinity of MCC, were determined by XRD, functional group by FT-IR and morphologycal analysis by SEM. Analysis of bioplastic mechanical properties includes tensile strength and elongation at break based on ASTM D882 standard. Bioplastics were produced by casting method from jackfruit seed starch and reinforced with MCC from cocoa pod husk at starch mass to MCC ratio of 6:4, 7:3, 8:2, and 9:1, using glycerol as plasticizer at 20%, 25%, 30% (wt/v of glycerol to starch). From the result, the isolated MCC from cocoa pod husk were in a form of rod-like shape of length 5-10 µm with diameter 11.635 nm and 74% crystallinity. The highest tensile strength of bioplastics was obtained at starch to MCC mass ratio of 8:2, addition of 20% glycerol with measured tensile strength of 0.637 MPa and elongation at break of 7.04%. Transform infrared spectroscopy showed the functional groups of bioplastics, which the majority of O-H groups were found at the bioplastics with reinforcing filler MCC that represented substantial hydrogen bonds.

  7. SELECTIVE HYDROGENOLYSIS OF GLYCEROL TO PROPYLENE GLYCOL IN A CONTINUOUS FLOW TRICKLE BED REACTOR USING COPPER CHROMITE AND Cu/Al2O3 CATALYSTS

    Directory of Open Access Journals (Sweden)

    Jorge Sepúlveda

    Full Text Available The glycerol hydrogenolysis reaction was performed in a continuous flow trickle bed reactor using a water glycerol feed and both copper chromite and Cu/Al2O3 catalysts. The commercial copper chromite had a higher activity than the laboratory prepared Cu/Al2O3 and was used for most of the tests. Propylene glycol was the main product with both catalysts, acetol being the main by-product. It was found that temperature is the main variable influencing the conversion of glycerol. When the state of the glycerol-water reactant mixture was completely liquid, at temperatures lower than 190 ºC, conversion was low and deactivation was observed. At reaction temperatures of 210-230 ºC the conversion of glycerol was complete and the selectivity to propylene glycol was stable at about 60-80% all throughout the reaction time span of 10 h, regardless of the hydrogen pressure level (1 to 20 atm. These optimal values could not be improved significantly by using other different reaction conditions or increasing the catalyst acidity. At higher temperatures (245-250 ºC the conversion was also 100%. Under reaction conditions at which copper chromite suffered deactivation, light by-products and surface deposits were formed. The deposits could be completely burned at 250 ºC and the catalyst activity fully recovered.

  8. Voltage-sensing phosphatase: its molecular relationship with PTEN.

    Science.gov (United States)

    Okamura, Yasushi; Dixon, Jack E

    2011-02-01

    Voltage-sensing phosphoinositide phosphatase (VSP) contains voltage sensor and cytoplasmic phosphatase domains. A unique feature of this protein is that depolarization-induced motions of the voltage sensor activate PtdIns(3,4,5)P(3) and PtdIns(4,5)P(2) phosphatase activities. VSP exhibits remarkable structural similarities with PTEN, the phosphatase and tensin homolog deleted on chromosome 10. These similarities include the cytoplasmic phosphatase region, the phosphoinositide binding region, and the putative membrane interacting C2 domain.

  9. Collagen-chitosan-glycerol bio-composite as artificial tympanic membrane for ruptured inner ear organ

    Science.gov (United States)

    Widiyanti, Prihartini; Setya Angtika, Rara; Githanadi, Brillyana; Hanif Kharisma, Ditya; Asyraf, Tarikh Omar; Wardani, Adita

    2017-05-01

    WHO data in 2012 shows that 5.3% of world population highly suffers from hearing loss and deafness. One of the deafness causes is rupture of tympanic membrane. Tympanic membrane damage which occurs often is perforated tympanic membrane, and it is also commonly known in medical term as tympanic membrane perforation. The causes, for instance, are high frequency of using earphones, traumatic accidents, noise, bacteria, viruses, and infectious microorganism. Tympanoplasty becomes the only treatment that can be widely accepted despite of deficiencies in postoperative complications. Therefore, this research aims to create artificial tympanic membrane made of natural materials such as type I collagen composited with chitosan and made of addition of glycerol to improve its mechanical strength and biodegradability. The method included the process of dissolving acetic acid in distilled water and mixation with chitosan. The solution is next added with glycerol and stirred to be homogeneous. After that, it was minted in petri dish and aerated before characterized. The sample characterization included tensile strength of which tensile test results showed that the value of the elasticity modulus tended to decrease with an increase in collagen concentration. The elasticity modulus values in a row for the variations of 7: 3, 8: 2, and 9: 1 were 35.10 MPa, 54,52MPa, and 47,45MPa respectively. The morphological test with 1000x, 2500x, and 5000x magnification showed their interaction in the formation of pores. Cytotoxicity results, moreover, showed that those samples were non-toxic and safe for the body due to the percentage of living cells. The sound absorption coefficient was between 1000 Hz - 2000 Hz which means that it could use as sound absorbing material. The antibacterial test results showed that all the sample variations were anti-bacterial due to the diameter of the clear zone. In conclusion, collagen and chitosan composite with addition of glycerol could be used for

  10. Mechanical properties and total hydroxycinnamic derivative release of starch/glycerol/Melissa officinalis extract films

    Directory of Open Access Journals (Sweden)

    Letícia Mello Rechia

    2010-09-01

    Full Text Available The aim of this study was to investigate the mechanical properties of starch/glycerol/Melissa officinalis, a topical drug delivery system for labial herpes treatment. Four films were prepared with different concentrations of starch, glycerol, and Melissa officinalis extract. The results revealed that increasing the glycerol concentration in the film reduced elasticity modulus and tensile strength, exhibiting a plasticizing effect. The increase in free volume resulted in increased release of hydroxycinnamic derivatives expressed as rosmarinic acid.O objetivo deste trabalho foi estudar as propriedades mecânicas e o mecanismo de liberação de um sistema tópico de liberação prolongada para o tratamento do Herpes labial a partir de filmes de amido/glicerol/extrato de Melissa officinalis, planta com comprovada atividade antiviral. Foram obtidos quatro filmes poliméricos com diferentes concentrações de amido, glicerol e extrato de Melissa officinalis os quais foram caracterizados mecanicamente e determinado o perfil de liberação de derivados hidroxicinâmicos. Os resultados demonstraram que o aumento da concentração de glicerol no filme produz uma redução no módulo de elasticidade e na tensão de deformação como conseqüência do efeito plastificante. O aumento no volume livre do polímero resultou em aumento da liberação dos derivados hidroxicinâmicos expressos como ácido rosmarínico.

  11. Simultaneous enzymatic synthesis of FAME and triacetyl glycerol from triglycerides and methyl acetate.

    Science.gov (United States)

    Usai, E M; Gualdi, E; Solinas, V; Battistel, E

    2010-10-01

    In the presence of methyl acetate triglycerides such as vegetable oils are transformed simultaneously into the corresponding fatty acid methyl esters and triacetyl glycerol (triacetin). The reaction, catalyzed by lipases, was studied as a function of some critical parameters, such as type of catalyst, enzyme hydration and immobilization support. The aim of the work was to achieve a conversion of the triglyceride as high as possible and to maximize the yield of the triacetin, the reaction end point. It was found that by using the immobilized lipase from Candida antarctica yields as high as 80% of both fatty acid esters and triacetin could be achieved. These results were obtained by carefully controlling the amount of water present in the reaction medium and the hydration level of the enzyme macromolecule. Copyright © 2010 Elsevier Ltd. All rights reserved.

  12. Novel high dielectric constant hybrid elastomers based on glycerol-insilicone emulsions

    DEFF Research Database (Denmark)

    Mazurek, Piotr Stanislaw; Skov, Anne Ladegaard

    2016-01-01

    Novel hybrid elastomers were prepared by speedmixing of two virtually immiscible liquids – glycerol and polydimethylsiloxane (PDMS) prepolymer. Upon crosslinking ofthe PDMS phase of the resulting glycerol-in-silicone emulsion freestanding films were obtained. In this way glycerol became uniformly...... elastomeractuators. Conductivities of samples based on various PDMS compositions with different loadings of embedded glycerol were thoroughly investigated providing useful information about the dielectric behavior....

