Identification of the 11-cis-specific retinyl-ester synthase in retinal Müller cells as multifunctional O-acyltransferase (MFAT)

Science.gov (United States)

Kaylor, Joanna J.; Cook, Jeremy D.; Makshanoff, Jacob; Bischoff, Nicholas; Yong, Jennifer; Travis, Gabriel H.

2014-01-01

Absorption of a photon by a rhodopsin or cone-opsin pigment isomerizes its 11-cis-retinaldehyde (11-cis-RAL) chromophore to all-trans-retinaldehyde (all-trans-RAL), which dissociates after a brief period of activation. Light sensitivity is restored to the resulting apo-opsin when it recombines with another 11-cis-RAL. Conversion of all-trans-RAL to 11-cis-RAL is carried out by an enzyme pathway called the visual cycle in cells of the retinal pigment epithelium. A second visual cycle is present in Müller cells of the retina. The retinol isomerase for this noncanonical pathway is dihydroceramide desaturase (DES1), which catalyzes equilibrium isomerization of retinol. Because 11-cis-retinol (11-cis-ROL) constitutes only a small fraction of total retinols in an equilibrium mixture, a subsequent step involving selective removal of 11-cis-ROL is required to drive synthesis of 11-cis-retinoids for production of visual chromophore. Selective esterification of 11-cis-ROL is one possibility. Crude homogenates of chicken retinas rapidly convert all-trans-ROL to 11-cis-retinyl esters (11-cis-REs) with minimal formation of other retinyl-ester isomers. This enzymatic activity implies the existence of an 11-cis-specific retinyl-ester synthase in Müller cells. Here, we evaluated multifunctional O-acyltransferase (MFAT) as a candidate for this 11-cis-RE-synthase. MFAT exhibited much higher catalytic efficiency as a synthase of 11-cis-REs versus other retinyl-ester isomers. Further, we show that MFAT is expressed in Müller cells. Finally, homogenates of cells coexpressing DES1 and MFAT catalyzed the conversion of all-trans-ROL to 11-cis-RP, similar to what we observed with chicken-retina homogenates. MFAT is therefore an excellent candidate for the retinyl-ester synthase that cooperates with DES1 to drive synthesis of 11-cis-retinoids by mass action. PMID:24799687

Detection of trans-cis flips and peptide-plane flips in protein structures

NARCIS (Netherlands)

Touw, W.G.; Joosten, R.P.; Vriend, G.

2015-01-01

A coordinate-based method is presented to detect peptide bonds that need correction either by a peptide-plane flip or by a trans-cis inversion of the peptide bond. When applied to the whole Protein Data Bank, the method predicts 4617 trans-cis flips and many thousands of hitherto unknown

Coevolution within a transcriptional network by compensatory trans and cis mutations

KAUST Repository

Kuo, D.

2010-10-26

Transcriptional networks have been shown to evolve very rapidly, prompting questions as to how such changes arise and are tolerated. Recent comparisons of transcriptional networks across species have implicated variations in the cis-acting DNA sequences near genes as the main cause of divergence. What is less clear is how these changes interact with trans-acting changes occurring elsewhere in the genetic circuit. Here, we report the discovery of a system of compensatory trans and cis mutations in the yeast AP-1 transcriptional network that allows for conserved transcriptional regulation despite continued genetic change. We pinpoint a single species, the fungal pathogen Candida glabrata, in which a trans mutation has occurred very recently in a single AP-1 family member, distinguishing it from its Saccharomyces ortholog. Comparison of chromatin immunoprecipitation profiles between Candida and Saccharomyces shows that, despite their different DNA-binding domains, the AP-1 orthologs regulate a conserved block of genes. This conservation is enabled by concomitant changes in the cis-regulatory motifs upstream of each gene. Thus, both trans and cis mutations have perturbed the yeast AP-1 regulatory system in such a way as to compensate for one another. This demonstrates an example of “coevolution” between a DNA-binding transcription factor and its cis-regulatory site, reminiscent of the coevolution of protein binding partners.

Physiological and Pathogenic Roles of Prolyl Isomerase Pin1 in Metabolic Regulations via Multiple Signal Transduction Pathway Modulations

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Yusuke Nakatsu

2016-09-01

Full Text Available Prolyl isomerases are divided into three groups, the FKBP family, Cyclophilin and the Parvulin family (Pin1 and Par14. Among these isomerases, Pin1 is a unique prolyl isomerase binding to the motif including pSer/pThr-Pro that is phosphorylated by kinases. Once bound, Pin1 modulates the enzymatic activity, protein stability or subcellular localization of target proteins by changing the cis- and trans-formations of proline. Several studies have examined the roles of Pin1 in the pathogenesis of cancers and Alzheimer’s disease. On the other hand, recent studies have newly demonstrated Pin1 to be involved in regulating glucose and lipid metabolism. Interestingly, while Pin1 expression is markedly increased by high-fat diet feeding, Pin1 KO mice are resistant to diet-induced obesity, non-alcoholic steatohepatitis and diabetic vascular dysfunction. These phenomena result from the binding of Pin1 to several key factors regulating metabolic functions, which include insulin receptor substrate-1, AMPK, Crtc2 and NF-κB p65. In this review, we focus on recent advances in elucidating the physiological roles of Pin1 as well as the pathogenesis of disorders involving this isomerase, from the viewpoint of the relationships between signal transductions and metabolic functions.

Modulation of neutrophil superoxide generation by inhibitors of protein kinase C, calmodulin, diacylglycerol and myosin light chain kinases, and peptidyl prolyl cis-trans isomerase.

Science.gov (United States)

Bergstrand, H; Eriksson, T; Hallberg, A; Johansson, B; Karabelas, K; Michelsen, P; Nybom, A

1992-12-01

To assess the role of protein kinase C (PKC) in the respiratory burst of adherent human polymorphonuclear leukocytes (PMNL), reduction of ferricytochrome C by cells triggered with a phorbol ester (PMA), ionophore A23187, serum-treated zymosan (STZ) or three lipid derivatives, 3-decanoyl-sn-glycerol (G-3-OCOC9), (R,R)-1,4-diethyl-2-O-decyl-L-tartrate (Tt-2-OC10) and 3-decyloxy-5-hydroxymethylphenol (DHP) was examined in a microtiter plate procedure in the presence of inhibitors of PKC and, for comparison, inhibitors of calmodulin, diacylglycerol and myosin light chain kinases and the peptidyl-prolyl cis-trans isomerase activity of fujiphilin. 1) Of the protein kinase inhibitors examined, Ro 31-7549 and staurosporine reduced responses to all stimuli except possibly STZ; in contrast, K252a and the myosin light chain kinase inhibitors ML-7 and ML-9 blocked responses to A23187 and STZ better than those triggered by PMA. H-7 reduced responses to A23187, DHP and G-3-OCOC9, and calphostin, palmitoyl carnitine, sphingosine and the multifunctional drugs TMB-8 and W-7 reduced A23187; they also, when examined, reduced decane derivative-induced O2- production more effectively than PMA- and STZ-triggered responses. Polymyxin B, 4 alpha-PMA and retinal displayed no inhibitory capacity. 2) Of the selective calmodulin antagonists, CGS 9343B, Ro 22-4839 and calmidazolium did not inhibit the oxidative response irrespective of the stimulus used, whereas metofenazate reduced those evoked by A23187, DHP, G-3-OCOC9 and STZ.(ABSTRACT TRUNCATED AT 250 WORDS)

Structural Elucidation of cis / trans Dicaffeoylquinic Acid Photoisomerization Using Ion Mobility Spectrometry-Mass Spectrometry

Energy Technology Data Exchange (ETDEWEB)

Zheng, Xueyun; Renslow, Ryan S.; Makola, Mpho M.; Webb, Ian K.; Deng, Liulin; Thomas, Dennis G.; Govind, Niranjan; Ibrahim, Yehia M.; Kabanda, Mwadham M.; Dubery, Ian A.; Heyman, Heino M.; Smith, Richard D.; Madala, Ntakadzeni E.; Baker, Erin S.

2017-03-15

Due to the recently uncovered health benefits and anti-HIV activities of dicaffeoylquinic acids (diCQAs), understanding their structures and functions is of great interest for drug discovery efforts. DiCQAs are analytically challenging to identify and quantify since they commonly exist as a diverse mixture of positional and geometric (cis/trans) isomers. In this work, we utilized ion mobility spectrometry coupled with mass spectrometry to separate the various isomers before and after UV irradiation. The experimental collision cross sections were then compared with theoretical structures to differentiate and identify the diCQA isomers. Our analyses found that naturally the diCQAs existed predominantly as trans/trans isomers, but after 3 h of UV irradiation, cis/cis, cis/trans, trans/cis, and trans/trans isomers were all present in the mixture. This is the first report of successful differentiation of cis/trans diCQA isomers individually, which shows the great promise of IMS coupled with theoretical calculations for determining the structure and activity relationships of different isomers in drug discovery studies.

Conserving Coherence and Storing Energy during Internal Conversion: Photoinduced Dynamics of cis- and trans-Azobenzene Radical Cations

KAUST Repository

Munkerup, Kristin

2017-10-24

Light harvesting via energy storage in azobenzene has been a key topic for decades, and the process of energy distribution over the molecular degrees of freedom following photoexcitation remains to be understood. Dynamics of a photoexcited system can exhibit high degrees of non-ergodicity when it is driven by just a few degrees of freedom. Typically, an internal conversion leads to the loss of such localization of dynamics, as the intramolecular energy becomes statistically redistributed over all molecular degrees of freedom. Here, we present a unique case where the excitation energy remains localized even subsequent to internal conversion. Strong-field ionization is used to prepare cis- and trans-azobenzene radical cations on the D1 surface with little excess energy, at the equilibrium neutral geometry. These D1 ions are preferably formed because in this case D1 and D0 switch place in the presence of the strong laser field. The post-ionization dynamics is dictated by the potential energy landscape. The D1 surface is steep downhill along the cis/trans isomerization coordinate and towards a common minimum shared by the two isomers in the region of D1/D0 conical intersection. Coherent cis/trans torsional motion along this coordinate is manifested in the ion transients by a cosine modulation. In this scenario, D0 becomes populated with molecules that are energized mainly along the cis-trans isomerization coordinate, with the kinetic energy above the cis-trans inter-conversion barrier. These activated azobenzene molecules easily cycle back and forth along the D0 surface, and give rise to several periods of modulated signal before coherence is lost. This persistent localization of the internal energy during internal conversion is provided by the steep downhill potential energy surface, small initial internal energy content, and a strong hole-lone pair interaction that drives the molecule along the cis-trans isomerization coordinate to facilitate the transition between

The synthesis and preliminary pharmacological evaluation of the racemic cis and trans 3-alkylfentanyl analogues

Directory of Open Access Journals (Sweden)

LJ. DOSEN-MICOVIC

2004-07-01

Full Text Available A general, five step method for the synthesis of 3-alkylfentanyl analogues (i.e., cis and trans 3-alkyl-4-anilidopiperidines 6.1–6.6 has been developed. The starting N-phenethyl-4-piperidone 1 was first converted into the cyclohexylimine derivative 2, a-deprotonated with butyllithium and the resulting imine anion efficiently monoalkylated with primary and secondary alkyl halides. After mild acid hydrolysis, the obtained 3-alkyl-4-piperidones 3.1–3.6 were isolated in good yields (79–85 %, then condensed with aniline to form imines 4.1–4.6. Subsequent reduction of the imines (LiAlH4/THF yielded cis/trans mixtures of 3-alkyl-4-anilinopiperidines 5.1–5.6. Quantitative separation of the diastereoisomers by column chromatography of Al2O3 gave pure cis 5.1–5.6 (29–51 % yield and trans 5.1–5.6 (19–27 % yield, with the cis/trans ratio in the range 7/3–6/4. The synthesis was concluded by N-acylation of the purified 5.1–5.6, with propionyl chloride, to afford cis and trans 3-alkyl-4-anilidopiperidines 6.1–6.6 (~95 % yield, as monooxalate salts. No enatioseparation was attempted at any stage. The relative cis/trans stereochemistry was provisionally assigned from the 1H-NMR spectra. Of the twelve synthesized 3-alkylfentanyls, ten compounds (two known and eight novel derivatives, all as the monooxalate salts were preliminarily tested as analgesics in rats, comparing the potency to fentanyl. Except for the known (±-cis-3-Me fentanyl 6.1cis, (8 × fentanyl, and the novel (±-cis-3-Et fentanyl 6.2cis, (1.5 × fentanyl, all of the others were less active than fentanyl or inactive. Some tentative conclusions on the structure-activity relationship (SAR in this series of derivatives have been made.

Cis- and trans-perfluorodecalin: Infrared spectra, radiative efficiency and global warming potential

Science.gov (United States)

Le Bris, Karine; DeZeeuw, Jasmine; Godin, Paul J.; Strong, Kimberly

2017-12-01

Perfluorodecalin (PFD) is a molecule used in various medical applications for its capacity to dissolve gases. This potent greenhouse gas was detected for the first time in the atmosphere in 2005. We present infrared absorption cross-section spectra of a pure vapour of cis- and trans-perfluorodecalin at a resolution of 0.1 cm-1. Measurements were performed in the 560-3000 cm-1 spectral range using Fourier transform spectroscopy. The spectra have been compared with previous experimental data and theoretical calculations by density functional theory. The new experimental absorption cross-sections have been used to calculate a lifetime-corrected radiative efficiency at 300 K of 0.62 W m-2 ppb-1 and 0.57 W.m-2.ppb-1 for the cis and trans isomers respectively. This leads to a 100-year time horizon global warming potential of 8030 for cis-PFD and 7440 for trans-PFD.

Ensemble of Transition State Structures for the Cis-Trans Isomerization of N-Methylacetamide

Energy Technology Data Exchange (ETDEWEB)

Mantz, Yves A. [National Energy Technology Lab. (NETL), Pittsburgh, PA, (United States); Branduardi, Davide [Italian Inst. of Technology, Genoa (Italy); Bussi, Giovanni [Univ. of Modena and Reggio Emilia and INFM-CNR (Italy); Parrinello, Michele [ETH Zurich, Lugano (Switzerland). Dept. of Chemistry and Applied Biosciences

2009-09-17

The cis-trans isomerization of N-methylacetamide (NMA), a model peptidic fragment, is studied theoretically in vacuo and in explicit water solvent at 300 K using the metadynamics technique. The computed cis-trans free energy difference is very similar for NMA(g) and NMA(aq), in agreement with experimental measurements of population ratios and theoretical studies at 0 K. By exploiting the flexibility in the definition of a pair of recently introduced collective variables (Branduardi, D.; Gervasio, F. L.; Parrinello, M. J. Chem. Phys. 2007, 126, 054103), an ensemble of transition state structures is generated at finite temperature for both NMA(g) and NMA(aq), as verified by computing committor distribution functions. Ensemble members of NMA(g) are shown to have correlated values of the backbone dihedral angle and a second dihedral angle involving the amide hydrogen atom. The dynamical character of these structures is preserved in the presence of solvent, whose influence on the committor functions can be modeled using effective friction/noise terms.

Synthesis, spectroscopic and TD-DFT quantum mechanical study of azo-azomethine dyes. A laser induced trans-cis-trans photoisomerization cycle.

Science.gov (United States)

Georgiev, Anton; Kostadinov, Anton; Ivanov, Deyan; Dimov, Deyan; Stoyanov, Simeon; Nedelchev, Lian; Nazarova, Dimana; Yancheva, Denitsa

2018-03-05

This paper describes the synthesis, spectroscopic characterization and quantum mechanical calculations of three azo-azomethine dyes. The dyes were synthesized via condensation reaction between 4-(dimethylamino)benzaldehyde and three different 4-aminobenzene azo dyes. Quantum chemical calculations on the optimized molecular geometry and electron densities of the trans (E) and cis (Z) isomers and their vibrational frequencies have been computed by using DFT/B3LYP density-functional theory with 6-311++G(d,p) basis set in vacuo. The thermodynamic parameters such as total electronic energy E (RB3LYP), enthalpy H 298 (sum of electronic and thermal enthalpies), free Gibbs energy G 298 (sum of electronic and thermal free Gibbs energies) and dipole moment μ were computed for trans (E) and cis (Z) isomers in order to estimate the ΔE trans→cis , Δμ trans→cis, ΔH trans→cis , ΔG trans→cis and ΔS trans→cis values. After molecular geometry optimization the electronic spectra have been obtained by TD-DFT calculations at same basis set and correlated with the spectra of vapour deposited nanosized films of the dyes. The NBO analysis was performed in order to understand the intramolecular charge transfer and energy of resonance stabilization. Solvatochromism was investigated by UV-VIS spectroscopy in five different organic solvents with increasing polarity. The dynamic photoisomerization experiments have been performed in DMF by pump lasers λ=355nm (mostly E→Z) and λ=491nm (mostly Z→E) in spectral region 300nm - 800nm at equal concentrations and times of illumination in order to investigate the photodynamical trans-cis-trans properties of the CHN and NN chromophore groups of the dyes. Copyright © 2017 Elsevier B.V. All rights reserved.

New probabilistic risk assessment of ethylhexyl methoxycinnamate: Comparing the genotoxic effects of trans- and cis-EHMC.

Science.gov (United States)

Nečasová, Anežka; Bányiová, Katarína; Literák, Jaromír; Čupr, Pavel

2017-02-01

Ethylhexyl methoxycinnamate (EHMC) is a widely used UV filter present in a large number of personal care products (PCPs). Under normal conditions, EHMC occurs in a mixture of two isomers: trans-EHMC and cis-EHMC in a ratio of 99:1. When exposed to sunlight, the trans isomer is transformed to the less stable cis isomer and the efficiency of the UV filter is reduced. To date, the toxicological effects of the cis-EHMC isomer remain largely unknown. We developed a completely new method for preparing cis-EHMC. An EHMC technical mixture was irradiated using a UV lamp and 98% pure cis-EHMC was isolated from the irradiated solution using column chromatography. The genotoxic effects of the isolated cis-EHMC isomer and the nonirradiated trans-EHMC were subsequently measured using two bioassays (SOS chromotest and UmuC test). In the case of trans-EHMC, significant genotoxicity was observed using both bioassays at the highest concentrations (0.5 - 4 mg mL -1 ). In the case of cis-EHMC, significant genotoxicity was only detected using the UmuC test at concentrations of 0.25 - 1 mg mL -1 . Based on these results, the NOEC was calculated for both cis- and trans-EHMC, 0.038 and 0.064 mg mL -1 , respectively. Risk assessment of dermal, oral and inhalation exposure to PCPs containing EHMC was carried out for a female population using probabilistic simulation and by using Quantitative in vitro to in vivo extrapolation (QIVIVE). The risk of cis-EHMC was found to be ∼1.7 times greater than trans-EHMC. In the case of cis-EHMC, a hazard index of 1 was exceeded in the 92nd percentile. Based on the observed differences between the isomers, EHMC application in PCPs requires detailed reassessment. Further exploration of the toxicological effects and properties of cis-EHMC is needed in order to correctly predict risks posed to humans and the environment. © 2016 Wiley Periodicals, Inc. Environ Toxicol 32: 569-580, 2017. © 2016 Wiley Periodicals, Inc.

Photocytotoxic trans-diam(m)ine platinum(IV) diazido complexes more potent than their cis isomers.

Science.gov (United States)

Farrer, Nicola J; Woods, Julie A; Munk, Vivienne P; Mackay, Fiona S; Sadler, Peter J

2010-02-15

The photocytotoxicity of a series of anticancer trans-dihydroxido [Pt(N(3))(2)(OH)(2)(NH(3))(X)] (X = alkyl or aryl amine) platinum(IV) diazido complexes has been examined, and the influence of cis-trans isomerism has been investigated. A series of photoactivatable Pt(IV)-azido complexes has been synthesized: The synthesis, characterization, and photocytotoxicity of six mixed-ligand ammine/amine Pt(IV) diazido complexes, cis,trans,cis-[Pt(N(3))(2)(OH)(2)(NH(3))(X)] where X = propylamine (4c), butylamine (5c), or pentylamine (6c) and aromatic complexes where X = pyridine (7c), 2-methylpyridine (8c), or 3-methylpyridine (9c) are reported. Six all-trans isomers have also been studied where X = methylamine (2t), ethylamine (3t), 2-methylpyridine (8t), 4-methylpyridine (10t), 3-methylpyridine (9t), and 2-bromo-3-methylpyridine (11t). All of the complexes exhibit intense azide-to-Pt(IV) LMCT bands (ca. 290 nm for trans and ca. 260 nm for cis). When irradiated with UVA light (365 nm), the Pt(IV) complexes undergo photoreduction to Pt(II) species, as monitored by UV-vis spectroscopy. The trans isomers of complexes containing aliphatic or aromatic amines were more photocytotoxic than their cis isomers. One of the cis complexes (9c) was nonphotocytotoxic despite undergoing photoreduction. Substitution of NH(3) ligands by MeNH(2) or EtNH(2) results in more potent photocytotoxicity for the all-trans complexes. The complexes were all nontoxic toward human keratinocytes (HaCaT) and A2780 human ovarian cancer cells in the dark, apart from the 3-methylpyridine (9t), 2-bromo-3-methylpyridine (11t), and 4-methylpyridine (10t) derivatives.

Synthesis and bacterial metabolism of cis- and trans-2-alkyl analogues of sodium cyclamate.

Science.gov (United States)

Wiley, R A; Pearson, D A; Schmidt, V; Wesche, S B; Roxon, J J

1983-07-01

Sodium cyclamate is an effective artificial sweetner, which has been banned from the U.SD. market because of alleged carcinogenic properties. It appears that cyclohexylamine, liberated from cyclamate as a result of bacterial mtabolism, is the proximate carcinogen. In an effort to elucidate the extent to which analogues of cyclamate would enter into the bacterial metabolic pathway, as well as any stereochemical requirements which might exist, several 2-alkaly analogues of sodium cyclamate were prepared. It was found that trans-N-(2-methylcyclohexyl)sulfamate (trans-2a) and trans-N-(2-ethylcyclohexyl)sulfamate were hydrolyzed by freshly collected fecal suspensions from rats fed cyclamate, but not from control rats, at the same rate as cyclamate itself. trans-N-(2-Isopropylcyclohexyl)sulfamate (trans-2c) was not hydrolyzed at all. Surprisingly, two of the analogous cis compounds (cis-2a and cis-2c, respectively) were hydrolyzed by fecal suspensions from control, as well as from cyclamate-fed, rats. Moreover, cis-2a was hydrolyzed by incubating it in medium only. Thus, it is apparent that stereochemical influences on the chemical properties of these compounds are substantial. These results do not appear to point the way toward a safe, nonmetabolizable sweetening agent.

Thiyl radical-induced cis-trans-isomerization of arachidonic acid inhibits prostaglandin metabolism

International Nuclear Information System (INIS)

Kratzsch, S.; Droessler, K.; Sprinz, H.; Brede, O.

2002-01-01

Complete text of publication follows. Thiyl radicals radiolytically generated from thiophenol in methanolic solution are known to isomerise double bonds of poly-unsaturated fatty acids (PUFA). γ-irradiating of such a system containing all-cis 5,8,11,14 eicosatetraenoic acid (arachidonic acid, AA) with low doses (0.1-0.8 kGy) results in a mixture of 8 to 32% mono-trans-isomers. Here we report about the influence of mono-trans-AA on the primary steps of AA-metabolism and prostaglandin synthesis, catalysed by cyclooxygenase (COX). In the cell-free model system the reaction of COX-1 with AA was analysed by controlling the oxygen level during the enzymatic reaction. As an example, a mixture of a low quantity of mono-trans-isomerized AA (10%) and 90% all-cis-isomer exhibits a marked reduced oxygen consumption by 45%. As further proofs - the yield of reactive oxygen species (ROS) generated by the COX-coupled peroxidase reaction was detected, - and the COX-1 activity in presence of different amounts of trans-AA was characterized using a photometric assay based on the oxidation of TMPD. All these methods indicated semiquantitatively a reduced activity of COX-1, depending on the trans-isomer yield. Therefore, an inhibition of COX-1 activity by only one trans-double-bond in AA could be concluded. Furthermore, in vitro cell-line experiments were performed analysing the influence of mono-trans-isomerized AA on the activity of the cell-own COX-2. Hence, VD 3 -differentiated and LPS-stimulated monocyte-like cells were incubated with mono-trans-AA and ROS-production was detected by the chemiluminescence measurements mentioned above. Compared to the reaction with all-cis-AA we found a considerable lowered formation of ROS. Likewise, we obtained a reduced PGE 2 -expression between 15 and 40% for cells treated with 8 to 29% trans-AA. The model as well as in vivo experiments demonstrate an inhibition effect of mono-trans-AA and give rise for postulating an enzyme blocking mechanism

Exploración estocástica de las superficies de energía potencial de dímeros cis-trans y trans-trans del ácido fórmico

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Said F. Figueredo

2014-01-01

Full Text Available Potential energy surface (PES of cis-trans and trans-trans formic acid dimers were sampled using a stochastic method, and the geometries, energies, and vibrational frequencies were computed at B3LYP/6-311++G(3df,2p level of theory. The results show that molar free energy of dimerization deviated up to 108.4% when basis set superposition error (BSSE and zero-point energy (ZPE were not considered. For cis-trans dimers, C=O and O - H bond weakened, whereas C - O bonds strengthened due to dimerization. Also, trans-trans FA dimers did not show a trend regarding strengthening or weakening of the C=O, O - H and C - O bonds.

An in vivo comparison of cis- and trans-[{sup 18}F]mefway in the nonhuman primate

Energy Technology Data Exchange (ETDEWEB)

Wooten, Dustin, E-mail: dwooten@wisc.edu [Department of Medical Physics, Waisman Laboratory for Brain Imaging and Behavior, University of Wisconsin-Madison, Madison, WI 53705 (United States); Hillmer, Ansel; Murali, Dhanabalan; Barnhart, Todd [Department of Medical Physics, Waisman Laboratory for Brain Imaging and Behavior, University of Wisconsin-Madison, Madison, WI 53705 (United States); Schneider, Mary L. [Department of Kinesiology, University of Wisconsin-Madison, Madison, WI 53706 (United States); Mukherjee, Jogeshwar [Preclinical Imaging Center, Department of Psychiatry and Human Behavior, University of California-Irvine, Irvine 92697 (United States); Christian, Bradley T. [Department of Medical Physics, Waisman Laboratory for Brain Imaging and Behavior, University of Wisconsin-Madison, Madison, WI 53705 (United States)

2011-10-15

Introduction: [{sup 18}F]Mefway is a serotonin 5-HT{sub 1A} PET radiotracer with high specificity and favorable in vivo imaging properties. The chemical structure of [{sup 18}F]mefway permits {sup 18}F labeling in either the cis or trans positions at the 4-cyclohexyl site. We have previously reported on the in vivo kinetics of trans-[{sup 18}F]mefway in the nonhuman primate. In this work, we compare the in vivo binding of cis-[{sup 18}F]mefway and trans-[{sup 18}F]mefway to evaluate the properties of cis-[{sup 18}F]mefway for 5-HT{sub 1A} PET imaging. Methods: The cis- and trans-[{sup 18}F]mefway tracers were synthesized via nucleophilic substitution with their respective tosyl precursors. Two monkeys (one male, one female) were given bolus injections of both cis- and trans-labeled [{sup 18}F]mefway in separate experiments. Dynamic scans were acquired for 90 min with a microPET P4 scanner. Time-activity curves were extracted in the areas of the mesial temporal cortex (MTC), anterior cingulate gyrus (aCG), insular cortex (IC), raphe nuclei (RN) and cerebellum (CB). The in vivo behavior of the radiotracers was compared based upon the nondisplaceable binding potential (BP{sub ND}) using the CB as a reference region. Results: Averaged over the two subjects, BP{sub ND} values were as follows: MTC: 7.7, 0.58; aCG: 4.95, 0.32; IC: 3.27, 0.2; and RN: 3.05, 0.13, for trans-[{sup 18}F]mefway and cis-[{sup 18}F]mefway, respectively. Conclusion: The cis-labeled [{sup 18}F]mefway tracer has low specific binding throughout the 5-HT{sub 1A} regions of the brain compared to trans-[{sup 18}F]mefway, suggesting that the target-to-background binding of cis-[{sup 18}F]mefway may limit its use for in vivo assessment of 5-HT{sub 1A} binding.

Both cis and trans Activities of Foot-and-Mouth Disease Virus 3D Polymerase Are Essential for Viral RNA Replication.

Science.gov (United States)

Herod, Morgan R; Ferrer-Orta, Cristina; Loundras, Eleni-Anna; Ward, Joseph C; Verdaguer, Nuria; Rowlands, David J; Stonehouse, Nicola J

2016-08-01

The Picornaviridae is a large family of positive-sense RNA viruses that contains numerous human and animal pathogens, including foot-and-mouth disease virus (FMDV). The picornavirus replication complex comprises a coordinated network of protein-protein and protein-RNA interactions involving multiple viral and host-cellular factors. Many of the proteins within the complex possess multiple roles in viral RNA replication, some of which can be provided in trans (i.e., via expression from a separate RNA molecule), while others are required in cis (i.e., expressed from the template RNA molecule). In vitro studies have suggested that multiple copies of the RNA-dependent RNA polymerase (RdRp) 3D are involved in the viral replication complex. However, it is not clear whether all these molecules are catalytically active or what other function(s) they provide. In this study, we aimed to distinguish between catalytically active 3D molecules and those that build a replication complex. We report a novel nonenzymatic cis-acting function of 3D that is essential for viral-genome replication. Using an FMDV replicon in complementation experiments, our data demonstrate that this cis-acting role of 3D is distinct from the catalytic activity, which is predominantly trans acting. Immunofluorescence studies suggest that both cis- and trans-acting 3D molecules localize to the same cellular compartment. However, our genetic and structural data suggest that 3D interacts in cis with RNA stem-loops that are essential for viral RNA replication. This study identifies a previously undescribed aspect of picornavirus replication complex structure-function and an important methodology for probing such interactions further. Foot-and-mouth disease virus (FMDV) is an important animal pathogen responsible for foot-and-mouth disease. The disease is endemic in many parts of the world with outbreaks within livestock resulting in major economic losses. Propagation of the viral genome occurs within

Synthesis of cis - and trans-diisothiocyanato-bis(NHC) complexes of nickel(II) and applications in the Kumada-Corriu reaction

KAUST Repository

Jothibasu, Ramasamy

2010-09-13

Metathetical reaction of AgSCN with a series of trans-dihalido-bis(carbene) nickel(II) complexes in CH3CN readily afforded the novel diisothiocyanato-bis(carbene) complexes [Ni(NCS)2(NHC)2] (trans-2a, NHC = 1,3-diisopropylbenzimidazolin-2-ylidene; trans-2b, NHC = 1,3-diisobutylbenzimidazolin-2-ylidene; trans-2c, NHC = 1,3- dibenzylbenzimidazolin-2-ylidene; cis-2d, NHC = 1,3-di(2-propenyl) benzimidazolin-2-ylidene; cis-2e, NHC = 1-propyl-3-methylbenzimidazolin-2- ylidene) as greenish-yellow powders in moderate to good yields. While dihalido-bis(carbene) Ni(II) complexes exclusively form trans-complexes, a trans-cis isomerization occurs upon halido-isothiocyanato exchange with complexes bearing less bulky carbene ligands, i.e., cis-2d/e. DFT calculations indicated that this isomerization can be attributed to a reduced energy difference between trans- and cis-isomers of diisothiocyanato complexes. All complexes have been characterized by multinuclear NMR spectroscopy, ESI mass spectrometry, and X-ray diffraction analysis. A catalytic study revealed that cis-complexes generally exhibit greater activities in the Kumada-Corriu coupling reaction. © 2010 American Chemical Society.

An Intracellular Peptidyl-Prolyl cis/trans Isomerase Is Required for Folding and Activity of the Staphylococcus aureus Secreted Virulence Factor Nuclease.

Science.gov (United States)

Wiemels, Richard E; Cech, Stephanie M; Meyer, Nikki M; Burke, Caleb A; Weiss, Andy; Parks, Anastacia R; Shaw, Lindsey N; Carroll, Ronan K

2017-01-01

Staphylococcus aureus is an important human pathogen that relies on a large repertoire of secreted and cell wall-associated proteins for pathogenesis. Consequently, the ability of the organism to cause disease is absolutely dependent on its ability to synthesize and successfully secrete these proteins. In this study, we investigate the role of peptidyl-prolyl cis/trans isomerases (PPIases) on the activity of the S. aureus secreted virulence factor nuclease (Nuc). We identify a staphylococcal cyclophilin-type PPIase (PpiB) that is required for optimal activity of Nuc. Disruption of ppiB results in decreased nuclease activity in culture supernatants; however, the levels of Nuc protein are not altered, suggesting that the decrease in activity results from misfolding of Nuc in the absence of PpiB. We go on to demonstrate that PpiB exhibits PPIase activity in vitro, is localized to the bacterial cytosol, and directly interacts with Nuc in vitro to accelerate the rate of Nuc refolding. Finally, we demonstrate an additional role for PpiB in S. aureus hemolysis and demonstrate that the S. aureus parvulin-type PPIase PrsA also plays a role in the activity of secreted virulence factors. The deletion of prsA leads to a decrease in secreted protease and phospholipase activity, similar to that observed in other Gram-positive pathogens. Together, these results demonstrate, for the first time to our knowledge, that PPIases play an important role in the secretion of virulence factors in S. aureus IMPORTANCE: Staphylococcus aureus is a highly dangerous bacterial pathogen capable of causing a variety of infections throughout the human body. The ability of S. aureus to cause disease is largely due to an extensive repertoire of secreted and cell wall-associated proteins, including adhesins, toxins, exoenzymes, and superantigens. These virulence factors, once produced, are typically transported across the cell membrane by the secretory (Sec) system in a denatured state. Consequently

Functional characterisation of parvulin-type peptidyl prolyl cis-trans isomerase, PinA in Dictyostelium discoideum

International Nuclear Information System (INIS)

Haokip, Nemneineng; Naorem, Aruna

2017-01-01

Pin1-type parvulins are unique among PPIases that can catalyse an otherwise slow cis-trans isomerisation of phosphorylated peptide bond preceding proline in target proteins. This prolyl isomerisation process can regulate activity, stability and localisation of target proteins and thus control cellular processes like eukaryotic cell proliferation, cell cycle progression and gene regulation. Towards understanding the function of Pin1-type prolyl isomerisation in Dictyostelium discoideum, a slime mould with distinct growth and developmental phases, we identified PinA as a novel Pin1-type parvulin by its ability to complement the temperature sensitivity phenotype associated with a mutation in ESS1 in S. cerevisiae. In D. discoideum, pinA is temporally and spatially regulated during growth and development. PinA is both nuclear as well as cytoplasmic in the growing cells. We further show that loss of pinA (pinA − ) leads to decreased growth rate, reduced spore formation and abnormal prespore-prestalk patterning. We conclude that PinA is required for normal growth as well as development in D. discoideum. - Highlights: • PinA is a bona fide homologue of S. cerevisiae Ess1. • PinA is required for normal cell proliferation of D. discoideum. • PinA is spatially localised in developmental structures. • PinA is important for cell differentiation and patterning.

PBPK modeling of the cis- and trans-permethrin isomers and their major urinary metabolites in rats

Energy Technology Data Exchange (ETDEWEB)

Willemin, Marie-Emilie [Institut National de l' Environnement Industriel et des Risques (INERIS), Unité Modèles pour l' Ecotoxicologie et la Toxicologie (METO), Parc ALATA BP2, 60550, Verneuil en Halatte (France); Sorbonne University, Université de Technologie de Compiègne, CNRS, UMR 7338 Biomechanics and Bioengineering, Centre de recherche Royallieu CS 60319,60203 Compiègnee Cedex (France); Desmots, Sophie [Institut National de l' Environnement Industriel et des Risques (INERIS), Unité Toxicologie Expérimentale (TOXI), Parc ALATA BP2, 60550, Verneuil en Halatte (France); Le Grand, Rozenn [Centre Hospitalo-Universitaire de Limoges, Service de Pharmacologie et de Toxicologie — Pharmacovigilance, 2, avenue Martin Luther King, 87042 Limoges (France); Lestremau, François [Institut National de l' Environnement Industriel et des Risques (INERIS), Unité Innovation pour la Mesure (NOVA), Parc ALATA BP2, 60550, Verneuil en Halatte (France); Zeman, Florence A. [Institut National de l' Environnement Industriel et des Risques (INERIS), Unité Modèles pour l' Ecotoxicologie et la Toxicologie (METO), Parc ALATA BP2, 60550, Verneuil en Halatte (France); Leclerc, Eric [Sorbonne University, Université de Technologie de Compiègne, CNRS, UMR 7338 Biomechanics and Bioengineering, Centre de recherche Royallieu CS 60319,60203 Compiègnee Cedex (France); Moesch, Christian [Centre Hospitalo-Universitaire de Limoges, Service de Pharmacologie et de Toxicologie — Pharmacovigilance, 2, avenue Martin Luther King, 87042 Limoges (France); and others

2016-03-01

Permethrin, a pyrethroid insecticide, is suspected to induce neuronal and hormonal disturbances in humans. The widespread exposure of the populations has been confirmed by the detection of the urinary metabolites of permethrin in biomonitoring studies. Permethrin is a chiral molecule presenting two forms, the cis and the trans isomers. Because in vitro studies indicated a metabolic interaction between the trans and cis isomers of permethrin, we adapted and calibrated a PBPK model for trans- and cis-permethrin separately in rats. The model also describes the toxicokinetics of three urinary metabolites, cis- and trans-3-(2,2 dichlorovinyl)-2,2-dimethyl-(1-cyclopropane) carboxylic acid (cis- and trans-DCCA), 3-phenoxybenzoic acid (3-PBA) and 4′OH-phenoxybenzoic acid (4′-OH-PBA). In vivo experiments performed in Sprague–Dawley rats were used to calibrate the PBPK model in a Bayesian framework. The model captured well the toxicokinetics of permethrin isomers and their metabolites including the rapid absorption, the accumulation in fat, the extensive metabolism of the parent compounds, and the rapid elimination of metabolites in urine. Average hepatic clearances in rats were estimated to be 2.4 and 5.7 L/h/kg for cis- and trans-permethrin, respectively. High concentrations of the metabolite 4′-OH-PBA were measured in urine compared to cis- and trans-DCCA and 3-PBA. The confidence in the extended PBPK model was then confirmed by good predictions of published experimental data obtained using the isomers mixture. The extended PBPK model could be extrapolated to humans to predict the internal dose of exposure to permethrin from biomonitoring data in urine. - Highlights: • A PBPK model of isomers of permethrin and its urinary metabolites was developed. • A quantitative link was established for permethrin and its biomarkers of exposure. • The bayesian framework allows getting confidence interval on the estimated parameters. • The PBPK model can be extrapolated

PBPK modeling of the cis- and trans-permethrin isomers and their major urinary metabolites in rats

International Nuclear Information System (INIS)

Willemin, Marie-Emilie; Desmots, Sophie; Le Grand, Rozenn; Lestremau, François; Zeman, Florence A.; Leclerc, Eric; Moesch, Christian

2016-01-01

Permethrin, a pyrethroid insecticide, is suspected to induce neuronal and hormonal disturbances in humans. The widespread exposure of the populations has been confirmed by the detection of the urinary metabolites of permethrin in biomonitoring studies. Permethrin is a chiral molecule presenting two forms, the cis and the trans isomers. Because in vitro studies indicated a metabolic interaction between the trans and cis isomers of permethrin, we adapted and calibrated a PBPK model for trans- and cis-permethrin separately in rats. The model also describes the toxicokinetics of three urinary metabolites, cis- and trans-3-(2,2 dichlorovinyl)-2,2-dimethyl-(1-cyclopropane) carboxylic acid (cis- and trans-DCCA), 3-phenoxybenzoic acid (3-PBA) and 4′OH-phenoxybenzoic acid (4′-OH-PBA). In vivo experiments performed in Sprague–Dawley rats were used to calibrate the PBPK model in a Bayesian framework. The model captured well the toxicokinetics of permethrin isomers and their metabolites including the rapid absorption, the accumulation in fat, the extensive metabolism of the parent compounds, and the rapid elimination of metabolites in urine. Average hepatic clearances in rats were estimated to be 2.4 and 5.7 L/h/kg for cis- and trans-permethrin, respectively. High concentrations of the metabolite 4′-OH-PBA were measured in urine compared to cis- and trans-DCCA and 3-PBA. The confidence in the extended PBPK model was then confirmed by good predictions of published experimental data obtained using the isomers mixture. The extended PBPK model could be extrapolated to humans to predict the internal dose of exposure to permethrin from biomonitoring data in urine. - Highlights: • A PBPK model of isomers of permethrin and its urinary metabolites was developed. • A quantitative link was established for permethrin and its biomarkers of exposure. • The bayesian framework allows getting confidence interval on the estimated parameters. • The PBPK model can be extrapolated

Mutation in cyclophilin B that causes hyperelastosis cutis in American Quarter Horse does not affect peptidylprolyl cis-trans isomerase activity but shows altered cyclophilin B-protein interactions and affects collagen folding.