  13. Renal handling of drugs in renal failure. I: Differential effects of uranyl nitrate- and glycerol-induced acute renal failure on renal excretion of TEAB and PAH in rats

    International Nuclear Information System (INIS)

    Lin, J.H.; Lin, T.H.

    1988-01-01

    Two etiologically different models of experimental acute renal failure were induced in rats by administration of either glycerol or uranyl nitrate. Both compounds caused a substantial decrease in the glomerular filtration rate (GFR) and the net tubular secretion of tetraethylammonium bromide (TEAB) and para-aminohippuric acid (PAH). The degree of renal impairment induced by uranyl nitrate and glycerol appeared to be dose related. Deprivation of drinking water 24 hr before the administration of glycerol potentiated the renal damage. In uranyl nitrate-induced renal failure, the decline of the net tubular secretion for TEAB and PAH was not proportional to the decrease in GFR; the secretion process deteriorated faster than the GFR. For example, when 0.5 mg/kg uranyl nitrate was administered, GFR fell to approximately 65% of normal, whereas the net tubular secretion was decreased to 30% of normal. These results suggest that the tubular transport was preferentially affected by uranyl nitrate. In contrast, in glycerol-induced renal failure, the decline of TEAB secretion fell in a parallel fashion with the GFR, suggesting that the glomeruli and the proximal tubules were equally damaged by glycerol. However, in this latter model, the decline of PAH secretion did not parallel the decrease in GFR, contradicting the proposal that glycerol affects equally the glomeruli and the proximal tubules. This discrepancy may be due to the selective competitive inhibition of PAH secretion by the accumulation of naturally occurring organic acids

  14. Investigation of glycerol polymerization in the clinker grinding process

    NARCIS (Netherlands)

    Parvulescu, A.N.; Rossi, M.; Della Pina, C.; Ciriminna, R.; Pagliaro, M.

    2011-01-01

    Concrete production is a large scale process that involves high energy consumption. In order to increase the sustainability of this process, the reduction of energy input is necessary. Bio-glycerol was demonstrated to be a highly efficient renewable-based additive in the grinding process for

  15. Methylene blue adsorption from glycerol solution onto the acicular ...

    African Journals Online (AJOL)

    The mechanism of methylene blue adsorption onto the surface of synthetic acicular habit of α-goethite from glycerol solution has been studied through batch experiment at 25, 30 and 35 0C in a glass cell of minimal dead volume. To describe the adsorption results, an attempt was made to fit the data to the Langmuir, ...

  16. Synthesis of High-Molecular-Weight Multifunctional Glycerol Polyhydroxyurethanes PHUs

    Directory of Open Access Journals (Sweden)

    Bassam Nohra

    2016-09-01

    Full Text Available Glycerol carbonate acrylate is a 5-membered cyclic carbonate synthesized from glycerol that is used as a chemical coupling agent and has proven highly suitable for use in the synthesis of multifunctional polyhydroxyurethanes (PHUs. The multifunctionality of the structure of PHUs is determined by the density of the carbon-amine groups generated by the Aza-Michael reaction and that of the urethane groups and adjacent primary and secondary hydroxyl groups generated by aminolysis. Glycerol carbonate acrylate is polymerized with polyfunctional mono-, di-, tri, and tetra-amines, by type-AB polyaddition, either in bulk or in solution, through stepwise or one-pot reaction strategies in the absence of added catalysts. These approaches result in the generation of linear, interchain, and crosslinked structures, through the polyaddition of linear and branched amines to the ethylene and cyclic carbonate sites of glycerol carbonate acrylate. The resulting collection of organic molecules gives rise to polyethylene amino ester PHUs with a high molar mass, exceeding 20,000 g·mol−1, with uniform dispersity.

  17. Crude glycerol combustion: particulate, acrolein, and other volatile organic emissions

    Science.gov (United States)

    Crude glycerol is an abundant by-product of biodiesel production. As volumes of this potential waste grow, there is increasing interest in developing new value added uses. One possible use, as a boiler fuel for process heating, offers added advantages of energy integration and ...

  18. Influence of hyperosmotic agent (glycerol) in contrast enhancement

    International Nuclear Information System (INIS)

    Moriyama, Takashi; Suzuki, Shigeharu; Nakaoka, Tsutomu

    1981-01-01

    For getting a better contrast enhancement (CE) of computed tomography (CT) in brain tumors, we tried to increase the extravascular iodine concentration. A vailing ourselves of the period of returning water following intravenously administered glycerol, a drip injection of the contrast medium gave a better CE effect than the usual CE. In two benign gliomas, CE with glycerol was much better than CE without glycerol, and in two malignant gliomas and two metastatic tumors, CE with glycerol was better, but not so much better as with the benign tumors. In general, the CE effect in primary brain tumors showed a decreasing pattern, whereas in metastatic brain tumors the best time was 60 minutes after the injection of the contrast material (increasing and decreasing pattern), suggesting an increase in the extravascular iodine and a severe failure of the blood brain barrier. Two cystic malignant gliomas allowed the intravenously injected contrast medium to enter the cysts. It appears that the contrast medium passes through and/or is secreted from the wall of the cyst. (author)

  19. Toxicity of palmitoyl glycerol to mice: depression of thyroid function

    International Nuclear Information System (INIS)

    Trumbo, P.R.; Meuten, D.J.; King, M.W.; Tove, S.B.

    1987-01-01

    Mice given propylthiouracil, a thyroid inhibitor, and fed a diet containing a nontoxic level of rac-1(3)-palmitoyl glycerol showed the hypothermia and mortality expected for a toxic dose, but did not show these signs when linoleate or oleate was added to the diet. Loss of radioiodine from the whole animal and thyroid gland was slower when mice were fed the toxic palmitoyl glycerol diet than when fed the same diet containing 4% safflower oil. However, mice fed the two diets did not differ in the extent of the incorporation of radioiodine, and essentially all was bound to protein in each case. Follicular thyroid cells from mice fed the potentially toxic diet that contained unsaturated fat were normal in appearance. Conversely, cells from mice fed the toxic diet were smaller and more densely stained, showing evidence of glycoprotein inside the cell. These findings show that the thyroid gland is affected by the palmitoyl glycerol diet. However, the thyroid is not the only organ affected, because giving either thyroxine or triiodothyronine had no effect on the toxicity of palmitoyl glycerol

  20. Isolation and chemical characterization of phosphatidyl glycerol from spinach leaves

    NARCIS (Netherlands)

    Haverkate, E.; Deenen, L.L.M. van

    1965-01-01

    Pure phosphatidyl glycerol was obtained from spinach leaves after repeated chromatography on silica columns. Ascertainment of the configuration of the hydrolysis products formed by the action of phospholipases C (EC 3.1.4.3) and D (EC 3.1.4.4) demonstrated that this phospholipid is identical with

  1. EFFECT OF GLYCEROL SEPARATION ON PALM OIL TRANSESTERIFICATION

    Directory of Open Access Journals (Sweden)

    Budy Rahmat

    2012-12-01

    Full Text Available This research was aimed to study the effect of glycerol separation on palm oil transesterification. Objectives of this study were to suppress the use of excess methanol and shorten the processing time. This research consisted of: design-build reactor, the effect of the glycerol separation on the transesterification reaction, characterization of biodiesel, and mass balance analysis. The reactor was designed by integrating circulate stirrer pump, static mixer, and sprayer that will bring out the intense reaction in the outer tank reactor. The experiment in this research was the treatment of decreasing the quantity of methanol to 5:1 molar ratio and reducing of processing time to 20 min, which was arranged in a completely randomized factorial design. The result showed that, (i the stirring system was effectively worked outside the reactor tank, and in its reactor tank occurred glycerol separation during the process; (ii the rate of glycerol during the process followed the inverse regression equation of Ŷ = 66.44-351.17 X-1; (iii the decrease in the level of methanol to 5:1 molar ratio and the reduction of processing time to 20 min in this engineering did not influence the biodiesel yield and quality that met the SNI 04-7182-2006 standard.

  2. [Long-term storage of obligate anaerobic microorganisms in glycerol].

    Science.gov (United States)

    Briukhanov, A I; Netrusov, A I

    2006-01-01

    We evaluated the possibility of storing the cultures of obligate anaerobic microorganisms (clostridia. acetogenic and sulfate-reducing bacteria, and methanogenic archaea) in 25% glycerol at -70 degrees C for a long time (up to 3 years). This method of storage is adequate to preserve cell viability in most obligate anaerobes.

  3. Liquid phase conversion of Glycerol to Propanediol over highly ...

    Indian Academy of Sciences (India)

    characterization results showed that the copper metal was well-dispersed over MgO support and a new phase. Cu-MgO was ... Currently propanediols are produced from petroleum derivatives .... of MgO.15 Barret-Joyner-Halenda (BJH) method is applied to ..... number of available Cu sites with respect to glycerol as. 0.8. 1.0.

  4. Enhanced hydrogen and 1,3-propanediol production from glycerol by fermentation using mixed cultures

    KAUST Repository

    Selembo, Priscilla A.; Perez, Joe M.; Lloyd, Wallis A.; Logan, Bruce E.

    2009-01-01

    The conversion of glycerol into high value products, such as hydrogen gas and 1,3-propanediol (PD), was examined using anaerobic fermentation with heat-treated mixed cultures. Glycerol fermentation produced 0.28 mol-H 2/mol-glycerol (72 mL-H2/g

  5. Glycerol reforming and methanol synthesis for the production of renewable methanol

    NARCIS (Netherlands)

    van Bennekom, Joost Gerardus

    2013-01-01

    De productie van biodiesel is flink toegenomen in het eerste decennium van de 21ste eeuw. Bij de productie van 100 kg biodiesel komt ongeveer 10 kg aan glycerol vrij, wat heeft geleid tot een sterk gestegen glycerol aanbod. Een mogelijkheid om wat met de glycerol te doen, is het omzetten van

  6. Efficient utilization of crude glycerol as fermentation substrate in the synthesis of poly(3-hydroxybutyrate) biopolymers

    Science.gov (United States)

    One refined and 2 crude glycerol samples were utilized to produce poly(3-hydroxybutyrate) (PHB) by Pseudomonas oleovorans NRRL B-14682. Fermentation conditions were determined to efficiently utilize glycerol while maintaining PHB yields. A batch culture protocol including 1% glycerol and an aerati...

  7. Effects of feeding dry glycerol to primiparous Holstein dairy cows on follicular development, reproductive performance and metabolic parameters related to fertility during the early post-partum period.

    Science.gov (United States)

    Karami-Shabankareh, H; Kafilzadeh, F; Piri, V; Mohammadi, H

    2013-12-01

    This study examined the effects of dry glycerol supplementation on follicular growth, post-partum interval to first ovulation, concentration of serum metabolites and hormones related to fertility, body condition score (BCS) and body weight (BW) in primiparous Holstein dairy cows. Sixty primiparous Holstein dairy cows were randomly assigned to two groups (control: n = 30 and glycerol supplemented: n = 30). Dry glycerol (250 g/day/cow) was fed as a top dressing to the common lactating total mixed ration (TMR) from parturition to 21 days post-partum. Ovaries were examined four times using ultrasonography on days 13, 19, 25 and 36 post-partum to determine ovarian follicular growth. Concentration of serum metabolites and hormones was determined weekly. Body condition score was evaluated weekly from weeks 1 to 5 after parturition, and BWs were recorded three times on days 1, 11 and 21 during the experimental period. The cows fed dry glycerol had more large follicles (p cows. Days to the first ovulation (p = 0.06), days to first oestrus (p = 0.05), services per conception (p = 0.06) and days open (p = 0.004) were positively affected by dry glycerol supplementation. Serum concentration of glucose and insulin was higher in dry glycerol-supplemented cows (p = 0.1; p = 0.06, respectively). Feeding glycerol had no effect on mean serum concentrations of β-hydroxybutyrate, non-esterified fatty acids and IGF-1 during the experimental period. However, significant differences were observed at concentration of BHBA and IGF-1 (p = 0.02 and p = 0.04, respectively) between two groups on day 21 after calving. The cows in the glycerol-fed group had higher serum progesterone concentrations on days 33 (p = 0.007) and 36 (p = 0.004) after calving. Supplemented cows had lower body condition loss during weeks 1-5 after calving compared with the control cows (0.34 vs 0.41 BCS). In week 13 post-partum, the proportion of cycling cows was 83.3 and 69.9% for those which

  8. Crystallization and transformation of polymorphic forms of trioleoyl glycerol and 1,2-dioleoyl-3-rac-linoleoyl glycerol.

    Science.gov (United States)

    Bayés-García, Laura; Calvet, Teresa; Cuevas-Diarte, Miquel Àngel; Ueno, Satoru; Sato, Kiyotaka

    2013-08-08

    This study examined the influence of different thermal treatments on the crystallization and transformation of trioleoyl glycerol (OOO) and 1,2-dioleoyl-3-rac-linoleoyl glycerol (OOL). Two triacylglycerol (TAG) samples were cooled at 0.5-15 °C·min(-1) and heated at 2 and 15 °C·min(-1). The polymorphic characteristics of the two TAGs were analyzed in situ using differential scanning calorimetry, Raman spectroscopy, and synchrotron radiation X-ray diffraction. Multiple polymorphic forms were identified in OOO (α, β'2, β'1, β2, and β1) and OOL (α, β'2, and β'1). Larger quantities of more stable forms (e.g., β2 and β1 of OOO and β'1 of OOL) were obtained when the samples were slowly cooled and heated. In contrast, less stable polymorphs were obtained with increased cooling and heating rates. Polymorphic transformations occurred in either solid-state or melt-mediation and were influenced by heating rates. The results were analyzed by considering the activation energies for crystallization and transformation of stable and less stable polymorphic forms in comparison with previous studies on 1,3-dipalmitoyl-2-oleoyl-glycerol and 1, 3-dioleoyl-2-palmitoyl-glycerol.

  9. A high glycerol-containing leave-on scalp care treatment to improve dandruff.

    Science.gov (United States)

    Harding, Clive R; Matheson, Jane R; Hoptroff, Michael; Jones, David A; Luo, Yanjun; Baines, Fiona L; Luo, Shengjun

    2014-01-01

    Dandruff is a common cosmetic condition associated with flaky scalp skin and pruritus. It is generally treated with regular use of antifungal-based shampoos. Research into factors underlying the characteristic skin lesions has revealed perturbations in epidermal differentiation and a dramatic deterioration in the associated process of stratum corneum (SC) maturation. These observations suggest that directly addressing the quality of the SC could have a scalp benefit. In this study, the authors investigated the efficacy of a moisturising leave-on lotion (LOL) containing a high concentration of glycerol (10%) and other known skin benefit agents (saturated fatty acid and sunflower seed oil) to reduce dandruff over an 8-week treatment period with 3 applications per week. Results of expert visual grading and biophysical measurements of SC parameters (transepidermal water loss and hydration) revealed a significant reduction in the dandruffcondition over this period, with significant improvement in both SC water barrier function and hydration. These scalp skin benefits were maintained for up to a week following cessation of the treatment. This study indicates that use of a glycerol-rich substantive LOL, designed to directly improve the quality of the SC barrier can have a significant impact on the dandruff condition.

  10. Poly(glycerol adipate) - indomethacin drug conjugates - synthesis and in vitro characterization.

    Science.gov (United States)

    Wersig, T; Hacker, M C; Kressler, J; Mäder, K

    2017-10-05

    The linear biodegradable polyester poly(glycerol adipate) (PGA) was synthesized via enzymatic polycondensation using lipase B from Candida antarctica (CAL-B). Every monomer unit of PGA possesses a pendant hydroxyl group which is responsible for the hydrophilic character and moisture swelling. These OH groups were esterified to different degrees with the anti-inflammatory drug indomethacin in order to create a prodrug with a pH-sensitive linker for modified drug release. The structure of the conjugates was determined via ATR FT-IR spectroscopy, NMR spectroscopy, GPC and UV/VIS spectroscopy. The physical properties of polymers with different drug load were investigated using DSC, contact angle measurements and oscillatory rheology. Drug release was monitored over one month in vitro. A very slow, but continuous release was observed in PBS. Slightly acidic conditions and lipase activity are accelerating the indomethacin release. Therefore, poly(glycerol adipate) - indomethacin conjugates are promising prodrugs for the local sustained release of indomethacin. Copyright © 2017 Elsevier B.V. All rights reserved.