Science.gov (United States)

Ishikawa, Yoshihiro; Vranka, Janice A; Boudko, Sergei P; Pokidysheva, Elena; Mizuno, Kazunori; Zientek, Keith; Keene, Douglas R; Rashmir-Raven, Ann M; Nagata, Kazuhiro; Winand, Nena J; Bächinger, Hans Peter

2012-06-22

The rate-limiting step of folding of the collagen triple helix is catalyzed by cyclophilin B (CypB). The G6R mutation in cyclophilin B found in the American Quarter Horse leads to autosomal recessive hyperelastosis cutis, also known as hereditary equine regional dermal asthenia. The mutant protein shows small structural changes in the region of the mutation at the side opposite the catalytic domain of CypB. The peptidylprolyl cis-trans isomerase activity of the mutant CypB is normal when analyzed in vitro. However, the biosynthesis of type I collagen in affected horse fibroblasts shows a delay in folding and secretion and a decrease in hydroxylysine and glucosyl-galactosyl hydroxylysine. This leads to changes in the structure of collagen fibrils in tendon, similar to those observed in P3H1 null mice. In contrast to cyclophilin B null mice, where little 3-hydroxylation was found in type I collagen, 3-hydroxylation of type I collagen in affected horses is normal. The mutation disrupts the interaction of cyclophilin B with the P-domain of calreticulin, with lysyl hydroxylase 1, and probably other proteins, such as the formation of the P3H1·CypB·cartilage-associated protein complex, resulting in less effective catalysis of the rate-limiting step in collagen folding in the rough endoplasmic reticulum.

Mutation in Cyclophilin B That Causes Hyperelastosis Cutis in American Quarter Horse Does Not Affect Peptidylprolyl cis-trans Isomerase Activity but Shows Altered Cyclophilin B-Protein Interactions and Affects Collagen Folding*

Science.gov (United States)

Ishikawa, Yoshihiro; Vranka, Janice A.; Boudko, Sergei P.; Pokidysheva, Elena; Mizuno, Kazunori; Zientek, Keith; Keene, Douglas R.; Rashmir-Raven, Ann M.; Nagata, Kazuhiro; Winand, Nena J.; Bächinger, Hans Peter

2012-01-01

The rate-limiting step of folding of the collagen triple helix is catalyzed by cyclophilin B (CypB). The G6R mutation in cyclophilin B found in the American Quarter Horse leads to autosomal recessive hyperelastosis cutis, also known as hereditary equine regional dermal asthenia. The mutant protein shows small structural changes in the region of the mutation at the side opposite the catalytic domain of CypB. The peptidylprolyl cis-trans isomerase activity of the mutant CypB is normal when analyzed in vitro. However, the biosynthesis of type I collagen in affected horse fibroblasts shows a delay in folding and secretion and a decrease in hydroxylysine and glucosyl-galactosyl hydroxylysine. This leads to changes in the structure of collagen fibrils in tendon, similar to those observed in P3H1 null mice. In contrast to cyclophilin B null mice, where little 3-hydroxylation was found in type I collagen, 3-hydroxylation of type I collagen in affected horses is normal. The mutation disrupts the interaction of cyclophilin B with the P-domain of calreticulin, with lysyl hydroxylase 1, and probably other proteins, such as the formation of the P3H1·CypB·cartilage-associated protein complex, resulting in less effective catalysis of the rate-limiting step in collagen folding in the rough endoplasmic reticulum. PMID:22556420

Density functional theory study of structural and electronic properties of trans and cis structures of thiothixene as a nano-drug.

Science.gov (United States)

Noori Tahneh, Akram; Bagheri Novir, Samaneh; Balali, Ebrahim

2017-11-25

The geometrical structure, electronic and optical properties, electronic absorption spectra, vibrational frequencies, natural charge distribution, MEP analysis and thermodynamic properties of the trans and cis structures of the drug thiothixene were investigated using density functional theory (DFT) and time-dependent DFT (TDDFT) methods with the B3LYP hybrid functional and 6-311 + G(d,p) basis set. The results of the calculations demonstrate that the cis structure of thiothixene has appropriate quantum properties that can act as an active medicine. The relative energies of trans and cis structures of thiothixene shows that the cis structure is more stable than the trans structure, with a small energy difference. TDDFT calculations show that the cis structure of thiothixene has the best absorption properties. The calculated NLO properties show that the NLO properties of the cis structure of thiothixene are higher than the trans structure, and the fact that the chemical hardness of the cis structure is lower than that of the trans structure that indicates that the reactivity and charge transfer of the cis isomer of thiothixene is higher than that of trans thiothixene. The molecular electrostatic potential (MEP) maps of both structures of thiothixene demonstrate that the oxygen atoms of the molecule are appropriate areas for electrophilic reactions. The vibrational frequencies of the two conformations of thiothixene demonstrate that both structures of thiothixene have almost similar modes of vibrations. The calculated thermodynamic parameters show that these quantities increase with enhancing temperature due to the enhancement of molecular vibrational intensities with temperature. Graphical abstract Trans/Cis isomerization of thiothixene drug.

Excited State s-cis Rotamers Produced by Extreme Red Edge Excitation of all-trans-1,4-Diphenyl-1,3-butadiene

DEFF Research Database (Denmark)

Wallace-Williams, Stacie E.; Møller, Søren; Goldbeck, Robert A.

1993-01-01

with the wavelength independence observed for the excited singlet-state absorption and fluorescence emission spectra of 1,5-diphenyl-2,3,4,6,7,8- hexahydronaphthalene and for the fluorescence emission spectra of 1,4diphenyl-1,3-cyclopentadiene, s-trans and s-cis structural analogs of DPB, respectively. The spectral...... changes in DPB can be explained in terms of an excitation wavelength-dependent production of s-cis and s-trans rotamer populations in the excited state. The DPB fluorescence emission spectrum was resolved into s-cis and s-trans components. The vibronic structure of the s-cis fluorescence spectrum...... is similar to that of s-trans, but the band origin is red-shifted and there is a slightly larger amplitude on the red edge. The excited-state absorption spectrum of s-cis DPB appears to be red-shifted relative to that of s-trans DPB as well....

On the structure and function of the phytoene desaturase CRTI from Pantoea ananatis, a membrane-peripheral and FAD-dependent oxidase/isomerase.

Directory of Open Access Journals (Sweden)

Patrick Schaub

Full Text Available CRTI-type phytoene desaturases prevailing in bacteria and fungi can form lycopene directly from phytoene while plants employ two distinct desaturases and two cis-tans isomerases for the same purpose. This property renders CRTI a valuable gene to engineer provitamin A-formation to help combat vitamin A malnutrition, such as with Golden Rice. To understand the biochemical processes involved, recombinant CRTI was produced and obtained in homogeneous form that shows high enzymatic activity with the lipophilic substrate phytoene contained in phosphatidyl-choline (PC liposome membranes. The first crystal structure of apo-CRTI reveals that CRTI belongs to the flavoprotein superfamily comprising protoporphyrinogen IX oxidoreductase and monoamine oxidase. CRTI is a membrane-peripheral oxidoreductase which utilizes FAD as the sole redox-active cofactor. Oxygen, replaceable by quinones in its absence, is needed as the terminal electron acceptor. FAD, besides its catalytic role also displays a structural function by enabling the formation of enzymatically active CRTI membrane associates. Under anaerobic conditions the enzyme can act as a carotene cis-trans isomerase. In silico-docking experiments yielded information on substrate binding sites, potential catalytic residues and is in favor of single half-site recognition of the symmetrical C(40 hydrocarbon substrate.

Separation behavior of octadecadienoic acid isomers and identification of cis- and trans-isomers using gas chromatography.

Science.gov (United States)

Shibamoto, Shigeaki; Gooley, Andrew; Yamamoto, Kouhei

2015-01-01

Using a strongly polar cyanopropyl capillary column we have investigated the gas chromatography (GC) separation behaviors of 24 octadecadienoic acid methyl ester (18:2ME) isomers compared against saturated methyl stearate (18:0ME) and arachidic acid methyl ester (20:0ME), and the dependency on the GC column temperature. The 24 isomers were obtained by performing cis-to trans-isomerization of six regioisomers: five of the 18:2ME isomers were prepared by the partial reduction of methyl α-linolenate and methyl γ-linolenate C18 trienoic acids with different double bond positions, whereas the sixth isomer, 18:2ME (c5, c9), was obtained from a raw constituent fatty acid methyl ester (FAME) sample extracted from Japanese yew seeds. There are no reference standards commercially available for 18:2ME isomers, and in elucidating the elution order of these isomers this study should help the future identification of cis- and trans-type of 18:2ME. We also report the identification method of cis- and trans-type of FAME using equivalent chain lengths and attempt the identification of cis- and trans-type of 18:2ME isomers from partially hydrogenated canola oil.

Mediation Analysis Demonstrates That Trans-eQTLs Are Often Explained by Cis-Mediation: A Genome-Wide Analysis among 1,800 South Asians

Science.gov (United States)

Pierce, Brandon L.; Tong, Lin; Chen, Lin S.; Rahaman, Ronald; Argos, Maria; Jasmine, Farzana; Roy, Shantanu; Paul-Brutus, Rachelle; Westra, Harm-Jan; Franke, Lude; Esko, Tonu; Zaman, Rakibuz; Islam, Tariqul; Rahman, Mahfuzar; Baron, John A.; Kibriya, Muhammad G.; Ahsan, Habibul

2014-01-01

A large fraction of human genes are regulated by genetic variation near the transcribed sequence (cis-eQTL, expression quantitative trait locus), and many cis-eQTLs have implications for human disease. Less is known regarding the effects of genetic variation on expression of distant genes (trans-eQTLs) and their biological mechanisms. In this work, we use genome-wide data on SNPs and array-based expression measures from mononuclear cells obtained from a population-based cohort of 1,799 Bangladeshi individuals to characterize cis- and trans-eQTLs and determine if observed trans-eQTL associations are mediated by expression of transcripts in cis with the SNPs showing trans-association, using Sobel tests of mediation. We observed 434 independent trans-eQTL associations at a false-discovery rate of 0.05, and 189 of these trans-eQTLs were also cis-eQTLs (enrichment Pmediator based on Sobel Pmediation signals in two European cohorts, and while only 7 trans-eQTL associations were present in one or both cohorts, 6 showed evidence of cis-mediation. Analyses of simulated data show that complete mediation will be observed as partial mediation in the presence of mediator measurement error or imperfect LD between measured and causal variants. Our data demonstrates that trans-associations can become significantly stronger or switch directions after adjusting for a potential mediator. Using simulated data, we demonstrate that this phenomenon is expected in the presence of strong cis-trans confounding and when the measured cis-transcript is correlated with the true (unmeasured) mediator. In conclusion, by applying mediation analysis to eQTL data, we show that a substantial fraction of observed trans-eQTL associations can be explained by cis-mediation. Future studies should focus on understanding the mechanisms underlying widespread cis-mediation and their relevance to disease biology, as well as using mediation analysis to improve eQTL discovery. PMID:25474530

Thermal degradation kinetics of all-trans and cis-carotenoids in a light-induced model system.

Science.gov (United States)

Xiao, Ya-Dong; Huang, Wu-Yang; Li, Da-Jing; Song, Jiang-Feng; Liu, Chun-Quan; Wei, Qiu-Yu; Zhang, Min; Yang, Qiu-Ming

2018-01-15

Thermal degradation kinetics of lutein, zeaxanthin, β-cryptoxanthin, β-carotene was studied at 25, 35, and 45°C in a model system. Qualitative and quantitative analyses of all-trans- and cis-carotenoids were conducted using HPLC-DAD-MS technologies. Kinetic and thermodynamic parameters were calculated by non-linear regression. A total of 29 geometrical isomers and four oxidation products were detected, including all-trans-, keto compounds, mono-cis- and di-cis-isomers. Degradations of all-trans-lutein, zeaxanthin, β-cryptoxanthin, and β-carotene were described by a first-order kinetic model, with the order of rate constants as k β -carotene >k β -cryptoxanthin >k lutein >k zeaxanthin . Activation energies of zeaxanthin, lutein, β-cryptoxanthin, and β-carotene were 65.6, 38.9, 33.9, and 8.6kJ/moL, respectively. cis-carotenoids also followed with the first-order kinetic model, but they did not show a defined sequence of degradation rate constants and activation energies at different temperatures. A possible degradation pathway of four carotenoids was identified to better understand the mechanism of carotenoid degradation. Copyright © 2017 Elsevier Ltd. All rights reserved.

Chemometric analysis of mass spectra of cis and trans fatty acid picolinyl esters

DEFF Research Database (Denmark)

Leth, Torben

1997-01-01

and trans fatty acids of C16:1, C18:1,n-9, C18:1,n-12, C18:2 and C22:1 in two- and three-dimensional score plots. With Soft Independent Modelling of Class Analogy (SIMCA), it is possible to calculate models that can predict from the mass spectra of unknown fatty acids whether they are of the cis or trans...... configuration, which is demonstrated for C18:1 trans from hardened margarine and butter....

Identification of absolute geometries of cis and trans molecular isomers by Coulomb Explosion Imaging.

Science.gov (United States)

Ablikim, Utuq; Bomme, Cédric; Xiong, Hui; Savelyev, Evgeny; Obaid, Razib; Kaderiya, Balram; Augustin, Sven; Schnorr, Kirsten; Dumitriu, Ileana; Osipov, Timur; Bilodeau, René; Kilcoyne, David; Kumarappan, Vinod; Rudenko, Artem; Berrah, Nora; Rolles, Daniel

2016-12-02

An experimental route to identify and separate geometric isomers by means of coincident Coulomb explosion imaging is presented, allowing isomer-resolved photoionization studies on isomerically mixed samples. We demonstrate the technique on cis/trans 1,2-dibromoethene (C 2 H 2 Br 2 ). The momentum correlation between the bromine ions in a three-body fragmentation process induced by bromine 3d inner-shell photoionization is used to identify the cis and trans structures of the isomers. The experimentally determined momentum correlations and the isomer-resolved fragment-ion kinetic energies are matched closely by a classical Coulomb explosion model.

Investigation of cis-trans isomer dependent dermatotoxicokinetics of UV filter ethylhexyl methoxycinnamate through stratum corneum in vivo.

Science.gov (United States)

Sharma, Anežka; Bányiová, Katarína; Vrana, Branislav; Justan, Ivan; Čupr, Pavel

2017-11-01

2-Ethylhexyl methoxycinnamate (EHMC) is one of the most used ultraviolet filters in personal care products. It undergoes cis/trans isomerization in sunlight, and there is limited toxicological understanding of the effects of the cis-isomer. It is known that two geometric isomers of one compound can have different physico-chemical properties and effects. However, there are no studies focusing on toxicokinetics of EHMC isomerization products to compare their potential difference in dermal exposure to cis-EHMC and trans-EHMC due to the difference in their dermatotoxicokinetics. In this study, dermal absorption of the parental trans-EHMC and its cis isomer was studied. A commercially available sunscreen lotion containing trans-EHMC and spiked with laboratory-prepared cis-EHMC was locally applied on the forearm skin of two volunteers. After 8 h of skin exposure, the stratum corneum (SC) layer was removed by tape stripping. The removed thickness of the SC was determined spectrophotometrically using a total protein assay. The concentration of both isomers in the removed SC was measured by HPLC-DAD. A new diffusion and permeability coefficient of both EHMC isomers in SC were determined by Fick's second law of diffusion in vivo. The difference in dermatotoxicokinetic parameters between the two isomers was not statistically significant. However, separate toxicological studies of isomeric forms and the determination of their dermatotoxicokinetic parameters are crucial for refinement of human risk assessment.

Graphene oxide catalyzed cis-trans isomerization of azobenzene

Directory of Open Access Journals (Sweden)

Dongha Shin

2014-09-01

Full Text Available We report the fast cis-trans isomerization of an amine-substituted azobenzene catalyzed by graphene oxide (GO, where the amine functionality facilitates the charge transfer from azobenzene to graphene oxide in contrast to non-substituted azobenzene. This catalytic effect was not observed in stilbene analogues, which strongly supports the existence of different isomerization pathways between azobenzene and stilbene. The graphene oxide catalyzed isomerization is expected to be useful as a new photoisomerization based sensing platform complementary to GO-based fluorescence quenching methods.

Cis/trans Coordination in olefin metathesis by static and molecular dynamic DFT calculations

KAUST Repository

Poater, Albert; Correa, Andrea; Pump, Eva; Cavallo, Luigi

2014-01-01

In regard to [(N-heterocyclic carbene)Ru]-based catalysts, it is still a matter of debate if the substrate binding is preferentially cis or trans to the N-heterocyclic carbene ligand. By means of static and molecular dynamic DFT calculations, a simple olefin, like ethylene, is shown to be prone to the trans binding. Bearing in mind the higher reactivity of trans isomers in olefin metathesis, this insight helps to construct small alkene substrates with increased reactivity. © 2014 Springer Science+Business Media New York.

Cis/trans Coordination in olefin metathesis by static and molecular dynamic DFT calculations

KAUST Repository

Poater, Albert

2014-05-25

In regard to [(N-heterocyclic carbene)Ru]-based catalysts, it is still a matter of debate if the substrate binding is preferentially cis or trans to the N-heterocyclic carbene ligand. By means of static and molecular dynamic DFT calculations, a simple olefin, like ethylene, is shown to be prone to the trans binding. Bearing in mind the higher reactivity of trans isomers in olefin metathesis, this insight helps to construct small alkene substrates with increased reactivity. © 2014 Springer Science+Business Media New York.

Multi-arrangement quantum dynamics in 6D: cis-trans isomerization and 1,3-hydrogen transfer in HONO

International Nuclear Information System (INIS)

Luckhaus, David

2004-01-01

The overtone spectrum and wave packet dynamics of nitrous acid (HONO) are studied with a global six-dimensional potential energy function interpolated directly from density functional calculations together with the corresponding dipole hypersurfaces. The quantum dynamics for the cis-trans isomerization and the symmetric 1,3-hydrogen transfer are treated in full dimensionality in terms of the generalized Z-matrix discrete variable representation. For the quantum mechanical description of complicated rearrangements a new approach to multi-arrangement quantum dynamics is introduced and applied to the symmetric hydrogen exchange tunneling in cis-HONO. The cis-trans isomerization is found to be dominated by adiabatic barrier crossing with only minor tunneling contributions, but with pronounced mode selectivity. The OH-stretching overtones of trans-HONO are adiabatically almost completely separated from the OH torsional dynamics with extremely slow intramolecular energy redistribution. The 1,3-hydrogen transfer, by contrast, proceeds largely via coherent tunneling even significantly below the barrier. The process is clearly non-adiabatic (at least in terms of valence coordinates) but remains highly state specific. While the absorption spectrum of trans-HONO remains largely unaffected, OH-stretching overtones of cis-HONO (above the barrier between 2ν OH and 3ν OH ) decompose into highly fragmented absorption patterns with corresponding tunneling periods on the picosecond time scale

Vibrational spectra and assignments for cis- and trans-1,2-difluorocyclopropane and three deuterium substituted modifications of each isomer

International Nuclear Information System (INIS)

Craig, N.C.; Hu Chao, T.N.; Cuellar, E.; Hendriksen, D.E.; Koepke, J.W.

1975-01-01

Infrared spectra under a variety of experimental conditions and Raman spectra for the liquid phase have been recorded for the cis and trans isomers of 1,2-difluorocyclopropane and the 1,2-d 2 , 3,3-d 2 , and d 4 deuterated modifications. Almost all of the 168 fundamentals of this set of eight molecules have been observed and assigned convincingly. For cis-1,2-difluorocyclopropane-d 0 the fundamentals are (a') 3105, 3063, 3023, 1450, 1365, 1224, 1135, 1047, 862, 784, 468, 209 cm -1 ; (a'') 3055, 1346, 1150, 1089, 1060, 993, 739, 621, 319 cm -1 . For trans-1,2-difluorocyclopropane-d 0 the fundamentals are (a) 3070, 3021, 1457, 1380, 1203, 1132, 1068, 961, 842, 415, 279 cm -1 ; (b) 3110, 3070, 1304, 1161, 1072, 1005, 937, 783, 452, 303 cm -1 . Only the 1089-cm -1 mode in the cis and the 937-cm -1 mode in the trans are in doubt. Group frequency descriptions are discussed qualitatively, and attention is drawn to the fundamentals near 1450 cm -1 which are characteristic of fluorocyclopropanes and appear to be largely due to ring stretching. From previously published equilibrium data for the cis-to-trans isomerization and the fundamental frequencies of the two isomers, an electronic energy difference of -2800 +- 200 cal/mol has been calculated. In contrast, the trans isomer of 1,2-difluoroethylene has an energy 1100 cal/mol greater than the cis, and the trans rotamer of 1,2-difluoroethane has an energy about 600 cal/mol greater than the gauche. (auth)

Trans and cis influences and effects in cobalamins and in their simple models.

Science.gov (United States)

De March, Matteo; Demitri, Nicola; Geremia, Silvano; Hickey, Neal; Randaccio, Lucio

2012-11-01

The interligand interactions in coordination compounds have been principally interpreted in terms of cis and trans influences and effects, which can be defined as the ability of a ligand X to affect the bond of another ligand, cis or trans to X, to the metal. This review analyzes these effects/influences in cobalamins (XCbl) and their simple models cobaloximes, LCo(chel)X. Important properties of these complexes, such as geometry, stability, and reactivity, can be rationalized in terms of steric and electronic factors of the ligands. Experimental evidence of normal and inverse trans influence is described in alkylcobaloximes for the first time. The study of simple B(12) models has complemented that on the more complex cobalamins, with particular emphasis on the properties of the axial L-Co-X moiety. Some of the conclusions reached for the axial fragment of simple models have also been qualitatively detected in cobalamins and have furnished new insight into the as yet unestablished mechanism for the homolytic cleavage of the Co - C bond in the AdoCbl-based enzymes. Copyright © 2012 Elsevier Inc. All rights reserved.

Enthalpy of sublimation/vaporization of trans-cyclohexyl-1,4-diamine and cis-cyclohexyl-1,2-diamine

OpenAIRE

Tomé, Luciana I. N.; Rosado, Mário T. S.; Nunes, Sandra C. C.; Maria, Teresa M. R.; Canotilho, João; Eusébio, M. Ermelinda S.

2007-01-01

The molar enthalpy of sublimation, , of trans-cyclohexyl-1,4-diamine and the molar enthalpy of vaporization, , of cis-cyclohexyl-1,2-diamine, at the temperature 298.15 K, were determined by calorimetry. was obtained for the trans-isomer and for the cis form. The molar enthalpy of fusion of the first compound, at T = 342.1 K, was determined by differential scanning calorimetry. The molar enthalpy of vaporization of the 1,4-isomer was estimated by combining the value of the enthalpy of sublimat...

Effective line strengths of trans-nitrous acid near 1275 cm−1 and cis-nitrous acid at 1660 cm−1

International Nuclear Information System (INIS)

Lee, B.H.; Wood, E.C.; Wormhoudt, J.; Shorter, J.H.; Herndon, S.C.; Zahniser, M.S.; Munger, J.W.

2012-01-01

We determined the effective line strengths of the trans conformer of nitrous acid (HONO) near 1275 cm −1 (R-branch of ν 3 mode, N---O---H bend) and of the cis conformer at 1660 cm −1 (R-branch of ν 2 mode, N=O stretch), both at a spectral resolution of 0.001 cm −1 by tunable infrared laser differential absorption spectroscopy (TILDAS) utilizing continuous-wave quantum cascade (cw-QC) lasers. Absorbance of one conformer was measured while simultaneously quantifying the mixing ratio of total HONO by catalytic conversion to nitric oxide (NO) followed by calibrated absorption spectroscopy. Line strengths obtained here are consistent with previously reported band strengths for the trans conformer but are lower by a factor of approximately 2.4 for the cis conformer. -- Highlights: ► Effective line strengths for the cis-HONO at 1660 cm −1 was quantified. ► Effective line strengths for the trans conformer near 1275 cm −1 was also quantified. ► Results for trans-HONO are in agreement with previously published band strength. ► Previous cis band strength is high by factor of 2.4 due to spectral interference.

A theoretical view on the thermodynamic cis-trans equilibrium of dihalo ruthenium olefin metathesis (pre-)catalysts

KAUST Repository

Pump, Eva

2015-02-24

Abstract: This work was conducted to provide an overview on the position of the thermodynamic cis–trans equilibrium of 85 conventional and X-chelated alkylidene-ruthenium complexes (X=O, S, Se, N, P, Cl, I, Br). The reported energies (ΔE) were obtained through single-point calculations with M06 functional and TZVP basis set from BP86/SVP-optimized cis- and trans-dichloro geometries and using the polarizable continuum model to simulate the influence of the solvent. Dichloromethane and toluene were selected as examples for solvents with high and low dielectric constants. The obtained relative stabilities of the cis- and trans-dihalo derivatives of the respective alkylidene complexes will serve for a better explanation of their catalytic activity as has been disclosed herein with selected examples.Graphical abstract: [Figure not available: see fulltext.

"There's no chasing involved": cis/trans relationships, "tranny chasers," and the future of a sex-positive trans politics.

Science.gov (United States)

Tompkins, Avery Brooks

2014-01-01

This article adds to a small, but growing, body of work on trans sexualities and partnerships, and provides a much-needed inquiry into the complex and contested politics of desire when we take trans identities, bodies, and sexualities into account. Using digital ethnographic data from YouTube videos along with in-person observational data from LGBTQ and trans conferences in the U.S., Tompkins argues that a sex-positive trans politics cannot emerge in trans and trans-allied communities if the rhetoric of the "tranny chaser" continues to inform discourses of desire and attraction to trans people.

Incorporation of deuterium-labeled trans- and cis-13-octadecenoic acids in human plasma lipids

International Nuclear Information System (INIS)

Emken, E.A.; Adlof, R.O.; Rohwedder, W.K.; Gulley, R.M.

1983-01-01

The absorption and distribution of deuterated trans- and cis-13-octadecenoic acid (13t-18:1 and 13c-18:1) in plasma lipids were compared to deuterated cis-9-octadecenoic acid (9c-18:1) in two young adult male subjects. A mixture of triglycerides was fed in a multiple-labeled experiment where each triglyceride contained a fatty acid labeled with a different number of deuterium atoms. Analysis of human plasma lipids by mass spectroscopy allowed the distribution of the two 13-octadecenoic acid isomers to be directly compared to cis-9-octadecenoic acid. Plasma lipids selectively excluded both the 13t-18:1 and 13c-18:1 isomers relative to 9c-18:1 in all neutral and phospholipid fractions. Discrimination against incorporation of the 13t-18:1 isomer into plasma cholesteryl ester and 2-acyl phosphatidylcholine was nearly absolute. The 1-acyl phosphatidylcholine fraction exhibited a large positive selectivity for the 13t-18:1 isomer. Differences in the relative distribution of the trans and cis 13-18:1 isomers vs. 9c-18:1 in the various lipoprotein lipid classes were found. Analysis of the chylomicron triglyceride component of the plasma lipids indicated all three fatty acids were equally well absorbed

Effects of peptidyl-prolyl isomerase 1 depletion in animal models of prion diseases.

Science.gov (United States)

Legname, Giuseppe; Virgilio, Tommaso; Bistaffa, Edoardo; De Luca, Chiara Maria Giulia; Catania, Marcella; Zago, Paola; Isopi, Elisa; Campagnani, Ilaria; Tagliavini, Fabrizio; Giaccone, Giorgio; Moda, Fabio

2018-04-20

Pin1 is a peptidyl-prolyl isomerase that induces the cis-trans conversion of specific Ser/Thr-Pro peptide bonds in phosphorylated proteins, leading to conformational changes through which Pin1 regulates protein stability and activity. Since down-regulation of Pin1 has been described in several neurodegenerative disorders, including Alzheimer's Disease (AD), Parkinson's Disease (PD) and Huntington's Disease (HD), we investigated its potential role in prion diseases. Animals generated on wild-type (Pin1 +/+ ), hemizygous (Pin1 +/- ) or knock-out (Pin1 -/- ) background for Pin1 were experimentally infected with RML prions. The study indicates that, neither the total depletion nor reduced levels of Pin1 significantly altered the clinical and neuropathological features of the disease.

Different DNA damage response of cis and trans isomers of commonly used UV filter after the exposure on adult human liver stem cells and human lymphoblastoid cells.

Science.gov (United States)

Sharma, Anežka; Bányiová, Katarína; Babica, Pavel; El Yamani, Naouale; Collins, Andrew Richard; Čupr, Pavel

2017-09-01

2-ethylhexyl 4-methoxycinnamate (EHMC), used in many categories of personal care products (PCPs), is one of the most discussed ultraviolet filters because of its endocrine-disrupting effects. EHMC is unstable in sunlight and can be transformed from trans-EHMC to emergent cis-EHMC. Toxicological studies are focusing only on trans-EHMC; thus the toxicological data for cis-EHMC are missing. In this study, the in vitro genotoxic effects of trans- and cis-EHMC on adult human liver stem cells HL1-hT1 and human-derived lymphoblastoid cells TK-6 using a high-throughput comet assay were studied. TK-6 cells treated with cis-EHMC showed a high level of DNA damage when compared to untreated cells in concentrations 1.56 to 25μgmL -1 . trans-EHMC showed genotoxicity after exposure to the two highest concentrations 12.5 and 25μgmL -1 . The increase in DNA damage on HL1-hT1 cells induced by cis-EHMC and trans-EHMC was detected at the concentration 25μgmL -1 . The No observed adverse effect level (NOAEL, mg kg -1 bwday -1 ) was determined using a Quantitative in vitro to in vivo extrapolation (QIVIVE) approach: NOAEL trans-EHMC =3.07, NOAEL cis-EHMC =0.30 for TK-6 and NOAEL trans-EHMC =26.46, NOAEL cis-EHMC =20.36 for HL1-hT1. The hazard index (HI) was evaluated by comparing the reference dose (RfD, mgkg -1 bwday -1 ) obtained from our experimental data with the chronic daily intake (CDI) of the female population. Using comet assay experimental data with the more sensitive TK-6 cells, HI cis-EHMC was 7 times higher than HI trans-EHMC . In terms of CDI, relative contributions were; dermal exposure route>oral>inhalation. According to our results we recommend the RfD trans-EHMC =0.20 and RfD cis-EHMC =0.02 for trans-EHMC and cis-EHMC, respectively, to use for human health risk assessment. The significant difference in trans-EHMC and cis-EHMC response points to the need for toxicological reevaluation and application reassessment of both isomers in PCPs. Copyright © 2017 Elsevier B

On the effect of tether composition on cis/trans selectivity in intramolecular Diels-Alder reactions.

Science.gov (United States)

Paddon-Row, Michael N; Longshaw, Alistair I; Willis, Anthony C; Sherburn, Michael S

2009-01-05

Intramolecular Diels-Alder (IMDA) transition structures (TSs) and energies have been computed at the B3LYP/6-31+G(d) and CBS-QB3 levels of theory for a series of 1,3,8-nonatrienes, H(2)C=CH-CH=CH-CH(2)-X-Z-CH=CH(2) [-X-Z- = -CH(2)-CH(2)- (1); -O-C(=O)- (2); -CH(2)-C(=O)- (3); -O-CH(2)- (4); -NH-C(=O)- (5); -S-C(=O)- (6); -O-C(=S)- (7); -NH-C(=S)- (8); -S-C(=S)- (9)]. For each system studied (1-9), cis- and trans-TS isomers, corresponding, respectively, to endo- and exo-positioning of the -C-X-Z- tether with respect to the diene, have been located and their relative energies (E(rel) (TS)) employed to predict the cis/trans IMDA product ratio. Although the E(rel) (TS) values are modest (typically NH or S), the IMDA cis stereoselectivity diminishes. The predicted stereochemical reaction preferences are explained in terms of two opposing effects operating in the cis-TS, namely (1) unfavorable torsional (eclipsing) strain about the C4-C5 bond, that is caused by the -C-X-C(=Y)- group's strong tendency to maintain local planarity; and (2) attractive electrostatic and secondary orbital interactions between the endo-(thio)carbonyl group, C=Y, and the diene. The former interaction predominates when X is weakly electronegative (X=N, S), while the latter is dominant when X is more strongly electronegative (X=O), or a methylene group (X=CH(2)) which increases tether flexibility. These predictions hold up to experimental scrutiny, with synthetic IMDA reactions of 1, 2, 3, and 4 (published work) and 5, 6, and 8 (this work) delivering ratios close to those calculated. The reactions of thiolacrylate 5 and thioamide 8 represent the first examples of IMDA reactions with tethers of these types. Our results point to strategies for designing tethers, which lead to improved cis/trans-selectivities in IMDAs that are normally only weakly selective. Experimental verification of the validity of this claim comes in the form of fumaramide 14, which undergoes a more trans-selective IMDA reaction

Estimation of cis-9, trans-11 conjugated linoleic acid content in UK foods and assessment of dietary intake in a cohort of healthy adults.

Science.gov (United States)

Mushtaq, Sohail; Heather Mangiapane, E; Hunter, Kirsty A

2010-05-01

Dietary conjugated linoleic acid (CLA) from ruminant-derived foods may be potentially beneficial to health. The quantity of cis-9, trans-11 CLA and trans-10, cis-12 CLA in a range of UK foodstuffs (112 foods) was determined using triple-column silver ion HPLC. The cis-9, trans-11 CLA content ranged from 1.9 mg/g lipid (mild Cheddar) to 7.3 mg/g lipid (processed cheese) in cheeses, from 0.9 mg/g lipid (ice cream) to 3.7 mg/g lipid (double cream) in non-cheese dairy products, and from 2.9 mg/g lipid (Swedish meatballs) to 6.0 mg/g lipid (minced lamb) in meat products. cis-9, trans-11 CLA concentrations for chocolate and sweets ranged from 0.1 mg/g lipid (hot chocolate) to 4.8 mg/g lipid (buttermint). The trans-10, cis-12 CLA isomer was undetected or negligible in the food samples examined. To provide information about dietary cis-9, trans-11 CLA intakes in the UK, a study was performed to estimate the daily intake of CLA in a cohort of eighteen healthy volunteers (nine female and nine male; aged 21-60 years; mean BMI = 24.0 kg/m2 (sd 2.2)) with a 7-d weighed food record. This information combined with the CLA isomer contents of UK foodstuffs was used to estimate the daily intake of the cohort. The mean daily intake of cis-9, trans-11 CLA was estimated to be 97.5 (sd 73.3) mg/d. Due to its potential health benefits, it is important to determine the CLA content of food and dietary intake as these data will be useful in determining the role of CLA in health and disease.

Cis and trans monoenoic fatty acids of hydrogenated mango kernel fats

International Nuclear Information System (INIS)

Ali, Z.; Saleem, M.; Siddiqui, H.L.

2007-01-01

The fats produced as a result of hydrogenation of the oils of three varieties of mango kernel (Mangifera indica), were found to consist of trans fatty acids, C/sub 16:1/ (0.02-0.60 %), C/sub 18:1/ (2.69-4.48 %), C/sub 20:1/ (0.02-0.04 %), C/sub 22:1/ (traces-0.05 %), C/sub 24:1/ (traces-0.02 %) in addition to cis fatty acids. (author)

Structural and Biochemical Characterization of the Human Cyclophilin Family of Peptidyl-Prolyl Isomerases

Energy Technology Data Exchange (ETDEWEB)

Davis, Tara L.; Walker, John R.; Campagna-Slater, Valérie; Finerty, Jr., Patrick J.; Paramanathan, Ragika; Bernstein, Galina; MacKenzie, Farrell; Tempel, Wolfram; Ouyang, Hui; Lee, Wen Hwa; Eisenmesser, Elan Z.; Dhe-Paganon, Sirano (Toronto); (Colorado)

2011-12-14

Peptidyl-prolyl isomerases catalyze the conversion between cis and trans isomers of proline. The cyclophilin family of peptidyl-prolyl isomerases is well known for being the target of the immunosuppressive drug cyclosporin, used to combat organ transplant rejection. There is great interest in both the substrate specificity of these enzymes and the design of isoform-selective ligands for them. However, the dearth of available data for individual family members inhibits attempts to design drug specificity; additionally, in order to define physiological functions for the cyclophilins, definitive isoform characterization is required. In the current study, enzymatic activity was assayed for 15 of the 17 human cyclophilin isomerase domains, and binding to the cyclosporin scaffold was tested. In order to rationalize the observed isoform diversity, the high-resolution crystallographic structures of seven cyclophilin domains were determined. These models, combined with seven previously solved cyclophilin isoforms, provide the basis for a family-wide structure:function analysis. Detailed structural analysis of the human cyclophilin isomerase explains why cyclophilin activity against short peptides is correlated with an ability to ligate cyclosporin and why certain isoforms are not competent for either activity. In addition, we find that regions of the isomerase domain outside the proline-binding surface impart isoform specificity for both in vivo substrates and drug design. We hypothesize that there is a well-defined molecular surface corresponding to the substrate-binding S2 position that is a site of diversity in the cyclophilin family. Computational simulations of substrate binding in this region support our observations. Our data indicate that unique isoform determinants exist that may be exploited for development of selective ligands and suggest that the currently available small-molecule and peptide-based ligands for this class of enzyme are insufficient for isoform

Separation of cis- and trans-Asarone from Acorus tatarinowii by Preparative Gas Chromatography

Directory of Open Access Journals (Sweden)

H. L. Zuo

2012-01-01

Full Text Available A preparative gas chromatography (pGC method was developed for the separation of isomers (cis- and trans-asarone from essential oil of Acorus tatarinowii. The oil was primarily fractionated by silica gel chromatography using different ratios of petroleum ether and ethyl acetate as gradient elution solvents. And then the fraction that contains mixture of the isomers was further separated by pGC. The compounds were separated on a stainless steel column packed with 10% OV-101 (3 m × 6 mm, i.d., and then the effluent was split into two gas flows. One percent of the effluent passed to the flame ionization detector (FID for detection and the remaining 99% was directed to the fraction collector. Two isomers were collected after 90 single injections (5 uL with the yield of 178 mg and 82 mg, respectively. Furthermore, the structures of the obtained compounds were identified as cis- and trans-asarone by 1H- and 13C-NMR spectra, respectively.

Los isómeros cis-9, trans-11 y trans-10, cis-12 de ácido linoleico conjugado y su relación con producción de leche de vacas Holstein-Friesian. Revisión

Directory of Open Access Journals (Sweden)

Rufino López Ordaz

2013-01-01

Full Text Available Los objetivos de la presente revisión fueron estudiar los mecanismos de la adición de cis-9, trans-11 y trans-10, cis- 12 del ácido linoleico conjugado (ALC en la dieta y su relación con producción de leche. Ambos isómeros se forman por la isomerización del ALC por la bacteria ruminal Butyrivibrio fribisolvens. También pueden ser producidos por desaturación del ácido vaccénico (18:1, trans-11 en el intestino delgado o el hígado de la vaca lechera. En humanos, el consumo de ambos se relaciona con funciones antiaterogénicas hipocolesterolemia, estimulantes del sistema inmune, protector contra ciertos tipos de cáncer, antioxidante y reductor del peso corporal. Por el contrario, en la vaca la adición de los isómeros incrementa el volumen de leche y reduce su contenido de grasa. El incremento en volumen se atribuye al cis-9, trans-11; mientras que la reducción de grasa se atribuye al tras-10, cis-12. La partición de la energía reduce el periodo del balance negativo de energía (BNE postparto. Este hecho se asocia con un mejoramiento de la eficiencia reproductiva y la salud de la vaca. La reducción de la grasa de leche por los isómeros o por las dietas que inducen reducción de grasa de leche se explica por la presencia de inhibidores de la síntesis de grasas. En conclusión, la adición de los isómeros a las dietas de vacas lecheras no influye en el consumo de materia seca, los cambios de peso y la producción de proteína. Por el contrario, la inclusión en la dieta de ambos isómeros incrementa el volumen de leche y se reduce su contenido de grasa.

17O NMR Studies of the Solvation State of cis/trans Isomers of Amides and Model Protected Peptides

Science.gov (United States)

Gerothanassis, Ioannis P.; Vakka, Constantina; Troganis, Anastasios

1996-06-01

17O shielding constants have been utilized to investigate solvation differences of the cis/trans isomers ofN-methylformamide (NMF),N-ethylformamide (NEF), andtert-butylformamide (TBF) in a variety of solvents with particular emphasis on aqueous solution. Comparisons are also made with protected peptides of the formulas CH3CO-YOH, CH3CO-Y-NHR (Y = Pro, Sar), and CH3CO-Y-Z-NHR (Y = Pro; Z =D-Ala) selectively enriched in17O at the acetyl oxygen atom. Hydration at the amide oxygen induces large and specific modifications of the17O shielding constants, which are practically the same for the cis and trans isomers of NMF, NEF, and the protected peptides. Fortert-butylformamide, the strong deshielding of the trans isomer compared to that of the cis isomer may be attributed to an out-of-plane (torsion-angle) deformation of the amide bond and/or a significant reduction of solvation of the trans isomer due to steric inhibition of the bulkytert-butyl group. Good linear correlation between δ(17O) of amides and δ(17O) of acetone was found for different solvents which have varying dielectric constants and solvation abilities. Sum-over-states calculations, within the solvaton model, underestimate effects of the dielectric constant of the medium on17O shielding, while finite-perturbation-theory calculations give good agreement with the experiment.

An oil mixture with trans-10, cis-12 conjugated linoleic acid increases markers of inflammation and in vivo lipid peroxidation compared with cis-9, trans-11 conjugated linoleic acid in postmenopausal women

DEFF Research Database (Denmark)

Tholstrup, Tine; Raff, Marianne; Straarup, Ellen Marie

2008-01-01

. The plasma cytokines interleukin-6 and tumor necrosis factor-a were not affected by the treatments, nor were any of the other variables measured. In conclusion, oil containing trans-10,cis-12 CLA has several adverse effects on classical and novel markers of coronary vascular disease, whereas the c9, t11 CLA...

Peptidyl prolyl isomerase Pin1-inhibitory activity of D-glutamic and D-aspartic acid derivatives bearing a cyclic aliphatic amine moiety.