  11. Enzymatic primer-extension with glycerol-nucleoside triphosphates on DNA templates.

    Directory of Open Access Journals (Sweden)

    Jesse J Chen

    Full Text Available BACKGROUND: Glycerol nucleic acid (GNA has an acyclic phosphoglycerol backbone repeat-unit, but forms stable duplexes based on Watson-Crick base-pairing. Because of its structural simplicity, GNA is of particular interest with respect to the possibility of evolving functional polymers by in vitro selection. Template-dependent GNA synthesis is essential to any GNA-based selection system. PRINCIPAL FINDINGS: In this study, we investigated the ability of various DNA polymerases to use glycerol-nucleoside triphosphates (gNTPs as substrates for GNA synthesis on DNA templates. Therminator DNA polymerase catalyzes quantitative primer-extension by the incorporation of two glyceronucleotides, with much less efficient extension up to five glyceronucleotides. Steady-state kinetic experiments suggested that GNA synthesis by Therminator was affected by both decreased catalytic rates and weakened substrate binding, especially for pyrimidines. In an attempt to improve pyrimidine incorporation by providing additional stacking interactions, we synthesized two new gNTP analogs with 5-propynyl substituted pyrimidine nucleobases. This led to more efficient incorporation of gC, but not gT. CONCLUSIONS: We suggest that directed evolution of Therminator might lead to mutants with improved substrate binding and catalytic efficiency.

  12. Purification and characterization of a polyisoprenyl phosphate phosphatase from pig brain. Possible dual specificity.

    Science.gov (United States)

    Frank, D W; Waechter, C J

    1998-05-08

    Microsomal fractions from pig and calf brain catalyze the enzymatic dephosphorylation of endogenous and exogenous dolichyl monophosphate (Dol-P) (Sumbilla, C. A., and Waechter, C. J. (1985) Methods Enzymol. 111, 471-482). The Dol-P phosphatase (EC 3.1.3.51) has been solubilized by extracting pig brain microsomes with the nonionic detergent Nonidet P-40 and purified approximately 1,107-fold by a combination of anion exchange chromatography, polyethylene glycol fractionation, dye-ligand chromatography, and wheat germ agglutinin affinity chromatography. Treatment of the enzyme with neuraminidase prevented binding to wheat germ agglutinin-Sepharose, indicating the presence of one or more N-acetylneuraminyl residues per molecule of enzyme. When the highly purified polyisoprenyl phosphate phosphatase was analyzed by SDS-polyacrylamide gel electrophoresis, a major 33-kDa polypeptide was observed. Enzymatic dephosphorylation of Dol-P by the purified phosphatase was 1) optimal at pH 7; 2) potently inhibited by F-, orthovanadate, and Zn2+ > Co2+ > Mn2+ but unaffected by Mg2+; 3) exhibited an approximate Km for C95-Dol-P of 45 microM; and 4) was sensitive to N-ethylmaleimide, phenylglyoxal, and diethylpyrocarbonate. The pig brain phosphatase did not dephosphorylate glucose 6-phosphate, mannose 6-phosphate, 5'-AMP, or p-nitrophenylphosphate, but it dephosphorylated dioleoyl-phosphatidic acid at initial rates similar to those determined for Dol-P. Based on the virtually identical sensitivity of Dol-P and phosphatidic acid dephosphorylation by the highly purified enzyme to N-ethylmaleimide, F-, phenylglyoxal, and diethylpyrocarbonate, both substrates appear to be hydrolyzed by a single enzyme with an apparent dual specificity. This is the first report of the purification of a neutral Dol-P phosphatase from mammalian tissues. Although the enzyme is Mg2+-independent and capable of dephosphorylating Dol-P and PA, several enzymological properties distinguish this lipid

  13. The role of glycerol-3-phosphate dehydrogenase 1 in the progression of fatty liver after acute ethanol administration in mice

    International Nuclear Information System (INIS)

    Sato, Tomoki; Morita, Akihito; Mori, Nobuko; Miura, Shinji

    2014-01-01

    Highlights: • Ethanol administration increased GPD1 mRNA expression. • Ethanol administration increased glucose incorporation into TG glycerol moieties. • No increase in hepatic TG levels was observed in ethanol-injected GPD1 null mice. • We propose that GPD1 is required for ethanol-induced TG accumulation in the liver. - Abstract: Acute ethanol consumption leads to the accumulation of triglycerides (TGs) in hepatocytes. The increase in lipogenesis and reduction of fatty acid oxidation are implicated as the mechanisms underlying ethanol-induced hepatic TG accumulation. Although glycerol-3-phosphate (Gro3P), formed by glycerol kinase (GYK) or glycerol-3-phosphate dehydrogenase 1 (GPD1), is also required for TG synthesis, the roles of GYK and GPD1 have been the subject of some debate. In this study, we examine (1) the expression of genes involved in Gro3P production in the liver of C57BL/6J mice in the context of hepatic TG accumulation after acute ethanol intake, and (2) the role of GPD1 in the progression of ethanol-induced fatty liver using GPD1 null mice. As a result, in C57BL/6J mice, ethanol-induced hepatic TG accumulation began within 2 h and was 1.7-fold greater than that observed in the control group after 6 h. The up-regulation of GPD1 began 2 h after administering ethanol, and significantly increased 6 h later with the concomitant escalation in the glycolytic gene expression. The incorporation of 14 C-labelled glucose into TG glycerol moieties increased during the same period. On the other hand, in GPD1 null mice carrying normal GYK activity, no significant increase in hepatic TG level was observed after acute ethanol intake. In conclusion, GPD1 and glycolytic gene expression is up-regulated by ethanol, and GPD1-mediated incorporation of glucose into TG glycerol moieties together with increased lipogenesis, is suggested to play an important role in ethanol-induced hepatic TG accumulation

  14. The role of glycerol-3-phosphate dehydrogenase 1 in the progression of fatty liver after acute ethanol administration in mice

    Energy Technology Data Exchange (ETDEWEB)

    Sato, Tomoki, E-mail: s13220@u-shizuoka-ken.ac.jp [Laboratory of Nutritional Biochemistry, Graduate School of Nutritional and Environmental Sciences, University of Shizuoka, 52-1 Yada, Suruga-ku, Shizuoka 422-8526 (Japan); Morita, Akihito, E-mail: moritaa@u-shizuoka-ken.ac.jp [Laboratory of Nutritional Biochemistry, Graduate School of Nutritional and Environmental Sciences, University of Shizuoka, 52-1 Yada, Suruga-ku, Shizuoka 422-8526 (Japan); Mori, Nobuko, E-mail: morin@b.s.osakafu-u.ac.jp [Department of Biological Science, Graduate School of Science, Osaka Prefecture University, 1-2 Gakuen-cho, Naka-ku, Sakai 599-8570 (Japan); Miura, Shinji, E-mail: miura@u-shizuoka-ken.ac.jp [Laboratory of Nutritional Biochemistry, Graduate School of Nutritional and Environmental Sciences, University of Shizuoka, 52-1 Yada, Suruga-ku, Shizuoka 422-8526 (Japan)

    2014-02-21

    Highlights: • Ethanol administration increased GPD1 mRNA expression. • Ethanol administration increased glucose incorporation into TG glycerol moieties. • No increase in hepatic TG levels was observed in ethanol-injected GPD1 null mice. • We propose that GPD1 is required for ethanol-induced TG accumulation in the liver. - Abstract: Acute ethanol consumption leads to the accumulation of triglycerides (TGs) in hepatocytes. The increase in lipogenesis and reduction of fatty acid oxidation are implicated as the mechanisms underlying ethanol-induced hepatic TG accumulation. Although glycerol-3-phosphate (Gro3P), formed by glycerol kinase (GYK) or glycerol-3-phosphate dehydrogenase 1 (GPD1), is also required for TG synthesis, the roles of GYK and GPD1 have been the subject of some debate. In this study, we examine (1) the expression of genes involved in Gro3P production in the liver of C57BL/6J mice in the context of hepatic TG accumulation after acute ethanol intake, and (2) the role of GPD1 in the progression of ethanol-induced fatty liver using GPD1 null mice. As a result, in C57BL/6J mice, ethanol-induced hepatic TG accumulation began within 2 h and was 1.7-fold greater than that observed in the control group after 6 h. The up-regulation of GPD1 began 2 h after administering ethanol, and significantly increased 6 h later with the concomitant escalation in the glycolytic gene expression. The incorporation of {sup 14}C-labelled glucose into TG glycerol moieties increased during the same period. On the other hand, in GPD1 null mice carrying normal GYK activity, no significant increase in hepatic TG level was observed after acute ethanol intake. In conclusion, GPD1 and glycolytic gene expression is up-regulated by ethanol, and GPD1-mediated incorporation of glucose into TG glycerol moieties together with increased lipogenesis, is suggested to play an important role in ethanol-induced hepatic TG accumulation.