Science.gov (United States)

Nakagawa, Hidehiko; Seike, Suguru; Sugimoto, Masatoshi; Ieda, Naoya; Kawaguchi, Mitsuyasu; Suzuki, Takayoshi; Miyata, Naoki

2015-12-01

Pin1 is a peptidyl prolyl isomerase that specifically catalyzes cis-trans isomerization of phosphorylated Thr/Ser-Pro peptide bonds in substrate proteins and peptides. Pin1 is involved in many important cellular processes, including cancer progression, so it is a potential target of cancer therapy. We designed and synthesized a novel series of Pin1 inhibitors based on a glutamic acid or aspartic acid scaffold bearing an aromatic moiety to provide a hydrophobic surface and a cyclic aliphatic amine moiety with affinity for the proline-binding site of Pin1. Glutamic acid derivatives bearing cycloalkylamino and phenylthiazole groups showed potent Pin1-inhibitory activity comparable with that of known inhibitor VER-1. The results indicate that steric interaction of the cyclic alkyl amine moiety with binding site residues plays a key role in enhancing Pin1-inhibitory activity. Copyright © 2015 The Authors. Published by Elsevier Ltd.. All rights reserved.

Ultraviolet irradiation produces cytotoxic synergy and increased DNA interstrand crosslinking with cis- and trans-diamminedichloroplatinum(II)

International Nuclear Information System (INIS)

Swinnen, L.J.; Erickson, L.C.

1989-01-01

The excision-repair mechanism responsible for the removal of UV-induced thymine dimers may also play a role in the repair of cis-diamminedichloroplatinum(II) (cis-DDP)-induced DNA adducts in both bacteria and mammalian cells. It was hypothesized that UV dimers and cis-DDP adducts, when present simultaneously, might compete for a common repair system. Colony survival assays were performed in HT-29 human colon carcinoma cells exposed either to cis-DDP alone or to cis-DDP immediately followed by UV exposure. Progressively greater cytotoxic synergy with both increasing UV dose and cis-DDP dose was observed, to a point of saturation beyond which further toxicity was purely additive. An approximate doubling in DNA crosslink frequency, relative to cis-DDP alone, was found in cells exposed to cis-DDP plus UV. Since cis-DDP produces both inter- and intrastrand DNA crosslinks similar studies were performed with trans-DDP, which is incapable of producing intrastrand crosslinks, but does produce interstrand crosslinks. Cytotoxic synergy and increased interstrand crosslinking again resulted from the addition of UV exposure, but not to the same extent as seen with cis-DDP. (author)

Stereospecific control of peptide gas-phase ion chemistry with cis and trans cyclo ornithine residues

Czech Academy of Sciences Publication Activity Database

Marek, Aleš; Nguyen, H. T. H.; Brož, Břetislav; Tureček, F.

2018-01-01

Roč. 53, č. 2 (2018), s. 124-137 ISSN 1076-5174 Institutional support: RVO:61388963 Keywords : cis and trans isomers * cyclo ornithine * peptide dissociations * peptide ion structures * stereochemistry Subject RIV: CB - Analytical Chemistry, Separation OBOR OECD: Analytical chemistry Impact factor: 2.422, year: 2016

Communication: An accurate calculation of the S1 C2H2 cis-trans isomerization barrier height

International Nuclear Information System (INIS)

Baraban, Joshua H.; Matthews, Devin A.; Stanton, John F.

2016-01-01

A high level ab initio calculation of the cis-trans isomerization barrier height in the first excited singlet electronic state of acetylene is found to agree very well with a recent experimental determination.

Cytokinin metabolism of pathogenic fungus Leptosphaeria maculans involves isopentenyltransferase, adenosine kinase and cytokinin oxidase/dehydrogenase

Czech Academy of Sciences Publication Activity Database

Trdá, Lucie; Barešová, Monika; Šašek, Vladimír; Nováková, Miroslava; Zahajská, Lenka; Dobrev, Petre; Motyka, Václav; Burketová, Lenka

2017-01-01

Roč. 8, JUL 21 (2017), č. článku 1374. ISSN 1664-302X R&D Projects: GA ČR GA13-26798S; GA ČR(CZ) GA16-14649S Institutional support: RVO:61389030 Keywords : Adenosine kinase * Cytokinin * Cytokinin oxidase/dehydrogenase * Isopentenyltransferase * Leptosphaeria maculans * Zeatin cis/trans isomerase Subject RIV: GF - Plant Pathology, Vermin, Weed, Plant Protection OBOR OECD: Microbiology Impact factor: 4.076, year: 2016

A theoretical view on the thermodynamic cis-trans equilibrium of dihalo ruthenium olefin metathesis (pre-)catalysts

KAUST Repository

Pump, Eva; Cavallo, Luigi; Slugovc, Christian

2015-01-01

obtained through single-point calculations with M06 functional and TZVP basis set from BP86/SVP-optimized cis- and trans-dichloro geometries and using the polarizable continuum model to simulate the influence of the solvent. Dichloromethane and toluene were

Photoionization and trans-to-cis isomerization of β-cyclodextrin-encapsulated azobenzene induced by two-color two-laser-pulse excitation.

Science.gov (United States)

Takeshita, Tatsuya; Hara, Michihiro

2018-03-15

Azobenzene (1) and the complex resulting from the incorporation of 1 with cyclodextrin (1/CD) are attractive for light-driven applications such as micromachining and chemical biology tools. The highly sensitive photoresponse of 1 is crucial for light-driven applications containing both 1 and 1/CD to reach their full potential. In this study, we investigated the photoionization and trans-to-cis isomerization of 1/CD induced by one- and two-color two-laser pulse excitation. Photoionization of 1/CD, which was induced by stepwise two-photon absorption, was observed using laser pulse excitation at 266nm. Additionally, simultaneous irradiation with 266 and 532nm laser pulses increased the trans-to-cis isomerization yield (Υ t→c ) by 27%. It was concluded that the increase in Υ t→c was caused by the occurrence of trans-to-cis isomerization in the higher-energy singlet state (S n ), which was reached by S 1 →S n transition induced by laser pulse excitation at 532nm. The results of this study are potentially applicable in light-driven applications such as micromachining and chemical biology tools. Copyright © 2018 Elsevier B.V. All rights reserved.

Fringe proteins modulate Notch-ligand cis and trans interactions to specify signaling states.

Science.gov (United States)

LeBon, Lauren; Lee, Tom V; Sprinzak, David; Jafar-Nejad, Hamed; Elowitz, Michael B

2014-09-25

The Notch signaling pathway consists of multiple types of receptors and ligands, whose interactions can be tuned by Fringe glycosyltransferases. A major challenge is to determine how these components control the specificity and directionality of Notch signaling in developmental contexts. Here, we analyzed same-cell (cis) Notch-ligand interactions for Notch1, Dll1, and Jag1, and their dependence on Fringe protein expression in mammalian cells. We found that Dll1 and Jag1 can cis-inhibit Notch1, and Fringe proteins modulate these interactions in a way that parallels their effects on trans interactions. Fringe similarly modulated Notch-ligand cis interactions during Drosophila development. Based on these and previously identified interactions, we show how the design of the Notch signaling pathway leads to a restricted repertoire of signaling states that promote heterotypic signaling between distinct cell types, providing insight into the design principles of the Notch signaling system, and the specific developmental process of Drosophila dorsal-ventral boundary formation.

cis elements and trans-acting factors involved in dimer formation of murine leukemia virus RNA.

Science.gov (United States)

Prats, A C; Roy, C; Wang, P A; Erard, M; Housset, V; Gabus, C; Paoletti, C; Darlix, J L

1990-02-01

The genetic material of all retroviruses examined so far consists of two identical RNA molecules joined at their 5' ends by the dimer linkage structure (DLS). Since the precise location of the DLS as well as the mechanism and role(s) of RNA dimerization remain unclear, we analyzed the dimerization process of Moloney murine leukemia virus (MoMuLV) genomic RNA. For this purpose we derived an in vitro model for RNA dimerization. By using this model, murine leukemia virus RNA was shown to form dimeric molecules. Deletion mutagenesis in the 620-nucleotide leader of MoMuLV RNA showed that the dimer promoting sequences are located within the encapsidation element Psi between positions 215 and 420. Furthermore, hybridization assays in which DNA oligomers were used to probe monomer and dimer forms of MoMuLV RNA indicated that the DLS probably maps between positions 280 and 330 from the RNA 5' end. Also, retroviral nucleocapsid protein was shown to catalyze dimerization of MoMuLV RNA and to be tightly bound to genomic dimer RNA in virions. These results suggest that MoMuLV RNA dimerization and encapsidation are probably controlled by the same cis element, Psi, and trans-acting factor, nucleocapsid protein, and thus might be linked during virion formation.

Mutations in PPIB (cyclophilin B) delay type I procollagen chain association and result in perinatal lethal to moderate osteogenesis imperfecta phenotypes.

Science.gov (United States)

Pyott, Shawna M; Schwarze, Ulrike; Christiansen, Helena E; Pepin, Melanie G; Leistritz, Dru F; Dineen, Richard; Harris, Catharine; Burton, Barbara K; Angle, Brad; Kim, Katherine; Sussman, Michael D; Weis, Maryann; Eyre, David R; Russell, David W; McCarthy, Kevin J; Steiner, Robert D; Byers, Peter H

2011-04-15

Recessive mutations in the cartilage-associated protein (CRTAP), leucine proline-enriched proteoglycan 1 (LEPRE1) and peptidyl prolyl cis-trans isomerase B (PPIB) genes result in phenotypes that range from lethal in the perinatal period to severe deforming osteogenesis imperfecta (OI). These genes encode CRTAP (encoded by CRTAP), prolyl 3-hydroxylase 1 (P3H1; encoded by LEPRE1) and cyclophilin B (CYPB; encoded by PPIB), which reside in the rough endoplasmic reticulum (RER) and can form a complex involved in prolyl 3-hydroxylation in type I procollagen. CYPB, a prolyl cis-trans isomerase, has been thought to drive the prolyl-containing peptide bonds to the trans configuration needed for triple helix formation. Here, we describe mutations in PPIB identified in cells from three individuals with OI. Cultured dermal fibroblasts from the most severely affected infant make some overmodified type I procollagen molecules. Proα1(I) chains are slow to assemble into trimers, and abnormal procollagen molecules concentrate in the RER, and bind to protein disulfide isomerase (PDI) and prolyl 4-hydroxylase 1 (P4H1). These findings suggest that although CYPB plays a role in helix formation another effect is on folding of the C-terminal propeptide and trimer formation. The extent of procollagen accumulation and PDI/P4H1 binding differs among cells with mutations in PPIB, CRTAP and LEPRE1 with the greatest amount in PPIB-deficient cells and the least in LEPRE1-deficient cells. These findings suggest that prolyl cis-trans isomerase may be required to effectively fold the proline-rich regions of the C-terminal propeptide to allow proα chain association and suggest an order of action for CRTAP, P3H1 and CYPB in procollagen biosynthesis and pathogenesis of OI.

Cyclosporine A-sensitive, cyclophilin B-dependent endoplasmic reticulum-associated degradation.

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Riccardo Bernasconi

2010-09-01

Full Text Available Peptidyl-prolyl cis/trans isomerases (PPIs catalyze cis/trans isomerization of peptide bonds preceding proline residues. The involvement of PPI family members in protein refolding has been established in test tube experiments. Surprisingly, however, no data is available on the involvement of endoplasmic reticulum (ER-resident members of the PPI family in protein folding, quality control or disposal in the living cell. Here we report that the immunosuppressive drug cyclosporine A (CsA selectively inhibits the degradation of a subset of misfolded proteins generated in the ER. We identify cyclophilin B (CyPB as the ER-resident target of CsA that catalytically enhances disposal from the ER of ERAD-L(S substrates containing cis proline residues. Our manuscript presents the first evidence for enzymatic involvement of a PPI in protein quality control in the ER of living cells.

Cyclosporine A-Sensitive, Cyclophilin B-Dependent Endoplasmic Reticulum-Associated Degradation

Science.gov (United States)

Luban, Jeremy; Molinari, Maurizio

2010-01-01

Peptidyl-prolyl cis/trans isomerases (PPIs) catalyze cis/trans isomerization of peptide bonds preceding proline residues. The involvement of PPI family members in protein refolding has been established in test tube experiments. Surprisingly, however, no data is available on the involvement of endoplasmic reticulum (ER)-resident members of the PPI family in protein folding, quality control or disposal in the living cell. Here we report that the immunosuppressive drug cyclosporine A (CsA) selectively inhibits the degradation of a subset of misfolded proteins generated in the ER. We identify cyclophilin B (CyPB) as the ER-resident target of CsA that catalytically enhances disposal from the ER of ERAD-LS substrates containing cis proline residues. Our manuscript presents the first evidence for enzymatic involvement of a PPI in protein quality control in the ER of living cells. PMID:20927389

Trans- and cis-2-phenylindole platinum(II) complexes as cytotoxic agents against human breast adenocarcinoma cell lines

Science.gov (United States)

Tomé, Maria; López, Concepción; González, Asensio; Ozay, Bahadir; Quirante, Josefina; Font-Bardía, Mercè; Calvet, Teresa; Calvis, Carme; Messeguer, Ramon; Baldomá, Laura; Badía, Josefa

2013-09-01

The synthesis and characterization of the new 2-phenylindole derivative: C8H3N-2-C6H5-3NOMe-5OMe (3c) and the trans- and cis-isomers of [Pt(3c)Cl2(DMSO)] complexes (4c and 5c, respectively) are described. The crystal structures of 4c·CH2Cl2 and 5c confirm: (a) the existence of a Pt-Nindole bond, (b) the relative arrangement of the Cl- ligands [trans- (in 4c) or cis- (in 5c)] and (c) the anti-(E) configuration of the oxime. The cytotoxic assessment of C8H3N-2-(C6H4-4‧R1)-3NOMe-5R2 [with R1 = R2 = H (3a); R1 = Cl, R2 = H (3b) and R1 = H, R2 = OMe (3c)] and the geometrical isomers of [Pt(L)Cl2(DMSO)] with L = 3a-3c [trans- (4a-4c) and cis- (5a-5c), respectively] against human breast adenocarcinoma cell lines (MDA-MB231 and MCF-7) is also reported and reveals that all the platinum(II) complexes (except 4a) are more cytotoxic than cisplatin in front of the MCF7 cell line. Electrophoretic DNA migration studies of the synthesized compounds in the absence and in the presence of topoisomerase-I have been performed, in order to get further insights into their mechanism of action.

Anion-assisted trans-cis isomerization of palladium(II) phosphine complexes containing acetanilide functionalities through hydrogen bonding interactions.

Science.gov (United States)

Lu, Xiao-Xia; Tang, Hau-San; Ko, Chi-Chiu; Wong, Jenny Ka-Yan; Zhu, Nianyong; Yam, Vivian Wing-Wah

2005-03-28

The anion-assisted shift of trans-cis isomerization equilibrium of a palladium(II) complex containing acetanilide functionalities brought about by allosteric hydrogen bonding interactions has been established by UV/Vis, 1H NMR, 31P NMR and ESI-MS studies.

Herpesvirus papio contains a plasmid origin of replication that acts in cis interspecies with an Epstein-Barr virus trans-acting function.

Science.gov (United States)

Pesano, R L; Pagano, J S

1986-01-01

Herpesvirus papio (HVP) and Epstein-Barr virus (EBV) are closely related biologically and biochemically; lymphoblastoid cells infected with either virus contain episomal viral DNA. The putative origin of replication for EBV plasmids (oriP) has been assigned to a 1,790-base-pair fragment (cis) in the short unique region of the genome which requires a viral function supplied in trans from elsewhere in the genome (J. Yates, N. Warren, D. Reisman, and B. Sugden, Proc. Natl. Acad. Sci. USA 81:3806-3810, 1984). We report here the identification of the putative origin of replication (cis) in HVP; we assigned it to the HVP EcoRI K fragment. The results indicate that the HVP replication process requires both a cis and a trans-acting function, analogous to that found in EBV. Images PMID:3023667

Ricinus communis cyclophilin: functional characterisation of a sieve tube protein involved in protein folding.

Science.gov (United States)

Gottschalk, Maren; Dolgener, Elmar; Xoconostle-Cázares, Beatriz; Lucas, William J; Komor, Ewald; Schobert, Christian

2008-09-01

The phloem translocation stream of the angiosperms contains a special population of proteins and RNA molecules which appear to be produced in the companion cells prior to being transported into the sieve tube system through the interconnecting plasmodesmata. During this process, these non-cell-autonomous proteins are thought to undergo partial unfolding. Recent mass spectroscopy studies identified peptidyl-prolyl cis-trans isomerase (PPIases) as potential molecular chaperones functioning in the phloem translocation stream (Giavalisco et al. 2006). In the present study, we describe the cloning and characterisation of a castor bean phloem cyclophilin, RcCYP1 that has high peptidyl-prolyl cis-trans isomerase activity. Equivalent enzymatic activity was detected with phloem sap or purified recombinant (His)(6)-tagged RcCYP1. Mass spectrometry analysis of proteolytic peptides, derived from a 22 kDa band in HPLC-fractionated phloem sap, immunolocalisation studies and Western analysis of proteins extracted from castor bean tissues/organs indicated that RcCYP1 is an abundant protein in the companion cell-sieve element complex. Microinjection experiments established that purified recombinant (His)(6)-RcCYP1 can interact with plasmodesmata to both induce an increase in size exclusion limit and mediate its own cell-to-cell trafficking. Collectively, these findings support the hypothesis that RcCYP1 plays a role in the refolding of non-cell-autonomous proteins after their entry into the phloem translocation stream.

Contents of conjugated linoleic acid isomers cis9,trans11 and trans10,cis12 in ruminant and non-ruminant meats available in the Italian market

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Francesca M. Cicognini

2014-04-01

Full Text Available Conjugated linoleic acid (CLA isomers are considered healthy factors due to their anticarcinogenic, anti-atherosclerotic and lipolytic effect. A recommended daily intake from 0.8 to 3 g CLA/day/person has been proposed to obtain biological effects in humans. The aim of this work was to provide data on cis9,trans11 (c9,t11 CLA and trans10,cis12 (t10,c12 CLA contents in meats collected from Italian largescale retail trade and completing a food CLA database. In a first trial, beef loin meats were characterised for label information available for consumers: origin (i.e., Ireland, France- Italy, Piedmont and sex of animals. No differences were observed for c9,t11 and t10,c12 CLA contents (mg/g fat of loin meat from male or female. Piedmontese meat showed lower (P<0.05 c9,t11 CLA level (mg/g fat than Irish and French-Italian meats, whereas similar t10,c12 CLA contents were measured in Piedmontese, Irish and French-Italian meats. Successively, meat samples from different animal species (male and female beef, veal, suckling lamb, belly beef, canned beef meat, pork and horse were characterised for their contents in c9,t11 and t10,c12 CLA. Lamb meat had the highest (P<0.05 c9,t11 CLA content (mg/g fat. The c9,t11 CLA was lower than 2 mg/g fat in veal, pork and horse meats. Low t10,c12 CLA amounts were found in all analysed meat samples. These data provided information to estimate the average daily intake of CLA from meats in an Italian cohort, which can be used in epidemiological studies.

Enthalpy of sublimation/vaporization of trans-cyclohexyl-1,4-diamine and cis-cyclohexyl-1,2-diamine

International Nuclear Information System (INIS)

Tome, Luciana I.N.; Rosado, Mario T.S.; Nunes, Sandra C.C.; Maria, Teresa M.R.; Canotilho, Joao; Eusebio, M. Ermelinda S.

2007-01-01

The molar enthalpy of sublimation, Δ cr g H m 0 , of trans-cyclohexyl-1,4-diamine and the molar enthalpy of vaporization, Δ l g H m 0 , of cis-cyclohexyl-1,2-diamine, at the temperature 298.15 K, were determined by calorimetry. Δ cr g H m 0 (T=298.15K)=(105.0±0.8)kJ.mol -1 was obtained for the trans-isomer and Δ l g H m 0 (T=298.15K)=(62.2±1.0)kJ.mol -1 for the cis form. The molar enthalpy of fusion of the first compound, at T = 342.1 K, was determined by differential scanning calorimetry. The molar enthalpy of vaporization of the 1,4-isomer was estimated by combining the value of the enthalpy of sublimation with that of the enthalpy of fusion. The values obtained for molar standard enthalpy of vaporization and those available for the enthalpy of the diamines in the gas state were used to calculate the difference between the enthalpies of both compounds in the liquid state

Selected cis- and trans-3-fluorostyrene rotamers studied by two-color resonant two-photon mass-analyzed threshold ionization spectroscopy

Science.gov (United States)

Wu, Pei Ying; Tzeng, Wen Bih

2015-10-01

We applied two-color resonant two-photon ionization and mass-analyzed threshold ionization techniques to record the vibronic, photoionization efficiency, and cation spectra of the selected rotamers of 3-fluorostyrene. The adiabatic ionization energies of cis- and trans-3-fluorostyrene were determined to be 69 960 ± 5 and 69 856 ± 5 cm-1, respectively. Cation vibrations 10a, 15, 6b, and 12 of both rotamers have been found to have frequencies of 218, 404, 452, and 971 cm-1, respectively. This finding shows that the relative orientation of the vinyl group with respect to the F atom does not affect these vibrations of the 3-fluorostyrene cation. Our one-dimensional potential energy surface calculations support that the cis-trans isomerization of 3-fluorostyrene does not occur under the present experimental conditions.

On the substrate specificity of the rice strigolactone biosynthesis enzyme DWARF27

KAUST Repository

Bruno, Mark

2016-03-05

Main conclusion: The β-carotene isomerase OsDWARF27 is stereo- and double bond-specific. It converts bicyclic carotenoids with at least one unsubstituted β-ionone ring. OsDWARF27 may contribute to the formation of α-carotene-based strigolactone-like compounds.Strigolactones (SLs) are synthesized from all-trans-β-carotene via a pathway involving the β-carotene isomerase DWARF27, the carotenoid cleavage dioxygenases 7 and 8 (CCD7, CCD8), and cytochrome P450 enzymes from the 711 clade (MAX1 in Arabidopsis). The rice enzyme DWARF27 was shown to catalyze the reversible isomerization of all-trans- into 9-cis-β-carotene in vitro. β-carotene occurs in different cis-isomeric forms, and plants accumulate other carotenoids, which may be substrates of DWARF27. Here, we investigated the stereo and substrate specificity of the rice enzyme DWARF27 in carotenoid-accumulating E. coli strains and in in vitro assays performed with heterologously expressed and purified enzyme. Our results suggest that OsDWARF27 is strictly double bond-specific, solely targeting the C9–C10 double bond. OsDWARF27 did not introduce a 9-cis-double bond in 13-cis- or 15-cis-β-carotene. Substrates isomerized by OsDWARF27 are bicyclic carotenoids, including β-, α-carotene and β,β-cryptoxanthin, that contain at least one unsubstituted β-ionone ring. Accordingly, OsDWARF27 did not produce the abscisic acid precursors 9-cis-violaxanthin or -neoxanthin from the corresponding all-trans-isomers, excluding a direct role in the formation of this carotenoid derived hormone. The conversion of all-trans-α-carotene yielded two different isomers, including 9′-cis-α-carotene that might be the precursor of strigolactones with an ε-ionone ring, such as the recently identified heliolactone. © 2016 Springer-Verlag Berlin Heidelberg

Sex Pheromone of the Almond Moth and the Indian Meal Moth: cis-9, trans-12-Tetradecadienyl Acetate.

Science.gov (United States)

Kuwahara, Y; Kitamura, C; Takashi, S; Hara, H; Ishii, S; Fukami, H

1971-02-26

Female moths of different species but belonging to the same subfamily produce an identical compound as their sex pheromone. The sex pheromone of the almond moth, Cadra cautella (Walker), and the Indian meal moth, Plodia interpunctella (Hübner), has been isolated and identified as cis-9, trans-12-tetradecadienyl acetate.

Synthesis and characterization of technetium(III) complexes containing 2,2'-bipyridine and 1,10-phenanthroline. X-ray crystal structures of cis (Cl),trans(P)-[TcCl2(P(CH3)2C6H5)2(bpy)]B(C6H5)4, cis (Cl),trans(P)-[TcCl2(P(CH3)2C6H5)2(phen)]B(C6H5)4, and cis (Cl),trans(P)-[TcCl2(P(CH3CH2)(C6H5)2)2(bpy)]SO3CF3

International Nuclear Information System (INIS)

Wilcox, B.E.; Ho, D.M.; Deutsch, E.

1989-01-01

Technetium(III) complexes of the general formula cis(Cl),trans(P)-[TcCl 2 (P) 2 L] + , where (P) is dimethylphenylphosphine (PMe 2 Ph) or ethyldiphenylphosphine (PEtPh 2 ) and L is 2,2'-bipyridine (bpy), 4,4'-dimethyl-2,2'-bipyridine (Me 2 bpy), or 1,10-phenanthroline (phen), have been synthesized and characterized. They are prepared by L substitution onto, with concomitant displacement of one chloride and one phosphine ligand from, the mer-TcCl 3 (P) 3 starting material in refluxing ethanol. Analysis of these complexes by fast atom bombardment mass spectrometry (in the positive ion mode) provides fingerprint mass spectra that exhibit peaks assigned to the molecular ion M + as well as peaks assigned to M + minus one or more monodentate ligands. Results of single-crystal x-ray structure determinations of cis(Cl),trans(P)-[TcCl 2 (PMe 2 Ph) 2 (bpy)]BPh 4 (A), cis(Cl),trans(P)-[TcCl 2- (PMe 2 Ph) 2 (phen)]BPh 4 (B), and cis(Cl),trans(P)-[TcCl 2 (PEtPh 2 ) 2 (bpy)]SO 3 CF 3 (C), with formula weights of 921.62, 945.64, and 903.65, respectively are reported. 26 refs., 5 figs., 5 tabs

Enolase 1 (ENO1 and protein disulfide-isomerase associated 3 (PDIA3 regulate Wnt/β-catenin-driven trans-differentiation of murine alveolar epithelial cells

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Kathrin Mutze

2015-08-01

Full Text Available The alveolar epithelium represents a major site of tissue destruction during lung injury. It consists of alveolar epithelial type I (ATI and type II (ATII cells. ATII cells are capable of self-renewal and exert progenitor function for ATI cells upon alveolar epithelial injury. Cell differentiation pathways enabling this plasticity and allowing for proper repair, however, are poorly understood. Here, we applied proteomics, expression analysis and functional studies in primary murine ATII cells to identify proteins and molecular mechanisms involved in alveolar epithelial plasticity. Mass spectrometry of cultured ATII cells revealed a reduction of carbonyl reductase 2 (CBR2 and an increase in enolase 1 (ENO1 and protein disulfide-isomerase associated 3 (PDIA3 protein expression during ATII-to-ATI cell trans-differentiation. This was accompanied by increased Wnt/β-catenin signaling, as analyzed by qRT-PCR and immunoblotting. Notably, ENO1 and PDIA3, along with T1α (podoplanin; an ATI cell marker, exhibited decreased protein expression upon pharmacological and molecular Wnt/β-catenin inhibition in cultured ATII cells, whereas CBR2 levels were stabilized. Moreover, we analyzed primary ATII cells from mice with bleomycin-induced lung injury, a model exhibiting activated Wnt/β-catenin signaling in vivo. We observed reduced CBR2 significantly correlating with surfactant protein C (SFTPC, whereas ENO1 and PDIA3 along with T1α were increased in injured ATII cells. Finally, siRNA-mediated knockdown of ENO1, as well as PDIA3, in primary ATII cells led to reduced T1α expression, indicating diminished cell trans-differentiation. Our data thus identified proteins involved in ATII-to-ATI cell trans-differentiation and suggest a Wnt/β-catenin-driven functional role of ENO1 and PDIA3 in alveolar epithelial cell plasticity in lung injury and repair.

Application of factorial design for the ab initio study of cis- and trans-1,2 dihaloethylene stabilities

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Silva João Bosco P. da

2000-01-01

Full Text Available The chemometric technique Two Level Factorial Design was used to evaluate the principal and interaction effects of wave function modifications on calculated energy differences (DE between the cis and trans isomers of 1,2-dihaloethylenes, C2H2X2 (X=F and Cl. The factorial profile of DE is quite different for these systems. The addition of polarization and diffuse functions to the basis set have the largest effects in describing cis 1,2-difluoroethylene as the most stable isomer. In contrast electronic correlation, at the MP2 level, and the inclusion of polarization functions in the basis set have the largest effects in describing the cis form as the most stable one in the 1,2-dichloroethylenes. In both systems the interaction effects are smaller than the principal effects.

Dissecting relative contributions of cis- and trans-determinants to nucleosome distribution by comparing Tetrahymena macronuclear and micronuclear chromatin.

Science.gov (United States)

Xiong, Jie; Gao, Shan; Dui, Wen; Yang, Wentao; Chen, Xiao; Taverna, Sean D; Pearlman, Ronald E; Ashlock, Wendy; Miao, Wei; Liu, Yifan

2016-12-01

The ciliate protozoan Tetrahymena thermophila contains two types of structurally and functionally differentiated nuclei: the transcriptionally active somatic macronucleus (MAC) and the transcriptionally silent germ-line micronucleus (MIC). Here, we demonstrate that MAC features well-positioned nucleosomes downstream of transcription start sites and flanking splice sites. Transcription-associated trans-determinants promote nucleosome positioning in MAC. By contrast, nucleosomes in MIC are dramatically delocalized. Nucleosome occupancy in MAC and MIC are nonetheless highly correlated with each other, as well as with in vitro reconstitution and predictions based upon DNA sequence features, revealing unexpectedly strong contributions from cis-determinants. In particular, well-positioned nucleosomes are often matched with GC content oscillations. As many nucleosomes are coordinately accommodated by both cis- and trans-determinants, we propose that their distribution is shaped by the impact of these nucleosomes on the mutational and transcriptional landscape, and driven by evolutionary selection. © The Author(s) 2016. Published by Oxford University Press on behalf of Nucleic Acids Research.

Tautomeric preferences of the cis and trans isomers of axitinib

Science.gov (United States)

Mirzaei, M. Saeed; Taherpour, Avat Arman

2018-05-01

The tautomeric preferences of axitinib, a potent anticancer drug, as tyrosine kinase inhibitor have been investigated using quantum chemical calculations and docking methods. The energy differences between the two tautomers of trans-isomer are around 4 and 3 kcal mol-1 in vacuo and water, respectively, and for its cis-isomer (major photochemical isomerization product) this equilibrium reversed completely in favour of the second tautomer (not considered previously), which is about 7-8 kcal mol-1 more stable in both gas and aqueous media. The results indicate a very high activation energy for proton exchange for both [1,2] and [1,5] H-shift (around 50 kcal mol-1) in the gas phase, but inclusion of protic solvents (e.g. water) decrease this barrier to around 14 and 35 kcal mol-1 for the both hydrogen shift processes, respectively. In order to have better insight about the electronic structure of axitinib tautomers, the NBO, HOMO-LUMO, NICS and molecular electrostatic potential surfaces (MESP) calculations have been carried out. Docking investigations on the two more stable tautomers revealed that binding of the trans isomer of tautomer I to the active site of the receptor is the most favourable in the terms of energy and structure. This more stability could be attributed to the more hydrogen bonding of this tautomer with the protein residues in comparison to the second tautomer.

Isotopic studies of trans- and cis-HOCO using rotational spectroscopy: Formation, chemical bonding, and molecular structures

Energy Technology Data Exchange (ETDEWEB)

McCarthy, Michael C., E-mail: mccarthy@cfa.harvard.edu; Martinez, Oscar; Crabtree, Kyle N.; Martin-Drumel, Marie-Aline [Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, Massachusetts 02138, USA and School of Engineering and Applied Sciences, Harvard University, 29 Oxford Street, Cambridge, Massachusetts 02138 (United States); McGuire, Brett A. [National Radio Astronomy Observatory, Charlottesville, Virginia 22901 (United States); Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, Massachusetts 02138, USA and School of Engineering and Applied Sciences, Harvard University, 29 Oxford Street, Cambridge, Massachusetts 02138 (United States); Stanton, John F. [Department of Chemistry and Biochemistry, The University of Texas at Austin, 1 University Station A5300, Austin, Texas 78712-0165 (United States)

2016-03-28

HOCO is an important intermediate in combustion and atmospheric processes because the OH + CO → H + CO{sub 2} reaction represents the final step for the production of CO{sub 2} in hydrocarbon oxidation, and theoretical studies predict that this reaction proceeds via various intermediates, the most important being this radical. Isotopic investigations of trans- and cis-HOCO have been undertaken using Fourier transform microwave spectroscopy and millimeter-wave double resonance techniques in combination with a supersonic molecular beam discharge source to better understand the formation, chemical bonding, and molecular structures of this radical pair. We find that trans-HOCO can be produced almost equally well from either OH + CO or H + CO{sub 2} in our discharge source, but cis-HOCO appears to be roughly two times more abundant when starting from H + CO{sub 2}. Using isotopically labelled precursors, the OH + C{sup 18}O reaction predominately yields HOC{sup 18}O for both isomers, but H{sup 18}OCO is observed as well, typically at the level of 10%-20% that of HOC{sup 18}O; the opposite propensity is found for the {sup 18}OH + CO reaction. DO + C{sup 18}O yields similar ratios between DOC{sup 18}O and D{sup 18}OCO as those found for OH + C{sup 18}O, suggesting that some fraction of HOCO (or DOCO) may be formed from the back-reaction H + CO{sub 2}, which, at the high pressure of our gas expansion, can readily occur. The large {sup 13}C Fermi-contact term (a{sub F}) for trans- and cis-HO{sup 13}CO implicates significant unpaired electronic density in a σ-type orbital at the carbon atom, in good agreement with theoretical predictions. By correcting the experimental rotational constants for zero-point vibration motion calculated theoretically using second-order vibrational perturbation theory, precise geometrical structures have been derived for both isomers.

A dual inhibitor against prolyl isomerase Pin1 and cyclophilin discovered by a novel real-time fluorescence detection method

International Nuclear Information System (INIS)

Mori, Tadashi; Hidaka, Masafumi; Lin, Yi-Chin; Yoshizawa, Ibuki; Okabe, Takayoshi; Egashira, Shinichiro; Kojima, Hirotatsu; Nagano, Tetsuo; Koketsu, Mamoru; Takamiya, Mari; Uchida, Takafumi

2011-01-01

Research highlights: → A Pin1 (prolyl isomerase) inhibitor, TME-001, has been discovered by using a new established high-throughput screening method. → The TME-001 showed a cell-active inhibition with lower cytotoxic effect than known Pin1 inhibitors. → Kinetic analyses revealed that the TME-001 is the first compound that exhibits dual inhibition of Pin1 and another type of prolyl isomerase, cyclophilin. → Thus, similarities of structure and reaction mechanism between Pin1 and cyclophilin are proposed. -- Abstract: Pin1, a peptidyl prolyl cis/trans isomerase (PPIase), is a potential target molecule for cancer, infectious disease, and Alzheimer's disease. We established a high-throughput screening method for Pin1 inhibitors, which employs a real-time fluorescence detector. This screening method identified 66 compounds that inhibit Pin1 out of 9756 compounds from structurally diverse chemical libraries. Further evaluations of surface plasmon resonance methods and a cell proliferation assay were performed. We discovered a cell-active inhibitor, TME-001 (2-(3-chloro-4-fluoro-phenyl)-isothiazol-3-one). Surprisingly, kinetic analyses revealed that TME-001 is the first compound that exhibits dual inhibition of Pin1 (IC 50 = 6.1 μM) and cyclophilin, another type of PPIase, (IC 50 = 13.7 μM). This compound does not inhibit FKBP. This finding suggests the existence of similarities of structure and reaction mechanism between Pin1 and cyclophilin, and may lead to a more complete understanding of the active sites of PPIases.

NMR spectroscopic studies of a TAT-derived model peptide in imidazolium-based ILs: influence on chemical shifts and the cis/trans equilibrium state.

Science.gov (United States)

Wiedemann, Christoph; Ohlenschläger, Oliver; Mrestani-Klaus, Carmen; Bordusa, Frank

2017-09-13

NMR spectroscopy was used to study systematically the impact of imidazolium-based ionic liquid (IL) solutions on a TAT-derived model peptide containing Xaa-Pro peptide bonds. The selected IL anions cover a wide range of the Hofmeister series of ions. Based on highly resolved one- and two-dimensional NMR spectra individual 1 H and 13 C peptide chemical shift differences were analysed and a classification of IL anions according to the Hofmeister series was derived. The observed chemical shift changes indicate significant interactions between the peptide and the ILs. In addition, we examined the impact of different ILs towards the cis/trans equilibrium state of the Xaa-Pro peptide bonds. In this context, the IL cations appear to be of exceptional importance for inducing an alteration of the native cis/trans equilibrium state of Xaa-Pro bonds in favour of the trans-isomers.

Mass-spectrometry-directed analysis and purification of pyrrolizidine alkaloid cis/trans isomers in Gynura japonica.

Science.gov (United States)

Fang, Lianxiang; Xiong, Aizhen; Yang, Xiao; Cheng, Wenzhi; Yang, Li; Wang, Zhengtao

2014-08-01

Pyrrolizidine alkaloids are highly hepatotoxic natural chemicals that produce irreversible chronic and acute hepatotoxic effects on human beings. Purification of large amounts of pyrrolizidine alkaloids is necessary for toxicity studies. In this study, an efficient method for targeted analysis and purification of pyrrolizidine alkaloid cis/trans isomers from herbal materials was developed for the first time. Targeted analysis of the hepatotoxic pyrrolizidine alkaloids was performed by liquid chromatography with tandem mass spectrometry (precursor ion scan and daughter ion scan), and the purification of pyrrolizidine alkaloids was achieved with a mass-directed auto purification system. The extraction and preparative liquid chromatography conditions were optimized. The developed method was applied to analysis of Gynura japonica (Thunb.) Juel., a herbal medicine traditionally used for detumescence and relieving pain but is potentially hepatotoxic as it contains pyrrolizidine alkaloids. Twelve pyrrolizidine alkaloids (six cis/trans isomer pairs) were identified with reference compounds or characterized by liquid chromatography with tandem mass spectrometry, and five individual pyrrolizidine alkaloids, including (E)-seneciphylline, seneciphylline, integerrimine, senecionine, and seneciphyllinine, were prepared from G. japonica roots with high efficiency. The results of this work provide a new technique for the preparation of large amounts of pyrrolizidine alkaloid reference substances, which will also benefit toxicological studies of pyrrolizidine alkaloids and treatments for pyrrolizidine alkaloid-induced toxicity. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

cis- and trans-2,3,3a,4,5,9b-Hexahydro-1H-benz[e]indoles: synthesis and evaluation of dopamine D2, and D3 receptor binding affinity

DEFF Research Database (Denmark)

Song, Xiaodong; Crider, Michael A.; Cruse, Sharon F.

1999-01-01

cis- and trans-2,3,3a,4,5,9b-hexahydro-1H-benz [e]indoles were synthesized as conformationally rigid analogues of 3-phenylpyrrolidine and evaluated for dopamine (DA) D2S and D3 receptor binding affinity. The tricyclic benz[e]indole nucleus was constructed by a previously reported reductive...... configuration. These novel ligands may be useful tools for gaining additional information about the DA D3 receptor. Copyright Elsevier, Paris.dopamine / D2S receptor / D3 receptor / cis- and trans-2,3,3a,4,5,9b-hexahydro-1H-benz[e]indoles / receptor binding affinity....... receptors was shown by compounds substituted with N-n-propyl or N-allyl groups. The cis-(+-)-N-allyl derivative 21e demonstrated a D2S/D3 selectivity of 290. Resolution of cis-(+-)-5 and trans-(+-)- 21c into individual enantiomers showed that in both series the more active isomer had 3aR absolute...

Accurate millimetre and submillimetre rest frequencies for cis- and trans-dithioformic acid, HCSSH

Science.gov (United States)

Prudenzano, D.; Laas, J.; Bizzocchi, L.; Lattanzi, V.; Endres, C.; Giuliano, B. M.; Spezzano, S.; Palumbo, M. E.; Caselli, P.

2018-04-01

Context. A better understanding of sulphur chemistry is needed to solve the interstellar sulphur depletion problem. A way to achieve this goal is to study new S-bearing molecules in the laboratory, obtaining accurate rest frequencies for an astronomical search. We focus on dithioformic acid, HCSSH, which is the sulphur analogue of formic acid. Aims: The aim of this study is to provide an accurate line list of the two HCSSH trans and cis isomers in their electronic ground state and a comprehensive centrifugal distortion analysis with an extension of measurements in the millimetre and submillimetre range. Methods: We studied the two isomers in the laboratory using an absorption spectrometer employing the frequency-modulation technique. The molecules were produced directly within a free-space cell by glow discharge of a gas mixture. We measured lines belonging to the electronic ground state up to 478 GHz, with a total number of 204 and 139 new rotational transitions, respectively, for trans and cis isomers. The final dataset also includes lines in the centimetre range available from literature. Results: The extension of the measurements in the mm and submm range lead to an accurate set of rotational and centrifugal distortion parameters. This allows us to predict frequencies with estimated uncertainties as low as 5 kHz at 1 mm wavelength. Hence, the new dataset provided by this study can be used for astronomical search. Frequency lists are only available at the CDS via anonymous ftp to http://cdsarc.u-strasbg.fr (http://130.79.128.5) or via http://cdsarc.u-strasbg.fr/viz-bin/qcat?J/A+A/612/A56

Human cyclophilin B: A second cyclophilin gene encodes a peptidyl-prolyl isomerase with a signal sequence

International Nuclear Information System (INIS)

Price, E.R.; Zydowsky, L.D.; Jin, Mingjie; Baker, C.H.; McKeon, F.D.; Walsh, C.T.