  15. Covalent immobilization of lipase, glycerol kinase, glycerol-3-phosphate oxidase & horseradish peroxidase onto plasticized polyvinyl chloride (PVC strip & its application in serum triglyceride determination

    Directory of Open Access Journals (Sweden)

    Nidhi Chauhan

    2014-01-01

    Full Text Available Background & objectives:Reusable biostrip consisting enzymes immobilized onto alkylamine glass beads affixed on plasticized PVC strip for determination of triglyceride (TG suffers from high cost of beads and their detachments during washings for reuse, leading to loss of activity. The purpose of this study was to develop a cheaper and stable biostrip for investigation of TG levels in serum. Methods: A reusable enzyme-strip was prepared for TG determination by co-immobilizing lipase, glycerol kinase (GK, glycerol-3-phosphate oxidase (GPO and peroxidase (HRP directly onto plasticized polyvinyl chloride (PVC strip through glutaraldehyde coupling. The method was evaluated by studying its recovery, precision and reusability. Results: The enzyme-strip showed optimum activity at pH 7.0, 35 o C and a linear relationship between its activity and triolein concentration in the range 0.1 to 15 mM. The strip was used for determination of serum TG. The detection limit of the method was 0.1 mM. Analytical recovery of added triolein was 96 per cent. Within and between batch coefficients of variation (CV were 2.2 and 3.7 per cent, respectively. A good correlation (r=0.99 was found between TG values by standard enzymic colrimetric method employing free enzymes and the present method. The strip lost 50 per cent of its initial activity after its 200 uses during the span of 100 days, when stored at 4 o C. Interpretation & conclusions: The nitrating acidic treatment of plasticized PVC strip led to glutaraldehyde coupling of four enzymes used for enzymic colourimetric determination of serum TG. The strip provided 200 reuses of enzymes with only 50 per cent loss of its initial activity. The method could be used for preparation of other enzyme strips also.

  16. Crystal structure of the cytoplasmic phosphatase and tensin homolog (PTEN)-like region of Ciona intestinalis voltage-sensing phosphatase provides insight into substrate specificity and redox regulation of the phosphoinositide phosphatase activity.

    Science.gov (United States)

    Matsuda, Makoto; Takeshita, Kohei; Kurokawa, Tatsuki; Sakata, Souhei; Suzuki, Mamoru; Yamashita, Eiki; Okamura, Yasushi; Nakagawa, Atsushi

    2011-07-01

    Ciona intestinalis voltage-sensing phosphatase (Ci-VSP) has a transmembrane voltage sensor domain and a cytoplasmic region sharing similarity to the phosphatase and tensin homolog (PTEN). It dephosphorylates phosphatidylinositol 4,5-bisphosphate and phosphatidylinositol 3,4,5-trisphosphate upon membrane depolarization. The cytoplasmic region is composed of a phosphatase domain and a putative membrane interaction domain, C2. Here we determined the crystal structures of the Ci-VSP cytoplasmic region in three distinct constructs, wild-type (248-576), wild-type (236-576), and G365A mutant (248-576). The crystal structure of WT-236 and G365A-248 had the disulfide bond between the catalytic residue Cys-363 and the adjacent residue Cys-310. On the other hand, the disulfide bond was not present in the crystal structure of WT-248. These suggest the possibility that Ci-VSP is regulated by reactive oxygen species as found in PTEN. These structures also revealed that the conformation of the TI loop in the active site of the Ci-VSP cytoplasmic region was distinct from the corresponding region of PTEN; Ci-VSP has glutamic acid (Glu-411) in the TI loop, orienting toward the center of active site pocket. Mutation of Glu-411 led to acquirement of increased activity toward phosphatidylinositol 3,5-bisphosphate, suggesting that this site is required for determining substrate specificity. Our results provide the basic information of the enzymatic mechanism of Ci-VSP.

  17. Cloning and characterization of R-PTP-kappa, a new member of the receptor protein tyrosine phosphatase family with a proteolytically cleaved cellular adhesion molecule-like extracellular region

    DEFF Research Database (Denmark)

    Jiang, Y P; Wang, H; D'Eustachio, P

    1993-01-01

    We describe a new member of the receptor protein tyrosine phosphatase family, R-PTP-kappa, cDNA cloning predicts that R-PTP-kappa is synthesized from a precursor protein of 1,457 amino acids. Its intracellular domain displays the classical tandemly repeated protein tyrosine phosphatase homology, ...

  18. Glycerol as source of energy in broiler chicken fattening

    Directory of Open Access Journals (Sweden)

    Leo Kroupa

    2011-01-01

    Full Text Available The objective of this study was to verify the possibility of replacing soybean oil in a diet with glycerol, and investigate the effect of glycerol on performance indicators and health in broiler chickens. The experiment was performed on 122 one-day-old chickens that were divided based on sex into two control groups (30 females and 31 males and two experimental groups (30 females and 31 males. Half (50% of the soybean oil in diets used in the experimental groups was replaced with glycerol at a ratio of 1:2. On 15, 32 and 38 day of age chickens of both sexes in the experimental group that were fed with diets containing glycerol showed significantly higher (p ≤ 0.01 mean body weight compared to the control group. At the end of the experiment, the mean weight of chickens in the control group was 2.078 kg, whereas the mean weight of chickens in the experimental group was 2.341 kg. In females, the overall consumption of diets within 38 days of fattening was 3.588 kg in the control group and 4.011 kg in the experimental group, in males, it was 3.915 kg in the control group and 4.366 kg in the experimental group, i.e. it was higher in experimental chickens. Feed conversion in chickens in experimental groups was better, being 1.84 kg in the control group and 1.81 kg in the experimental group in females, and 1.73 kg in the control group and 1.72 kg in the experimental group in males. It follows from our results that the optimum amount of glycerol in feed for poultry is 5%.This study presents an original solution to optimize feed formula by replacing plant oil with glycerol. The results of the study can improve production indicators and economy in broiler fattening.

  19. Persistently increased intestinal fraction of alkaline phosphatase

    DEFF Research Database (Denmark)

    Nathan, E; Baatrup, G; Berg, H

    1984-01-01

    Persistent elevation of the intestinal fraction of the alkaline phosphatase (API) as an isolated finding has to our knowledge not been reported previously. It was found in a boy followed during a period of 5.5 years. The only symptom was transient periodic fatigue observed at home, but not apparent...... during hospitalization. His blood type was O, RH+, Le (a-, b+) and he was a secretor of H-substance, which may be associated with rising API activity after fat-loading. In this case API was unchanged after fat-loading. Neither intestinal nor liver diseases were found, and no other cause for the elevated...

  20. Inhibition of AcpA phosphatase activity with ascorbate attenuates Francisella tularensis intramacrophage survival.

    Science.gov (United States)

    McRae, Steven; Pagliai, Fernando A; Mohapatra, Nrusingh P; Gener, Alejandro; Mahmou, Asma Sayed Abdelgeliel; Gunn, John S; Lorca, Graciela L; Gonzalez, Claudio F

    2010-02-19

    Acid phosphatase activity in the highly infectious intracellular pathogen Francisella tularensis is directly related with the ability of these bacteria to survive inside host cells. Pharmacological inactivation of acid phosphatases could potentially help in the treatment of tularemia or even be utilized to neutralize the infection. In the present work, we report inhibitory compounds for three of the four major acid phosphatases produced by F. tularensis SCHU4: AcpA, AcpB, and AcpC. The inhibitors were identified using a catalytic screen from a library of chemicals approved for use in humans. The best results were obtained against AcpA. The two compounds identified, ascorbate (K(i) = 380 +/- 160 microM) and 2-phosphoascorbate (K(i) = 3.2 +/- 0.85 microM) inhibit AcpA in a noncompetitive, nonreversible fashion. A potential ascorbylation site in the proximity of the catalytic pocket of AcpA was identified using site-directed mutagenesis. The effects of the inhibitors identified in vitro were evaluated using bioassays determining the ability of F. tularensis to survive inside infected cells. The presence of ascorbate or 2-phosphoascorbate impaired the intramacrophage survival of F. tularensis in an AcpA-dependent manner as it was probed using knockout strains. The evidence presented herein indicated that ascorbate could be a good alternative to be used clinically to improve treatments against tularemia.