1991-01-01

The authors report the cloning and characterization of a cDNA encoding a second human cyclosporin A-binding protein (hCyPB). Homology analyses reveal that hCyPB is a member of the cyclophilin B (CyPB) family, which includes yeast CyPB, Drosophila nina A, and rat cyclophilin-like protein. This family is distinguished from the cyclophilin A (CyPA) family by the presence of endoplasmic reticulum (ER)-directed signal sequences. hCyPB has a hydrophobic leader sequence not found in hCyPA, and its first 25 amino acids are removed upon expression in Escherichia coli. Moreover, they show that hCyPB is a peptidyl-prolyl cis-trans isomerase which can be inhibited by cyclosporin A. These observations suggest that other members of the CyPB family will have similar enzymatic properties. Sequence comparisons of the CyPB proteins show a central, 165-amino acid peptidyl-prolyl isomerase and cyclosprorin A-binding domain, flanked by variable N-terminal and C-terminal domains. These two variable regions may impart compartmental specificity and regulation to this family of cyclophilin proteins containing the conserved core domain. Northern blot analyses show that hCyPB mRNA is expressed in the Jurkat T-cell line, consistent with its possible target role in cyclosporin A-mediated immunosuppression

Amino acid-catalyzed conversion of citral : cis-trans isomerization and its conversion into 6-methyl-5-hepten-2-one and acetaldehyde

NARCIS (Netherlands)

Wolken, W.A.M.; Have, R. ten; Werf, M.J. van der

2000-01-01

Under alkaline conditions, amino acids or proteins catalyze the deacetylation of citral, a major aroma component, resulting in methylheptenone and acetaldehyde formation. 3-Hydroxycitronellal is an intermediate in this reaction. Amino acids also catalyze the cis-trans isomerization of the pure

Water-stable helical structure of tertiary amides of bicyclic β-amino acid bearing 7-azabicyclo[2.2.1]heptane. Full control of amide cis-trans equilibrium by bridgehead substitution.

Science.gov (United States)

Hosoya, Masahiro; Otani, Yuko; Kawahata, Masatoshi; Yamaguchi, Kentaro; Ohwada, Tomohiko

2010-10-27

Helical structures of oligomers of non-natural β-amino acids are significantly stabilized by intramolecular hydrogen bonding between main-chain amide moieties in many cases, but the structures are generally susceptible to the environment; that is, helices may unfold in protic solvents such as water. For the generation of non-hydrogen-bonded ordered structures of amides (tertiary amides in most cases), control of cis-trans isomerization is crucial, even though there is only a small sterical difference with respect to cis and trans orientations. We have established methods for synthesis of conformationally constrained β-proline mimics, that is, bridgehead-substituted 7-azabicyclo[2.2.1]heptane-2-endo-carboxylic acids. Our crystallographic, 1D- and 2D-NMR, and CD spectroscopic studies in solution revealed that a bridgehead methoxymethyl substituent completely biased the cis-trans equilibrium to the cis-amide structure along the main chain, and helical structures based on the cis-amide linkage were generated independently of the number of residues, from the minimalist dimer through the tetramer, hexamer, and up to the octamer, and irrespective of the solvent (e.g., water, alcohol, halogenated solvents, and cyclohexane). Generality of the control of the amide equilibrium by bridgehead substitution was also examined.

Inhibition of nuclear T3 binding by fatty acids: dependence on chain length, unsaturated bonds, cis-trans configuration and esterification

NARCIS (Netherlands)

Wiersinga, W. M.; Platvoet-ter Schiphorst, M.

1990-01-01

1. Fatty acids have the capacity for inhibition of nuclear T3 binding (INB). The present studies were undertaken to describe the INB-activity of fatty acids as a function of chain length, unsaturated bonds, cis-trans configuration, and esterification. 2. Isolated rat liver nuclei were incubated with

Optomechanical Control of Quantum Yield in Trans-Cis Ultrafast Photoisomerization of a Retinal Chromophore Model.

Science.gov (United States)

Valentini, Alessio; Rivero, Daniel; Zapata, Felipe; García-Iriepa, Cristina; Marazzi, Marco; Palmeiro, Raúl; Fdez Galván, Ignacio; Sampedro, Diego; Olivucci, Massimo; Frutos, Luis Manuel

2017-03-27

The quantum yield of a photochemical reaction is one of the most fundamental quantities in photochemistry, as it measures the efficiency of the transduction of light energy into chemical energy. Nature has evolved photoreceptors in which the reactivity of a chromophore is enhanced by its molecular environment to achieve high quantum yields. The retinal chromophore sterically constrained inside rhodopsin proteins represents an outstanding example of such a control. In a more general framework, mechanical forces acting on a molecular system can strongly modify its reactivity. Herein, we show that the exertion of tensile forces on a simplified retinal chromophore model provokes a substantial and regular increase in the trans-to-cis photoisomerization quantum yield in a counterintuitive way, as these extension forces facilitate the formation of the more compressed cis photoisomer. A rationale for the mechanochemical effect on this photoisomerization mechanism is also proposed. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

Biochemical characterization of the prolyl 3-hydroxylase 1.cartilage-associated protein.cyclophilin B complex.

Science.gov (United States)

Ishikawa, Yoshihiro; Wirz, Jackie; Vranka, Janice A; Nagata, Kazuhiro; Bächinger, Hans Peter

2009-06-26

The rough endoplasmic reticulum-resident protein complex consisting of prolyl 3-hydroxylase 1 (P3H1), cartilage-associated protein (CRTAP), and cyclophilin B (CypB) can be isolated from chick embryos on a gelatin-Sepharose column, indicating some involvement in the biosynthesis of procollagens. Prolyl 3-hydroxylase 1 modifies a single proline residue in the alpha chains of type I, II, and III collagens to (3S)-hydroxyproline. The peptidyl-prolyl cis-trans isomerase activity of cyclophilin B was shown previously to catalyze the rate of triple helix formation. Here we show that cyclophilin B in the complex shows peptidyl-prolyl cis-trans isomerase activity and that the P3H1.CRTAP.CypB complex has another important function: it acts as a chaperone molecule when tested with two classical chaperone assays. The P3H1.CRTAP.CypB complex inhibited the thermal aggregation of citrate synthase and was active in the denatured rhodanese refolding and aggregation assay. The chaperone activity of the complex was higher than that of protein-disulfide isomerase, a well characterized chaperone. The P3H1.CRTAP.CypB complex also delayed the in vitro fibril formation of type I collagen, indicating that this complex is also able to interact with triple helical collagen and acts as a collagen chaperone.

Biochemical Characterization of the Prolyl 3-Hydroxylase 1·Cartilage-associated Protein·Cyclophilin B Complex*

Science.gov (United States)

Ishikawa, Yoshihiro; Wirz, Jackie; Vranka, Janice A.; Nagata, Kazuhiro; Bächinger, Hans Peter

2009-01-01

The rough endoplasmic reticulum-resident protein complex consisting of prolyl 3-hydroxylase 1 (P3H1), cartilage-associated protein (CRTAP), and cyclophilin B (CypB) can be isolated from chick embryos on a gelatin-Sepharose column, indicating some involvement in the biosynthesis of procollagens. Prolyl 3-hydroxylase 1 modifies a single proline residue in the α chains of type I, II, and III collagens to (3S)-hydroxyproline. The peptidyl-prolyl cis-trans isomerase activity of cyclophilin B was shown previously to catalyze the rate of triple helix formation. Here we show that cyclophilin B in the complex shows peptidyl-prolyl cis-trans isomerase activity and that the P3H1·CRTAP·CypB complex has another important function: it acts as a chaperone molecule when tested with two classical chaperone assays. The P3H1·CRTAP·CypB complex inhibited the thermal aggregation of citrate synthase and was active in the denatured rhodanese refolding and aggregation assay. The chaperone activity of the complex was higher than that of protein-disulfide isomerase, a well characterized chaperone. The P3H1·CRTAP·CypB complex also delayed the in vitro fibril formation of type I collagen, indicating that this complex is also able to interact with triple helical collagen and acts as a collagen chaperone. PMID:19419969

A theoretical study of the hydrogen bonding between the vic-, cis- and trans-C 2H 2F 2 isomers and hydrogen fluoride

Science.gov (United States)

Rusu, Victor H.; da Silva, João Bosco P.; Ramos, Mozart N.

2009-04-01

MP2/6-31++G(d,p) and B3LYP/6-31++G(d,p) theoretical calculations have been employed to investigate the hydrogen bonding formation involving the vic-, cis- and trans-C 2H 2F 2 isomers and hydrogen fluoride. Our calculations have revealed for each isomer the preferential existence of two possible hydrogen-bonded complexes: a non-cyclic complex and a cyclic complex. For all the three isomers the binding energies for the non-cyclic and cyclic hydrogen complexes are essentially equal using both the MP2 and B3LYP calculations, being that the cyclic structure is slightly more stable. For instance, the binding energies including BSSE and ZPE corrections for the non-cyclic and cyclic structures of cis-C 2H 2F···HF are 8.7 and 9.0 kJ mol -1, respectively, using B3LYP calculations. The cyclic complex formation reduces the polarity, in contrast to what occurs with the non-cyclic complex. This result is more accentuated in vic-C 2H 2F 2···HF. In this latter, Δ μ(cyclic) is -3.07 D, whereas Δ μ(non-cyclic) is +1.92 D using B3LYP calculations. Their corresponding MP2 values are +0.44 D and -1.89 D, respectively. As expected, the complexation produces an H sbnd F stretching frequency downward shift, whereas its IR intensity is enhanced. On the other hand, the vibrational modes of the vic-, cis- and trans-C 2H 2F 2 isomers are little affected by complexation. The new vibrational modes due to hydrogen bonding formation show several interesting features, in particular the HF bending modes which are pure rotations in the free molecule.

Network-directed cis-mediator analysis of normal prostate tissue expression profiles reveals downstream regulatory associations of prostate cancer susceptibility loci.

Science.gov (United States)

Larson, Nicholas B; McDonnell, Shannon K; Fogarty, Zach; Larson, Melissa C; Cheville, John; Riska, Shaun; Baheti, Saurabh; Weber, Alexandra M; Nair, Asha A; Wang, Liang; O'Brien, Daniel; Davila, Jaime; Schaid, Daniel J; Thibodeau, Stephen N

2017-10-17

Large-scale genome-wide association studies have identified multiple single-nucleotide polymorphisms associated with risk of prostate cancer. Many of these genetic variants are presumed to be regulatory in nature; however, follow-up expression quantitative trait loci (eQTL) association studies have to-date been restricted largely to cis -acting associations due to study limitations. While trans -eQTL scans suffer from high testing dimensionality, recent evidence indicates most trans -eQTL associations are mediated by cis -regulated genes, such as transcription factors. Leveraging a data-driven gene co-expression network, we conducted a comprehensive cis -mediator analysis using RNA-Seq data from 471 normal prostate tissue samples to identify downstream regulatory associations of previously identified prostate cancer risk variants. We discovered multiple trans -eQTL associations that were significantly mediated by cis -regulated transcripts, four of which involved risk locus 17q12, proximal transcription factor HNF1B , and target trans -genes with known HNF response elements ( MIA2 , SRC , SEMA6A , KIF12 ). We additionally identified evidence of cis -acting down-regulation of MSMB via rs10993994 corresponding to reduced co-expression of NDRG1 . The majority of these cis -mediator relationships demonstrated trans -eQTL replicability in 87 prostate tissue samples from the Gene-Tissue Expression Project. These findings provide further biological context to known risk loci and outline new hypotheses for investigation into the etiology of prostate cancer.

Theoretical study of the nucleophilic addition of oximes to the nitrile complexes trans-/cis-[ReCl4(NCCH3)2

International Nuclear Information System (INIS)

Klestova-Nadeeva, E. A.; Kuznetsov, M. L.; Dement'ev, A. I.

2005-01-01

The reaction of nucleophilic addition of oximes (HON=CRR 1 ) to organic nitriles coordinated in the rhenium complexes trans-/cis-[ReCl 4 (NCCH 3 ) 2 ] was theoretically studied by the Hartree-Fock and density functional theory (B3LYP) methods. The reaction mechanism involves (I) the initial change of the oxime conformation; (II) the formation of the orientation complex with the coordinated nitrile molecule, which transforms into a four-membered transition state; (III) the formation of the addition product in a less stable conformation; and (IV) the formation of the ultimate addition product. The calculations make it possible to interpret the activation of nitriles in terms of the activated complex theory as a result of stabilization of the transition state in going from the free to the coordinated nitrile [ru

Homogeneous conversion of methane to methanol. 2. Catalytic activation of methane by cis- and trans-platin: A density functional study of the Shilov type reaction

Energy Technology Data Exchange (ETDEWEB)

Mylvaganam, K.; Bacskay, G.B.; Hush, N.S.

2000-03-08

The C-H activation of methane catalyzed by cis- and trans-platin in aqueous solution has been studied by density functional based computational methods. By analogy with the Shilov reaction, the initial step is the replacement of an ammonia ligand by methane, followed by the formation of a methyl complex and the elimination o a proton. The computations utilize the B3LYP hybrid functionals, effective core potentials, and double-{zeta} to polarized double-{zeta} basis sets and include solvation effects by a dielectric continuum method. In contrast with the Shilov reaction studied by Seigbahn and Crabtree (J.Am.Chem.Soc. 1996, 118, 4443), in the platins the replacement of an ammonia ligand by methane is found to be effectively rate determining, in that the energy barriers to C-H activation are comparable with those of the initial substitution reaction, viz. {approximately} 34 and 44 kcal/mol for cis- and trans-platin, respectively. Several reaction pathways for C-H activation and subsequent proton elimination were identified. For cis-platin the energy barriers associated with the oxidative addition and {sigma}-bond metathesis type mechanisms were found to be comparable, while for trans-platin oxidative addition is predicted to be strongly preferred over {sigma}-bond metathesis, which, interestingly, also proceeds through a Pt(IV) methyl hydrido complex as reaction intermediate. In line with accepted ideas on trans influence, the methyl and hydride ligands in the Pt(IV) complexes that arise in the oxidative addition reactions were always found to be cis to each other. On the basis of the population analyses on the Pt(IV) complexes it is suggested that the Pt-H and Pt-CH{sub 3} bonds are best described as covalent bonds and, further, that the preference of the hydride and methyl anions to be cis to each other is a consequence of such covalent bonding. In light of these findings, the energies of several methyl Pt(IV) hydrido bisulfate complexes were also recalculated

FKBP immunophilins and Alzheimer's disease: A chaperoned affair

Indian Academy of Sciences (India)

All FKBPs contain a domain with prolyl cis/trans isomerase (PPIase) activity. ... FKBP proteins are expressed ubiquitously but show relatively high levels of expression in the nervous .... evolution, higher organisms like humans, who normally.

Replication of chromosomal and episomal DNA in X-ray-damaged human cells: A cis- or trans-acting mechanism

International Nuclear Information System (INIS)

Cleaver, J.E.; Rose, R.; Mitchell, D.L.

1990-01-01

Episomal plasmids and viruses in mammalian cells present small targets for X-ray-induced DNA damage. At doses up to 100 Gy, DNA strand breaks or endonuclease III-sensitive sites were not discernible in 10.3-kb Epstein-Barr virus-based plasmid DNA or in 4.9-kb defective simian virus 40 DNA. DNA replication in these small molecules, however, was inhibited strongly by X-ray doses of greater than or equal to 20 Gy, decreasing to only 20 to 40% of control values. Inhibition was relieved slightly by growth in caffeine but was increased by growth in 3-aminobenzamide. Inhibition of DNA replication in episomal DNA molecules that are too small to sustain significant damage directly to their DNA may be due to either (a) a trans-acting diffusible factor that transfers the consequences of DNA breakage to episomes and to other replicating molecules, (b) a cis-acting mechanism in which episomes are structurally linked to genomic chromatin, and replication of both episomal and chromosomal replicons is under common control, or (c) radiation damage on other cellular structures unrelated to DNA. The resolution of these cellular mechanisms may shed light on the X-ray-resistant replication in ataxia-telangiectasia and may suggest strategies for molecular characterization of potential trans- or cis-acting factors

Potential of the Antibody Against cis-Phosphorylated Tau in the Early Diagnosis, Treatment, and Prevention of Alzheimer Disease and Brain Injury.

Science.gov (United States)

Lu, Kun Ping; Kondo, Asami; Albayram, Onder; Herbert, Megan K; Liu, Hekun; Zhou, Xiao Zhen

2016-11-01

Alzheimer disease (AD) and chronic traumatic encephalopathy (CTE) share a common neuropathologic signature-neurofibrillary tangles made of phosphorylated tau-but do not have the same pathogenesis or symptoms. Although whether traumatic brain injury (TBI) could cause AD has not been established, CTE is shown to be associated with TBI. Until recently, whether and how TBI leads to tau-mediated neurodegeneration was unknown. The unique prolyl isomerase Pin1 protects against the development of tau-mediated neurodegeneration in AD by converting the phosphorylated Thr231-Pro motif in tau (ptau) from the pathogenic cis conformation to the physiologic trans conformation, thereby restoring ptau function. The recent development of antibodies able to distinguish and eliminate both conformations specifically has led to the discovery of cis-ptau as a precursor of tau-induced pathologic change and an early driver of neurodegeneration that directly links TBI to CTE and possibly to AD. Within hours of TBI in mice or neuronal stress in vitro, neurons prominently produce cis-ptau, which causes and spreads cis-ptau pathologic changes, termed cistauosis. Cistauosis eventually leads to widespread tau-mediated neurodegeneration and brain atrophy. Cistauosis is effectively blocked by the cis-ptau antibody, which targets intracellular cis-ptau for proteasome-mediated degradation and prevents extracellular cis-ptau from spreading to other neurons. Treating TBI mice with cis-ptau antibody not only blocks early cistauosis but also prevents development and spreading of tau-mediated neurodegeneration and brain atrophy and restores brain histopathologic features and functional outcomes. Thus, cistauosis is a common early disease mechanism for AD, TBI, and CTE, and cis-ptau and its antibody may be useful for early diagnosis, treatment, and prevention of these devastating diseases.

Transient-Absorption Spectroscopy of Cis-Trans Isomerization of N,N-dimethyl-4,4'-Azodianiline with 3D-Printed Temperature-Controlled Sample Holder

Science.gov (United States)

Kosenkov, Dmytro; Shaw, James; Zuczek, Jennifer; Kholod, Yana

2016-01-01

The laboratory unit demonstrates a project based approach to teaching physical chemistry laboratory where upper-division undergraduates carry out a transient-absorption experiment investigating the kinetics of cis-trans isomerization of N,N-dimethyl-4,4'-azodianiline. Students participate in modification of a standard flash-photolysis spectrometer…

Sunscreens with broad-spectrum absorption decrease the trans TO cis photoisomerization of urocanic acid in the human stratum corneum after multiple UV light exposures

International Nuclear Information System (INIS)

Krien, P.M.; Moyal, D.

1994-01-01

The trans to cis photoisomerization of urocanic acid (UCA) in skin is considered to play an important role in the mechanism of immunosuppression. We have investigated the effects of skin type and various sunscreens with low sun protection factor (SPF) on the UV-induced cis-UCA formation in human skin after exposure to artificial UV light. The rate of cis-UCA formation depends little on the skin type and is reduced by topical application of sunscreens. The rate of cis-UCA formation decreases with increasing SPF and only broad-spectrum, highly protective sunscreens offer protection against the UV-induced formation of cis-UCA, which accumulates in the stratum corneum after multiple UV exposures. A theoretical approach to estimate the distribution of cis-UCA after irradiation indicates that this compound may diffuse into the deeper layers of the epidermis with D ∼ 10 -17 m 2 /s, and that its elimination from the stratum corneum is mainly due to desquamation. (author)

Biochemistry and pharmacology of rhodopsin regeneration in the vertebrate eye

International Nuclear Information System (INIS)

Bernstein, P.S.

1988-01-01

In this thesis, the missing reaction of the vertebrate visual cycle, the energy-dependent isomerization of all-trans-retinoids to 11-cis-retinoids, is investigated through biochemical and pharmacological means. The biochemical processes of vision are first probed through the use of 1,5-di-(p-aminophenoxy) pentane (DAPP), the most powerful and selective pharmacological inhibitor of dark adaptation known. Next, the biochemical pathway of isomerization of retinoids in living animals is examined through double-label radioisotope studies in normal animals and in animals treated with DAPP or other inhibitors of dark adaptation. Finally, a novel retinoid isomerase activity was discovered in homogenates of frog retina/pigment epithelium that catalyzes the endergonic isomerization of all-trans-retinoids to 11-cis-retinoids in darkness. In partially purified preparations, added [11,12- 3 H]-all-trans-retinol is converted to 11-cis-retinol and other 11-cis-retinoids, while added labeled all-trans-retinal and all-trans-retinyl palmitate are not isomerized to a significant extent

Roles of Prolyl Isomerases in RNA-Mediated Gene Expression

Directory of Open Access Journals (Sweden)

Roopa Thapar

2015-05-01

Full Text Available The peptidyl-prolyl cis-trans isomerases (PPIases that include immunophilins (cyclophilins and FKBPs and parvulins (Pin1, Par14, Par17 participate in cell signaling, transcription, pre-mRNA processing and mRNA decay. The human genome encodes 19 cyclophilins, 18 FKBPs and three parvulins. Immunophilins are receptors for the immunosuppressive drugs cyclosporin A, FK506, and rapamycin that are used in organ transplantation. Pin1 has also been targeted in the treatment of Alzheimer’s disease, asthma, and a number of cancers. While these PPIases are characterized as molecular chaperones, they also act in a nonchaperone manner to promote protein-protein interactions using surfaces outside their active sites. The immunosuppressive drugs act by a gain-of-function mechanism by promoting protein-protein interactions in vivo. Several immunophilins have been identified as components of the spliceosome and are essential for alternative splicing. Pin1 plays roles in transcription and RNA processing by catalyzing conformational changes in the RNA Pol II C-terminal domain. Pin1 also binds several RNA binding proteins such as AUF1, KSRP, HuR, and SLBP that regulate mRNA decay by remodeling mRNP complexes. The functions of ribonucleoprotein associated PPIases are largely unknown. This review highlights PPIases that play roles in RNA-mediated gene expression, providing insight into their structures, functions and mechanisms of action in mRNP remodeling in vivo.

Hsp70 facilitates trans-membrane transport of bacterial ADP-ribosylating toxins into the cytosol of mammalian cells.

Science.gov (United States)

Ernst, Katharina; Schmid, Johannes; Beck, Matthias; Hägele, Marlen; Hohwieler, Meike; Hauff, Patricia; Ückert, Anna Katharina; Anastasia, Anna; Fauler, Michael; Jank, Thomas; Aktories, Klaus; Popoff, Michel R; Schiene-Fischer, Cordelia; Kleger, Alexander; Müller, Martin; Frick, Manfred; Barth, Holger

2017-06-02

Binary enterotoxins Clostridium (C.) botulinum C2 toxin, C. perfringens iota toxin and C. difficile toxin CDT are composed of a transport (B) and a separate non-linked enzyme (A) component. Their B-components mediate endocytic uptake into mammalian cells and subsequently transport of the A-components from acidic endosomes into the cytosol, where the latter ADP-ribosylate G-actin resulting in cell rounding and cell death causing clinical symptoms. Protein folding enzymes, including Hsp90 and peptidyl-prolyl cis/trans isomerases facilitate transport of the A-components across endosomal membranes. Here, we identified Hsp70 as a novel host cell factor specifically interacting with A-components of C2, iota and CDT toxins to facilitate their transport into the cell cytosol. Pharmacological Hsp70-inhibition specifically prevented pH-dependent trans-membrane transport of A-components into the cytosol thereby protecting living cells and stem cell-derived human miniguts from intoxication. Thus, Hsp70-inhibition might lead to development of novel therapeutic strategies to treat diseases associated with bacterial ADP-ribosylating toxins.

Identification of isomers in the gas phase and as adsorbates by near-edge X-ray absorption fine structure spectroscopy: Cis- and trans-stilbene

International Nuclear Information System (INIS)

Püttner, Ralph; Schmidt-Weber, Philipp; Kampen, Thorsten; Kolczewski, Christine; Hermann, Klaus; Horn, Karsten

2017-01-01

Highlights: • NEXAFS spectra of the cis- and trans-isomer of stilbene reveal distinct differences by which the isomers can be distinguished. • DFT calculations using the transition potential approach assign specific transitions that are different in the two isomers. • On Si(100), these differences in NEXAFS are also observed, suggesting that their conformations survive in the bonding situation. • NEXAFS is thus shown to be a sensitive tool to distinguish isomers in adsorbed species. - Abstract: Near-edge x-ray absorption fine structure spectra of the cis- and trans-isomers of stilbene in the gas phase reveal clear differences, which are analyzed by results from density-functional theory calculations using the transition potential approach. The differences between the two species also occur in stilbene adsorbed on Si(100), opening the way towards studying structural changes in molecules in different surface environments, and configurational switching in organic molecules on surfaces in particular.

Identification of isomers in the gas phase and as adsorbates by near-edge X-ray absorption fine structure spectroscopy: Cis- and trans-stilbene

Energy Technology Data Exchange (ETDEWEB)

Püttner, Ralph [Department of Physics, Freie Universität Berlin, 14195 Berlin (Germany); Schmidt-Weber, Philipp [Fritz Haber Institute of the Max Planck Society, 14195 Berlin (Germany); Kampen, Thorsten [SPECS Surface Nano Analysis GmbH, 13355 Berlin (Germany); Kolczewski, Christine [Deutsches Museum München, 80538 Munich (Germany); Hermann, Klaus [Fritz Haber Institute of the Max Planck Society, 14195 Berlin (Germany); Horn, Karsten, E-mail: horn@fhi-berlin.mpg.de [Fritz Haber Institute of the Max Planck Society, 14195 Berlin (Germany)

2017-02-15

Highlights: • NEXAFS spectra of the cis- and trans-isomer of stilbene reveal distinct differences by which the isomers can be distinguished. • DFT calculations using the transition potential approach assign specific transitions that are different in the two isomers. • On Si(100), these differences in NEXAFS are also observed, suggesting that their conformations survive in the bonding situation. • NEXAFS is thus shown to be a sensitive tool to distinguish isomers in adsorbed species. - Abstract: Near-edge x-ray absorption fine structure spectra of the cis- and trans-isomers of stilbene in the gas phase reveal clear differences, which are analyzed by results from density-functional theory calculations using the transition potential approach. The differences between the two species also occur in stilbene adsorbed on Si(100), opening the way towards studying structural changes in molecules in different surface environments, and configurational switching in organic molecules on surfaces in particular.

Cis elements and trans-acting factors involved in the RNA dimerization of the human immunodeficiency virus HIV-1.

Science.gov (United States)

Darlix, J L; Gabus, C; Nugeyre, M T; Clavel, F; Barré-Sinoussi, F

1990-12-05

The retroviral genome consists of two identical RNA molecules joined at their 5' ends by the Dimer Linkage Structure (DLS). To study the mechanism of dimerization and the DLS of HIV-1 RNA, large amounts of bona fide HIV-1 RNA and of mutants have been synthesized in vitro. We report that HIV-1 RNA forms dimeric molecules and that viral nucleocapsid (NC) protein NCp15 greatly activates dimerization. Deletion mutagenesis in the RNA 5' 1333 nucleotides indicated that a small domain of 100 nucleotides, located between positions 311 to 415 from the 5' end, is necessary and sufficient to promote HIV-1 RNA dimerization. This dimerization domain encompasses an encapsidation element located between the 5' splice donor site and initiator AUG of gag and shows little sequence variations in different strains of HIV-1. Furthermore, cross-linking analysis of the interactions between NC and HIV-1 RNA (311 to 415) locates a major contact site in the encapsidation element of HIV-1 RNA. The genomic RNA dimer is tightly associated with nucleocapsid protein molecules in avian and murine retroviruses, and this ribonucleoprotein structure is believed to be the template for reverse transcription. Genomic RNA-protein interactions have been analyzed in human immunodeficiency virus (HIV) virions and results showed that NC protein molecules are tightly bound to the genomic RNA dimer. Since retroviral RNA dimerization and packaging appear to be under the control of the same cis element, the encapsidation sequences, and trans-acting factor, the NC protein, they are probably related events in the course of virion assembly.

Kinetics of olefin arylation by bis(triphenylphosphine) diacetatopalladium(II) (PPAP) and trans-cis isomerization of the latter

Energy Technology Data Exchange (ETDEWEB)

Ryabov, A.D.; Yatsimirskii, A.K.

1979-01-01

In the absence of olefins, at 70/sup 0/C, PPAP dissolved in glacial acetic acid rapidly decomposed into triphenylphosphine (TPP) oxide, biphenyl, and metallic palladium, after an induction period of about ten minutes. At lower temperatures in this solvent, pure trans-PPAP was converted into the more stable cis-isomer. The conversion was 70-80Vertical Bar3<, increased with temperature (25/sup 0/-45/sup 0/C), and was inhibited by free TPP. Interaction of PPAP with styrene in glacial acetic acid at 70/sup 0/C occurred with an induction period and gave stilbene (80Vertical Bar3< yield) and TPP oxide. The induction period was independent of the concentration of PPAP or olefin and coincided with that in PPAP decomposition in the absence of olefin. Similar regularities were observed in PPAP interaction with p-methoxystyrene and p-nitrostyrene. Apparently, the induction period involves Pd(II) reduction to a phenypalladium(0) species stabilized by TPP and is followed by rapid transfer of phenyl from palladium to olefin.

Proton affinity of diastereoisomers of modified prolines using the kinetic method and density functional theory calculations: role of the cis/trans substituent on the endo/exo ring conformation.

Science.gov (United States)

Mezzache, S; Pepe, C; Karoyan, P; Fournier, F; Tabet, J-C

2005-01-01

The proton affinity (PA) of cis/trans-3-prolinoleucines and cis/trans-3-prolinoglutamic acids have been studied by the kinetic method and density functional theory (DFT) calculations. Several conformations of the neutral and the protonated modified prolines, in particular the endo and exo ring conformations, were analyzed with respect to their contribution to the PA values. When the substituent is an alkyl, both the diastereoisomers have the same PA value. However, the PA values for the diastereoisomers are different when the substituted chain contains functional groups (e.g. a carboxyl group). This variation in PA values could be attributed to the existence of intramolecular hydrogen bonds. Copyright (c) 2005 John Wiley & Sons, Ltd.

Homologous SV40 RNA trans-splicing: Special case or prime example of viral RNA trans-splicing?

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Sushmita Poddar

2014-06-01

Full Text Available To date the Simian Virus 40 (SV40 is the only proven example of a virus that recruits the mechanism of RNA trans-splicing to diversify its sequences and gene products. Thereby, two identical viral transcripts are efficiently joined by homologous trans-splicing triggering the formation of a highly transforming 100 kDa super T antigen. Sequences of other viruses including HIV-1 and the human adenovirus type 5 were reported to be involved in heterologous trans-splicing towards cellular or viral sequences but the meaning of these events remains unclear. We computationally and experimentally investigated molecular features associated with viral RNA trans-splicing and identified a common pattern: Viral RNA trans-splicing occurs between strong cryptic or regular viral splice sites and strong regular or cryptic splice sites of the trans-splice partner sequences. The majority of these splice sites are supported by exonic splice enhancers. Splice sites that could compete with the trans-splicing sites for cis-splice reactions are weaker or inexistent. Finally, all but one of the trans-splice reactions seem to be facilitated by one or more complementary binding domains of 11 to 16 nucleotides in length which, however occur with a statistical probability close to one for the given length of the involved sequences. The chimeric RNAs generated via heterologous viral RNA trans-splicing either did not lead to fusion proteins or led to proteins of unknown function. Our data suggest that distinct viral RNAs are highly susceptible to trans-splicing and that heterologous viral trans-splicing, unlike homologous SV40 trans-splicing, represents a chance event.

Trans-10, cis-12-conjugated linoleic acid alters hepatic gene expression in a polygenic obese line of mice displaying hepatic lipidosis.

Science.gov (United States)

Ashwell, Melissa S; Ceddia, Ryan P; House, Ralph L; Cassady, Joseph P; Eisen, Eugene J; Eling, Thomas E; Collins, Jennifer B; Grissom, Sherry F; Odle, Jack

2010-09-01

The trans-10, cis-12 isomer of conjugated linoleic acid (CLA) causes a rapid reduction of body and adipose mass in mice. In addition to changes in adipose tissue, numerous studies have reported alterations in hepatic lipid metabolism. Livers of CLA-fed mice gain mass, partly due to lipid accumulation; however, the precise molecular mechanisms are unknown. To elucidate these mechanisms, we examined fatty acid composition and gene expression profiles of livers from a polygenic obese line of mice fed 1% trans-10, cis-12-CLA for 14 days. Analysis of gene expression data led to the identification of 1393 genes differentially expressed in the liver of CLA-fed male mice at a nominal P value of .01, and 775 were considered significant using a false discovery rate (FDR) threshold of .05. While surprisingly few genes in lipid metabolism were impacted, pathway analysis found that protein kinase A (PKA) and cyclic adenosine monophosphate (cAMP) pathways signaling pathways were affected by CLA treatment and 98 of the 775 genes were found to be regulated by hepatocyte nuclear factor 4alpha, a transcription factor important in controlling liver metabolic status. Copyright 2010 Elsevier Inc. All rights reserved.

Antidiabetic Bis-Maltolato-OxoVanadium(IV: Conversion of inactive trans- to bioactive cis-BMOV for possible binding to target PTP-1B

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Thomas Scior

2008-11-01

Full Text Available Thomas Scior1, Hans-Georg Mack2, José Antonio Guevara García3, Wolfhard Koch41Departamento de Farmacia. Facultad de Ciencias Químicas, Benemérita Universidad Autónoma de Puebla, Colonia San Manuel, Puebla, Mexico; 2Institut für Physikalische Chemie, Universität Tübingen, Tübingen, Germany; 3Laboratorio de Investigación en Bioinorgánica y Biorremediación (LIByB. Departamento de Ciencias Básicas, Ingeniería y Tecnología, Universidad Autónoma de Tlaxcala, Apizaco, Tlaxcala, Mexico; 4Facultad de Estudios Superiores Zaragoza (FESZ, Universidad Nacional Autónoma de México (UNAM, Colonia Ejército de Oriente, Delegación Iztapalapa, Mexico City, MexicoAbstract: The postulated transition of Bis-Maltolato-OxoVanadium(IV (BMOV from its inactive trans- into its cis-aquo-BMOV isomeric form in solution was simulated by means of computational molecular modeling. The rotational barrier was calculated with DFT – B3LYP under a stepwise optimization protocol with STO-3G, 3-21G, 3-21G*, and 6-31G ab initio basis sets. Our computed results are consistent with reports on the putative molecular mechanism of BMOV triggering the insulin-like cellular response (insulin mimetic as a potent inhibitor of the protein tyrosine phosphatase-1B (PTP-1B. Initially, trans-BMOV is present in its solid dosage form but in aqueous solution, and during oral administration, it is readily converted into a mixture of “open-type” and “closed-type” complexes of cis-aquo-BMOV under equilibrium conditions. However, in the same measure as the “closed-type” complex binds to the cytosolic PTP-1B, it disappears from solution, and the equilibrium shifts towards the “closed-type” species. In full accordance, the computed binding mode of cis-BMOV is energetically favored over sterically hindered trans-BMOV. In view of our earlier report on prodrug hypothesis of vanadium organic compounds the present results suggest that cis-BMOV is the bioactive species

A high-throughput screen for inhibitors of the prolyl isomerase, Pin1, identifies a seaweed polyphenol that reduces adipose cell differentiation.

Science.gov (United States)

Mori, Tadashi; Hidaka, Masafumi; Ikuji, Hiroko; Yoshizawa, Ibuki; Toyohara, Haruhiko; Okuda, Toru; Uchida, Chiyoko; Asano, Tomoichiro; Yotsu-Yamashita, Mari; Uchida, Takafumi

2014-01-01

The peptidyl prolyl cis/trans isomerase Pin1 enhances the uptake of triglycerides and the differentiation of fibroblasts into adipose cells in response to insulin stimulation. Pin1 downregulation could be a potential approach to prevent and treat obesity-related disorders. In order to identify an inhibitor of Pin1 that exhibited minimal cytotoxicity, we established a high-throughput screen for Pin1 inhibitors and used this method to identify an inhibitor from 1,056 crude fractions of two natural product libraries. The candidate, a phlorotannin called 974-B, was isolated from the seaweed, Ecklonia kurome. 974-B inhibited the differentiation of mouse embryonic fibroblasts and 3T3-L1 cells into adipose cells without inducing cytotoxicity. We discovered the Pin1 inhibitor, 974-B, from the seaweed, E. kurome, and showed that it blocks the differentiation of fibroblasts into adipose cells, suggesting that 974-B could be a lead drug candidate for obesity-related disorders.

Absorption and distribution of deuterium-labeled trans- and cis-11-octadecenoic acid in human plasma and lipoprotein lipids

International Nuclear Information System (INIS)

Emken, E.A.; Rohwedder, W.K.; Adlof, R.O.; DeJarlais, W.J.; Gulley, R.M.

1986-01-01

Triglycerides of deuterium-labeled trans-11-, trans-11-cis-11- and cis-9-octadecenoic acid (11t-18:1-2H, 11c-18:1-2H) were simultaneously fed to two young adult male subjects. Plasma lipids from blood samples collected periodically for 48 hr were analyzed by gas chromatography-mass spectroscopy. The results indicate the delta 11-18:1-2H acids and 9c-18:1-2H were equally well absorbed; relative turnover rates were higher for the delta 11-18-1-2H acids in plasma triglycerides; incorporation of the delta 11-18:1-2H acids into plasma phosphatidylcholine was similar to 9c-18:1-2H, but distribution at the 1- and 2-acyl positions was substantially different; esterification of cholesterol with 11t-18:1 was extremely low; chain shortening of the delta 11-18:1-2H acids was 2-3 times greater than for 9c-18:1-2H; no evidence for desaturation or elongation of the 18:1-2H acids was detected; and a 40% isotopic dilution of the 18:1-2H acids in the chylomicron triglyceride fraction indicated the presence of a substantial intestinal triglyceride pool. Based on our present knowledge, these metabolic results for delta 11-18:1 acids present in hydrogenated oils and animal fats indicate that the delta 11 isomers are no more likely than 9c-18:1 to contribute to dietary fat-related health problems

Synthesis, Crystal Structure, and Biological Activity of cis/trans Amide Rotomers of (Z-N′-(2-Oxoindolin-3-ylideneformohydrazide

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Hatem A. Abdel-Aziz

2014-01-01

Full Text Available (Z-N′-(2-Oxoindolin-3-ylideneformohydrazide (2 was synthesized by the reaction of (Z-3-hydrazonoindolin-2-one (1 with formic acid under reflux. The structure of 2 was characterized by IR, Mass, 1H NMR, and X-ray crystal structure determination. Interestingly, compound 2 appeared in DMSO-d6 as cis and trans amide rotomers in 25% and 75%, respectively. The X-ray analysis showed the Z geometrical isomer of 2 around –C=N– for cis and trans amide rotomers. The crystal of 2 belongs to monoclinic, space group P21/c, with a=4.5206 (1 Å, b=22.4747 (7 Å, c=17.3637 (5 Å, β=103.752 (1°, Z=8, V=1713.57 (8 Å3, Dc=1.467 Mg m−3, μ=0.11 mm−1, F(000=784, R=0.047, and wR=0.123 for 3798 observed reflections with I>2σ(I. Compound 2 exhibited a moderate activity in its antimicrobial evaluation against E. coli and P. aeruginosa and a good activity against S. aureus close to that of the standard drug ciprofloxacin. The in vitro anticancer activity of 2 was evaluated against two human tumor cell lines, namely, HepG2 hepatocellular carcinoma and MCF-7 breast cancer. HepG2 cancer cell line was more susceptible to compound 2 than MCF-7.

Different integration site structures between L1 protein-mediated retrotransposition in cis and retrotransposition in trans

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Kojima Kenji K

2010-07-01

Full Text Available Abstract Background Long interspersed nuclear element-1 (LINE-1 or L1 is a dominant repetitive sequence in the human genome. Besides mediating its own retrotransposition, L1 can mobilize Alu and messenger RNA (mRNA in trans, and probably also SVA and non-coding RNA. The structures of L1 copies and trans-mobilized retrocopies are variable and can be classified into three categories: full-length; 5'-truncated; and 5'-inverted insertions. These structures may be generated by different 5' integration mechanisms. Results In this study, a method to correctly characterize insertions with short target site duplications (TSDs is developed and extranucleotides, TSDs and microhomologies (MHs at junctions were analysed for the three types of insertions. Only 5'-truncated L1 insertions were found to be associated with short TSDs. Both full-length and 5'-truncated retrotransposed sequences in trans, including Alu, SVA and mRNA retrocopies and also full-length and 5'-inverted L1, were not associated with short TSDs, indicating the difference of 5' attachment between retrotransposition in cis and retrotransposition in trans. Target sequence analysis suggested that short TSDs were generated in an L1 endonuclease-dependent manner. The MHs were longer for 5'-inverted L1 than for 5'-truncated L1, indicating less dependence on annealing in 5'-truncated L1 insertions. Conclusions The results suggest that insertions flanked by short TSDs occur more often coupled with the insertion of 5'-truncated L1 than with those of other types of insertions in vivo. The method used in this study can be used to characterize elements without any apparent boundary structures.

cis,trans-Dicarbonyldichlorido(1,10-phenanthroline-5,6-dione-κ2N,N′ruthenium(II

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Tsugiko Takase

2017-02-01

Full Text Available In the title compound, [RuCl2(C12H6N2O2(CO2], the RuII atom (site symmetry ..2 adopts a distorted octahedral coordination sphere defined by two carbonyl C atoms, two Cl− anions and two N atoms from the chelating 1,10-phenanthroline-5,6-dione (phendione ligand. The carbonyl ligands are cis to each other, while the Cl atoms are trans. In the phendione ligand, the C=O [1.239 (5 Å] and the C—C [1.537 (5 Å] bond lengths in the diketone moiety have typical values. In the crystal, C—H...Cl and C—H...O hydrogen bonds lead to the formation of a three-dimensional supramolecular network.

cis-Tetrachlorido-bis(indazole)osmium(iv) and its osmium(iii) analogues: paving the way towards the cis-isomer of the ruthenium anticancer drugs KP1019 and/or NKP1339

KAUST Repository

Bü chel, Gabriel E.; Kossatz, Susanne; Sadique, Ahmad; Rapta, Peter; Zalibera, Michal; Bucinsky, Lukas; Komorovsky, Stanislav; Telser, Joshua; Eppinger, Jö rg; Reiner, Thomas; Arion, Vladimir B.