  1. Glycerol-3-phosphate metabolism in wheat contributes to systemic acquired resistance against Puccinia striiformis f. sp. tritici.

    Directory of Open Access Journals (Sweden)

    Yuheng Yang

    Full Text Available Glycerol-3-phosphate (G3P is a proposed regulator of plant defense signaling in basal resistance and systemic acquired resistance (SAR. The GLY1-encoded glycerol-3-phosphate dehydrogenase (G3PDH and GLI1-encoded glycerol kinase (GK are two key enzymes involved in the G3P biosynthesis in plants. However, their physiological importance in wheat defense against pathogens remains unclear. In this study, quantification analysis revealed that G3P levels were significantly induced in wheat leaves challenged by the avirulent Puccinia striiformis f. sp. tritici (Pst race CYR23. The transcriptional levels of TaGLY1 and TaGLI1 were likewise significantly induced by avirulent Pst infection. Furthermore, knocking down TaGLY1 and TaGLI1 individually or simultaneously with barley stripe mosaic virus-induced gene silencing (BSMV-VIGS inhibited G3P accumulation and compromised the resistance in the wheat cultivar Suwon 11, whereas the accumulation of salicylic acid (SA and the expression of the SA-induced marker gene TaPR1 in plant leaves were altered significantly after gene silencing. These results suggested that G3P contributes to wheat systemic acquired resistance (SAR against stripe rust, and provided evidence that the G3P function as a signaling molecule is conserved in dicots and monocots. Meanwhile, the simultaneous co-silencing of multiple genes by the VIGS system proved to be a powerful tool for multi-gene functional analysis in plants.

  2. Extraction, partial characterization and susceptibility to Hg2+ of acid phosphatase from the microalgae Pseudokirchneriella subcapitata Extração, caracterização parcial e susceptibilidade ao Hg2+ da fosfatase ácida da microalga Pseudokirchneriella subcapitata

    Directory of Open Access Journals (Sweden)

    Claudio Martín Jonsson

    2009-10-01

    Full Text Available Pseudokirchneriella subcapitata is a unicellular green algae widely distributed in freshwater and soils. Due to its cosmopolitan characteristic, its use is recommended by national and international protocols in ecotoxicity studies. The alteration of phosphatase activities by agriculture pollutants like heavy metals has been extensively used as a biomarker in risk assessment and biomonitoring. In this study, we compared the extraction of acid phosphatase from P. subcapitata by different procedures and we studied the stability, substrates specificity, kinetics and the effect of Hg2+ in the crude extract. The freezing and thawing technique associated with probe sonication was the most suitable method of extraction. The enzyme was stable when frozen at -20ºC for at least six months, showed an optimum pH of 5 and a Km value of 0.27 mM for p-nitrophenylphosphate (pNPP as substrate. Some natural organic substrates were cleaved by a similar extent as the synthetic substrate pNPP. Short term exposure (24 hours to Hg2+ had little effect but inhibition of the specific activity was observed after 7 days with EC50 (concentration of Hg2+ that promotes 50% decrease of specific activity value of 12.63 μM Hg2+.Pseudokirchneriella subcapitata é uma alga verde unicelular amplamente distribuída em corpos d´agua e solos. Devido a sua natureza cosmopolita, seu uso é recomendado por protocolos nacionais e internacionais na realização de estudos de ecotoxicidade. A alteração da atividade de fosfatases por agentes poluentes de origem agrícola, como metais pesados, tem sido largamente usada como um biomarcador na avaliação de risco e biomonitoramento. No presente trabalho foi comparada a extração da fosfatase ácida de P. subcapitata por diferentes métodos e estudada a sua estabilidade, especificidade por substratos, cinética e efeito do Hg2+ no extrato bruto. O congelamento e descongelamento, associado com ultrassom, foi o método que proporcionou maior

  3. Extracellular release of acid phosphatase from blood stream forms ...

    African Journals Online (AJOL)

    Phase separation of the extracts using the detergent Triton X-114 (TX-114), resulted in protein partitioning into aqueous and detergent phases. ACP activity was higher in the detergent phases (56.2 μmol/min and 28.8 μmol/min) of WPE and ESE respectively. ACP activity recorded in the aqueous phases of WPE and EPE ...

  4. Bovine oocytes and early embryos express mRNA encoding glycerol kinase but addition of glycerol to the culture media interferes with oocyte maturation.

    Science.gov (United States)

    Okawara, Sumika; Hamano, Seizo; Tetsuka, Masafumi

    2009-04-01

    Glycerol plays multi-functional roles in cellular physiology. Other than forming the backbone molecule for glycerophospholipid and triglyceride (TG), glycerol acts as an energy substrate for glycolysis. Spermatozoa are known to utilize glycerol for energy production, but there are no reports of this in oocytes. In this study, the value of glycerol as an energy substrate for bovine oocyte maturation (Exp. 1) and the gene expression of glycerol kinase (GK), an enzyme crucial for cellular glycerol utilization, in bovine oocytes and early embryos (Exp. 2) were examined. In Exp. 1, in vitro maturation (IVM) was conducted using synthetic oviduct fluid supplemented with/without glucose (1.5 mM) and/or glycerol (1.0 mM), and maturation rate, degree of cumulus expansion, glucose consumption and lactate production by cumulus-oocyte complexes (COC) were examined. In Exp. 2, to examine the developmental expression of GK mRNA, cumulus cells, oocytes and embryos at the 2-, 8- and 16-cell, morula, expanded blastocyst and hatched blastocyst stages were obtained in separate experiments, and the expression of GK mRNA was quantified using a real-time PCR. Glycerol did not support oocyte maturation or cumulus expansion. Addition of glycerol to glucose-supplemented media significantly decreased the maturation rate. Expression of GK mRNA was very low in cumulus cells, whereas an appreciable level of the transcript was observed in the oocytes. GK mRNA was detected in embryos at all the stages examined, and its expression significantly increased at the morula stage. These results indicate that glycerol, at least at the present concentration, is not beneficial as a constituent of the medium for bovine oocyte maturation. However, the appreciable levels of GK mRNA found in the oocyte and embryo imply a physiological role for glycerol in bovine oocyte maturation and embryo development.

  5. Modified silica-based heterogeneous catalysts for etherification of glycerol

    Energy Technology Data Exchange (ETDEWEB)

    Gholami, Zahra, E-mail: zahra.gholami@petronas.com.my [Centralized Analytical Laboratory, Universiti Teknologi PETRONAS, Bandar Seri Iskandar, 31750 Tronoh, Perak (Malaysia); Abdullah, Ahmad Zuhairi, E-mail: chzuhairi@usm.my; Gholami, Fatemeh, E-mail: fgholami59@gmail.com [School of Chemical Engineering, Universiti Sains Malaysia, Engineering Campus,14300 Nibong Tebal, Penang (Malaysia); Vakili, Mohammadtaghi, E-mail: farshid3601@gmail.com [School of Industrial Technology, Universiti Sains Malaysia, 11800 Penang (Malaysia)

    2015-07-22

    The advent of mesoporous silicas such as MCM-41 has provided new opportunities for research into supported metal catalysis. The loading of metals into framework structures and particularly into the pores of porous molecular sieves, has long been of interest because of their potential catalytic activity. Stable heterogeneous mesoporous basic catalysts were synthesized by wet impregnation of MCM-41 with calcium nitrate and lanthanum nitrate. The surface and structural properties of the prepared catalysts were characterized using BET surface analysis, SEM and TEM. MCM-41 and modified MCM-41 were used in the solventless etherification of glycerol to produce diglycerol as the desired product. The reaction was performed at 250 °C for 8 h, and catalyst activity was evaluated. Catalytic etherification over the 20%Ca{sub 1.6}La{sub 0.6}/MCM-41 catalyst resulted in the highest glycerol conversion of 91% and diglycerol yield of 43%.