2017-01-01

The relationship between cis-trans isomerism and anticancer activity has been mainly addressed for square-planar metal complexes, in particular, for platinum(II), e.g., cis- and trans-[PtCl2(NH3)(2)], and a number of related compounds, of which, however, only cis-counterparts are in clinical use today. For octahedral metal complexes, this effect of geometrical isomerism on anticancer activity has not been investigated systematically, mainly because the relevant isomers are still unavailable. An example of such an octahedral complex is trans-[RuCl4(Hind)(2)](-), which is in clinical trials now as its indazolium (KP1019) or sodium salt (NKP1339), but the corresponding cis-isomers remain inaccessible. We report the synthesis of Na[cis-(OsCl4)-Cl-III(kappa N2-1H-ind)(2)] . (Na[1]) suggesting a route to the cis-isomer of NKP1339. The procedure involves heating (H(2)ind)[(OsCl5)-Cl-IV(kappa N1-2H-ind)] in a high boiling point organic solvent resulting in an Anderson rearrangement with the formation of cis-[(OsCl4)-Cl-IV(kappa N2-1H-ind)(2)] ([1]) in high yield. The transformation is accompanied by an indazole coordination mode switch from kappa N1 to kappa N2 and stabilization of the 1H-indazole tautomer. Fully reversible spectroelectrochemical reduction of [1] in acetonitrile at 0.46 V vs. NHE is accompanied by a change in electronic absorption bands indicating the formation of cis-[(OsCl4)-Cl-III(kappa N2-1H-ind)(2)](-) ([1](-)). Chemical reduction of [1] in methanol with NaBH4 followed by addition of nBu(4)NCl afforded the osmium(III) complex nBu(4)N[cis-(OsCl4)-Cl-III(kappa N2-1H-ind)(2)] (nBu(4)N [1]). A metathesis reaction of nBu(4)N[1] with an ion exchange resin led to the isolation of the water-soluble salt Na[1]. The X-ray diffraction crystal structure of [1] . Me2CO was determined and compared with that of trans-[(OsCl4)-Cl-IV(kappa N2-1H-ind)(2)] . 2Me(2)SO (2 . 2Me(2)SO), also prepared in this work. EPR spectroscopy was performed on the Os-III complexes and

cis-Tetrachlorido-bis(indazole)osmium(iv) and its osmium(iii) analogues: paving the way towards the cis-isomer of the ruthenium anticancer drugs KP1019 and/or NKP1339

KAUST Repository

Büchel, Gabriel E.

2017-08-15

The relationship between cis-trans isomerism and anticancer activity has been mainly addressed for square-planar metal complexes, in particular, for platinum(II), e.g., cis- and trans-[PtCl2(NH3)(2)], and a number of related compounds, of which, however, only cis-counterparts are in clinical use today. For octahedral metal complexes, this effect of geometrical isomerism on anticancer activity has not been investigated systematically, mainly because the relevant isomers are still unavailable. An example of such an octahedral complex is trans-[RuCl4(Hind)(2)](-), which is in clinical trials now as its indazolium (KP1019) or sodium salt (NKP1339), but the corresponding cis-isomers remain inaccessible. We report the synthesis of Na[cis-(OsCl4)-Cl-III(kappa N2-1H-ind)(2)] . (Na[1]) suggesting a route to the cis-isomer of NKP1339. The procedure involves heating (H(2)ind)[(OsCl5)-Cl-IV(kappa N1-2H-ind)] in a high boiling point organic solvent resulting in an Anderson rearrangement with the formation of cis-[(OsCl4)-Cl-IV(kappa N2-1H-ind)(2)] ([1]) in high yield. The transformation is accompanied by an indazole coordination mode switch from kappa N1 to kappa N2 and stabilization of the 1H-indazole tautomer. Fully reversible spectroelectrochemical reduction of [1] in acetonitrile at 0.46 V vs. NHE is accompanied by a change in electronic absorption bands indicating the formation of cis-[(OsCl4)-Cl-III(kappa N2-1H-ind)(2)](-) ([1](-)). Chemical reduction of [1] in methanol with NaBH4 followed by addition of nBu(4)NCl afforded the osmium(III) complex nBu(4)N[cis-(OsCl4)-Cl-III(kappa N2-1H-ind)(2)] (nBu(4)N [1]). A metathesis reaction of nBu(4)N[1] with an ion exchange resin led to the isolation of the water-soluble salt Na[1]. The X-ray diffraction crystal structure of [1] . Me2CO was determined and compared with that of trans-[(OsCl4)-Cl-IV(kappa N2-1H-ind)(2)] . 2Me(2)SO (2 . 2Me(2)SO), also prepared in this work. EPR spectroscopy was performed on the Os-III complexes and

Dicty_cDB: SLA264 [Dicty_cDB

Lifescience Database Archive (English)

Full Text Available -propyl cis-trans isomerase (CYP1) gene, complete cds. 52 3e-22 4 AJ537762 |AJ537762.1 Timarcha... balearica EST, clone Timarcha3B3. 88 5e-22 3 AJ537662 |AJ537662.1 Timarcha balearica EST, clone Timarcha

Complete determination of the Pin1 catalytic domain thermodynamic cycle by NMR lineshape analysis

International Nuclear Information System (INIS)

Greenwood, Alexander I.; Rogals, Monique J.; De, Soumya; Lu, Kun Ping; Kovrigin, Evgenii L.; Nicholson, Linda K.

2011-01-01

The phosphorylation-specific peptidyl-prolyl isomerase Pin1 catalyzes the isomerization of the peptide bond preceding a proline residue between cis and trans isomers. To best understand the mechanisms of Pin1 regulation, rigorous enzymatic assays of isomerization are required. However, most measures of isomerase activity require significant constraints on substrate sequence and only yield rate constants for the cis isomer, k cat cis and apparent Michaelis constants, K M App . By contrast, NMR lineshape analysis is a powerful tool for determining microscopic rates and populations of each state in a complex binding scheme. The isolated catalytic domain of Pin1 was employed as a first step towards elucidating the reaction scheme of the full-length enzyme. A 24-residue phosphopeptide derived from the amyloid precurser protein intracellular domain (AICD) phosphorylated at Thr668 served as a biologically-relevant Pin1 substrate. Specific 13 C labeling at the Pin1-targeted proline residue provided multiple reporters sensitive to individual isomer binding and on-enzyme catalysis. We have performed titration experiments and employed lineshape analysis of phosphopeptide 13 C– 1 H constant time HSQC spectra to determine k cat cis , k cat trans , K D cis , and K D trans for the catalytic domain of Pin1 acting on this AICD substrate. The on-enzyme equilibrium value of [E·trans]/[E·cis] = 3.9 suggests that the catalytic domain of Pin1 is optimized to operate on this substrate near equilibrium in the cellular context. This highlights the power of lineshape analysis for determining the microscopic parameters of enzyme catalysis, and demonstrates the feasibility of future studies of Pin1-PPIase mutants to gain insights on the catalytic mechanism of this important enzyme.

Triosephosphate isomerase is a common crystallization contaminant of soluble His-tagged proteins produced in Escherichia coli

International Nuclear Information System (INIS)

Kozlov, Guennadi; Vinaik, Roohi; Gehring, Kalle

2013-01-01

Crystals of E. coli triosephosphate isomerase were obtained as a contaminant and its structure was determined to 1.85 Å resolution. Attempts to crystallize several mammalian proteins overexpressed in Escherichia coli revealed a common contaminant, triosephosphate isomerase, a protein involved in glucose metabolism. Even with triosephosphate isomerase present in very small amounts, similarly shaped crystals appeared in the crystallization drops in a number of polyethylene glycol-containing conditions. All of the target proteins were His-tagged and their purification involved immobilized metal-affinity chromatography (IMAC), a step that was likely to lead to triosephosphate isomerase contamination. Analysis of the triosephosphate isomerase crystals led to the structure of E. coli triosephosphate isomerase at 1.85 Å resolution, which is a significant improvement over the previous structure

Genome-wide identification and quantification of cis- and trans-regulated genes responding to Marek’s disease virus infection via analysis of allele-specific expression

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Sean eMaceachern

2012-01-01

Full Text Available Marek’s disease (MD is a commercially important neoplastic disease of chickens caused by Marek’s disease virus (MDV, an oncogenic alphaherpesvirus. Selecting for increased genetic resistance to MD is a control strategy that can augment vaccinal control measures. To identify high-confidence candidate MD resistance genes, we conducted a genome-wide screen for allele-specific expression (ASE amongst F1 progeny of two inbred chicken lines that differ in MD resistance. High throughput sequencing was used to profile transcriptomes from pools of uninfected and infected individuals at 4 days post-infection to identify any genes showing ASE in response to MDV infection. RNA sequencing identified 22,655 single nucleotide polymorphisms (SNPs of which 5,360 in 3,773 genes exhibited significant allelic imbalance. Illumina GoldenGate assays were subsequently used to quantify regulatory variation controlled at the gene (cis and elsewhere in the genome (trans by examining differences in expression between F1 individuals and artificial F1 RNA pools over 6 time periods in 1,536 of the most significant SNPs identified by RNA sequencing. Allelic imbalance as a result of cis-regulatory changes was confirmed in 861 of the 1,233 GoldenGate assays successfully examined. Furthermore we have identified 7 genes that display trans-regulation only in infected animals and approximately 500 SNP that show a complex interaction between cis- and trans-regulatory changes. Our results indicate ASE analyses are a powerful approach to identify regulatory variation responsible for differences in transcript abundance in genes underlying complex traits. And the genes with SNPs exhibiting ASE provide a strong foundation to further investigate the causative polymorphisms and genetic mechanisms for MD resistance. Finally, the methods used here for identifying specific genes and SNPs may have practical implications for applying marker-assisted selection to complex traits that are

Acides gras polyinsaturés trans : aspects métaboliques

Directory of Open Access Journals (Sweden)

Sebedio Jean-Louis

2000-01-01

Full Text Available Les acides gras trans polyinsaturés sont formés à partir des acides gras indispensables (acides linoléique et a-linolénique au cours des traitements technologiques comme par exemple le raffinage des huiles ou la friture [1, 2]. L’acide linolénique est plus sensible à l’isomérisation que l’acide linoléique. En effet, comme l’a montré Wolff dans une revue récente [3], le degré d’isomérisation de l’acide linolénique peut atteindre 30 à 35 %. On retrouve également ces pourcentages dans les formules infantiles et le lait de femme [1]. Les principaux isomères formés sont les composés monotrans, à savoir les 18 :2-9trans,12cis, 18 :2-9cis,12trans, 18 :3-9trans,12cis,15cis, et le 18 :3-9cis,12cis,15-trans. Cependant, une température de désodorisation supérieure à 220 °C entraîne la formation d’isomères di-trans [4]. À titre d’exemple, nous avons représenté dans le tableau le contenu de quelques huiles végétales en isomères des acides linoléique et a-linolénique. Compte tenu de leur présence dans l’alimentation, on peut s’interroger sur les conséquences nutritionnelles et biochimiques de leur ingestion.

Metabolism of all-trans-retinoic acid and all-trans-retinyl acetate. Demonstration of common physiological metabolites in rat small intestinal mucosa and circulation

International Nuclear Information System (INIS)

Cullum, M.E.; Zile, M.H.

1985-01-01

The kinetics and metabolism of physiological doses of all-trans-retinoic acid were examined in blood and small intestinal mucosa of vitamin A-depleted rats. A major portion of intrajugularly injected retinoic acid is rapidly (within 2 min) sequestered by tissues; subsequently 13-cis-retinoic acid and polar metabolites are released into circulation. All-trans-retinoic acid appears in small intestinal epithelium within 2 min after dosing and is the major radioactive compound there for at least 2 h. Retinoyl glucuronide and 13-cis-retinoic acid are early metabolites of all-trans-retinoic acid in the small intestine of bile duct-cannulated rats. Retinoyl glucuronide, the major metabolite of retinoic acid intestinal epithelium, in contrast to other polar metabolites, was not detected in circulation. An examination of [ 3 H]retinyl acetate metabolites under steady state conditions in vitamin A-repleted rats demonstrates the occurrence of all-trans-retinoic acid and 13-cis-retinoic acid in circulation and in intestinal epithelium, in a pattern similar to that found after injection of retinoic acid into vitamin A-depleted rats. These data establish that all-trans-retinoic acid, 13-cis-retinoic acid, and retinoyl glucuronide are physiological metabolites of vitamin A in target tissues, and therefore are important candidates as mediators of the biological effect of the vitamin

Reaction rate and isomer-specific product branching ratios of C2H + C4H8: 1-butene, cis-2-butene, trans-2-butene, and isobutene at 79 K.

Science.gov (United States)

Bouwman, Jordy; Fournier, Martin; Sims, Ian R; Leone, Stephen R; Wilson, Kevin R

2013-06-20

The reactions of C2H radicals with C4H8 isomers 1-butene, cis-2-butene, trans-2-butene, and isobutene are studied by laser photolysis-vacuum ultraviolet mass spectrometry in a Laval nozzle expansion at 79 K. Bimolecular-reaction rate constants are obtained by measuring the formation rate of the reaction product species as a function of the reactant density under pseudo-first-order conditions. The rate constants are (1.9 ± 0.5) × 10(-10), (1.7 ± 0.5) × 10(-10), (2.1 ± 0.7) × 10(-10), and (1.8 ± 0.9) × 10(-10) cm(3) s(-1) for the reaction of C2H with 1-butene, cis-2-butene, trans-2-butene, and isobutene, respectively. Bimolecular rate constants for 1-butene and isobutene compare well to values measured previously at 103 K using C2H chemiluminescence. Photoionization spectra of the reaction products are measured and fitted to ionization spectra of the contributing isomers. In conjunction with absolute-ionization cross sections, these fits provide isomer-resolved product branching fractions. The reaction between C2H and 1-butene yields (65 ± 10)% C4H4 in the form of vinylacetylene and (35 ± 10)% C5H6 in the form of 4-penten-1-yne. The cis-2-butene and trans-2-butene reactions yield solely 3-penten-1-yne, and no discrimination is made between cis- and trans-3-penten-1-yne. Last, the isobutene reaction yields (26 ± 15)% 3-penten-1-yne, (35 ± 15)% 2-methyl-1-buten-3-yne, and (39 ± 15)% 4-methyl-3-penten-1-yne. The branching fractions reported for the C2H and butene reactions indicate that these reactions preferentially proceed via CH3 or C2H3 elimination rather than H-atom elimination. Within the experimental uncertainties, no evidence is found for the formation of cyclic species.

Neurological findings in triosephosphate isomerase deficiency

NARCIS (Netherlands)

Poll-The, B. T.; Aicardi, J.; Girot, R.; Rosa, R.

1985-01-01

Two siblings with hemolytic anemia caused by triosephosphate isomerase deficiency developed a progressive neurological syndrome featuring dystonic movements, tremor, pyramidal tract signs, and evidence of spinal motor neuron involvement. Intelligence was unaffected. The findings in these patients

Separation properties of the MIL-125(Ti) Metal-Organic Framework in high-performance liquid chromatography revealing cis/trans selectivity.

Science.gov (United States)

Van der Perre, Stijn; Liekens, Anuschka; Bueken, Bart; De Vos, Dirk E; Baron, Gino V; Denayer, Joeri F M

2016-10-21

Monodisperse MIL-125(Ti) Metal-Organic Framework crystals were synthesized and studied as stationary phase in high performance liquid chromatography (HPLC). Different pure compounds and model mixtures (including stereoisomer mixtures) were injected from which chromatographic parameters, including selectivities and resolution factors, were determined to evaluate the adsorption properties and separation performance of MIL-125(Ti) in liquid phase. The MIL-125(Ti) framework displayed a trans selectivity for cis/trans difunctionalized cyclohexane molecules with high selectivity and resolution for 1,3-dimethylcyclohexane and 4-ethylcyclohexanol. The slurry-packed column was further characterized via van Deemter analysis. Fitting of the van Deemter equation through the experimental points allowed to define the contributions of the different processes to plate height with a significant proportion of the A-term, reflecting the importance of a good crystal packing. Although high in comparison to commercial HPLC stationary phases, a very good plate height of around 50μm was found. Copyright © 2016 Elsevier B.V. All rights reserved.

Isoform-specific inhibition of cyclophilins.

Science.gov (United States)

Daum, Sebastian; Schumann, Michael; Mathea, Sebastian; Aumüller, Tobias; Balsley, Molly A; Constant, Stephanie L; de Lacroix, Boris Féaux; Kruska, Fabian; Braun, Manfred; Schiene-Fischer, Cordelia

2009-07-07

Cyclophilins belong to the enzyme class of peptidyl prolyl cis-trans isomerases which catalyze the cis-trans isomerization of prolyl bonds in peptides and proteins in different folding states. Cyclophilins have been shown to be involved in a multitude of cellular functions like cell growth, proliferation, and motility. Among the 20 human cyclophilin isoenzymes, the two most abundant members of the cyclophilin family, CypA and CypB, exhibit specific cellular functions in several inflammatory diseases, cancer development, and HCV replication. A small-molecule inhibitor on the basis of aryl 1-indanylketones has now been shown to discriminate between CypA and CypB in vitro. CypA binding of this inhibitor has been characterized by fluorescence anisotropy- and isothermal titration calorimetry-based cyclosporin competition assays. Inhibition of CypA- but not CypB-mediated chemotaxis of mouse CD4(+) T cells by the inhibitor provided biological proof of discrimination in vivo.

Zero-point Energy is Needed in Molecular Dynamics Calculations to Access the Saddle Point for H+HCN→H2CN* and cis/trans-HCNH* on a New Potential Energy Surface.

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Wang, Xiaohong; Bowman, Joel M

2013-02-12

We calculate the probabilities for the association reactions H+HCN→H2CN* and cis/trans-HCNH*, using quasiclassical trajectory (QCT) and classical trajectory (CT) calculations, on a new global ab initio potential energy surface (PES) for H2CN including the reaction channels. The surface is a linear least-squares fit of roughly 60 000 CCSD(T)-F12b/aug-cc-pVDZ electronic energies, using a permutationally invariant basis with Morse-type variables. The reaction probabilities are obtained at a variety of collision energies and impact parameters. Large differences in the threshold energies in the two types of dynamics calculations are traced to the absence of zero-point energy in the CT calculations. We argue that the QCT threshold energy is the realistic one. In addition, trajectories find a direct pathway to trans-HCNH, even though there is no obvious transition state (TS) for this pathway. Instead the saddle point (SP) for the addition to cis-HCNH is evidently also the TS for direct formation of trans-HCNH.

The role of 11-cis-retinyl esters in vertebrate cone vision.

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Babino, Darwin; Perkins, Brian D; Kindermann, Aljoscha; Oberhauser, Vitus; von Lintig, Johannes

2015-01-01

A cycle of cis-to-trans isomerization of the chromophore is intrinsic to vertebrate vision where rod and cone photoreceptors mediate dim- and bright-light vision, respectively. Daylight illumination can greatly exceed the rate at which the photoproduct can be recycled back to the chromophore by the canonical visual cycle. Thus, an additional supply pathway(s) must exist to sustain cone-dependent vision. Two-photon microscopy revealed that the eyes of the zebrafish (Danio rerio) contain high levels of 11-cis-retinyl esters (11-REs) within the retinal pigment epithelium. HPLC analyses demonstrate that 11-REs are bleached by bright light and regenerated in the dark. Pharmacologic treatment with all-trans-retinylamine (Ret-NH2), a potent and specific inhibitor of the trans-to-cis reisomerization reaction of the canonical visual cycle, impeded the regeneration of 11-REs. Intervention with 11-cis-retinol restored the regeneration of 11-REs in the presence of all-trans-Ret-NH2. We used the XOPS:mCFP transgenic zebrafish line with a functional cone-only retina to directly demonstrate that this 11-RE cycle is critical to maintain vision under bright-light conditions. Thus, our analyses reveal that a dark-generated pool of 11-REs helps to supply photoreceptors with the chromophore under the varying light conditions present in natural environments. © FASEB.

MTH1745, a protein disulfide isomerase-like protein from thermophilic archaea, Methanothermobacter thermoautotrophicum involving in stress response.

Science.gov (United States)

Ding, Xia; Lv, Zhen-Mei; Zhao, Yang; Min, Hang; Yang, Wei-Jun

2008-01-01

MTH1745 is a putative protein disulfide isomerase characterized with 151 amino acid residues and a CPAC active-site from the anaerobic archaea Methanothermobacter thermoautotrophicum. The potential functions of MTH1745 are not clear. In the present study, we show a crucial role of MTH1745 in protecting cells against stress which may be related to its functions as a disulfide isomerase and its chaperone properties. Using real-time polymerase chain reaction analyses, the level of MTH1745 messenger RNA (mRNA) in the thermophilic archaea M. thermoautotrophicum was found to be stress-induced in that it was significantly higher under low (50 degrees C) and high (70 degrees C) growth temperatures than under the optimal growth temperature for the organism (65 degrees C). Additionally, the expression of MTH1745 mRNA was up-regulated by cold shock (4 degrees C). Furthermore, the survival of MTH1745 expressing Escherichia coli cells was markedly higher than that of control cells in response to heat shock (51.0 degrees C). These results indicated that MTH1745 plays an important role in the resistance of stress. By assay of enzyme activities in vitro, MTH1745 also exhibited a chaperone function by promoting the functional folding of citrate synthase after thermodenaturation. On the other hand, MTH1745 was also shown to function as a disulfide isomerase on the refolding of denatured and reduced ribonuclease A. On the basis of its single thioredoxin domain, function as a disulfide isomerase, and its chaperone activity, we suggest that MTH1745 may be an ancient protein disulfide isomerase. These studies may provide clues to the understanding of the function of protein disulfide isomerase in archaea.

Metabolism in humans of cis-12,trans-15-octadecadienoic acid relative to palmitic, stearic, oleic and linoleic acids

International Nuclear Information System (INIS)

Emken, E.A.; Rohwedder, W.K.; Adlof, R.O.; Rakoff, H.; Gulley, R.M.

1987-01-01

Mixtures of triglycerides containing deuterium-labeled hexadecanoic acid (16:0), octadecanoic acid (18:0), cis-9-octadecenoic acid (9c-18:1), cis-9,cis-12-octadecadienoic acid (9c, 12c-18:2) and cis-12,trans-15-octadecadienoic acid (12c,15t-18:2) were fed to two young-adult males. Plasma lipid classes were isolated from samples collected periodically over 48 hr. Incorporation and turnover of the deuterium-labeled fats in plasma lipids were followed by gas chromatography-mass spectrometry (GC-MS) analysis of the methyl ester derivatives. Absorption of the deuterated fats was followed by GC-MS analysis of chylomicron triglycerides isolated by ultracentrifugation. Results were the following: (i) endogenous fat contributed about 40% of the total fat incorporated into chylomicron triglycerides; (ii) elongation, desaturation and chain-shortened products from the deuterated fats were not detected; (iii) the polyunsaturated isomer 12c,15t-18:2 was metabolically more similar to saturated and 9c-18:1 fatty acids than to 9c,12c-18:2; (iv) relative incorporation of 9c,12c-18:2 into phospholipids did not increase proportionally with an increase of 9c,12c-18:2 in the mixture of deuterated fats fed; (v) absorption of 16:0, 18:0, 9c-18:1, 9c,12c-18:2 and 12c,15t-18:2 were similar; and (vi) data for the 1- and 2-acyl positions of phosphatidylcholine and for cholesteryl ester fractions reflected the known high specificity of phosphatidylcholine acyltransferase and lecithin:cholesteryl acyltransferase for 9c,12c-18:2. These results illustrate that incorporation of dietary fatty acids into human plasma lipid classes is selectively controlled and that incorporation of dietary 9c,12c-18:2 is limited

Evidence for RPE65-independent vision in the cone-dominated zebrafish retina.

Science.gov (United States)

Schonthaler, Helia B; Lampert, Johanna M; Isken, Andrea; Rinner, Oliver; Mader, Andreas; Gesemann, Matthias; Oberhauser, Vitus; Golczak, Marcin; Biehlmaier, Oliver; Palczewski, Krzysztof; Neuhauss, Stephan C F; von Lintig, Johannes

2007-10-01

An enzyme-based cyclic pathway for trans to cis isomerization of the chromophore of visual pigments (11-cis-retinal) is intrinsic to vertebrate cone and rod vision. This process, called the visual cycle, is mostly characterized in rod-dominated retinas and essentially depends on RPE65, an all-trans to 11-cis-retinoid isomerase. Here we analysed the role of RPE65 in zebrafish, a species with a cone-dominated retina. We cloned zebrafish RPE65 and showed that its expression coincided with photoreceptor development. Targeted gene knockdown of RPE65 resulted in morphologically altered rod outer segments and overall reduced 11-cis-retinal levels. Cone vision of RPE65-deficient larvae remained functional as demonstrated by behavioural tests and by metabolite profiling for retinoids. Furthermore, all-trans retinylamine, a potent inhibitor of the rod visual cycle, reduced 11-cis-retinal levels of control larvae to a similar extent but showed no additive effects in RPE65-deficient larvae. Thus, our study of zebrafish provides in vivo evidence for the existence of an RPE65-independent pathway for the regeneration of 11-cis-retinal for cone vision.

2,3-trans-3,4-trans-3,4-Dihydroxy-L-proline: An amino acid in toxic peptides of Amanita virosa mushrooms

Science.gov (United States)

Buku, A.; Faulstich, H.; Wieland, T.; Dabrowski, J.

1980-01-01

Among the four possible stereoisomers of 3,4-dihydroxy-L-proline,2,3-trans-3,4-trans-3,4-dihydroxy-L-proline (IV) had not been found in nature previously. It has now been detected as a component of virotoxins, toxic peptides of Amanita virosa mushrooms. Because periodate failed to effect an oxidative glycol splitting reaction, the two hydroxyl groups in positions 3 and 4 were expected to be in a trans configuration. Furthermore, the formation of a 4-lactone on treatment with acids pointed to the carboxyl group and the hydroxyl group at position 4 being in a cis configuration. These results are in agreement with structure IV only. Final proof for structure IV was given by NMR spectroscopy and direct comparison with the 2,3-cis-3,4-trans-3,4-dihydroxy-L-proline isomer. PMID:16592813

cis–trans Isomerization of silybins A and B

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Michaela Novotná

2014-05-01

Full Text Available Methods were developed and optimized for the preparation of the 2,3-cis- and the 10,11-cis-isomers of silybin by the Lewis acid catalyzed (BF3∙OEt2 isomerization of silybins A (1a and B (1b (trans-isomers. The absolute configuration of all optically pure compounds was determined by using NMR and comparing their electronic circular dichroism data with model compounds of known absolute configurations. Mechanisms for cis–trans-isomerization of silybin are proposed and supported by quantum mechanical calculations.

TransPlanckian Particles and the Quantization of Time

NARCIS (Netherlands)

Hooft, G. 't

1999-01-01

Trans-Planckian particles are elementary particles accelerated such that their energies surpass the Planck value. There are several reasons to believe that trans-Planckian particles do not represent independent degrees of freedom in Hilbert space, but they are controlled by the cis-Planckian

Narrowband NIR-Induced In Situ Generation of the High-Energy Trans Conformer of Trichloroacetic Acid Isolated in Solid Nitrogen and its Spontaneous Decay by Tunneling to the Low-Energy Cis Conformer

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R. F. G. Apóstolo

2015-12-01

Full Text Available The monomeric form of trichloroacetic acid (CCl3COOH; TCA was isolated in a cryogenic nitrogen matrix (15 K and the higher energy trans conformer (O=C–O–H dihedral: 180° was generated in situ by narrowband near-infrared selective excitation the 1st OH stretching overtone of the low-energy cis conformer (O=C–O–H dihedral: 0°. The spontaneous decay, by tunneling, of the generated high-energy conformer into the cis form was then evaluated and compared with those observed previously for the trans conformers of acetic and formic acids in identical experimental conditions. The much faster decay of the high-energy conformer of TCA compared to both formic and acetic acids (by ~35 and ca. 25 times, respectively was found to correlate well with the lower energy barrier for the trans→cis isomerization in the studied compound. The experimental studies received support from quantum chemistry calculations undertaken at the DFT(B3LYP/cc-pVDZ level of approximation, which allowed a detailed characterization of the potential energy surface of the molecule and the detailed assignment of the infrared spectra of the two conformers.

Cis-to- Trans Isomerization of Azobenzene Derivatives Studied with Transition Path Sampling and Quantum Mechanical/Molecular Mechanical Molecular Dynamics.

Science.gov (United States)

Muždalo, Anja; Saalfrank, Peter; Vreede, Jocelyne; Santer, Mark

2018-04-10

Azobenzene-based molecular photoswitches are becoming increasingly important for the development of photoresponsive, functional soft-matter material systems. Upon illumination with light, fast interconversion between a more stable trans and a metastable cis configuration can be established resulting in pronounced changes in conformation, dipole moment or hydrophobicity. A rational design of functional photosensitive molecules with embedded azo moieties requires a thorough understanding of isomerization mechanisms and rates, especially the thermally activated relaxation. For small azo derivatives considered in the gas phase or simple solvents, Eyring's classical transition state theory (TST) approach yields useful predictions for trends in activation energies or corresponding half-life times of the cis isomer. However, TST or improved theories cannot easily be applied when the azo moiety is part of a larger molecular complex or embedded into a heterogeneous environment, where a multitude of possible reaction pathways may exist. In these cases, only the sampling of an ensemble of dynamic reactive trajectories (transition path sampling, TPS) with explicit models of the environment may reveal the nature of the processes involved. In the present work we show how a TPS approach can conveniently be implemented for the phenomenon of relaxation-isomerization of azobenzenes starting with the simple examples of pure azobenzene and a push-pull derivative immersed in a polar (DMSO) and apolar (toluene) solvent. The latter are represented explicitly at a molecular mechanical (MM) and the azo moiety at a quantum mechanical (QM) level. We demonstrate for the push-pull azobenzene that path sampling in combination with the chosen QM/MM scheme produces the expected change in isomerization pathway from inversion to rotation in going from a low to a high permittivity (explicit) solvent model. We discuss the potential of the simulation procedure presented for comparative calculation of

Cyclophilin and Viruses: Cyclophilin as a Cofactor for Viral Infection and Possible Anti-Viral Target

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Koichi Watashi

2007-01-01

Full Text Available Cyclophilin (CyP is a peptidyl prolyl cis/trans isomerase, catalyzing the cis-trans isomerization of proline residues in proteins. CyP plays key roles in several different aspects of cellular physiology including the immune response, transcription, mitochondrial function, cell death, and chemotaxis. In addition to these cellular events, a number of reports demonstrated that CyP plays a critical role in the life cycle of viruses, especially human immunodeficiency virus (HIV and hepatitis C virus (HCV. These two viruses are significant causes of morbidity and mortality worldwide, but current therapies are often insufficient. CyP may provide a novel therapeutic target for the management and/or cure of these diseases, in particular HCV.

Combining results of two GC separations partly achieves determination of all cis and trans 16:1, 18:1, 18:2 and 18:3 except CLA isomers of milk fat as demonstrated using Ag-ion SPE fractionation.

Science.gov (United States)

Kramer, John K G; Hernandez, Marta; Cruz-Hernandez, Cristina; Kraft, Jana; Dugan, Michael E R

2008-03-01

Milk fat is a complex mixture of geometric and positional isomers of monounsaturated and polyunsaturated, including short-, long- and branch-chain fatty acids (FAs). There has been partial success to resolve this mixture of FAs using different GC temperature programs, or a combination of GC isothermal and temperature programs. To overcome the problem associated with overlapping isomers prior silver-ion separation was recommended. However, this procedure is time consuming and not practical for routine analysis. In addition, previous methods focused mainly on the trans and cis isomers of 18:1. The present method takes advantage of differences in the relative elution times between different types of FAs. The method involved analyzing each milk fat using the same highly polar 100-m capillary column and GC instrument, and conducting two separations using temperature programs that plateau at 175 and 150 degrees C. The relative shift among the geometric and positional isomers at these two temperature settings was enough to permit identification of most of the trans and cis 16:1, 18:1 and 20:1, the c/t-18:2 and the c/c/t-18:3 isomers found in milk fat. The identity of these FAs was confirmed by prior separation of the total fatty acid methyl esters (FAMEs) of milk fat using Ag(+)-SPE columns, and comparing the fractions to the total milk fat. The Ag(+)-SPE technique was modified to obtain pure saturated, trans- and cis-monounsaturated and diunsaturated FAMEs. By combining the results from these two separate GC analyses, knowing the elution order, it was possible to determine most of the geometric and positional isomers of 16:1, 18:1, 20:1, 18:2 and 18:3 without a prior silver-ion separation. Only few minor FAs could not be resolved, notable the conjugated linoleic acid isomers that still required the complimentary Ag(+)-HPLC separation. The two GC temperature programs have been successfully used to routinely analyze most FA isomers in total milk and beef fats in about 200

Sequential analysis of trans-SNARE formation in intracellular membrane fusion.

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Kannan Alpadi

2012-01-01

Full Text Available SNARE complexes are required for membrane fusion in the endomembrane system. They contain coiled-coil bundles of four helices, three (Q(a, Q(b, and Q(c from target (t-SNAREs and one (R from the vesicular (v-SNARE. NSF/Sec18 disrupts these cis-SNARE complexes, allowing reassembly of their subunits into trans-SNARE complexes and subsequent fusion. Studying these reactions in native yeast vacuoles, we found that NSF/Sec18 activates the vacuolar cis-SNARE complex by selectively displacing the vacuolar Q(a SNARE, leaving behind a Q(bcR subcomplex. This subcomplex serves as an acceptor for a Q(a SNARE from the opposite membrane, leading to Q(a-Q(bcR trans-complexes. Activity tests of vacuoles with diagnostic distributions of inactivating mutations over the two fusion partners confirm that this distribution accounts for a major share of the fusion activity. The persistence of the Q(bcR cis-complex and the formation of the Q(a-Q(bcR trans-complex are both sensitive to the Rab-GTPase inhibitor, GDI, and to mutations in the vacuolar tether complex, HOPS (HOmotypic fusion and vacuolar Protein Sorting complex. This suggests that the vacuolar Rab-GTPase, Ypt7, and HOPS restrict cis-SNARE disassembly and thereby bias trans-SNARE assembly into a preferred topology.

Effect of ultrasonic waves on the stability of all-trans lutein and its degradation kinetics.

Science.gov (United States)

Song, Jiang-Feng; Li, Da-Jing; Pang, Hui-Li; Liu, Chun-Quan

2015-11-01

Ultrasound treatment has been widely applied in the extraction of biologically active compounds including carotenoids. However, there are few reports on their effects on the stability of these compounds. In the present study, the stability of all-trans lutein, one of the carotenoids, was investigated under the action of ultrasound. Results showed that ultrasound induced the isomerization of all-trans lutein to its isomers, namely to 13-cis lutein, 13'-cis lutein, 9-cis lutein and 9'-cis lutein as analyzed by HPLC coupled with DAD and LC-MS; and the percentage of the isomerization increased with increasing both ultrasonic frequency and power. The stability of all-trans lutein in dichloromethane was worst among multiple kinds of solvents. Interestingly, the retention rate of all-trans lutein improved as the temperature increased, which runs counter to the Arrhenius law. Under ultrasound irradiation, the degradation mechanism might be different with various temperatures, the degradation of all-trans lutein followed first-order kinetics at 20°C, while second-order kinetics was followed at 30-50°C. As the ultrasonic reaction time prolonged, lutein epoxidation nearly occurred. Those results presented here emphasized that UAE techniques should be carefully used in the extraction of all-trans lutein. Copyright © 2015 Elsevier B.V. All rights reserved.

Distribution and metabolism of cis- and trans-resmethrin (5-benzyl-3-furyl-methyl-2,2-dimethyl 3-(2-methyl-propenyl)cyclopropanecarboxylate) in laying hens

International Nuclear Information System (INIS)

Christopher, R.J.

1986-01-01

The cis and trans isomers of the synthetic pyrethroid, resmethrin (5-benzyl-3-furylmethyl-(IRS)-chrysanthemate), labeled with radiocarbon in either the alcohol or acid moiety, were individually administered orally to White Leghorn laying hens at a dosage of 10 mg/kg. With each isomer and label position, greater than 90% of the radiocarbon was eliminated in the excreta within 24 hours posttreatment. Radiocarbon residues in the egg white and yolk fractions were low, with peak levels observed at 1-2 and 4-5 days post-treatment in white and yolk, respectively. Residues were considerably lower in egg whites than in yolks. In birds killed 12 hours post-treatment, radiocarbon residues in tissues were low with peak levels in liver and kidney. Unmetabolized cis- or trans-resmethrin was detected in all tissues analyzed from birds killed at 12 hours post-treatment and represented the major metabolite in fat. The majority of the tissues from hens 14 days post-treatment contained no detectable levels of radiocarbon and would appear not to be indicative of appreciable residue retention. Numerous metabolites were isolated and were present in both the free and conjugated form. The metabolic routes for both resmethrin isomers arise from ester hydrolysis and oxidation of the hydrolytic products. Certain of these metabolites are further conjugated with glucuronic acid, sulfate or other unidentified compounds before excretion

Trans-10, cis 12-Conjugated Linoleic Acid-Induced Milk Fat Depression Is Associated with Inhibition of PPARγ Signaling and Inflammation in Murine Mammary Tissue

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Anil K. G. Kadegowda

2013-01-01

Full Text Available Exogenous trans-10, cis-12-CLA (CLA reduces lipid synthesis in murine adipose and mammary (MG tissues. However, genomewide alterations in MG and liver (LIV associated with dietary CLA during lactation remain unknown. We fed mice (n=5/diet control or control + trans-10, cis-12-CLA (37 mg/day between d 6 and d 10 postpartum. The 35,302 annotated murine exonic evidence-based oligo (MEEBO microarray and quantitative RT-PCR were used for transcript profiling. Milk fat concentration was 44% lower on d 10 versus d 6 due to CLA. The CLA diet resulted in differential expression of 1,496 genes. Bioinformatics analyses underscored that a major effect of CLA on MG encompassed alterations in cellular signaling pathways and phospholipid species biosynthesis. Dietary CLA induced genes related to ER stress (Xbp1, apoptosis (Bcl2, and inflammation (Orm1, Saa2, and Cp. It also induced marked inhibition of PPARγ signaling, including downregulation of Pparg and Srebf1 and several lipogenic target genes (Scd, Fasn, and Gpam. In LIV, CLA induced hepatic steatosis probably through perturbations in the mitochondrial functions and induction of ER stress. Overall, results from this study underscored the role of PPARγ signaling on mammary lipogenic target regulation. The proinflammatory effect due to CLA could be related to inhibition of PPARγ signaling.

Degradative pro-vitamin A active compounds of all- trans -&beta ...

African Journals Online (AJOL)

Dark green leafy vegetables (DGLV) are rich source of pro-vitamin A carotenoids, with all-trans-b-carotene as the main compound contributing over 90% of the vitamin A content. The other pro-vitamin A carotenoids present in DGLV are the cis isomers of b-carotene; the 9-cis and the 13-cis, and a-carotene in some ...

Interaction of photoactive cis(CO)-trans(I)-Ru-(4,4‧-dicarboxylate-2,2‧-bipyridine)(CO)2I2 with anatase (1 0 1) surface

Science.gov (United States)

Haukka, Matti; Hirva, Pipsa

2002-06-01

The coordination of cis(CO)-trans(I)-Ru(4,4‧-dicarboxylate-2,2‧-bipyridine)(CO)2I2 on an anatase (1 0 1) surface was investigated using a computational density functional method. The adsorbate is able to interact with the anatase surface by one or two carboxylate substituents of the bipyridine ligand. Three of the studied coordination modes involved a single carboxylate as the binding group, including monodentate (1M), bidentate chelating (1BC) and bidentate bridging (1BB) modes. The possibility of monodentate binding via both carboxylate groups in (2M) was also studied. The results showed that the multidentate binding is clearly preferred over monodentate coordination. The stability of the modes increased in the order 1M, 1BC, 1BB and 2M. The flexibility of the bipyridine ligand was found to be the key factor in the binding via two carboxylate groups.

Metallic conductivity in a disordered charge-transfer salt derived from cis-BET-TTF

Energy Technology Data Exchange (ETDEWEB)

Rovira, C. [Inst. de Ciencia de Materials de Barcelona (CSIC) (Spain); Tarres, J. [Inst. de Ciencia de Materials de Barcelona (CSIC) (Spain); Ribera, E. [Inst. de Ciencia de Materials de Barcelona (CSIC) (Spain); Veciana, J. [Inst. de Ciencia de Materials de Barcelona (CSIC) (Spain); Canadell, E. [Inst. de Ciencia de Materials de Barcelona (CSIC) (Spain); Molins, E. [Inst. de Ciencia de Materials de Barcelona (CSIC) (Spain); Mas, M. [Inst. de Ciencia de Materials de Barcelona (CSIC) (Spain); Laukhin, V. [Inst. de Ciencia de Materials de Barcelona (CSIC) (Spain)]|[Rossijskaya Akademiya Nauk, Chernogolovka (Russian Federation). Inst. Khimicheskoj Fiziki; Doublet, M.L. [Lab. de Structure et Dynamique (CNRS), Univ. de Montpellier 2 (France); Cowan, D.O. [Johns Hopkins Univ., Baltimore, MD (United States). Dept. of Chemistry; Yang, S. [Johns Hopkins Univ., Baltimore, MD (United States). Dept. of Chemistry

1997-02-28

The first example of a metallic charge-transfer salt derived from cis-bis(ethylenethio)-tetrathiafulvalene (BET-TTF) is reported. (BET-TTF){sub 2}SCN and (BET-TTF)SCN salts were obtained by electrocrystallization starting from trans-BET-TTF. X-ray crystal structure of the mixed-valence salt revealed that trans-cis isomerization occurs upon one electron oxidation. In spite of the structural disorder in both BET-TTF and the counterion, 2:1 salt is metallic down to 60 K and then resistance increases slowly down to 4 K. (orig.)