  6. Gut Microbial Glycerol Metabolism as an Endogenous Acrolein Source

    Directory of Open Access Journals (Sweden)

    Jianbo Zhang

    2018-01-01

    Full Text Available Acrolein is a highly reactive electrophile causing toxic effects, such as DNA and protein adduction, oxidative stress, endoplasmic reticulum stress, immune dysfunction, and membrane damage. This Opinion/Hypothesis provides an overview of endogenous and exogenous acrolein sources, acrolein’s mode of action, and its metabolic fate. Recent reports underpin the finding that gut microbial glycerol metabolism leading to the formation of reuterin is an additional source of endogenous acrolein. Reuterin is an antimicrobial multicomponent system consisting of 3-hydroxypropionaldehyde, its dimer and hydrate, and also acrolein. The major conclusion is that gut microbes can metabolize glycerol to reuterin and that this transformation occurs in vivo. Given the known toxicity of acrolein, the observation that acrolein is formed in the gut necessitates further investigations on functional relevance for gut microbiota and the host.

  7. Sodahvede og glycerol til malkekøer

    DEFF Research Database (Denmark)

    Hvelplund, Torben; Weisbjerg, Martin Riis

    2011-01-01

    Et fodringsforsøg på Kvægbrugets Forsøgscenter har vist, at glycerol kan anvendes som et alternativt fodermiddel til højtydende malkekøer. De anvendte mængder gav dog en lavere EKM ydelse end sodahvede, men øgede samtidigt mælkens proteinindhold.......Et fodringsforsøg på Kvægbrugets Forsøgscenter har vist, at glycerol kan anvendes som et alternativt fodermiddel til højtydende malkekøer. De anvendte mængder gav dog en lavere EKM ydelse end sodahvede, men øgede samtidigt mælkens proteinindhold....

  8. Glycerol and microwave preservation of annual statice (Limonium sinuatum Mill.)

    International Nuclear Information System (INIS)

    Paparozzi, E.T.; McCallister, D.E.

    1988-01-01

    Stems of annual statice (Limonium sinuatum Mill.) were harvested from the field in 1982 and soaked in varying concentrations of glycerol: water solutions for 24 and 48 h and then microwaved for 0, 1, 3 or 5 min. Half of the branch stems were measured for flexibility, with the remainder being assessed 1 year later. Stems harvested in 1983 were wet- and dry-stored at 3°C for varying lengths of time and then preserved. Preservation was best when statice was preserved immediately. Cold storage decreased preserved statice flexibility, but was better than air-drying. Fresh cut statice stems, up to 34 cm long, should be preserved by soaking in a 1:2 or 1:3 glycerol: water solution for 48 h followed by microwaving for 1 min at medium-high (34°C)

  9. Modified silica-based heterogeneous catalysts for etherification of glycerol

    International Nuclear Information System (INIS)

    Gholami, Zahra; Abdullah, Ahmad Zuhairi; Gholami, Fatemeh; Vakili, Mohammadtaghi

    2015-01-01

    The advent of mesoporous silicas such as MCM-41 has provided new opportunities for research into supported metal catalysis. The loading of metals into framework structures and particularly into the pores of porous molecular sieves, has long been of interest because of their potential catalytic activity. Stable heterogeneous mesoporous basic catalysts were synthesized by wet impregnation of MCM-41 with calcium nitrate and lanthanum nitrate. The surface and structural properties of the prepared catalysts were characterized using BET surface analysis, SEM and TEM. MCM-41 and modified MCM-41 were used in the solventless etherification of glycerol to produce diglycerol as the desired product. The reaction was performed at 250 °C for 8 h, and catalyst activity was evaluated. Catalytic etherification over the 20%Ca 1.6 La 0.6 /MCM-41 catalyst resulted in the highest glycerol conversion of 91% and diglycerol yield of 43%

  10. Antibacterial effect of glycerol as preservative on donor skin

    International Nuclear Information System (INIS)

    Van Baare, J.; Ligtvoet, E.E.J.; Middelkoop, E.

    1999-01-01

    Glycerolised cadavetic allografts have been used widely since 1984 in the treatment of bum wounds. Rejections reaction to glycerolised skin were reported to be attenuated. Structural integrity of the skin was maintained and antiviral and antibacterial effects were noted. The Euro Skin Bank has gathered approximately 2000 data since 1987 concerning bacteriology cultures of glycerolised skin. These data are presented. Bacteriological data from skin donors were examined from 1987 till 1995 (1927 data). Donor skin sent to the laboratory and found to be positive for bacteria was quarantined and another container with skin samples was sent to the laboratory at a later time point. This was repeated until all cultures were negative. In 1987, 25 donors were processed without using antibiotics. These results were compared with donor skin treated with antibiotics. The average day for first culture was 19.7 ? 17.2. The average percentage of contaminated skin was 10.1? 3.7%. Antibiotics reduced contamination of glycerolised skin from 80% to 10.1%. Glycerol treatment also showed an antibacterial effect as all contaminated skin eventually became negative. Of the contaminated skin Staphylococcus epidermidis was found most frequently: in 70.7 ? 10.8% of the cases. Not all bacteria are equally sensitive to glycerol: Staphylococcus epidennidis contaminated skin became sterile after 48?24 days, whereas for Bacillus species it took 195? 1 37.9 days. We show that glycerol preservation of donor skin has important advantages over conservative methods such as cryopreservation. Initial contamination of the skin is no longer a reason to discard the material. Prolonged storage in glycerol will eliminate bacterial contamination. This allows an increase in yield of at least 10%

  11. Gut Microbial Glycerol Metabolism as an Endogenous Acrolein Source

    OpenAIRE

    Zhang, Jianbo; Sturla, Shana; Lacroix, Christophe; Schwab, Clarissa

    2018-01-01

    ABSTRACT Acrolein is a highly reactive electrophile causing toxic effects, such as DNA and protein adduction, oxidative stress, endoplasmic reticulum stress, immune dysfunction, and membrane damage. This Opinion/Hypothesis provides an overview of endogenous and exogenous acrolein sources, acrolein’s mode of action, and its metabolic fate. Recent reports underpin the finding that gut microbial glycerol metabolism leading to the formation of reuterin is an additional source of endogenous acrole...

  12. Phosphatase activity in sandy soil influenced by mycorrhizal and non-mycorrhizal cover crops

    Directory of Open Access Journals (Sweden)

    Alceu Kunze

    2011-06-01

    Full Text Available Cover crops may difffer in the way they affect rhizosphere microbiota nutrient dynamics. The purpose of this study was to evaluate the effect of mycorrhizal and non-mycorrhizal cover crops on soil phosphatase activity and its persistence in subsequent crops. A three-year experiment was carried out with a Typic Quartzipsamment. Treatments were winter species, either mycorrhizal black oat (Avena strigosa Schreb or the non-mycorrhizal species oilseed radish (Raphanus sativus L. var. oleiferus Metzg and corn spurry (Spergula arvensis L.. The control treatment consisted of resident vegetation (fallow in the winter season. In the summer, a mixture of pearl millet (Pennisetum americanum L. with sunnhemp (Crotalaria juncea L. or with soybean (Glycine max L. was sown in all plots. Soil cores (0-10 cm and root samples were collected in six growing seasons (winter and summer of each year. Microbial biomass P was determined by the fumigation-extraction method and phosphatase activity using p-nitrophenyl-phosphate as enzyme substrate. During the flowering stage of the winter cover crops, acid phosphatase activity was 30-35 % higher in soils with the non-mycorrhizal species oilseed radish, than in the control plots, regardless of the amount of P immobilized in microbial biomass. The values of enzyme activity were intermediate in the plots with corn spurry and black oat. Alkaline phosphatase activity was 10-fold lower and less sensitive to the treatments, despite the significant relationship between the two phosphatase activities. The effect of plant species on the soil enzyme profile continued in the subsequent periods, during the growth of mycorrhizal summer crops, after completion of the life cycle of the cover crops.