Evolution of cichlid vision via trans-regulatory divergence

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O’Quin Kelly E

2012-12-01

Full Text Available Abstract Background Phenotypic evolution may occur through mutations that affect either the structure or expression of protein-coding genes. Although the evolution of color vision has historically been attributed to structural mutations within the opsin genes, recent research has shown that opsin regulatory mutations can also tune photoreceptor sensitivity and color vision. Visual sensitivity in African cichlid fishes varies as a result of the differential expression of seven opsin genes. We crossed cichlid species that express different opsin gene sets and scanned their genome for expression Quantitative Trait Loci (eQTL responsible for these differences. Our results shed light on the role that different structural, cis-, and trans-regulatory mutations play in the evolution of color vision. Results We identified 11 eQTL that contribute to the divergent expression of five opsin genes. On three linkage groups, several eQTL formed regulatory “hotspots” associated with the expression of multiple opsins. Importantly, however, the majority of the eQTL we identified (8/11 or 73% occur on linkage groups located trans to the opsin genes, suggesting that cichlid color vision has evolved primarily via trans-regulatory divergence. By modeling the impact of just two of these trans-regulatory eQTL, we show that opsin regulatory mutations can alter cichlid photoreceptor sensitivity and color vision at least as much as opsin structural mutations can. Conclusions Combined with previous work, we demonstrate that the evolution of cichlid color vision results from the interplay of structural, cis-, and especially trans-regulatory loci. Although there are numerous examples of structural and cis-regulatory mutations that contribute to phenotypic evolution, our results suggest that trans-regulatory mutations could contribute to phenotypic divergence more commonly than previously expected, especially in systems like color vision, where compensatory changes in the

Thermal decay of rhodopsin: role of hydrogen bonds in thermal isomerization of 11-cis retinal in the binding site and hydrolysis of protonated Schiff base.

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Liu, Jian; Liu, Monica Yun; Nguyen, Jennifer B; Bhagat, Aditi; Mooney, Victoria; Yan, Elsa C Y

2009-07-01

Although thermal stability of the G protein-coupled receptor rhodopsin is directly related to its extremely low dark noise level and has recently generated considerable interest, the chemistry behind the thermal decay process of rhodopsin has remained unclear. Using UV-vis spectroscopy and HPLC analysis, we have demonstrated that the thermal decay of rhodopsin involves both hydrolysis of the protonated Schiff base and thermal isomerization of 11-cis to all-trans retinal. Examining the unfolding of rhodopsin by circular dichroism spectroscopy and measuring the rate of thermal isomerization of 11-cis retinal in solution, we conclude that the observed thermal isomerization of 11-cis to all-trans retinal happens when 11-cis retinal is in the binding pocket of rhodopsin. Furthermore, we demonstrate that solvent deuterium isotope effects are involved in the thermal decay process by decreasing the rates of thermal isomerization and hydrolysis, suggesting that the rate-determining step of these processes involves breaking hydrogen bonds. These results provide insight into understanding the critical role of an extensive hydrogen-bonding network on stabilizing the inactive state of rhodopsin and contribute to our current understanding of the low dark noise level of rhodopsin, which enables this specialized protein to function as an extremely sensitive biological light detector. Because similar hydrogen-bonding networks have also been suggested by structural analysis of two other GPCRs, beta1 and beta2 adrenergic receptors, our results could reveal a general role of hydrogen bonds in facilitating GPCR function.

Is HO3 minimum cis or trans? An analytic full-dimensional ab initio isomerization path.

Science.gov (United States)

Varandas, A J C

2011-05-28

The minimum energy path for isomerization of HO(3) has been explored in detail using accurate high-level ab initio methods and techniques for extrapolation to the complete basis set limit. In agreement with other reports, the best estimates from both valence-only and all-electron single-reference methods here utilized predict the minimum of the cis-HO(3) isomer to be deeper than the trans-HO(3) one. They also show that the energy varies by less than 1 kcal mol(-1) or so over the full isomerization path. A similar result is found from valence-only multireference configuration interaction calculations with the size-extensive Davidson correction and a correlation consistent triple-zeta basis, which predict the energy difference between the two isomers to be of only Δ = -0.1 kcal mol(-1). However, single-point multireference calculations carried out at the optimum triple-zeta geometry with basis sets of the correlation consistent family but cardinal numbers up to X = 6 lead upon a dual-level extrapolation to the complete basis set limit of Δ = (0.12 ± 0.05) kcal mol(-1). In turn, extrapolations with the all-electron single-reference coupled-cluster method including the perturbative triples correction yield values of Δ = -0.19 and -0.03 kcal mol(-1) when done from triple-quadruple and quadruple-quintuple zeta pairs with two basis sets of increasing quality, namely cc-cpVXZ and aug-cc-pVXZ. Yet, if added a value of 0.25 kcal mol(-1) that accounts for the effect of triple and perturbative quadruple excitations with the VTZ basis set, one obtains a coupled cluster estimate of Δ = (0.14 ± 0.08) kcal mol(-1). It is then shown for the first time from systematic ab initio calculations that the trans-HO(3) isomer is more stable than the cis one, in agreement with the available experimental evidence. Inclusion of the best reported zero-point energy difference (0.382 kcal mol(-1)) from multireference configuration interaction calculations enhances further the relative

Cis–Trans Configuration of Coumaric Acid Acylation Affects the Spectral and Colorimetric Properties of Anthocyanins

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Gregory T. Sigurdson

2018-03-01

Full Text Available The color expression of anthocyanins can be affected by a variety of environmental factors and structural characteristics. Anthocyanin acylation (type and number of acids is known to be key, but the influence of acyl isomers (with unique stereochemistries remains to be explored. The objective of this study was to investigate the effects of cis–trans configuration of the acylating group on the spectral and colorimetric properties of anthocyanins. Petunidin-3-rutinoside-5-glucoside (Pt-3-rut-5-glu and Delphinidin-3-rutinoside-5-glucoside (Dp-3-rut-5-glu and their cis and trans coumaroylated derivatives were isolated from black goji and eggplant, diluted in pH 1–9 buffers, and analyzed spectrophotometrically (380–700 nm and colorimetrically (CIELAB during 72 h of storage (25 °C, dark. The stereochemistry of the acylating group strongly impacted the spectra, color, and stability of the Dp and Pt anthocyanins. Cis acylated pigments exhibited the greatest λmax in all pH, as much as 66 nm greater than their trans counterparts, showing bluer hues. Cis acylation seemed to reduce hydration across pH, increasing color intensity, while trans acylation generally improved color retention over time. Dp-3-cis-p-cou-rut-5-glu exhibited blue hues even in pH 5 (C*ab = 10, hab = 256° where anthocyanins are typically colorless. Cis or trans double bond configurations of the acylating group affected anthocyanin spectral and stability properties.

Potential energy profile, structural, vibrational and reactivity descriptors of trans-2-methoxycinnamic acid by FTIR, FT-Raman and quantum chemical studies

Science.gov (United States)

Arjunan, V.; Anitha, R.; Thenmozhi, S.; Marchewka, M. K.; Mohan, S.

2016-06-01

The stable conformers of trans-2-methoxycinnamic acid (trans-2MCA) are determined by potential energy profile analysis. The energies of the s-cis and s-trans conformers of trans-2MCA determined by B3LYP/cc-pVTZ method are -612.9788331 Hartrees and -612.9780953 Hartrees, respectively. The vibrational and electronic investigations of the stable s-cis and s-trans conformers of trans-2-methoxycinnamic acid have been carried out extensively with FTIR and FT-Raman spectral techniques. The s-cis conformer (I) with a (C16-C17-C18-O19) dihedral angle equal to 0° is found to be more favoured relative to the one s-trans (II) with (C16-C17-C18-O19) = 180°, possibly due to delocalization, hydrogen bonding and steric repulsion effects between the methoxy and acrylic acid groups. The DFT studies are performed with B3LYP method by utilizing 6-311++G** and cc-pVTZ basis sets to determine the structure, thermodynamic properties, vibrational characteristics and chemical shifts of the compound. The total dipole moments of the conformers determined by B3LYP/cc-pVTZ method are 3.35 D and 4.87 D for s-cis and s-trans, respectively. It reveals the higher polarity of s-trans conformer of trans-2MCA molecule. The electronic and steric influence of the methoxy group on the skeletal frequencies has been analysed. The energies of the frontier molecular orbitals and the LUMO-HOMO energy gap have been determined. The MEP of s-cis conformer lie in the range +1.374e × 10-2 to -1.374e × 10-2 while for s-trans it is +1.591e × 10-2 to -1.591e × 10-2. The total electron density of s-cis conformer lie in the range +5.273e × 10-2 to -5.273e × 10-2 while for s-trans it is +5.403e × 10-2 to -5.403e × 10-2. The MEP and total electron density shows that the s-cis conformer is less polar, less reactive and more stable than the s-trans conformer. All the reactivity descriptors of the molecule have been discussed. Intramolecular electronic interactions and their stabilisation energies have analysed

DC-SIGN mediates avian H5N1 influenza virus infection in cis and in trans

International Nuclear Information System (INIS)

Wang, S.-F.; Huang, Jason C.; Lee, Y.-M.; Liu, S.-J.; Chan, Yu-Jiun; Chau, Y.-P.; Chong, P.; Chen, Y.-M.A.

2008-01-01

DC-SIGN, a C-type lectin receptor expressed in dendritic cells (DCs), has been identified as a receptor for human immunodeficiency virus type 1, hepatitis C virus, Ebola virus, cytomegalovirus, dengue virus, and the SARS coronavirus. We used H5N1 pseudotyped and reverse-genetics (RG) virus particles to study their ability to bind with DC-SIGN. Electronic microscopy and functional assay results indicate that pseudotyped viruses containing both HA and NA proteins express hemagglutination and are capable of infecting cells expressing α-2,3-linked sialic acid receptors. Results from a capture assay show that DC-SIGN-expressing cells (including B-THP-1/DC-SIGN and T-THP-1/DC-SIGN) and peripheral blood dendritic cells are capable of transferring H5N1 pseudotyped and RG virus particles to target cells; this action can be blocked by anti-DC-SIGN monoclonal antibodies. In summary, (a) DC-SIGN acts as a capture or attachment molecule for avian H5N1 virus, and (b) DC-SIGN mediates infections in cis and in trans

Cloning and characterization of peptidylprolyl isomerase B in the ...

African Journals Online (AJOL)

Peptidylprolyl isomerases (PPIases) play essential roles in protein folding and are implicated in immune response and cell cycle control. Our previous proteomic analysis indicated that Bombyx mori PPIases may be involved in anti- Bombyx mori nucleopolyhedrovirus (BmNPV) response. To help investigate this mechanism, ...

Integrating genome-wide genetic variations and monocyte expression data reveals trans-regulated gene modules in humans.

Directory of Open Access Journals (Sweden)

Maxime Rotival

2011-12-01

Full Text Available One major expectation from the transcriptome in humans is to characterize the biological basis of associations identified by genome-wide association studies. So far, few cis expression quantitative trait loci (eQTLs have been reliably related to disease susceptibility. Trans-regulating mechanisms may play a more prominent role in disease susceptibility. We analyzed 12,808 genes detected in at least 5% of circulating monocyte samples from a population-based sample of 1,490 European unrelated subjects. We applied a method of extraction of expression patterns-independent component analysis-to identify sets of co-regulated genes. These patterns were then related to 675,350 SNPs to identify major trans-acting regulators. We detected three genomic regions significantly associated with co-regulated gene modules. Association of these loci with multiple expression traits was replicated in Cardiogenics, an independent study in which expression profiles of monocytes were available in 758 subjects. The locus 12q13 (lead SNP rs11171739, previously identified as a type 1 diabetes locus, was associated with a pattern including two cis eQTLs, RPS26 and SUOX, and 5 trans eQTLs, one of which (MADCAM1 is a potential candidate for mediating T1D susceptibility. The locus 12q24 (lead SNP rs653178, which has demonstrated extensive disease pleiotropy, including type 1 diabetes, hypertension, and celiac disease, was associated to a pattern strongly correlating to blood pressure level. The strongest trans eQTL in this pattern was CRIP1, a known marker of cellular proliferation in cancer. The locus 12q15 (lead SNP rs11177644 was associated with a pattern driven by two cis eQTLs, LYZ and YEATS4, and including 34 trans eQTLs, several of them tumor-related genes. This study shows that a method exploiting the structure of co-expressions among genes can help identify genomic regions involved in trans regulation of sets of genes and can provide clues for understanding the

Speeding cis-trans regulation discovery by phylogenomic analyses coupled with screenings of an arrayed library of Arabidopsis transcription factors.

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Gabriel Castrillo

Full Text Available Transcriptional regulation is an important mechanism underlying gene expression and has played a crucial role in evolution. The number, position and interactions between cis-elements and transcription factors (TFs determine the expression pattern of a gene. To identify functionally relevant cis-elements in gene promoters, a phylogenetic shadowing approach with a lipase gene (LIP1 was used. As a proof of concept, in silico analyses of several Brassicaceae LIP1 promoters identified a highly conserved sequence (LIP1 element that is sufficient to drive strong expression of a reporter gene in planta. A collection of ca. 1,200 Arabidopsis thaliana TF open reading frames (ORFs was arrayed in a 96-well format (RR library and a convenient mating based yeast one hybrid (Y1H screening procedure was established. We constructed an episomal plasmid (pTUY1H to clone the LIP1 element and used it as bait for Y1H screenings. A novel interaction with an HD-ZIP (AtML1 TF was identified and abolished by a 2 bp mutation in the LIP1 element. A role of this interaction in transcriptional regulation was confirmed in planta. In addition, we validated our strategy by reproducing the previously reported interaction between a MYB-CC (PHR1 TF, a central regulator of phosphate starvation responses, with a conserved promoter fragment (IPS1 element containing its cognate binding sequence. Finally, we established that the LIP1 and IPS1 elements were differentially bound by HD-ZIP and MYB-CC family members in agreement with their genetic redundancy in planta. In conclusion, combining in silico analyses of orthologous gene promoters with Y1H screening of the RR library represents a powerful approach to decipher cis- and trans-regulatory codes.

Dietary effect of pomegranate seed oil rich in 9cis, 11trans, 13cis conjugated linolenic acid on lipid metabolism in obese, hyperlipidemic OLETF Rats

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Cha Jae-Young

2004-11-01

Full Text Available Abstract Conjugated fatty acid, the general term of positional and geometric isomers of polyunsaturated fatty acids with conjugated double bonds, has attracted considerable attention because of its potentially beneficial biological effects. In the present study, dietary effect of pomegranate seed oil rich in punicic acid (9cis, 11trans, 13cis-conjugated linolenic acid; 9c, 11t, 13c-CLNA on lipid metabolism was investigated in obese, hyperlipidemic Otsuka Long-Evans Tokushima Fatty (OLETF rats. After 2 weeks feeding period, OLETF rats revealed obesity and hyperlipidemia compared with their progenitor LETO rats. Feeding of the diet supplemented with 9% safflower oil and 1% pomegranate seed oil (9c, 11t, 13c-CLNA diet did not affect abdominal white adipose tissue weights and serum lipid levels compared with the diet supplemented with 10% safflower oil (control diet in OLETF rats. However, the accumulated hepatic triacylglycerol was markedly decreased by 9c, 11t, 13c-CLNA diet in OLETF rats. Activities of hepatic enzymes related to fatty acid synthesis and fatty acid β-oxidation were not altered by 9c, 11t, 13c-CLNA diet. Levels of monounsaturated fatty acid (MUFA, major storage form of fatty acid, in serum triacylglycerol were markedly higher in obese, hyperlipidemic OLETF rats than in lean LETO rats. In addition, 9c, 11t, 13c-CLNA diet significantly decreased MUFA levels in OLETF rats. This is the first study showing that 9c, 11t, 13c-CLNA suppresses delta-9 desaturation in vivo, and we suggest that the alleviation of hepatic triacylglycerol accumulation by 9c, 11t, 13c-CLNA diet was, at least in part, attributable to the suppression of delta-9 desaturation in OLETF rats.

DEB025 (Alisporivir inhibits hepatitis C virus replication by preventing a cyclophilin A induced cis-trans isomerisation in domain II of NS5A.

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Lotte Coelmont

2010-10-01

Full Text Available DEB025/Debio 025 (Alisporivir is a cyclophilin (Cyp-binding molecule with potent anti-hepatitis C virus (HCV activity both in vitro and in vivo. It is currently being evaluated in phase II clinical trials. DEB025 binds to CypA, a peptidyl-prolyl cis-trans isomerase which is a crucial cofactor for HCV replication. Here we report that it was very difficult to select resistant replicons (genotype 1b to DEB025, requiring an average of 20 weeks (four independent experiments, compared to the typically <2 weeks with protease or polymerase inhibitors. This indicates a high genetic barrier to resistance for DEB025. Mutation D320E in NS5A was the only mutation consistently selected in the replicon genome. This mutation alone conferred a low-level (3.9-fold resistance. Replacing the NS5A gene (but not the NS5B gene from the wild type (WT genome with the corresponding sequence from the DEB025(res replicon resulted in transfer of resistance. Cross-resistance with cyclosporine A (CsA was observed, whereas NS3 protease and NS5B polymerase inhibitors retained WT-activity against DEB025(res replicons. Unlike WT, DEB025(res replicon replicated efficiently in CypA knock down cells. However, DEB025 disrupted the interaction between CypA and NS5A regardless of whether the NS5A protein was derived from WT or DEB025(res replicon. NMR titration experiments with peptides derived from the WT or the DEB025(res domain II of NS5A corroborated this observation in a quantitative manner. Interestingly, comparative NMR studies on two 20-mer NS5A peptides that contain D320 or E320 revealed a shift in population between the major and minor conformers. These data suggest that D320E conferred low-level resistance to DEB025 probably by reducing the need for CypA-dependent isomerisation of NS5A. Prolonged DEB025 treatment and multiple genotypic changes may be necessary to generate significant resistance to DEB025, underlying the high barrier to resistance.

Separation and identification of beta-carotene and its cis isomers by high pressure liquid chromatography (HPLC); Separacion e identificacion del beta-caroteno y sus isomeros cis por cromatografia liquida de alta resolucion (HPLC)

Energy Technology Data Exchange (ETDEWEB)

Carrillo de Padilla, F [Universidad Central de Venezuela (UCV), Facultad de Farmacia, Catedra de Analisis de Alimentos, Caracas (Venezuela)

1996-07-01

The separation and identification by HPLC of the cis isomers of beta-carotene was studied. A 1.26 mg/ml beta-carotene solution previously isomerized with iodine as a catalyst, was eluted with 2% acetone in hexane, from a Ca(OH)2 chromatographic column in three bands. The fractions were identified by spectrophotometry and the retention times of 2.05, 2.4 and 2.8 min for the 13 cis, all-trans, and 9 cis beta-carotene isomers, determined by HPLC, with 1% acetone in hexane as Mobil phase. 22.13 mg % of all-trans beta-carotene were found in a sample of canned carrots. It is recommended the analyses of a greater number of samples, the determination of the method's sensitivity, reproducibility, and the use of a standard of reference of a response factor for calculations.

A Slow Conformational Switch in the BMAL1 Transactivation Domain Modulates Circadian Rhythms.

Science.gov (United States)

Gustafson, Chelsea L; Parsley, Nicole C; Asimgil, Hande; Lee, Hsiau-Wei; Ahlbach, Christopher; Michael, Alicia K; Xu, Haiyan; Williams, Owen L; Davis, Tara L; Liu, Andrew C; Partch, Carrie L

2017-05-18

The C-terminal transactivation domain (TAD) of BMAL1 (brain and muscle ARNT-like 1) is a regulatory hub for transcriptional coactivators and repressors that compete for binding and, consequently, contributes to period determination of the mammalian circadian clock. Here, we report the discovery of two distinct conformational states that slowly exchange within the dynamic TAD to control timing. This binary switch results from cis/trans isomerization about a highly conserved Trp-Pro imide bond in a region of the TAD that is required for normal circadian timekeeping. Both cis and trans isomers interact with transcriptional regulators, suggesting that isomerization could serve a role in assembling regulatory complexes in vivo. Toward this end, we show that locking the switch into the trans isomer leads to shortened circadian periods. Furthermore, isomerization is regulated by the cyclophilin family of peptidyl-prolyl isomerases, highlighting the potential for regulation of BMAL1 protein dynamics in period determination. Copyright © 2017 Elsevier Inc. All rights reserved.

Involvement of cyclophilin B in the replication of Japanese encephalitis virus.

Science.gov (United States)

Kambara, Hiroto; Tani, Hideki; Mori, Yoshio; Abe, Takayuki; Katoh, Hiroshi; Fukuhara, Takasuke; Taguwa, Shuhei; Moriishi, Kohji; Matsuura, Yoshiharu

2011-03-30

Japanese encephalitis virus (JEV) is a mosquito-borne RNA virus that belongs to the Flaviviridae family. In this study, we have examined the effect of cyclosporin A (CsA) on the propagation of JEV. CsA exhibited potent anti-JEV activity in various mammalian cell lines through the inhibition of CypB. The propagation of JEV was impaired in the CypB-knockdown cells and this reduction was cancelled by the expression of wild-type but not of peptidylprolyl cis-trans isomerase (PPIase)-deficient CypB, indicating that PPIase activity of CypB is critical for JEV propagation. Infection of pseudotype viruses bearing JEV envelope proteins was not impaired by the knockdown of CypB, suggesting that CypB participates in the replication but not in the entry of JEV. CypB was colocalized and immunoprecipitated with JEV NS4A in infected cells. These results suggest that CypB plays a crucial role in the replication of JEV through an interaction with NS4A. Copyright © 2011 Elsevier Inc. All rights reserved.

The basic tilted helix bundle domain of the prolyl isomerase FKBP25 is a novel double-stranded RNA binding module

Science.gov (United States)

Dilworth, David; Bonnafous, Pierre; Edoo, Amiirah Bibi; Bourbigot, Sarah; Pesek-Jardim, Francy; Gudavicius, Geoff; Serpa, Jason J.; Petrotchenko, Evgeniy V.; Borchers, Christoph H.

2017-01-01

Abstract Prolyl isomerases are defined by a catalytic domain that facilitates the cis–trans interconversion of proline residues. In most cases, additional domains in these enzymes add important biological function, including recruitment to a set of protein substrates. Here, we report that the N-terminal basic tilted helix bundle (BTHB) domain of the human prolyl isomerase FKBP25 confers specific binding to double-stranded RNA (dsRNA). This binding is selective over DNA as well as single-stranded oligonucleotides. We find that FKBP25 RNA-association is required for its nucleolar localization and for the vast majority of its protein interactions, including those with 60S pre-ribosome and early ribosome biogenesis factors. An independent mobility of the BTHB and FKBP catalytic domains supports a model by which the N-terminus of FKBP25 is anchored to regions of dsRNA, whereas the FKBP domain is free to interact with neighboring proteins. Apart from the identification of the BTHB as a new dsRNA-binding module, this domain adds to the growing list of auxiliary functions used by prolyl isomerases to define their primary cellular targets. PMID:29036638

CYCLOPHILIN A: STRUCTURE AND FUNCTIONS

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A. A. Kalinina

2017-01-01

Full Text Available Cyclophilins belong to a large family of ancient conservative proteins with peptidyl-prolyl-cis-trans isomerase activity. The main member of this family – cyclophilin A – was discovered as an intracellular ligand for cyclosporine A. Further investigations revealed a wide range of functions of cyclophilin A. Cyclophilin A is involved in T-cell signaling, it takes part in folding, assembly and intracellular transport of proteins, as well as acts as an antioxidant. Different cell types secrete cyclophilin A under infection or oxidative stress. Cyclophilin A is one of the main factors involved in inflammation and pathogenesis of autoimmune, cardiovascular and other diseases. This protein is thought to take part in tumor progression. In this review we describe the structure of cyclophilin A and its main known functions in health and disease.

The effect of conjugated linoneic acid, a natural trans fat from milk and meat, on human blood pressure: results from a randomized crossover feeding study

NARCIS (Netherlands)

Engberink, M.F.; Geleijnse, J.M.; Wanders, A.J.; Brouwer, I.A.

2012-01-01

Cis-9, trans-11 conjugated linoleic acid (CLA) is a natural trans fatty acid that is largely restricted to ruminant fats and consumed in foods and supplements. Its role in blood pressure (BP) regulation is still unclear. We examined the effect of cis-9, trans-11 CLA on BP compared with oleic acid. A

Glucose (xylose) isomerase production from thermotolerant and ...

African Journals Online (AJOL)

Owner

2012-11-13

Nov 13, 2012 ... in the production of the high fructose corn syrup (HFCS) from corn starch. ... Key words: Glucose isomerase, xylose isomerase, enzyme activity, Klebsiella, ... Soil, water, and manure (five samples each) were collected from.

From Carotenoids to Strigolactones

KAUST Repository

Jia, Kunpeng

2017-12-13

Strigolactones (SLs) are phytohormones that regulate different plant developmental and adaptation processes. When released into soil, SLs act as chemical signals attracting symbiotic arbuscular fungi and inducing seed germination in root parasitic weeds. SLs are carotenoid-derivatives characterized by the presence of a butenolide ring that is connected by an enol ether bridge to a less conserved, second moiety. Carotenoids are isopenoid pigments that differ in structure, number of conjugated double bonds and stereo-configuration. Genetic analysis and enzymatic studies demonstrate that SLs originate from all-trans-β-carotene in a pathway that involves the all-trans-/9-cis-β-carotene isomerase DWARF27 (D27) and the carotenoid cleavage dioxygenase 7 and 8 (CCD7, 8). The CCD7-mediated, regio- and stereospecific double bond cleavage of 9-cis-β-carotene leads to a 9-cis-configured intermediate that is converted by CCD8 via a combination of reactions into the central metabolite carlactone. By catalyzing repeated oxygenation reactions that can be coupled to ring closure, CYP711 enzymes convert carlactone into tricyclic ring containing, canonical and non-canonical SLs. Mostly unknown, modifying enzymes further increase SLs diversity. In this review, we touch on carotenogenesis, provide an update on SL biosynthesis, with emphasis on the substrate specificity and reactions catalyzed by the different enzymes, and describe the regulation of the pathway.

Biochemical function of typical and variant Arabidopsis thaliana U-box E3 ubiquitin-protein ligases

DEFF Research Database (Denmark)

Wiborg, Jakob; O'Shea, Charlotte; Skriver, Karen

2008-01-01

of the distant U-box protein, AtPUB49, representing a large family of eukaryotic proteins containing a U-box linked to a cyclophilin-like peptidyl-prolyl cis-trans isomerase domain, was characterized biochemically. AtPUB49 functioned both as a prolyl isomerase and a chaperone by catalysing cis......The variance of the U-box domain in 64 Arabidopsis thaliana (thale cress) E3s (ubiquitin-protein ligases) was used to examine the interactions between E3s and E2s (ubiquitin-conjugating enzymes). E2s and E3s are components of the ubiquitin protein degradation pathway. Seven U-box proteins were...... analysed for their ability to ubiquitinate proteins in vitro in co-operation with different E2s. All U-box domains exhibited ubiquitination activity and interacted productively with UBC4/5-type E2s. Three and four of the U-box domains mediated ubiquitin addition in the presence of UBC13 and UBC7 E2s...

Starch plus sunflower oil addition to the diet of dry dairy cows results in a trans-11 to trans-10 shift of biohydrogenation.

Science.gov (United States)

Zened, A; Enjalbert, F; Nicot, M C; Troegeler-Meynadier, A

2013-01-01

Trans fatty acids (FA), exhibit different biological properties. Among them, cis-9,trans-11 conjugated linoleic acid has some interesting putative health properties, whereas trans-10,cis-12 conjugated linoleic acid has negative effects on cow milk fat production and would negatively affect human health. In high-yielding dairy cows, a shift from trans-11 to trans-10 pathway of biohydrogenation (BH) can occur in the rumen of cows receiving high-concentrate diets, especially when the diet is supplemented with unsaturated fat sources. To study this shift, 4 rumen-fistulated nonlactating Holstein cows were assigned to a 4×4 Latin square design with 4 different diets during 4 periods. Cows received 12 kg of dry matter per day of 4 diets based on corn silage during 4 successive periods: a control diet (22% starch, diet supplemented with wheat plus barley (35% starch, diet supplemented with 5% of sunflower oil (20% starch, 7.6% crude fat), and a high-starch plus sunflower oil diet (33% starch, 7.3% crude fat). Five hours after feeding, proportions of trans-11 BH isomers greatly increased in the rumen content with the addition of sunflower oil, without change in ruminal pH compared with the control diet. Addition of starch to the control diet had no effect on BH pathways but decreased ruminal pH. The addition of a large amount of starch in association with sunflower oil increased trans-10 FA at the expense of trans-11 FA in the rumen content, revealing a trans-11 to trans-10 shift. Interestingly, with this latter diet, ruminal pH did not change compared with a single addition of starch. This trans-11 to trans-10 shift occurred progressively, after a decrease in the proportion of trans-11 FA in the rumen, suggesting that this shift could result from a dysbiosis in the rumen in favor of trans-10-producing bacteria at the expense of those producing trans-11 or a modification of bacterial activities. Copyright © 2013 American Dairy Science Association. Published by Elsevier

Cyclophilin B facilitates the replication of Orf virus

OpenAIRE

Zhao, Kui; Li, Jida; He, Wenqi; Song, Deguang; Zhang, Ximu; Zhang, Di; Zhou, Yanlong; Gao, Feng

2017-01-01

Background Viruses interact with host cellular factors to construct a more favourable environment for their efficient replication. Expression of cyclophilin B (CypB), a cellular peptidyl-prolyl cis-trans isomerase (PPIase), was found to be significantly up-regulated. Recently, a number of studies have shown that CypB is important in the replication of several viruses, including Japanese encephalitis virus (JEV), hepatitis C virus (HCV) and human papillomavirus type 16 (HPV 16). However, the f...

[Separation and identification of beta-carotene and its cis isomers by high pressure liquid chromatography (HPLC)].

Science.gov (United States)

Carrillo de Padilla, F

1996-06-01

The separation and identification by HPLC of the cis isomers of beta-carotene was studied. A 1.26 mg/ml beta-carotene solution previously isomerized with iodine as a catalyst, was eluted with 2% acetone in hexane, from a Ca(OH)2 chromatographic column in three bands. The fractions were identified by spectrophotometry and the retention times of 2.05, 2.4 and 2.8 min for the 13 cis, all-trans, and 9 cis beta-carotene isomers, determined by HPLC, with 1% acetone in hexane as movil phase. 22.13 mg % of all-trans beta-carotene were found in a sample of canned carrots. It is recommended the analyses of a greater number of samples, the determination of the method's sensitivity, reproductibility, and the use of a standard of reference of a response factor for calculations.

Separation and identification of beta-carotene and its cis isomers by high pressure liquid chromatography (HPLC)

International Nuclear Information System (INIS)

Carrillo de Padilla, F.

1996-01-01

The separation and identification by HPLC of the cis isomers of beta-carotene was studied. A 1.26 mg/ml beta-carotene solution previously isomerized with iodine as a catalyst, was eluted with 2% acetone in hexane, from a Ca(OH)2 chromatographic column in three bands. The fractions were identified by spectrophotometry and the retention times of 2.05, 2.4 and 2.8 min for the 13 cis, all-trans, and 9 cis beta-carotene isomers, determined by HPLC, with 1% acetone in hexane as Mobil phase. 22.13 mg % of all-trans beta-carotene were found in a sample of canned carrots. It is recommended the analyses of a greater number of samples, the determination of the method's sensitivity, reproducibility, and the use of a standard of reference of a response factor for calculations

Coevolution within a transcriptional network by compensatory trans and cis mutations

KAUST Repository

Kuo, D.; Licon, K.; Bandyopadhyay, S.; Chuang, R.; Luo, C.; Catalana, J.; Ravasi, Timothy; Tan, K.; Ideker, T.

2010-01-01

Transcriptional networks have been shown to evolve very rapidly, prompting questions as to how such changes arise and are tolerated. Recent comparisons of transcriptional networks across species have implicated variations in the cis-acting DNA

Interaction of p53 with prolyl isomerases: Healthy and unhealthy relationships.

Science.gov (United States)

Mantovani, Fiamma; Zannini, Alessandro; Rustighi, Alessandra; Del Sal, Giannino

2015-10-01

The p53 protein family, comprising p53, p63 and p73, is primarily involved in preserving genome integrity and preventing tumor onset, and also affects a range of physiological processes. Signal-dependent modifications of its members and of other pathway components provide cells with a sophisticated code to transduce a variety of stress signaling into appropriate responses. TP53 mutations are highly frequent in cancer and lead to the expression of mutant p53 proteins that are endowed with oncogenic activities and sensitive to stress signaling. p53 family proteins have unique structural and functional plasticity, and here we discuss the relevance of prolyl-isomerization to actively shape these features. The anti-proliferative functions of the p53 family are carefully activated upon severe stress and this involves the interaction with prolyl-isomerases. In particular, stress-induced stabilization of p53, activation of its transcriptional control over arrest- and cell death-related target genes and of its mitochondrial apoptotic function, as well as certain p63 and p73 functions, all require phosphorylation of specific S/T-P motifs and their subsequent isomerization by the prolyl-isomerase Pin1. While these functions of p53 counteract tumorigenesis, under some circumstances their activation by prolyl-isomerases may have negative repercussions (e.g. tissue damage induced by anticancer therapies and ischemia-reperfusion, neurodegeneration). Moreover, elevated Pin1 levels in tumor cells may transduce deregulated phosphorylation signaling into activation of mutant p53 oncogenic functions. The complex repertoire of biological outcomes induced by p53 finds mechanistic explanations, at least in part, in the association between prolyl-isomerases and the p53 pathway. This article is part of a Special Issue entitled Proline-directed foldases: Cell signaling catalysts and drug targets. Copyright © 2015 Elsevier B.V. All rights reserved.

Biosynthesis of (+)-cis- and (+)-trans-sabinene hydrate from geranyl pyrophosphate by a soluble enzyme system from sweet marjoram (Majorana hortensis)

International Nuclear Information System (INIS)

Hallahan, T.W.

1988-01-01

A soluble enzyme preparation from the leaves of sweet marjoram (Majorana hortensis Moench) catalyzes the divalent cation-dependent cyclization of [1- 3 H]geranyl pyrophosphate to the bicyclic monoterpene alcohols (+)-cis- and (+)-trans-[6 3 H]sabinene hydrate, providing labeling patterns consistent with current mechanistic considerations. The two enzymatic activities were inseparable by several chromatographic procedures, and differential inactivation studies suggesting that the two activities reside with the same enzyme. The enzymatic cyclization is considered to proceed by the initial ionization and isomerization of geranyl pyrophosphate to (-)-(3R)-linalyl pyrophosphate and the subsequent cyclization of this enzyme bound tertiary allylic intermediate to the monocyclic (+)-(4R)-α-terpinyl cation. A 1,2-hydride shift and a second cyclization with water capture of the resulting cation completes the reaction sequence. No free intermediates were detectable in the conversion of geranyl pyrophosphate to the sabinene hydrates as determined by isotopic dilution experiments

Identification of trans-acting factors regulating SamDC expression in Oryza sativa

Energy Technology Data Exchange (ETDEWEB)

Basu, Supratim, E-mail: supratim_genetics@yahoo.co.in [Department of Crop Soil and Environmental Sciences, University of Arkansas, Fayetteville, AR 72701 (United States); Division of Plant Biology, Bose Institute, Kolkata (India); Roychoudhury, Aryadeep [Post Graduate Department of Biotechnology, St. Xavier' s College (Autonomous), 30, Mother Teresa Sarani, Kolkata - 700016, West Bengal (India); Sengupta, Dibyendu N. [Division of Plant Biology, Bose Institute, Kolkata (India)

2014-03-07

Highlights: • Identification of cis elements responsible for SamDC expression by in silico analysis. • qPCR analysis of SamDC expression to abiotic and biotic stress treatments. • Detection of SamDC regulators using identified cis-elements as probe by EMSA. • Southwestern Blot analysis to predict the size of the trans-acting factors. - Abstract: Abiotic stress affects the growth and productivity of crop plants; to cope with the adverse environmental conditions, plants have developed efficient defense machinery comprising of antioxidants like phenolics and flavonoids, and osmolytes like polyamines. SamDC is a key enzyme in the polyamine biosynthesis pathway in plants. In our present communication we have done in silico analysis of the promoter region of SamDC to look for the presence of different cis-regulatory elements contributing to its expression. Based on the presence of different cis-regulatory elements we completed comparative analysis of SamDC gene expression in rice lamina of IR-29 and Nonabokra by qPCR in response to the abiotic stress treatments of salinity, drought, cold and the biotic stress treatments of ABA and light. Additionally, to explore the role of the cis-regulatory elements in regulating the expression of SamDC gene in plants we comparatively analyzed the binding of rice nuclear proteins prepared from IR-29 and Nonabokra undergoing various stress treatments. The intensity of the complex formed was low and inducible in IR-29 in contrast to Nonabokra. Southwestern blot analysis helped in predicting the size of the trans-acting factors binding to these cis-elements. To our knowledge this is the first report on the comprehensive analysis of SamDC gene expression in rice and identification of the trans-acting factors regulating its expression.

cis-3-Hexenol and trans-2-hexenal mixture prevents development of PTSD-like phenotype in rats.

Science.gov (United States)

Nikaido, Yoshikazu; Yamada, Junko; Migita, Keisuke; Shiba, Yuko; Furukawa, Tomonori; Nakashima, Toshihiro; Ueno, Shinya

2016-01-15

Several green leaf volatiles have anxiolytic/antidepressant properties and attenuate adrenocortical stress response in rodents. However, it remains unknown whether a mixture of cis-3-hexenol and trans-2-hexenal so-called 'green odor (GO)' affects fear-associated post-traumatic stress disorder (PTSD)-like behavior. In the present study, fear memory of the initial conditioning stimulus was stably maintained by weekly presentation of conditioned tone. Examination of open field behavior, acoustic startle response, prepulse inhibition, and immobility in the forced swim test for 2 weeks after initial conditioning revealed that conditioned rats sustained anxiety, enhanced startle response, hypervigilance, depression-like behavior, and hypocortisolism, which is consistent with PTSD symptoms. Daily, not acute, GO presentation facilitated fear extinction and reduced PTSD-like behavioral and endocrinal responses. To further investigate the mechanism of effect of GO, we examined the effect of paroxetine (a selective serotonin reuptake inhibitor), p-chlorophenylalanine (PCPA, an irreversible serotonin synthesis inhibitor), alone or in combination of GO on PTSD-like phenotype. The alleviative effects of GO were masked by simultaneous paroxetine administration. PCPA-induced serotonin depletion abolished the effects of GO. Our results suggest that daily GO presentation facilitates fear extinction and prevents development of PTSD-like symptoms. Copyright © 2015 Elsevier B.V. All rights reserved.

Analysis of cis and trans Requirements for DNA Replication at the Right-End Hairpin of the Human Bocavirus 1 Genome.

Science.gov (United States)

Shen, Weiran; Deng, Xuefeng; Zou, Wei; Engelhardt, John F; Yan, Ziying; Qiu, Jianming

2016-09-01

capsid has been developed to efficiently deliver the cystic fibrosis transmembrane conductance regulator gene to human airway epithelia. Here, we identified both cis-acting elements and trans-acting proteins that are required for HBoV1 DNA replication at the right-end hairpin in HEK293 cells. We localized the minimal replication origin, which contains both NS1 nicking and binding sites, to a 46-nucleotide sequence in the right-end hairpin. The identification of these essential elements of HBoV1 DNA replication acting both in cis and in trans will provide guidance to develop antiviral strategies targeting viral DNA replication at the right-end hairpin and to design next-generation recombinant HBoV1 vectors, a promising tool for gene therapy of lung diseases. Copyright © 2016, American Society for Microbiology. All Rights Reserved.

The Mitochondrial Genome of the Prasinophyte Prasinoderma coloniale Reveals Two Trans-Spliced Group I Introns in the Large Subunit rRNA Gene

Science.gov (United States)

Pombert, Jean-François; Otis, Christian; Turmel, Monique; Lemieux, Claude

2013-01-01

Organelle genes are often interrupted by group I and or group II introns. Splicing of these mobile genetic occurs at the RNA level via serial transesterification steps catalyzed by the introns'own tertiary structures and, sometimes, with the help of external factors. These catalytic ribozymes can be found in cis or trans configuration, and although trans-arrayed group II introns have been known for decades, trans-spliced group I introns have been reported only recently. In the course of sequencing the complete mitochondrial genome of the prasinophyte picoplanktonic green alga Prasinoderma coloniale CCMP 1220 (Prasinococcales, clade VI), we uncovered two additional cases of trans-spliced group I introns. Here, we describe these introns and compare the 54,546 bp-long mitochondrial genome of Prasinoderma with those of four other prasinophytes (clades II, III and V). This comparison underscores the highly variable mitochondrial genome architecture in these ancient chlorophyte lineages. Both Prasinoderma trans-spliced introns reside within the large subunit rRNA gene (rnl) at positions where cis-spliced relatives, often containing homing endonuclease genes, have been found in other organelles. In contrast, all previously reported trans-spliced group I introns occur in different mitochondrial genes (rns or coxI). Each Prasinoderma intron is fragmented into two pieces, forming at the RNA level a secondary structure that resembles those of its cis-spliced counterparts. As observed for other trans-spliced group I introns, the breakpoint of the first intron maps to the variable loop L8, whereas that of the second is uniquely located downstream of P9.1. The breakpoint In each Prasinoderma intron corresponds to the same region where the open reading frame (ORF) occurs when present in cis-spliced orthologs. This correlation between the intron breakpoint and the ORF location in cis-spliced orthologs also holds for other trans-spliced introns; we discuss the possible implications

The mitochondrial genome of the prasinophyte Prasinoderma coloniale reveals two trans-spliced group I introns in the large subunit rRNA gene.

Directory of Open Access Journals (Sweden)

Jean-François Pombert

Full Text Available Organelle genes are often interrupted by group I and or group II introns. Splicing of these mobile genetic occurs at the RNA level via serial transesterification steps catalyzed by the introns'own tertiary structures and, sometimes, with the help of external factors. These catalytic ribozymes can be found in cis or trans configuration, and although trans-arrayed group II introns have been known for decades, trans-spliced group I introns have been reported only recently. In the course of sequencing the complete mitochondrial genome of the prasinophyte picoplanktonic green alga Prasinoderma coloniale CCMP 1220 (Prasinococcales, clade VI, we uncovered two additional cases of trans-spliced group I introns. Here, we describe these introns and compare the 54,546 bp-long mitochondrial genome of Prasinoderma with those of four other prasinophytes (clades II, III and V. This comparison underscores the highly variable mitochondrial genome architecture in these ancient chlorophyte lineages. Both Prasinoderma trans-spliced introns reside within the large subunit rRNA gene (rnl at positions where cis-spliced relatives, often containing homing endonuclease genes, have been found in other organelles. In contrast, all previously reported trans-spliced group I introns occur in different mitochondrial genes (rns or coxI. Each Prasinoderma intron is fragmented into two pieces, forming at the RNA level a secondary structure that resembles those of its cis-spliced counterparts. As observed for other trans-spliced group I introns, the breakpoint of the first intron maps to the variable loop L8, whereas that of the second is uniquely located downstream of P9.1. The breakpoint In each Prasinoderma intron corresponds to the same region where the open reading frame (ORF occurs when present in cis-spliced orthologs. This correlation between the intron breakpoint and the ORF location in cis-spliced orthologs also holds for other trans-spliced introns; we discuss the

cis- and trans-acting elements of the estrogen-regulated vitellogenin gene B1 of Xenopus laevis.

Science.gov (United States)

Wahli, W; Martinez, E; Corthésy, B; Cardinaux, J R

1989-01-01

Vitellogenin genes are expressed under strict estrogen control in the liver of female oviparous vertebrates. Gene transfer experiments using estrogen-responsive cells have shown that the 13 bp perfect palindromic element GGTCACTGTGACC found upstream of the Xenopus laevis vitellogenin gene A2 promoter mediates hormonal stimulation and thus, was called the estrogen-responsive element (ERE). In the Xenopus vitellogenin genes B1 and B2 there are two closely adjacent EREs with one or more base substitutions when compared to the consensus ERE GGTCANNNTGACC. On their own, these degenerated elements have only a low or no regulatory capacity at all but act together synergistically to form an estrogen-responsive unit (ERU) with the same strength as the perfect palindromic 13 bp element. Analysis of estrogen receptor binding to the gene B1 ERU revealed a cooperative interaction of receptor dimers to the two adjacent imperfect EREs which most likely explains the synergistic stimulation observed in vivo. Furthermore, a promoter activator element located between positions --113 and --42 of the gene B1 and functional in the human MCF-7 and the Xenopus B3.2 cells has been identified and shown to be involved in the high level of induced transcription activity when the ERE is placed at a distance from the promoter. Finally, a hormone-controlled in vitro transcription system derived from Xenopus liver nuclear extracts was exploited to characterize two additional novel cis-acting elements within the vitellogenin gene B1 promoter. One of them, a negative regulatory element (NRE), is responsible for repression of promoter activity in the absence of hormone. The second is related to the NF-I binding site and is required, together with the ERE, to mediate hormonal induction. Moreover, we detected three trans-acting activities in Xenopus liver nuclear extracts that interact with these regions and demonstrated that they participate in the regulation of the expression of the vitellogenin

Impact of electronic modification of the chelating benzylidene ligand in cis-dichloro-configured second-generation olefin metathesis catalysts on their activity

KAUST Repository

Pump, Eva; Poater, Albert; Zirngast, Michaela; Torvisco, Ana; Fischer, Roland C.; Cavallo, Luigi; Slugovc, Christian

2014-01-01

A series of electronically modified second-generation cis-dichloro ruthenium ester chelating benzylidene complexes was prepared, characterized, and benchmarked in a typical ring-opening metathesis polymerization (ROMP) experiment. The electronic tuning of the parent chelating benzylidene ligand (2-ethyl ester benzylidene) was achieved by substitution at the 4- and 5-positions with electron-withdrawing nitro or electron-donating methoxy groups. The effect of the electronic tuning on the cis-trans isomerization process was studied experimentally and theoretically. Density functional theory calculations clearly revealed the influence of electronic modification on the relative stability between the cis and trans isomers, which is decisive for the activity of the studied compounds as initiators in ROMP. © 2014 American Chemical Society.

Impact of electronic modification of the chelating benzylidene ligand in cis-dichloro-configured second-generation olefin metathesis catalysts on their activity

KAUST Repository

Pump, Eva

2014-06-09

A series of electronically modified second-generation cis-dichloro ruthenium ester chelating benzylidene complexes was prepared, characterized, and benchmarked in a typical ring-opening metathesis polymerization (ROMP) experiment. The electronic tuning of the parent chelating benzylidene ligand (2-ethyl ester benzylidene) was achieved by substitution at the 4- and 5-positions with electron-withdrawing nitro or electron-donating methoxy groups. The effect of the electronic tuning on the cis-trans isomerization process was studied experimentally and theoretically. Density functional theory calculations clearly revealed the influence of electronic modification on the relative stability between the cis and trans isomers, which is decisive for the activity of the studied compounds as initiators in ROMP. © 2014 American Chemical Society.

Different coordination modes for disulfoxides towards diorganotin(IV) dichlorides. X-ray crystal structures of 1,2-cis-bis-(phenylsulfinyl)ethene (rac-,cis-cbpse) and adducts [{l_brace}Ph{sub 2}SnCl{sub 2}(meso-bpse){r_brace}{sub n}] and [{l_brace}n-Bu{sub 2}SnCl{sub 2}(pdtd){r_brace}{sub 2}

Energy Technology Data Exchange (ETDEWEB)

Sousa, Gerimario F. de [Universidade de Brasilia (UnB), DF (Brazil). Inst. de Quimica], e-mail: gfreitas@unb.br; Ellena, Javier [Universidade de Sao Paulo (USP), Sao Carlos, SP (Brazil). Inst. de Fisica; Malta, Valeria R.S. [Universidade Federal de Alagoas (UFAL), Maceio, AL (Brazil). Dept. de Quimica e Biotecnologia; Ardisson, Jose D. [Centro de Desenvolvimento da Tecnologia Nuclear (CDTN/CNEN-MG), Belo Horizonte, MG (Brazil). Lab. de Fisica Aplicada

2009-07-01

The reactions of meso-1,2-bis(phenylsulfinyl)ethane (meso-bpse) with Ph{sub 2}SnCl{sub 2}, 2-phenyl-1,3-dithiane trans-1-trans-3-dioxide (pdtd) with n-Bu{sub 2}SnCl{sub 2} and 1,2-cis-bis-(phenylsulfinyl) ethene (rac-,cis-cbpse) with Ph{sub 2}SnCl{sub 2}, in 1:1 molar ratio, yielded [{l_brace}Ph{sub 2}SnCl{sub 2}(meso-bpse){r_brace}{sub n}], [{l_brace}n-Bu{sub 2}SnCl{sub 2}(pdtd){r_brace}{sub 2}] and [{l_brace}Ph{sub 2}SnCl{sub 2}(rac,cis-cbpse){r_brace}x] (x = 2 or n), respectively. All adducts were studied by IR, Moessbauer and {sup 119}Sn NMR spectroscopic methods, elemental analysis and single crystal X-ray diffractometry. The X-ray crystal structure of [{l_brace}Ph{sub 2}SnCl{sub 2}(meso-bpse){r_brace}{sub n}] revealed the occurrence of infinite chains in which the tin(IV) atoms appear in a distorted octahedral geometry with Cl atoms in cis and Ph groups in trans positions. The X-ray crystal structure of [{l_brace}n-Bu{sub 2}SnCl{sub 2}(pdtd){r_brace}{sub 2}] revealed discrete centrosymmetric dimeric species in which the tin(IV) atoms possess a distorted octahedral geometry with bridging disulfoxides in cis and n-butyl moieties in trans positions. The spectroscopic data indicated that the adduct containing the rac,cis-cbpse ligand can be dimeric or polymeric. The X-ray structural analysis of the free rac-,cis-cbpse sulfoxide revealed that the crystals belong to the C2/c space group. (author)

Purification and characterization of the d-xylose isomerase gene from Escherichia coli

Energy Technology Data Exchange (ETDEWEB)

Ho, N W.Y.; Rosenfeld, S; Stevis, P; Tsao, G T

1983-11-01

A DNA fragment containing both the Escherichia coli D-xylose isomerase (D-xylose ketol-isomerase, EC 5.3.1.5) gene and the D-xylulokinase (ATP: D-xylulose 5-phosphotransferase, EC 2.7.1.17) gene has been cloned on an E. coli plasmid. The D-xylose isomerase gene was separated from the D-xylulokinase gene by the construction of a new deletion plasmid, pLX7. The D-xylose isomerase gene cloned on pLX7 was found still to be an intact gene. The precise location of the D-xylose isomerase gene on the plasmid pLX7 was further determined by the construction of two more plasmids, pLX8 and pLX9. This is believed to be the first D-xylose isomerase gene that has been isolated and extensively purified from any organism. D-Xylose isomerase, the enzyme product of the D-xylose isomerase gene, is responsible for the conversion of D-xylose to D-xylulose, as well as D-glucose to D-fructose. It is widely believed that yeast cannot ferment D-xylose to ethanol primarily because of the lack of D-xylose isomerase in yeast. D-Xylose isomerase (also known as D-glucose isomerase) is also used for the commercial production of high-fructose syrups. The purification of the D-xylose isomerase gene may lead to the following industrial applications: (1) cloning and expression of the gene in yeast to make the latter organism capable of directly fermenting D-xylose to ethanol, and (2) cloning of the gene on a high-copy-number plasmid in a proper host to overproduce the enzyme, which should have a profound impact on the high-fructose syrup technology. 14 references.

Cis-retinoids and the chemistry of vision.

Science.gov (United States)

Cascella, Michele; Bärfuss, Simon; Stocker, Achim

2013-11-15

We discuss here principal biochemical transformations of retinoid molecules in the visual cycle. We focus our analysis on the accumulating evidence of alternate pathways and functional redundancies in the cycle. The efficiency of the visual cycle depends, on one hand, on fast regeneration of the photo-bleached chromophores. On the other hand, it is crucial that the cyclic process should be highly selective to avoid accumulation of byproducts. The state-of-the-art knowledge indicates that single enzymatically active components of the cycle are not strictly selective and may require chaperones to enhance their rates. It appears that protein-protein interactions significantly improve the biological stability of the visual cycle. In particular, synthesis of thermodynamically less stable 11-cis-retinoid conformers is favored by physical interactions of the isomerases present in the retina with cellular retinaldehyde binding protein. Copyright © 2013 Elsevier Inc. All rights reserved.

Membrane engineering via trans unsaturated fatty acids production improves Escherichia coli robustness and production of biorenewables.

Science.gov (United States)

Tan, Zaigao; Yoon, Jong Moon; Nielsen, David R; Shanks, Jacqueline V; Jarboe, Laura R

2016-05-01

Constructing microbial biocatalysts that produce biorenewables at economically viable yields and titers is often hampered by product toxicity. For production of short chain fatty acids, membrane damage is considered the primary mechanism of toxicity, particularly in regards to membrane integrity. Previous engineering efforts in Escherichia coli to increase membrane integrity, with the goal of increasing fatty acid tolerance and production, have had mixed results. Herein, a novel approach was used to reconstruct the E. coli membrane by enabling production of a novel membrane component. Specifically, trans unsaturated fatty acids (TUFA) were produced and incorporated into the membrane of E. coli MG1655 by expression of cis-trans isomerase (Cti) from Pseudomonas aeruginosa. While the engineered strain was found to have no increase in membrane integrity, a significant decrease in membrane fluidity was observed, meaning that membrane polarization and rigidity were increased by TUFA incorporation. As a result, tolerance to exogenously added octanoic acid and production of octanoic acid were both increased relative to the wild-type strain. This membrane engineering strategy to improve octanoic acid tolerance was found to require fine-tuning of TUFA abundance. Besides improving tolerance and production of carboxylic acids, TUFA production also enabled increased tolerance in E. coli to other bio-products, e.g. alcohols, organic acids, aromatic compounds, a variety of adverse industrial conditions, e.g. low pH, high temperature, and also elevated styrene production, another versatile bio-chemical product. TUFA permitted enhanced growth due to alleviation of bio-product toxicity, demonstrating the general effectiveness of this membrane engineering strategy towards improving strain robustness. Copyright © 2016 International Metabolic Engineering Society. Published by Elsevier Inc. All rights reserved.

trans-Double Bond-Containing Liposomes as Potential Carriers for Drug Delivery

Directory of Open Access Journals (Sweden)

Giorgia Giacometti

2017-11-01

Full Text Available The use of liposomes has been crucial for investigations in biomimetic chemical biology as a membrane model and in medicinal chemistry for drug delivery. Liposomes are made of phospholipids whose biophysical characteristics strongly depend on the type of fatty acid moiety, where natural unsaturated lipids always have the double bond geometry in the cis configuration. The influence of lipid double bond configuration had not been considered so far with respect to the competence of liposomes in delivery. We were interested in evaluating possible changes in the molecular properties induced by the conversion of the double bond from cis to trans geometry. Here we report on the effects of the addition of trans-phospholipids supplied in different amounts to other liposome constituents (cholesterol, neutral phospholipids and cationic surfactants, on the size, ζ-potential and stability of liposomal formulations and on their ability to encapsulate two dyes such as rhodamine B and fluorescein. From a biotechnological point of view, trans-containing liposomes proved to have different characteristics from those containing the cis analogues, and to influence the incorporation and release of the dyes. These results open new perspectives in the use of the unnatural lipid geometry, for the purpose of changing liposome behavior and/or of obtaining molecular interferences, also in view of synergic effects of cell toxicity, especially in antitumoral strategies.

Cis-urocanic acid, a sunlight-induced immunosuppressive factor, activates immune suppression via the 5-HT2A receptor

Science.gov (United States)

Walterscheid, Jeffrey P.; Nghiem, Dat X.; Kazimi, Nasser; Nutt, Leta K.; McConkey, David J.; Norval, Mary; Ullrich, Stephen E.

2006-01-01

Exposure to UV radiation induces skin cancer and suppresses the immune response. To induce immune suppression, the electromagnetic energy of UV radiation must be absorbed by an epidermal photoreceptor and converted into a biologically recognizable signal. Two photoreceptors have been recognized: DNA and trans-urocanic acid (UCA). Trans-UCA is normally found in the outermost layer of skin and isomerizes to the cis isomer upon exposure to UV radiation. Although UCA was identified as a UV photoreceptor years ago, and many have documented its ability to induce immune suppression, its exact mode of action remains elusive. Particularly vexing has been the identity of the molecular pathway by which cis-UCA mediates immune suppression. Here we provide evidence that cis-UCA binds to the serotonin [5-hydroxytryptamine (5-HT)] receptor with relatively high affinity (Kd = 4.6 nM). Anti-cis-UCA antibody precipitates radiolabeled 5-HT, and the binding is inhibited by excess 5-HT and/or excess cis-UCA. Similarly, anti-5-HT antibody precipitates radiolabeled cis-UCA, and the binding is inhibited by excess 5-HT or excess cis-UCA. Calcium mobilization was activated when a mouse fibroblast line, stably transfected with the human 5-HT2A receptor, was treated with cis-UCA. Cis-UCA-induced calcium mobilization was blocked with a selective 5-HT2A receptor antagonist. UV- and cis-UCA-induced immune suppression was blocked by antiserotonin antibodies or by treating the mice with 5-HT2A receptor antagonists. Our findings identify cis-UCA as a serotonin receptor ligand and indicate that the immunosuppressive effects of cis-UCA and UV radiation are mediated by activation of the 5-HT2A receptor. PMID:17085585

Synthesis, DFT and antimicrobial activity assays in vitro for novel cis/trans-but-2-enedioic acid esters

Science.gov (United States)

Ma, Yan-Long; Zhou, Ru-Jin; Zeng, Xing-Ye; An, Ya-Xiong; Qiu, Song-Shan; Nie, Li-Jun

2014-04-01

Six novel cis/trans-but-2-enedioic acid esters had been synthesized to discover the new bioactive molecules that could kill food-related bacteria and fungi. Their structures were analyzed by melting point, LC-MS, 1H NMR and 13C NMR. 4-(Methoxycarbonyl) phenyl ethyl fumarate (6b) was also characterized by single-crystal X-ray diffraction. Their antimicrobial activities were evaluated in vitro by measuring the minimal inhibitory concentration (MIC). Compared with the single monomethyl fumarate and methyl 4-hydroxybenzoate, these compounds had stronger antimicrobial activity against all the eight microorganisms. Among the antibacterial and antifungal compounds, 4-(methoxycarbonyl) phenyl methyl fumarate (6a) showed the best antimicrobial activity. The electronic properties of these compounds were calculated by the density functional theory (DFT) method with 6-31G (d, p) basis set. DFT studies indicated that molecular electrostatic potential (MEP) map, ELUMO, energy gap, electronegativity and electrophilicity index could be helpful to understand the various antimicrobial activities among these compounds. The antimicrobial activity of compound 6a was evaluated in vitro against Salmonellacholeraesuis subsp. choleraesuis, Lactococcus lactis subsp. lactis and Saccharomyces cerevisiae by time-kill, and it was found that compound 6a exhibited significant microbiocidal activity against the three microorganisms.

Biodistribution and pharamacokinetics of /sup 195m/Pt-labeled cis-dichlorotrans-dihydroxo-bis(isopropylamine)platinum(IV), CHIP, in normal female Fischer 344 rat

International Nuclear Information System (INIS)

Hoeschele, J.D.; Ferren, L.A.; Roberts, J.A.; Whitfield, L.R.

1983-01-01

The discovery and successful clinical application of the potent anti-tumor compound, cis-Dichlorodiammineplatinum(II), cis-DDP* has stimulated considerable interest in developing effective but less toxic second-generation platinum antitumor drugs. One such candidate drug is cis-Dichloro-trans-dihydroxo-bis-(isopropylamine)platinum(IV), cis-trans-[PtCl 2 (OH) 2 (i-PrNH 2 ) 2 ], (CHIP). An important feature of this Pt(IV) agent is that in addition to exhibiting a generally milder clinical toxicity than cisplatin, the dose-limiting toxicity of CHIP is the more common myelosuppression rather than the less desirable nephrotoxicity. Also, CHIP has been reported recently to be more effective than cisplatin against both alkylating agent sensitive and resistant strains of the Yoshida sarcoms. A microscale synthesis for /sup 195m/Pt-labelled CHIP and the tissue distribution and pharmacokinetic properties of this agent in normal female Fischer 344 rats are reported. A comparison with similar data for /sup 195m/Pt-cis-DDP is included

Vph6 Mutants of Saccharomyces Cerevisiae Require Calcineurin for Growth and Are Defective in Vacuolar H(+)-Atpase Assembly

OpenAIRE

Hemenway, C. S.; Dolinski, K.; Cardenas, M. E.; Hiller, M. A.; Jones, E. W.; Heitman, J.

1995-01-01

We have characterized a Saccharomyces cerevisiae mutant strain that is hypersensitive to cyclosporin A (CsA) and FK506, immunosuppressants that inhibit calcineurin, a serine-threonine-specific phosphatase (PP2B). A single nuclear mutation, designated cev1 for calcineurin essential for viability, is responsible for the CsA-FK506-sensitive phenotype. The peptidyl-prolyl cis-trans isomerases cyclophilin A and FKBP12, respectively, mediate CsA and FK506 toxicity in the cev1 mutant strain. We demo...

Trans-Lesion DNA Polymerases May Be Involved in Yeast Meiosis

Science.gov (United States)

Arbel-Eden, Ayelet; Joseph-Strauss, Daphna; Masika, Hagit; Printzental, Oxana; Rachi, Eléanor; Simchen, Giora

2013-01-01

Trans-lesion DNA polymerases (TLSPs) enable bypass of DNA lesions during replication and are also induced under stress conditions. Being only weakly dependent on their template during replication, TLSPs introduce mutations into DNA. The low processivity of these enzymes ensures that they fall off their template after a few bases are synthesized and are then replaced by the more accurate replicative polymerase. We find that the three TLSPs of budding yeast Saccharomyces cerevisiae Rev1, PolZeta (Rev3 and Rev7), and Rad30 are induced during meiosis at a time when DNA double-strand breaks (DSBs) are formed and homologous chromosomes recombine. Strains deleted for one or any combination of the three TLSPs undergo normal meiosis. However, in the triple-deletion mutant, there is a reduction in both allelic and ectopic recombination. We suggest that trans-lesion polymerases are involved in the processing of meiotic double-strand breaks that lead to mutations. In support of this notion, we report significant yeast two-hybrid (Y2H) associations in meiosis-arrested cells between the TLSPs and DSB proteins Rev1-Spo11, Rev1-Mei4, and Rev7-Rec114, as well as between Rev1 and Rad30. We suggest that the involvement of TLSPs in processing of meiotic DSBs could be responsible for the considerably higher frequency of mutations reported during meiosis compared with that found in mitotically dividing cells, and therefore may contribute to faster evolutionary divergence than previously assumed. PMID:23550131

cis-Golgi proteins accumulate near the ER exit sites and act as the scaffold for Golgi regeneration after brefeldin A treatment in tobacco BY-2 cells.

Science.gov (United States)

Ito, Yoko; Uemura, Tomohiro; Shoda, Keiko; Fujimoto, Masaru; Ueda, Takashi; Nakano, Akihiko

2012-08-01

The Golgi apparatus forms stacks of cisternae in many eukaryotic cells. However, little is known about how such a stacked structure is formed and maintained. To address this question, plant cells provide a system suitable for live-imaging approaches because individual Golgi stacks are well separated in the cytoplasm. We established tobacco BY-2 cell lines expressing multiple Golgi markers tagged by different fluorescent proteins and observed their responses to brefeldin A (BFA) treatment and BFA removal. BFA treatment disrupted cis, medial, and trans cisternae but caused distinct relocalization patterns depending on the proteins examined. Medial- and trans-Golgi proteins, as well as one cis-Golgi protein, were absorbed into the endoplasmic reticulum (ER), but two other cis-Golgi proteins formed small punctate structures. After BFA removal, these puncta coalesced first, and then the Golgi stacks regenerated from them in the cis-to-trans order. We suggest that these structures have a property similar to the ER-Golgi intermediate compartment and function as the scaffold of Golgi regeneration.

Regular square planer bis-(4,4,4-trifluoro-1-(thiophen-2-yl)butane-1,3-dione)/copper(II) complex: Trans/cis-DFT isomerization, crystal structure, thermal, solvatochromism, hirshfeld surface and DNA-binding analysis

Science.gov (United States)

Hema, M. K.; Karthik, C. S.; Warad, Ismail; Lokanath, N. K.; Zarrouk, Abdelkader; Kumara, Karthik; Pampa, K. J.; Mallu, P.

2018-04-01

Trans-[Cu(O∩O)2] complex, O∩O = 4,4,4-trifluoro-1-(thiophen-2-yl)butane-1,3-dione was reported with high potential toward CT-DNA binder. The solved XRD-structure of complex indicated a perfect regular square-planer geometry around the Cu(II) center. The trans/cis-DFT-isomerization calculation supported the XRD seen in reflecting the trans-isomer as the kinetic-favor isomer. The desired complex structure was also characterized by conductivity measurement, CHN-elemental analyses, MS, EDX, SEM, UV-Vis., FT-IR, HAS and TG/DTG. The Solvatochromism behavior of the complex was evaluated using four different polar solvents. MPE and Hirshfeld surface analysis (HSA) come to an agreement that fluoride and thiophene protons atoms are with suitable electro-potential environment to form non-classical H-bonds of type CThsbnd H⋯F. The DNA-binding properties were investigated by viscosity tests and spectrometric titrations, the results revealed the complex as strong calf-thymus DNA binder. High intrinsic-binding constants value ∼1.8 × 105 was collected.

Enhanced bioavailability of lycopene when consumed as cis-isomers from tangerine compared to red tomato juice, a randomized, cross-over clinical trial.

Science.gov (United States)

Cooperstone, Jessica L; Ralston, Robin A; Riedl, Ken M; Haufe, Thomas C; Schweiggert, Ralf M; King, Samantha A; Timmers, Cynthia D; Francis, David M; Lesinski, Gregory B; Clinton, Steven K; Schwartz, Steven J

2015-04-01

Tangerine tomatoes (Solanum lycopersicum) are rich in tetra-cis-lycopene resulting from natural variation in carotenoid isomerase. Our objective was to compare the bioavailability of lycopene from tangerine to red tomato juice, and elucidate physical deposition forms of these isomers in tomatoes by light and electron microscopy. Following a randomized cross-over design, subjects (n = 11, 6 M/5 F) consumed two meals delivering 10 mg lycopene from tangerine (94% cis) or red tomato juice (10% cis). Blood was sampled over 12 h and triglyceride-rich lipoprotein fractions of plasma were isolated and analyzed using HPLC-DAD-MS/MS. Lycopene was crystalline in red tomato chromoplasts and globular in tangerine tomatoes. With tangerine tomato juice we observed a marked 8.5-fold increase in lycopene bioavailability compared to red tomato juice (p rich foods. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Expression of Cyclophilin B is Associated with Malignant Progression and Regulation of Genes Implicated in the Pathogenesis of Breast Cancer

OpenAIRE

Fang, Feng; Flegler, Ayanna J.; Du, Pan; Lin, Simon; Clevenger, Charles V.

2009-01-01

Cyclophilin B (CypB) is a 21-kDa protein with peptidyl-prolyl cis-trans isomerase activity that functions as a transcriptional inducer for Stat5 and as a ligand for CD147. To better understand the global function of CypB in breast cancer, T47D cells with a small interfering RNA-mediated knockdown of CypB were generated. Subsequent expression profiling analysis showed that 663 transcripts were regulated by CypB knockdown, and that many of these gene products contributed to cell proliferation, ...

The inverse-trans-influence in tetravalent lanthanide and actinide bis(carbene) complexes

Science.gov (United States)

Gregson, Matthew; Lu, Erli; Mills, David P.; Tuna, Floriana; McInnes, Eric J. L.; Hennig, Christoph; Scheinost, Andreas C.; McMaster, Jonathan; Lewis, William; Blake, Alexander J.; Kerridge, Andrew; Liddle, Stephen T.

2017-02-01

Across the periodic table the trans-influence operates, whereby tightly bonded ligands selectively lengthen mutually trans metal-ligand bonds. Conversely, in high oxidation state actinide complexes the inverse-trans-influence operates, where normally cis strongly donating ligands instead reside trans and actually reinforce each other. However, because the inverse-trans-influence is restricted to high-valent actinyls and a few uranium(V/VI) complexes, it has had limited scope in an area with few unifying rules. Here we report tetravalent cerium, uranium and thorium bis(carbene) complexes with trans C=M=C cores where experimental and theoretical data suggest the presence of an inverse-trans-influence. Studies of hypothetical praseodymium(IV) and terbium(IV) analogues suggest the inverse-trans-influence may extend to these ions but it also diminishes significantly as the 4f orbitals are populated. This work suggests that the inverse-trans-influence may occur beyond high oxidation state 5f metals and hence could encompass mid-range oxidation state actinides and lanthanides. Thus, the inverse-trans-influence might be a more general f-block principle.

Photoinduced intramolecular charge transfer and trans-cis isomerization of the DCM styrene dye. Picosecond and nanosecond laser spectroscopy, high-performance liquid chromatography, and nuclear magnetic resonance studies

Energy Technology Data Exchange (ETDEWEB)

Meyer, M.; Mialocq, J.C.; Perly, B. (CNRS, Gif-sur-Yvette (France))

1990-01-11

The photoexcitation of 4-(dicyanomethylene)-2-methyl-6-(p-(dimethylamino)styryl)-4H-pyran (DCM) induces a large intramolecular charge transfer (ICT) from the dimethylamino electron-donor group to the dicyanomethylene acceptor group. The dramatic effect of the solvent polarity on the absorption and fluorescence spectra on the one hand and the competition between the nonradiative S{sub 1} {yields} S{sub 0} deactivation and trans {yields} cis isomerization processes on the other hand has been examined. Our results clearly show that DCM isomerization efficiency is very low in the more polar solvents. The S{sub 1} {yields} S{sub 0} internal conversion may intervene at a torsional angle smaller than 90{degree} before reaching the perpendicular configuration.

Further Insight into the Lability of MeCN Ligands of Cytotoxic Cycloruthenated Compounds: Evidence for the Antisymbiotic Effect Trans to the Carbon Atom at the Ru Center.

Science.gov (United States)

Barbosa, Ana Soraya Lima; Werlé, Christophe; Colunga, Claudia Olivia Oliva; Rodríguez, Cecilia Franco; Toscano, Ruben Alfredo; Le Lagadec, Ronan; Pfeffer, Michel

2015-08-03

The two MeCN ligands in [Ru(2-C6H4-2'-Py-κC,N)(Phen, trans-C)(MeCN)2]PF6 (1), both trans to a sp(2) hybridized N atom, cannot be substituted by any other ligand. In contrast, the isomerized derivative [Ru(2-C6H4-2'-Py-κC,N)(Phen, cis-C)(MeCN)2]PF6 (2), in which one MeCN ligand is now trans to the C atom of the phenyl ring orthometalated to Ru, leads to fast and quantitative substitution reactions with several monodentate ligands. With PPh3, 2 affords [Ru(2-C6H4-2'-Py-κC,N)(Phen, cis-C)(PPh3)(MeCN)]PF6 (3), in which PPh3 is trans to the C σ bound to Ru. Compound 3 is not kinetically stable, because, under thermodynamic control, it leads to 4, in which the PPh3 is trans to a N atom of the Phen ligand. Dimethylsulfoxide (DMSO) can also substitute a MeCN ligand in 2, leading to 5, in which DMSO is coordinated to Ru via its S atom trans to the N atom of the Phen ligand, the isomer under thermodynamic control being the only compound observed. We also found evidence for the fast to very fast substitution of MeCN in 2 by water or a chloride anion by studying the electronic spectra of 2 in the presence of water or NBu4Cl, respectively. An isomerization related to that observed between 3 and 4 is also found for the known monophosphine derivative [Ru(2-C6H4-2'-Py-κC,N)(PPh3, trans-C)(MeCN)3]PF6 (10), in which the PPh3 is located trans to the C of the cyclometalated 2-phenylpyridine, since, upon treatment by refluxing MeCN, it leads to its isomer 11, [Ru(2-C6H4-2'-Py-κC,N)(PPh3, cis-C)(MeCN)3]PF6. Further substitutions are also observed on 11, whereby N^N chelates (N^N = 2,2'-bipyridine and phenanthroline) substitute two MeCN ligands, affording [Ru(2-C6H4-2'-Py-κC,N)(PPh3, cis-C)(N^N)(MeCN)]PF6 (12a and 12b). Altogether, the behavior of the obtained complexes by ligand substitution reactions can be rationalized by an antisymbiotic effect on the Ru center, trans to the C atom of the cyclometalated unit, leading to compounds having the least nucleophilic ligand trans to C

Inflammation and insulin resistance induced by trans-10, cis-12 conjugated linoleic acid depend on intracellular calcium levels in primary cultures of human adipocytes

DEFF Research Database (Denmark)

Kennedy, Arion; Martinez, Kristina; Chung, Soonkyu

2010-01-01

We previously demonstrated that trans-10, cis-12 (10,12) conjugated linoleic acid (CLA) induced inflammation and insulin resistance in primary human adipocytes by activating nuclear factor kappaB (NFkappaB) and extracellular signal-related kinase (ERK) signaling. In this study, we demonstrated...... that the initial increase in intracellular calcium ([Ca2+]i) mediated by 10,12 CLA was attenuated by TMB-8, an inhibitor of calcium release from the endoplasmic reticulum (ER), by BAPTA, an intracellular calcium chelator, and by D609, a phospholipase C (PLC) inhibitor. Moreover, BAPTA, TMB-8, and D609 attenuated......, and suppression of peroxisome proliferator activated receptor gamma protein levels and insulin-stimulated glucose uptake. These data suggest that 10,12 CLA increases inflammation and insulin resistance in human adipocytes, in part by increasing [Ca2+]i levels, particularly calcium from the ER....

An in vivo genetic screen for genes involved in spliced leader trans-splicing indicates a crucial role for continuous de novo spliced leader RNP assembly.

Science.gov (United States)

Philippe, Lucas; Pandarakalam, George C; Fasimoye, Rotimi; Harrison, Neale; Connolly, Bernadette; Pettitt, Jonathan; Müller, Berndt

2017-08-21

Spliced leader (SL) trans-splicing is a critical element of gene expression in a number of eukaryotic groups. This process is arguably best understood in nematodes, where biochemical and molecular studies in Caenorhabditis elegans and Ascaris suum have identified key steps and factors involved. Despite this, the precise details of SL trans-splicing have yet to be elucidated. In part, this is because the systematic identification of the molecules involved has not previously been possible due to the lack of a specific phenotype associated with defects in this process. We present here a novel GFP-based reporter assay that can monitor SL1 trans-splicing in living C. elegans. Using this assay, we have identified mutants in sna-1 that are defective in SL trans-splicing, and demonstrate that reducing function of SNA-1, SNA-2 and SUT-1, proteins that associate with SL1 RNA and related SmY RNAs, impairs SL trans-splicing. We further demonstrate that the Sm proteins and pICln, SMN and Gemin5, which are involved in small nuclear ribonucleoprotein assembly, have an important role in SL trans-splicing. Taken together these results provide the first in vivo evidence for proteins involved in SL trans-splicing, and indicate that continuous replacement of SL ribonucleoproteins consumed during trans-splicing reactions is essential for effective trans-splicing. © The Author(s) 2017. Published by Oxford University Press on behalf of Nucleic Acids Research.

A single and two step isomerization process for d-tagatose and l-ribose bioproduction using l-arabinose isomerase and d-lyxose isomerase.

Science.gov (United States)

Patel, Manisha J; Akhani, Rekha C; Patel, Arti T; Dedania, Samir R; Patel, Darshan H

2017-02-01

l-ribose and d-tagatose are biochemically synthesized using sugar isomerases. The l-arabinose isomerase gene from Shigella flexneri (Sf-AI) was cloned and expressed in Escherichia coli BL-21. Sf-AI was applied for the bioproduction of d-tagatose from d-galactose. l-ribose synthesis was performed by two step isomerization using Sf-AI and d-lyxose/ribose isomerase from Cohnella laevoribosii. The overall 22.3% and 25% conversion rate were observed for d-tagatose and l-ribose production from d-galactose and l-arabinose respectively. In the present manuscript, synthesis of rare sugars from naturally available sugars is discussed along with the biochemical characterization of Sf-AI and its efficiency. Copyright © 2016 Elsevier Inc. All rights reserved.

The multidrug resistance IncA/C transferable plasmid encodes a novel domain-swapped dimeric protein-disulfide isomerase.

Science.gov (United States)

Premkumar, Lakshmanane; Kurth, Fabian; Neyer, Simon; Schembri, Mark A; Martin, Jennifer L

2014-01-31

The multidrug resistance-encoding IncA/C conjugative plasmids disseminate antibiotic resistance genes among clinically relevant enteric bacteria. A plasmid-encoded disulfide isomerase is associated with conjugation. Sequence analysis of several IncA/C plasmids and IncA/C-related integrative and conjugative elements (ICE) from commensal and pathogenic bacteria identified a conserved DsbC/DsbG homolog (DsbP). The crystal structure of DsbP reveals an N-terminal domain, a linker region, and a C-terminal catalytic domain. A DsbP homodimer is formed through domain swapping of two DsbP N-terminal domains. The catalytic domain incorporates a thioredoxin-fold with characteristic CXXC and cis-Pro motifs. Overall, the structure and redox properties of DsbP diverge from the Escherichia coli DsbC and DsbG disulfide isomerases. Specifically, the V-shaped dimer of DsbP is inverted compared with EcDsbC and EcDsbG. In addition, the redox potential of DsbP (-161 mV) is more reducing than EcDsbC (-130 mV) and EcDsbG (-126 mV). Other catalytic properties of DsbP more closely resemble those of EcDsbG than EcDsbC. These catalytic differences are in part a consequence of the unusual active site motif of DsbP (CAVC); substitution to the EcDsbC-like (CGYC) motif converts the catalytic properties to those of EcDsbC. Structural comparison of the 12 independent subunit structures of DsbP that we determined revealed that conformational changes in the linker region contribute to mobility of the catalytic domain, providing mechanistic insight into DsbP function. In summary, our data reveal that the conserved plasmid-encoded DsbP protein is a bona fide disulfide isomerase and suggest that a dedicated oxidative folding enzyme is important for conjugative plasmid transfer.

Enhanced bioavailability of lycopene when consumed as cis-isomers from tangerine compared to red tomato juice, a randomized, cross-over clinical trial

Science.gov (United States)

Cooperstone, Jessica L.; Ralston, Robin A.; Riedl, Ken M.; Haufe, Thomas C.; Schweiggert, Ralf M.; King, Samantha A.; Timmers, Cynthia D.; Francis, David M.; Lesinski, Gregory B.; Clinton, Steven K.; Schwartz, Steven J.

2015-01-01

Scope Tangerine tomatoes (Solanum lycopersicum) are rich in tetra-cis-lycopene resulting from natural variation in carotenoid isomerase. Our objective was to compare the bioavailability of lycopene from tangerine to red tomato juice, and elucidate physical deposition forms of these isomers in tomatoes by light and electron microscopy. Methods and results Following a randomized crossover design, subjects (n=11, 6M/5F) consumed two meals delivering 10 mg lycopene from tangerine (94% cis) or red tomato juice (10% cis). Blood was sampled over 12 hours and triglyceride-rich lipoprotein fractions of plasma (TRLs) were isolated and analyzed using HPLC-DAD-MS/MS. Lycopene was crystalline in red tomato chromoplasts and globular in tangerine tomatoes. With tangerine tomato juice we observed a marked 8.5-fold increase in lycopene bioavailability compared to red tomato juice (PLycopene is markedly more bioavailable from tangerine than from red tomato juice, consistent with a predominance of cis-lycopene isomers and presence in chromoplasts in a lipid dissolved globular state. These results justify using tangerine tomatoes as a lycopene source in studies examining the potential health benefits of lycopene-rich foods. PMID:25620547

Hydrogenation Alternatives - Effects of Trans-Fatty-Acids and Stearic-Acid Versus Linoleic-Acid on Serum-Lipids and Lipoproteins in Humans

NARCIS (Netherlands)

Zock, P.L.; Katan, M.B.

1992-01-01

The objective of this study was to compare the effects of linoleic acid (cis,cis-C18:2(n-6)) and its hydrogenation products elaidic (trans-C18:1(n-9)) and stearic acid (C18:0) on serum lipoprotein levels in humans.Twenty-six men and 30 women, all nor

TAL effectors target the C-terminal domain of RNA polymerase II (CTD by inhibiting the prolyl-isomerase activity of a CTD-associated cyclophilin.

Directory of Open Access Journals (Sweden)

Mariane Noronha Domingues

Full Text Available Transcriptional activator-like (TAL effectors of plant pathogenic bacteria function as transcription factors in plant cells. However, how TAL effectors control transcription in the host is presently unknown. Previously, we showed that TAL effectors of the citrus canker pathogen Xanthomonas citri, named PthAs, targeted the citrus protein complex comprising the thioredoxin CsTdx, ubiquitin-conjugating enzymes CsUev/Ubc13 and cyclophilin CsCyp. Here we show that CsCyp complements the function of Cpr1 and Ess1, two yeast cyclophilins that regulate transcription by the isomerization of proline residues of the regulatory C-terminal domain (CTD of RNA polymerase II. We also demonstrate that CsCyp, CsTdx, CsUev and four PthA variants interact with the citrus CTD and that CsCyp co-immunoprecipitate with the CTD in citrus cell extracts and with PthA2 transiently expressed in sweet orange epicotyls. The interactions of CsCyp with the CTD and PthA2 were inhibited by cyclosporin A (CsA, a cyclophilin inhibitor. Moreover, we present evidence that PthA2 inhibits the peptidyl-prolyl cis-trans isomerase (PPIase activity of CsCyp in a similar fashion as CsA, and that silencing of CsCyp, as well as treatments with CsA, enhance canker lesions in X. citri-infected leaves. Given that CsCyp appears to function as a negative regulator of cell growth and that Ess1 negatively regulates transcription elongation in yeast, we propose that PthAs activate host transcription by inhibiting the PPIase activity of CsCyp on the CTD.

Pin1 and neurodegeneration: a new player for prion disorders?