  13. Lymphatic absorption of hypolipidemic compound, 1-O-[p-(myristyloxy)-alpha-methylcinnamoyl] glycerol (LK-903).

    Science.gov (United States)

    Sugihara, J; Furuuchi, S

    1988-02-01

    The intestinal absorption process of 1-O-[p-(myristyloxy)-alpha-methylcinnamoyl] glycerol (LK-903), a new hypolipidemic compound, was studied in rats. When 3H-LK-903 or 3H-LKA [3H-p- (myristyloxy)-alpha-methyl cinnamic acid], labeled at the cinnamic acid moiety, or 14C-LK-903, labeled at the glycerol moiety, were administered orally to thoracic duct-cannulated rats at a dose of 0.233 mmol/kg, 31.1, 6.7 and 18.1% of the dose, respectively, appeared in the lymph within 24 h. In this case, radioactive compounds in the lymph lipids consisted of LKA (radioactivity was not detected in the fraction of LKA with 14C-LK-903), LK-903, diglyceride analogues and triglyceride analogues. The percentages of the triglyceride analogues were the highest, followed by the diglyceride analogues. On the other hand, when doubly labeled LK-903 (3H/14C = 1, corrected ratio) was administered orally, the values of 3H/14C for the monoglyceride, diglyceride and triglyceride analogues in the lymph were 1.2-1.5, 1.7-1.9 and 1.9-2.7, respectively. The lymphatic absorption of LK-903 was stimulated by the presence of lecithin but inhibited by a high dose of triolein. The results indicated that (1) LK-903 formed micelles in the intestine, (2) a large part of LK-903 was absorbed as such, (3) a part of LK-903 was hydrolyzed in the intestinal mucosa, and (4) a part of LKA formed by hydrolysis was again utilized to synthesize the higher glycerides and absorbed via the lymphatic absorption route for lipids.

  14. Electrospun Gelatin/poly(Glycerol Sebacate Membrane with Controlled Release of Antibiotics for Wound Dressing

    Directory of Open Access Journals (Sweden)

    Parisa Shirazaki

    2017-01-01

    Full Text Available Background: The most important risk that threatens the skin wounds is infections. Therefore, fabrication of a membrane as a wound dressing with the ability of antibiotic delivery in a proper delivery rate is especially important. Materials and Methods: Poly(glycerol sebacate (PGS was prepared from sebacic acid and glycerol with 1:1 ratio; then, it was added to gelatin in the 1:3 ratio and was dissolved in 80% (v/v acetic acid, and finally, ciprofloxacin was added in 10% (w/v of polymer solution. The gelatin/PGS membrane was fabricated using an electrospinning method. The membrane was cross-linked using ethyl-3-(3-dimethylaminopropyl carbodiimide ethyl-3-(3-dimethylaminopropylcarbodiim (EDC and N-hydroxysuccinimide (NHS in different time periods to achieve a proper drug release rate. Fourier-transform infrared (FTIR spectroscopy was being used to manifest the peaks of polymers and drug in the membrane. Scanning electron microscopy (SEM was used to evaluate the morphology, fibers diameter, pore size, and porosity before and after crosslinking process. Ultraviolet (UV-visible spectrophotometry was used to show the ciprofloxacin release from the cross-linked membrane. Results: FTIR analysis showed the characteristic peaks of gelatin, PGS, and ciprofloxacin without any added peaks after the crosslinking process. SEM images revealed that nanofibers' size increased during the crosslinking process and porosity was higher than 80% before and after crosslinking process. UV-visible spectrophotometry showed the proper rate of ciprofloxacin release occurred from cross-linked membrane that remaining in EDC/NHS ethanol solution for 120 min. Conclusion: The obtained results suggest that this recently developed gelatin/PGS membrane with controlled release of ciprofloxacin could be a promising biodegradable membrane for wound dressing.

  15. Provenance of tetraether membrane lipids in a large temperate lake (Loch Lomond, UK): implications for glycerol dialkyl glycerol tetraether (GDGT)-based palaeothermometry

    NARCIS (Netherlands)

    Buckles, L.K.; Weijers, J.W.H.; Tran, X.-M.; Waldron, S.; Sinninghe Damsté, J.S.

    2014-01-01

    The application of glycerol dialkyl glycerol tetraether (GDGT)-based palaeoenvironmental proxies, such as the branched vs. isoprenoidal tetratether (BIT) index, TEX86 and the MBT–CBT palaeothermometer, has lately been expanded to lacustrine sediments. Given recent research identifying the production

  16. Provenance of tetraether membrane lipids in a large temperate lake (Loch Lomond, UK) : Implications for glycerol dialkyl glycerol tetraether (GDGT)-based palaeothermometry

    NARCIS (Netherlands)

    Buckles, L. K.; Weijers, J. W H; Tran, X.-M.; Waldron, S.; Sinninghe Damsté, J. S.

    2014-01-01

    The application of glycerol dialkyl glycerol tetraether (GDGT)-based palaeoenvironmental proxies, such as the branched vs. isoprenoidal tetratether (BIT) index, TEX86 and the MBT-CBT palaeothermometer, has lately been expanded to lacustrine sediments. Given recent research identifying the production

  17. Methanol-dependent production of dihydroxyacetone and glycerol by mutants of the methylotrophic yeast Hansenula polymorpha blocked in dihydroxyacetone kinase and glycerol kinase

    NARCIS (Netherlands)

    Koning, W. de; Weusthuis, R.A.; Harder, W.; Dijkhuizen, L.

    Various factors controlling dihydroxyacetone (DHA) and glycerol production from methanol by resting cell suspensions of a mutant of Hansenula polymorpha, blocked in DHA kinase and glycerol kinase, were investigated. The presence of methanol (250 mM) and an additional substrate (0.5%, w/v) to

  18. Influence of lake water pH and alkalinity on the distribution of core and intact polar branched glycerol dialkyl glycerol tetraethers (GDGTs) in lakes

    NARCIS (Netherlands)

    Schoon, P.L.; de Kluijver, A.; Middelburg, J.J.; Downing, J.A.; Sinninghe Damsté, J.S.; Schouten, S.

    2013-01-01

    Branched glycerol dialkyl glycerol tetraethers (GDGTs) are bacterial membrane lipids, ubiquitously present in soils and peat bogs, as well as in rivers, lakes and lake sediments. Their distribution in soil is controlled mainly by pH and mean annual air temperature, but the controls on their

  19. Influence of lake water pH and alkalinity on the distribution of coreand intact polar branched glycerol dialkyl glycerol tetraethers (GDGTs) in lakes

    NARCIS (Netherlands)

    Schoon, P.L.; de Kluijver, A.; Middelburg, J.J.; Downing, J.A.; Sinninghe Damsté, J.S.; Schouten, S.

    2013-01-01

    Branched glycerol dialkyl glycerol tetraethers (GDGTs) are bacterial membrane lipids, ubiquitously present in soils and peat bogs, as well as in rivers, lakes and lake sediments. Their distribution in soil is controlled mainly by pH and mean annual air temperature, but the controls on their

  20. Enhanced hydrogen and 1,3-propanediol production from glycerol by fermentation using mixed cultures

    KAUST Repository

    Selembo, Priscilla A.

    2009-12-15

    The conversion of glycerol into high value products, such as hydrogen gas and 1,3-propanediol (PD), was examined using anaerobic fermentation with heat-treated mixed cultures. Glycerol fermentation produced 0.28 mol-H 2/mol-glycerol (72 mL-H2/g-COD) and 0.69 mol-PD/mol-glycerol. Glucose fermentation using the same mixed cultures produced more hydrogen gas (1.06 mol-H2/mol-glucose) but no PD. Changing the source of inoculum affected gas production likely due to prior acclimation of bacteria to this type of substrate. Fermentation of the glycerol produced from biodiesel fuel production (70% glycerol content) produced 0.31 mol-H 2/mol-glycerol (43 mL H2/g-COD) and 0.59 mol-PD/mol-glycerol. These are the highest yields yet reported for both hydrogen and 1,3-propanediol production from pure glycerol and the glycerol byproduct from biodiesel fuel production by fermentation using mixed cultures. These results demonstrate that production of biodiesel can be combined with production of hydrogen and 1,3-propanediol for maximum utilization of resources and minimization of waste. © 2009 Wiley Periodicals, Inc.