Directory of Open Access Journals (Sweden)

Elisa Isopi

2015-07-01

Full Text Available Pin1 is a peptidyl-prolyl isomerase that catalyzes the cis/trans conversion of phosphorylated proteins at serine or threonine residues which precede a proline. The peptidyl-prolyl isomerization induces a conformational change of the proteins involved in cell signaling process. Pin1 dysregulation has been associated with some neurodegenerative disorders such as Alzheimer's disease, Parkinson's disease and Huntington's disease. Proline-directed phosphorylation is a common regulator of these pathologies and a recent work showed that it is also involved in prion disorders. In fact, prion protein phosphorylation at the Ser-43-Pro motif induces prion protein conversion into a disease-associated form. Furthermore, phosphorylation at Ser-43-Pro has been observed to increase in the cerebral spinal fluid of sporadic Creutzfeldt-Jakob Disease patients. These findings provide new insights into the pathogenesis of prion disorders, suggesting Pin1 as a potential new player in the disease. In this paper, we review the mechanisms underlying Pin1 involvement in the aforementioned neurodegenerative pathologies focusing on the potential role of Pin1 in prion disorders.

Biochemical function of typical and variant Arabidopsis thaliana U-box E3 ubiquitin-protein ligases.

Science.gov (United States)

Wiborg, Jakob; O'Shea, Charlotte; Skriver, Karen

2008-08-01

The variance of the U-box domain in 64 Arabidopsis thaliana (thale cress) E3s (ubiquitin-protein ligases) was used to examine the interactions between E3s and E2s (ubiquitin-conjugating enzymes). E2s and E3s are components of the ubiquitin protein degradation pathway. Seven U-box proteins were analysed for their ability to ubiquitinate proteins in vitro in co-operation with different E2s. All U-box domains exhibited ubiquitination activity and interacted productively with UBC4/5-type E2s. Three and four of the U-box domains mediated ubiquitin addition in the presence of UBC13 and UBC7 E2s respectively, but no productive interaction was observed with the UBC15 E2 tested. The activity of AtPUB54 [Arabidopsis thaliana (thale cress) plant U-box 54 protein] was dependent on Trp(266) in the E2-binding cleft, and the E2 selectivity was changed by substitution of this position. The function of the distant U-box protein, AtPUB49, representing a large family of eukaryotic proteins containing a U-box linked to a cyclophilin-like peptidyl-prolyl cis-trans isomerase domain, was characterized biochemically. AtPUB49 functioned both as a prolyl isomerase and a chaperone by catalysing cis-trans isomerization of peptidyl-prolyl bonds and dissolving protein aggregates. In conclusion, both typical and atypical Arabidopsis U-box proteins were active E3s. The overlap in the E3/E2 selectivity suggests that in vivo specificity is not determined only by the E3-E2 interactions, but also by other parameters, e.g. co-existence or interactions with additional domains. The biochemical functions of AtPUB49 suggest that the protein can be involved in folding or degradation of protein substrates. Similar functions can also be retained within a protein complex with separate chaperone and U-box proteins.

Immobilization of Recombinant Glucose Isomerase for Efficient Production of High Fructose Corn Syrup.

Science.gov (United States)

Jin, Li-Qun; Xu, Qi; Liu, Zhi-Qiang; Jia, Dong-Xu; Liao, Cheng-Jun; Chen, De-Shui; Zheng, Yu-Guo

2017-09-01

Glucose isomerase is the important enzyme for the production of high fructose corn syrup (HFCS). One-step production of HFCS containing more than 55% fructose (HFCS-55) is receiving much attention for its industrial applications. In this work, the Escherichia coli harboring glucose isomerase mutant TEGI-W139F/V186T was immobilized for efficient production of HFCS-55. The immobilization conditions were optimized, and the maximum enzyme activity recovery of 92% was obtained. The immobilized glucose isomerase showed higher pH, temperature, and operational stabilities with a K m value of 272 mM and maximum reaction rate of 23.8 mM min -1 . The fructose concentration still retained above 55% after the immobilized glucose isomerase was reused for 10 cycles, and more than 85% of its initial activity was reserved even after 15 recycles of usage at temperature of 90 °C. The results highlighted the immobilized glucose isomerase as a potential biocatalyst for HFCS-55 production.

Crystal structure of cis-anti-cis-dicyclohexane-18-crown-6 acetonitrile disolvate

Directory of Open Access Journals (Sweden)

Alexander Nazarenko

2015-07-01

Full Text Available The title compound (systematic name: cis-anti-cis-2,5,8,15,18,21-hexaoxatricyclo[20.4.0.09,14]hexacosane acetonitrile disolvate, C20H36O6·2CH3CN, crystallizes from an acetonitrile solution of dicyclohexane-18-crown-6 on evaporation. The molecule is arranged around a center of symmetry with half the crown ether molecule and one molecule of acetonitrile symmetry independent. All O—C—C—O torsion angles are gauche while all C—O—C—C angles are trans. The sequence of torsion angles is [(tg+t(tg−t]3; the geometry of oxygen atoms is close to pseudo-D3d with three atoms below and three atoms above the mean plane, with an average deviation of ±0.16 (1 Å from the mean plane. This geometry is identical to that observed in metal ion complexes of dicyclohexane-18-crown-6 but differs significantly from the conformation of a free unsolvated molecule. Each acetonitrile molecule connects to a crown ether molecule via two of its methyl group H atoms (C—H...O. Weaker interactions exist between the third H atom of the acetonitrile methyl group and an O atom of a neighbouring crown ether molecule (C—H...O; and between the N atom of the acetonitrile molecule and a H atom of another neighbouring crown ether molecule. All these intermolecular interactions create a three-dimensional network stabilizing the disolvate.

Chemotactic Activity of Cyclophilin A in the Skin Mucus of Yellow Catfish (Pelteobagrus fulvidraco) and Its Active Site for Chemotaxis

Science.gov (United States)

Dawar, Farman Ullah; Tu, Jiagang; Xiong, Yang; Lan, Jiangfeng; Dong, Xing Xing; Liu, Xiaoling; Khattak, Muhammad Nasir Khan; Mei, Jie; Lin, Li

2016-01-01

Fish skin mucus is a dynamic barrier for invading pathogens with a variety of anti-microbial enzymes, including cyclophilin A (CypA), a multi-functional protein with peptidyl-prolyl cis/trans isomerase (PPIase) activity. Beside various other immunological functions, CypA induces leucocytes migration in vitro in teleost. In the current study, we have discovered several novel immune-relevant proteins in yellow catfish skin mucus by mass spectrometry (MS). The CypA present among them was further detected by Western blot. Moreover, the CypA present in the skin mucus displayed strong chemotactic activity for yellow catfish leucocytes. Interestingly, asparagine (like arginine in mammals) at position 69 was the critical site in yellow catfish CypA involved in leucocyte attraction. These novel efforts do not only highlight the enzymatic texture of skin mucus, but signify CypA to be targeted for anti-inflammatory therapeutics. PMID:27589721

Chemotactic Activity of Cyclophilin A in the Skin Mucus of Yellow Catfish (Pelteobagrus fulvidraco and Its Active Site for Chemotaxis

Directory of Open Access Journals (Sweden)

Farman Ullah Dawar

2016-08-01

Full Text Available Fish skin mucus is a dynamic barrier for invading pathogens with a variety of anti-microbial enzymes, including cyclophilin A (CypA, a multi-functional protein with peptidyl-prolyl cis/trans isomerase (PPIase activity. Beside various other immunological functions, CypA induces leucocytes migration in vitro in teleost. In the current study, we have discovered several novel immune-relevant proteins in yellow catfish skin mucus by mass spectrometry (MS. The CypA present among them was further detected by Western blot. Moreover, the CypA present in the skin mucus displayed strong chemotactic activity for yellow catfish leucocytes. Interestingly, asparagine (like arginine in mammals at position 69 was the critical site in yellow catfish CypA involved in leucocyte attraction. These novel efforts do not only highlight the enzymatic texture of skin mucus, but signify CypA to be targeted for anti-inflammatory therapeutics.

Characterization of a novel and potentially lethal designer drug (±)-cis-para-methyl-4-methylaminorex (4,4'-DMAR, or 'Serotoni').

Science.gov (United States)

Brandt, Simon D; Baumann, Michael H; Partilla, John S; Kavanagh, Pierce V; Power, John D; Talbot, Brian; Twamley, Brendan; Mahony, Olivia; O'Brien, John; Elliott, Simon P; Archer, Roland P; Patrick, Julian; Singh, Kuldip; Dempster, Nicola M; Cosbey, Simon H

2014-01-01

During the second half of 2013, a total of 26 deaths involving para-methyl-4-methylaminorex (4,4'-DMAR) were reported to the European Monitoring Centre for Drugs and Drug Addiction. While aminorex and 4-methylaminorex (4-MAR) are known psychostimulants, nothing is known about the comparatively new para-methyl analog. Analytical characterization of two independent samples obtained from online vendors confirmed the presence of the (±)-cis isomer that also appeared to be associated with at least 18 of the 26 deaths. Extensive characterizations included crystal structure analysis, single, tandem, and high-resolution mass spectrometry, liquid and gas chromatography, and nuclear magnetic resonance spectroscopy. For the work described here, both the (±)-cis and (±)-trans racemates were also synthesized, confirming that the differentiation between these two forms was straight-forward. Monoamine transporter activity was studied using rat brain synaptosomes which included the comparison with d-amphetamine, aminorex and (±)-cis-4-MAR. (±)-cis-4,4'-DMAR was a potent, efficacious substrate-type releaser at transporters for dopamine, norepinephrine and serotonin with EC50 values of 8.6 ± 1.1 nM (DAT), 26.9 ± 5.9 nM (NET) and 18.5 ± 2.8 nM (SERT), respectively. The potency of (±)-cis-4,4'-DMAR at DAT and NET rivalled that of other psychomotor stimulant drugs like d-amphetamine and aminorex. However, (±)-cis-4,4'-DMAR had much more potent actions at SERT and activity at SERT varied more than 100-fold across the four drugs. The potent releasing activity of (±)-cis-4,4'-DMAR at all three monoamine transporters predicts a potential for serious side-effects such as psychotic symptoms, agitation, hyperthermia and cardiovascular stimulation, especially after high-dose exposure or following combination with other psychostimulants. Copyright © 2014 John Wiley & Sons, Ltd.

Lecithin:Retinol Acyltransferase: A Key Enzyme Involved in the Retinoid (visual) Cycle

OpenAIRE

Sears, Avery E.; Palczewski, Krzysztof

2016-01-01

Lecithin:retinol acyltransferase (LRAT) catalyzes the acyl transfer from the sn-1 position of phosphatidylcholine (PC) to all-trans-retinol, creating fatty acid retinyl esters (palmitoyl, stearoyl, and some unsaturated derivatives). In the eye, these retinyl esters are substrates for the 65 kDa retinoid isomerase (RPE65). LRAT is well characterized biochemically, and recent structural data from closely related family members of the NlpC/P60 superfamily and a chimeric protein have established ...

Structural Insights into Arl1-Mediated Targeting of the Arf-GEF BIG1 to the trans-Golgi

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Antonio Galindo

2016-07-01

Full Text Available The GTPase Arf1 is the major regulator of vesicle traffic at both the cis- and trans-Golgi. Arf1 is activated at the cis-Golgi by the guanine nucleotide exchange factor (GEF GBF1 and at the trans-Golgi by the related GEF BIG1 or its paralog, BIG2. The trans-Golgi-specific targeting of BIG1 and BIG2 depends on the Arf-like GTPase Arl1. We find that Arl1 binds to the dimerization and cyclophilin binding (DCB domain in BIG1 and report a crystal structure of human Arl1 bound to this domain. Residues in the DCB domain that bind Arl1 are required for BIG1 to locate to the Golgi in vivo. DCB domain-binding residues in Arl1 have a distinct conformation from those in known Arl1-effector complexes, and this plasticity allows Arl1 to interact with different effectors of unrelated structure. The findings provide structural insight into how Arf1 GEFs, and hence active Arf1, achieve their correct subcellular distribution.

Overexpression, purification, crystallization and preliminary X-ray crystal analysis of Bacillus pallidusd-arabinose isomerase

International Nuclear Information System (INIS)

Takeda, Kosei; Yoshida, Hiromi; Takada, Goro; Izumori, Ken; Kamitori, Shigehiro

2008-01-01

Recombinant B. pallidusd-arabinose isomerase was crystallized and diffraction data were collected to 2.3 Å resolution. d-Arabinose isomerase catalyzes the isomerization of d-arabinose to d-ribulose. Bacillus pallidusd-arabinose isomerase has broad substrate specificity and can catalyze the isomerization of d-arabinose, l-fucose, l-xylose, l-galactose and d-altrose. Recombinant B. pallidusd-arabinose isomerase was overexpressed, purified and crystallized. A crystal of the enzyme was obtained by the sitting-drop method at room temperature and belonged to the orthorhombic space group P2 1 2 1 2, with unit-cell parameters a = 144.9, b = 127.9, c = 109.5 Å. Diffraction data were collected to 2.3 Å resolution

Allergens involved in the cross-reactivity of Aedes aegypti with other arthropods.

Science.gov (United States)

Cantillo, Jose Fernando; Puerta, Leonardo; Lafosse-Marin, Sylvie; Subiza, Jose Luis; Caraballo, Luis; Fernandez-Caldas, Enrique

2017-06-01

Cross-reactivity between Aedes aegypti and mites, cockroaches, and shrimp has been previously suggested, but the involved molecular components have not been fully described. To evaluate the cross-reactivity between A aegypti and other arthropods. Thirty-four serum samples from patients with asthma and/or allergic rhinitis were selected, and specific IgE to A aegypti, Dermatophagoides pteronyssinus, Dermatophagoides farinae, Blomia tropicalis, Periplaneta americana. and Litopenaeus vannamei was measured by enzyme-linked immunosorbent assay. Cross-reactivity was investigated using pooled serum samples from allergic patients, allergenic extracts, and the recombinant tropomyosins (Aed a 10.0201, Der p 10, Blo t 10, Lit v 1, and Per a 7). Four IgE reactive bands were further characterized by matrix-assisted laser desorption/ionization tandem time of flight. Frequency of positive IgE reactivity was 82.35% to at least one mite species, 64.7% to A aegypti, 29.4% to P americana, and 23.5% to L vannamei. The highest IgE cross-reactivity was seen between A aegypti and D pteronyssinus (96.6%) followed by L vannamei (95.4%), B tropicalis (84.4%), and P americana (75.4%). Recombinant tropomyosins from mites, cockroach, or shrimp inhibited the IgE reactivity to the mosquito at a lower extent than the extracts from these arthropods. Several bands of A aegypti cross-reacted with arthropod extracts, and 4 of them were identified as odorant binding protein, mitochondrial cytochrome C, peptidyl-prolyl cis-trans isomerase, and protein with hypothetical magnesium ion binding function. We identified 4 novel cross-reactive allergens in A aegypti allergenic extract. These molecules could influence the manifestation of allergy to environmental allergens in the tropics. Copyright © 2017 American College of Allergy, Asthma & Immunology. Published by Elsevier Inc. All rights reserved.

Synthesis, characterization, MCD spectroscopy, and TD-DFT calculations of copper-metalated nonperipherally substituted octaoctyl derivatives of tetrabenzotriazaporphyrin, cis- and trans-tetrabenzodiazaporphyrin, tetrabenzomonoazaporphyrin, and tetrabenzoporphyrin.

Science.gov (United States)

Mack, John; Sosa-Vargas, Lydia; Coles, Simon J; Tizzard, Graham J; Chambrier, Isabelle; Cammidge, Andrew N; Cook, Michael J; Kobayashi, Nagao

2012-12-03

Synthesis of the title compounds has been achieved through refinement of a recently reported synthetic protocol whereby varying equivalents of MeMgBr are reacted with 1,4-dioctylphthalonitrile to produce mixtures favoring specific hybrid structures. The initially formed magnesium-metalated compounds are obtained as pure materials and include, for the first time, both isomers (cis and trans) of tetrabenzodiazaporphyrin. The compounds were demetalated to the metal-free analogues, which were then converted into the copper-metalated derivatives. The X-ray structure of the copper tetrabenzotriazaporphyrin derivative is reported. The metal-free and copper-metalated macrocycles exhibit columnar mesophase behavior, and it is found that the mesophase stability is unexpectedly reduced in the diazaporphyrin derivatives compared to the rest of the series. The results of time-dependent density functional theory calculations for the copper complexes are compared to the observed optical properties. Michl's perimeter model was used as a conceptual framework for analyzing the magnetic circular dichroism spectral data, which predicted and accounted for trends in the observed experimental spectra.

Detection of discriminative sequence patterns in the neighborhood of proline cis peptide bonds and their functional annotation

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Papaloukas Costas

2009-04-01

Full Text Available Abstract Background Polypeptides are composed of amino acids covalently bonded via a peptide bond. The majority of peptide bonds in proteins is found to occur in the trans conformation. In spite of their infrequent occurrence, cis peptide bonds play a key role in the protein structure and function, as well as in many significant biological processes. Results We perform a systematic analysis of regions in protein sequences that contain a proline cis peptide bond in order to discover non-random associations between the primary sequence and the nature of proline cis/trans isomerization. For this purpose an efficient pattern discovery algorithm is employed which discovers regular expression-type patterns that are overrepresented (i.e. appear frequently repeated in a set of sequences. Four types of pattern discovery are performed: i exact pattern discovery, ii pattern discovery using a chemical equivalency set, iii pattern discovery using a structural equivalency set and iv pattern discovery using certain amino acids' physicochemical properties. The extracted patterns are carefully validated using a specially implemented scoring function and a significance measure (i.e. log-probability estimate indicative of their specificity. The score threshold for the first three types of pattern discovery is 0.90 while for the last type of pattern discovery 0.80. Regarding the significance measure, all patterns yielded values in the range [-9, -31] which ensure that the derived patterns are highly unlikely to have emerged by chance. Among the highest scoring patterns, most of them are consistent with previous investigations concerning the neighborhood of cis proline peptide bonds, and many new ones are identified. Finally, the extracted patterns are systematically compared against the PROSITE database, in order to gain insight into the functional implications of cis prolyl bonds. Conclusion Cis patterns with matches in the PROSITE database fell mostly into two

Lack of cyclophilin B in osteogenesis imperfecta with normal collagen folding.

Science.gov (United States)

Barnes, Aileen M; Carter, Erin M; Cabral, Wayne A; Weis, MaryAnn; Chang, Weizhong; Makareeva, Elena; Leikin, Sergey; Rotimi, Charles N; Eyre, David R; Raggio, Cathleen L; Marini, Joan C

2010-02-11

Osteogenesis imperfecta is a heritable disorder that causes bone fragility. Mutations in type I collagen result in autosomal dominant osteogenesis imperfecta, whereas mutations in either of two components of the collagen prolyl 3-hydroxylation complex (cartilage-associated protein [CRTAP] and prolyl 3-hydroxylase 1 [P3H1]) cause autosomal recessive osteogenesis imperfecta with rhizomelia (shortening of proximal segments of upper and lower limbs) and delayed collagen folding. We identified two siblings who had recessive osteogenesis imperfecta without rhizomelia. They had a homozygous start-codon mutation in the peptidyl-prolyl isomerase B gene (PPIB), which results in a lack of cyclophilin B (CyPB), the third component of the complex. The proband's collagen had normal collagen folding and normal prolyl 3-hydroxylation, suggesting that CyPB is not the exclusive peptidyl-prolyl cis-trans isomerase that catalyzes the rate-limiting step in collagen folding, as is currently thought. 2010 Massachusetts Medical Society

Overexpressed cyclophilin B suppresses apoptosis associated with ROS and Ca2+ homeostasis after ER stress.

Science.gov (United States)

Kim, Jinhwan; Choi, Tae Gyu; Ding, Yan; Kim, Yeonghwan; Ha, Kwon Soo; Lee, Kyung Ho; Kang, Insug; Ha, Joohun; Kaufman, Randal J; Lee, Jinhwa; Choe, Wonchae; Kim, Sung Soo

2008-11-01

Prolonged accumulation of misfolded proteins in the endoplasmic reticulum (ER) results in ER stress-mediated apoptosis. Cyclophilins are protein chaperones that accelerate the rate of protein folding through their peptidyl-prolyl cis-trans isomerase (PPIase) activity. In this study, we demonstrated that ER stress activates the expression of the ER-localized cyclophilin B (CypB) gene through a novel ER stress response element. Overexpression of wild-type CypB attenuated ER stress-induced cell death, whereas overexpression of an isomerase activity-defective mutant, CypB/R62A, not only increased Ca(2+) leakage from the ER and ROS generation, but also decreased mitochondrial membrane potential, resulting in cell death following exposure to ER stress-inducing agents. siRNA-mediated inhibition of CypB expression rendered cells more vulnerable to ER stress. Finally, CypB interacted with the ER stress-related chaperones, Bip and Grp94. Taken together, we concluded that CypB performs a crucial function in protecting cells against ER stress via its PPIase activity.

Screening and selection of wild strains for L-arabinose isomerase production

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R. M. Manzo

2013-12-01

Full Text Available The majority of L-arabinose isomerases have been isolated by recombinant techniques, but this methodology implies a reduced technological application. For this reason, 29 bacterial strains, some of them previously characterized as L-arabinose isomerase producers, were assayed as L-arabinose fermenting strains by employing conveniently designed culture media with 0.5% (w/v L-arabinose as main carbon source. From all evaluated bacterial strains, Enterococcus faecium DBFIQ ID: E36, Enterococcus faecium DBFIQ ID: ETW4 and Pediococcus acidilactici ATCC ID: 8042 were, in this order, the best L-arabinose fermenting strains. Afterwards, to assay L-arabinose metabolization and L-arabinose isomerase activity, cell-free extract and saline precipitated cell-free extract of the three bacterial cultures were obtained and the production of ketoses was determined by the cysteine carbazole sulfuric acid method. Results showed that the greater the L-arabinose metabolization ability, the higher the enzymatic activity achieved, so Enterococcus faecium DBFIQ ID: E36 was selected to continue with production, purification and characterization studies. This work thus describes a simple microbiological method for the selection of L-arabinose fermenting bacteria for the potential production of the enzyme L-arabinose isomerase.

Cis–Trans Amide Bond Rotamers in β-Peptoids and Peptoids: Evaluation of Stereoelectronic

DEFF Research Database (Denmark)

Laursen, Jonas Striegler; Engel-Andreasen, Jens; Fristrup, Peter

2013-01-01

to folding propensity. Thus, we here report an investigation of the effect of structural variations on the cis–trans amide bond rotamer equilibria in a selection of monomer model systems. In addition to various side chain effects, which correlated well with previous studies of α-peptoids, we present...... the synthesis and investigation of cis–trans isomerism in the first examples of peptoids and β-peptoids containing thioamide bonds as well as trifluoroacetylated peptoids and β-peptoids. These systems revealed an increase in the preference for cis-amides as compared to their parent compounds, and thus provide...

MicroRNA signature of cis-platin resistant vs. cis-platin sensitive ovarian cancer cell lines

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Kumar Smriti

2011-09-01

Full Text Available Abstract Background Ovarian cancer is the leading cause of death from gynecologic cancer in women worldwide. According to the National Cancer Institute, ovarian cancer has the highest mortality rate among all the reproductive cancers in women. Advanced stage diagnosis and chemo/radio-resistance is a major obstacle in treating advanced ovarian cancer. The most commonly employed chemotherapeutic drug for ovarian cancer treatment is cis-platin. As with most chemotherapeutic drugs, many patients eventually become resistant to cis-platin and therefore, diminishing its effect. The efficacy of current treatments may be improved by increasing the sensitivity of cancer cells to chemo/radiation therapies. Methods The present study is focused on identifying the differential expression of regulatory microRNAs (miRNAs between cis-platin sensitive (A2780, and cis-platin resistant (A2780/CP70 cell lines. Cell proliferation assays were conducted to test the sensitivity of the two cell lines to cis-platin. Differential expression patterns of miRNA between cis-platin sensitive and cis-platin resistant cell lines were analyzed using novel LNA technology. Results Our results revealed changes in expression of 11 miRNAs out of 1,500 miRNAs analyzed. Out of the 11 miRNAs identified, 5 were up-regulated in the A2780/CP70 cell line and 6 were down regulated as compared to cis-platin sensitive A2780 cells. Our microRNA data was further validated by quantitative real-time PCR for these selected miRNAs. Ingenuity Pathway Analysis (IPA and Kyoto Encyclopedia of Genes and Genomes (KEGG analysis was performed for the selected miRNAs and their putative targets to identify the potential pathways and networks involved in cis-platin resistance. Conclusions Our data clearly showed the differential expression of 11 miRNAs in cis-platin resistant cells, which could potentially target many important pathways including MAPK, TGF-β signaling, actin cytoskeleton, ubiquitin mediated

Solution structure of the parvulin-type PPIase domain of Staphylococcus aureus PrsA – Implications for the catalytic mechanism of parvulins

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Koskela Harri

2009-03-01

Full Text Available Abstract Background Staphylococcus aureus is a Gram-positive pathogenic bacterium causing many kinds of infections from mild respiratory tract infections to life-threatening states as sepsis. Recent emergence of S. aureus strains resistant to numerous antibiotics has created a need for new antimicrobial agents and novel drug targets. S. aureus PrsA is a membrane associated extra-cytoplasmic lipoprotein which contains a parvulin-type peptidyl-prolyl cis-trans isomerase domain. PrsA is known to act as an essential folding factor for secreted proteins in Gram-positive bacteria and thus it is a potential target for antimicrobial drugs against S. aureus. Results We have solved a high-resolution solution structure of the parvulin-type peptidyl-prolyl cis-trans isomerase domain of S. aureus PrsA (PrsA-PPIase. The results of substrate peptide titrations pinpoint the active site and demonstrate the substrate preference of the enzyme. With detailed NMR spectroscopic investigation of the orientation and tautomeric state of the active site histidines we are able to give further insight into the structure of the catalytic site. NMR relaxation analysis gives information on the dynamic behaviour of PrsA-PPIase. Conclusion Detailed structural description of the S. aureus PrsA-PPIase lays the foundation for structure-based design of enzyme inhibitors. The structure resembles hPin1-type parvulins both structurally and regarding substrate preference. Even though a wealth of structural data is available on parvulins, the catalytic mechanism has yet to be resolved. The structure of S. aureus PrsA-PPIase and our findings on the role of the conserved active site histidines help in designing further experiments to solve the detailed catalytic mechanism.

Investigation of heart proteome of different consomic mouse strains. Testing the effect of polymorphisms on the proteome-wide trans-variation of proteins

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Stefanie Forler

2015-06-01

Full Text Available We investigated to which extent polymorphisms of an individual affect the proteomic network. Consomic mouse strains (CS were used to study the trans-effect of the cis-variant (polymorphic proteins of the strain PWD/Ph on the proteins of the host strain C57BL/6J. The cardiac proteome of ten CSs was analyzed by 2-DE and MS. Cis-variant PWD proteins altered a high number of C57BL/6J proteins, but the number of trans-variant proteins differed considerably between different CSs. Cardiac hypertrophy was induced in CSs. We found that high variability of the proteome, as induced by polymorphisms in CS14, acts protective against the complex disease.

Strigolactones, a novel carotenoid-derived plant hormone

KAUST Repository

Al-Babili, Salim

2015-04-29

Strigolactones (SLs) are carotenoid-derived plant hormones and signaling molecules. When released into the soil, SLs indicate the presence of a host to symbiotic fungi and root parasitic plants. In planta, they regulate several developmental processes that adapt plant architecture to nutrient availability. Highly branched/tillered mutants in Arabidopsis, pea, and rice have enabled the identification of four SL biosynthetic enzymes: a cis/trans-carotene isomerase, two carotenoid cleavage dioxygenases, and a cytochrome P450 (MAX1). In vitro and in vivo enzyme assays and analysis of mutants have shown that the pathway involves a combination of new reactions leading to carlactone, which is converted by a rice MAX1 homolog into an SL parent molecule with a tricyclic lactone moiety. In this review, we focus on SL biosynthesis, describe the hormonal and environmental factors that determine this process, and discuss SL transport and downstream signaling as well as the role of SLs in regulating plant development. ©2015 by Annual Reviews. All rights reserved.

Xylose isomerase improves growth and ethanol production rates from biomass sugars for both Saccharomyces pastorianus and Saccharomyces cerevisiae.

Science.gov (United States)

Miller, Kristen P; Gowtham, Yogender Kumar; Henson, J Michael; Harcum, Sarah W

2012-01-01

The demand for biofuel ethanol made from clean, renewable nonfood sources is growing. Cellulosic biomass, such as switch grass (Panicum virgatum L.), is an alternative feedstock for ethanol production; however, cellulosic feedstock hydrolysates contain high levels of xylose, which needs to be converted to ethanol to meet economic feasibility. In this study, the effects of xylose isomerase on cell growth and ethanol production from biomass sugars representative of switch grass were investigated using low cell density cultures. The lager yeast species Saccharomyces pastorianus was grown with immobilized xylose isomerase in the fermentation step to determine the impact of the glucose and xylose concentrations on the ethanol production rates. Ethanol production rates were improved due to xylose isomerase; however, the positive effect was not due solely to the conversion of xylose to xylulose. Xylose isomerase also has glucose isomerase activity, so to better understand the impact of the xylose isomerase on S. pastorianus, growth and ethanol production were examined in cultures provided fructose as the sole carbon. It was observed that growth and ethanol production rates were higher for the fructose cultures with xylose isomerase even in the absence of xylose. To determine whether the positive effects of xylose isomerase extended to other yeast species, a side-by-side comparison of S. pastorianus and Saccharomyces cerevisiae was conducted. These comparisons demonstrated that the xylose isomerase increased ethanol productivity for both the yeast species by increasing the glucose consumption rate. These results suggest that xylose isomerase can contribute to improved ethanol productivity, even without significant xylose conversion. Copyright © 2012 American Institute of Chemical Engineers (AIChE).

cis and trans requirements for the selective packaging of adenovirus type 5 DNA.

OpenAIRE

Gräble, M; Hearing, P

1992-01-01

Polar packaging of adenovirus DNA into virions is dependent on the presence of cis-acting sequences at the left end of the viral genome. Our previous analyses demonstrated that the adenovirus type 5 (Ad5) packaging domain (nucleotides 194 to 358) is composed of at least five elements that are functionally redundant. A repeated sequence, termed the A repeat, was associated with packaging function. Here we report a more detailed analysis of the requirements for the selective packaging of Ad5 DN...

21 CFR 862.1570 - Phosphohexose isomerase test system.

Science.gov (United States)

2010-04-01

.... Measurements of phosphohexose isomerase are used in the diagnosis and treatment of muscle diseases such as muscular dystrophy, liver diseases such as hepatitis or cirrhosis, and metastatic carcinoma. (b...

A single cis element maintains repression of the key developmental regulator Gata2.

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Jonathan W Snow

2010-09-01

Full Text Available In development, lineage-restricted transcription factors simultaneously promote differentiation while repressing alternative fates. Molecular dissection of this process has been challenging as transcription factor loci are regulated by many trans-acting factors functioning through dispersed cis elements. It is not understood whether these elements function collectively to confer transcriptional regulation, or individually to control specific aspects of activation or repression, such as initiation versus maintenance. Here, we have analyzed cis element regulation of the critical hematopoietic factor Gata2, which is expressed in early precursors and repressed as GATA-1 levels rise during terminal differentiation. We engineered mice lacking a single cis element -1.8 kb upstream of the Gata2 transcriptional start site. Although Gata2 is normally repressed in late-stage erythroblasts, the -1.8 kb mutation unexpectedly resulted in reactivated Gata2 transcription, blocked differentiation, and an aberrant lineage-specific gene expression pattern. Our findings demonstrate that the -1.8 kb site selectively maintains repression, confers a specific histone modification pattern and expels RNA Polymerase II from the locus. These studies reveal how an individual cis element establishes a normal developmental program via regulating specific steps in the mechanism by which a critical transcription factor is repressed.

The secreted l-arabinose isomerase displays anti-hyperglycemic effects in mice

OpenAIRE

Rhimi, Moez; Bermudez-Humaran, Luis G.; Huang, Yuan; Boudebbouze, Samira; Gaci, Nadia; Garnier, Alexandrine; Gratadoux, Jean-Jacques; Mkaouar, H?la; Langella, Philippe; Maguin, Emmanuelle

2015-01-01

Background The l-arabinose isomerase is an intracellular enzyme which converts l-arabinose into l-ribulose in living systems and d-galactose into d-tagatose in industrial processes and at industrial scales. d-tagatose is a natural ketohexose with potential uses in pharmaceutical and food industries. The d-galactose isomerization reaction is thermodynamically equilibrated, and leads to secondary subproducts at high pH. Therefore, an attractive l-arabinose isomerase should be thermoactive and a...

Formulation, Characterization, and Antitumor Properties of Trans- and Cis-Citral in the 4T1 Breast Cancer Xenograft Mouse Model.

Science.gov (United States)

Zeng, San; Kapur, Arvinder; Patankar, Manish S; Xiong, May P

2015-08-01

Citral is composed of a random mixture of two geometric stereoisomers geranial (trans-citral) and neral (cis-citral) yet few studies have directly compared their in vivo antitumor properties. A micelle formulation was therefore developed. Geranial and neral were synthesized. Commercially-purchased citral, geranial, and neral were formulated in PEG-b-PCL (block sizes of 5000:10,000, Mw/Mn 1.26) micelles. In vitro degradation, drug release, cytotoxicity, flow cytometry, and western blot studies were conducted. The antitumor properties of drug formulations (40 and 80 mg/kg based on MTD studies) were evaluated on the 4T1 xenograft mouse model and tumor tissues were analyzed by western blot. Micelles encapsulated drugs with >50% LE at 5-40% drug to polymer (w/w), displayed sustained release (t1/2 of 8-9 h), and improved drug stability at pH 5.0. The IC50 of drug formulations against 4T1 cells ranged from 1.4 to 9.9 μM. Western blot revealed that autophagy was the main cause of cytotoxicity. Geranial at 80 mg/kg was most effective at inhibiting tumor growth. Geranial is significantly more potent than neral and citral at 80 mg/kg (p < 0.001) and western blot of tumor tissues confirms that autophagy and not apoptosis is the major mechanism of tumor growth inhibition in p53-null 4T1 cells.

Proteomic analysis of Oesophagostomum dentatum (Nematoda during larval transition, and the effects of hydrolase inhibitors on development.

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Martina Ondrovics

Full Text Available In this study, in vitro drug testing was combined with proteomic and bioinformatic analyses to identify and characterize proteins involved in larval development of Oesophagostomum dentatum, an economically important parasitic nematode. Four hydrolase inhibitors ο-phenanthroline, sodium fluoride, iodoacetamide and 1,2-epoxy-3-(pnitrophenoxy-propane (EPNP significantly inhibited (≥90% larval development. Comparison of the proteomic profiles of the development-inhibited larvae with those of uninhibited control larvae using two-dimensional gel electrophoresis, and subsequent MALDI-TOF mass spectrometric analysis identified a down-regulation of 12 proteins inferred to be involved in various larval developmental processes, including post-embryonic development and growth. Furthermore, three proteins (i.e. intermediate filament protein B, tropomyosin and peptidyl-prolyl cis-trans isomerase inferred to be involved in the moulting process were down-regulated in moulting- and development-inhibited O. dentatum larvae. This first proteomic map of O. dentatum larvae provides insights in the protein profile of larval development in this parasitic nematode, and significantly improves our understanding of the fundamental biology of its development. The results and the approach used might assist in developing new interventions against parasitic nematodes by blocking or disrupting their key biological pathways.

Mechanism of ultraviolet light induced catabolite repression of L-arabinose isomerase

Energy Technology Data Exchange (ETDEWEB)

Bhatnagar, D; Bhattacharya, A K [Banaras Hindu Univ. (India). Inst. of Medical Sciences

1982-12-01

An attempt has been made to find out how U.V. irradiation of E.coli B/r cells causes catabolite repression to inhibit L-arabinose isomerase synthesis. The results presented show that U.V. irradiation leads to a lowering of the cellular cyclic AMP level and of the cyclic AMP binding activity. Unlike catabolite repression by glucose, no small molecular weight compound is involved in U.V. light induced inhibition of the binding activity. It is therefore concluded that the mechanism of catabolite repression induced by U.V. appears to be different from that of the catabolite repression by glucose.

Sphingomyelin synthesis in rat liver occurs predominantly at the cis and medial cisternae of the Golgi apparatus

International Nuclear Information System (INIS)

Futerman, A.H.; Stieger, B.; Hubbard, A.L.; Pagano, R.E.

1990-01-01

The intracellular site of sphingomyelin (SM) synthesis was examined in subcellular fractions from rat liver using a radioactive ceramide analog N-([1-14C]hexanoyl)-D-erythro-sphingosine. This lipid readily transferred from a complex with bovine serum albumin to liver fractions without disrupting the membranes, and was metabolized to radioactive SM. To prevent degradation of the newly synthesized SM to ceramide, all experiments were performed in the presence of EDTA to minimize neutral sphingomyelinase activity and at neutral pH to minimize acid sphingomyelinase activity. An intact Golgi apparatus fraction gave an 85-98-fold enrichment of SM synthesis and a 58-83-fold enrichment of galactosyltransferase activity. Controlled trypsin digestion demonstrated that SM synthesis was localized to the lumen of intact Golgi apparatus vesicles. Although small amounts of SM synthesis were detected in plasma membrane and rough microsome fractions, after accounting for contamination by Golgi apparatus membranes, their combined activity contributed less than 13% of the total SM synthesis in rat liver. Subfractions of the Golgi apparatus were obtained and characterized by immunoblotting and biochemical assays using cis/medial (mannosidase II) and trans (sialyltransferase and galactosyltransferase) Golgi apparatus markers. The specific activity of SM synthesis was highest in enriched cis and medial fractions but far lower in a trans fraction. We conclude that SM synthesis in rat liver occurs predominantly in the cis and medial cisternae of the Golgi apparatus and not at the plasma membrane or endoplasmic reticulum as has been previously suggested

Phospho-carboxyl-terminal domain binding and the role of a prolyl isomerase in pre-mRNA 3'-End formation.

Science.gov (United States)

Morris, D P; Phatnani, H P; Greenleaf, A L

1999-10-29

A phospho-carboxyl-terminal domain (CTD) affinity column created with yeast CTD kinase I and the CTD of RNA polymerase II was used to identify Ess1/Pin1 as a phospho-CTD-binding protein. Ess1/Pin1 is a peptidyl prolyl isomerase involved in both mitotic regulation and pre-mRNA 3'-end formation. Like native Ess1, a GSTEss1 fusion protein associates specifically with the phosphorylated but not with the unphosphorylated CTD. Further, hyperphosphorylated RNA polymerase II appears to be the dominant Ess1 binding protein in total yeast extracts. We demonstrate that phospho-CTD binding is mediated by the small WW domain of Ess1 rather than the isomerase domain. These findings suggest a mechanism in which the WW domain binds the phosphorylated CTD of elongating RNA polymerase II and the isomerase domain reconfigures the CTD though isomerization of proline residues perhaps by a processive mechanism. This process may be linked to a variety of pre-mRNA maturation events that use the phosphorylated CTD, including the coupled processes of pre-mRNA 3'-end formation and transcription termination.

Trans labilization of am(m)ine ligands from platinum(II) complexes by cancer cell extracts.

Science.gov (United States)

Kasherman, Yonit; Sturup, Stefan; Gibson, Dan

2009-03-01

Cisplatin, cis-[Pt(NH(3))(2)Cl(2)], is an effective anticancer agent in wide clinical use whose efficacy is affected by cellular interactions with sulfur-containing nucleophiles. These interactions can potentially enhance the efficacy of the drug by mediating its delivery to nuclear DNA or inactivate the drug by binding to it irreversibly or by labilizing the NH(3) ligands. Despite the potential importance of trans-labilization reactions in the mechanism of action of the drug, few detailed studies on trans labilization of the ammines have been conducted. We used 2D NMR to show that some trans labilization occurs in proliferating cells and that aqueous extracts of cancer cells labilized 20% of the amine ligands of cis-[PtCl(2)((13)CH(3)NH(2))(2)] after a 12-h incubation. Both low molecular mass nucleophiles (less than 3 kDa) and high molecular mass nucleophiles (more than 3 kDa) labilize the amines with similar efficiency. Studies with model compounds show that thiols and thioethers bind to platinum(II) at similar rates, but thioethers are significantly more efficient at labilizing the am(m)ine at lower pH. N-Acetylcysteine is a more efficient trans-labilizer than glutathione, suggesting that the displacement of the amine proceeds through an associative mechanism. The lag time, the time that elapses from the formation of the Pt-S bond till the release of the amine trans to the sulfur, depends on the pH (for thiols), increasing at lower pH. Quantification of the platinum adducts obtained from incubation of cisplatin with cell extracts indicates that two thirds of the platinum is bound to cellular components with molecular mass greater than 3 kDa.

Landscape of the spliced leader trans-splicing mechanism in Schistosoma mansoni.

Science.gov (United States)

Boroni, Mariana; Sammeth, Michael; Gava, Sandra Grossi; Jorge, Natasha Andressa Nogueira; Macedo, Andréa Mara; Machado, Carlos Renato; Mourão, Marina Moraes; Franco, Glória Regina

2018-03-01

Spliced leader dependent trans-splicing (SLTS) has been described as an important RNA regulatory process that occurs in different organisms, including the trematode Schistosoma mansoni. We identified more than seven thousand putative SLTS sites in the parasite, comprising genes with a wide spectrum of functional classes, which underlines the SLTS as a ubiquitous mechanism in the parasite. Also, SLTS gene expression levels span several orders of magnitude, showing that SLTS frequency is not determined by the expression level of the target gene, but by the presence of particular gene features facilitating or hindering the trans-splicing mechanism. Our in-depth investigation of SLTS events demonstrates widespread alternative trans-splicing (ATS) acceptor sites occurring in different regions along the entire gene body, highlighting another important role of SLTS generating alternative RNA isoforms in the parasite, besides the polycistron resolution. Particularly for introns where SLTS directly competes for the same acceptor substrate with cis-splicing, we identified for the first time additional and important features that might determine the type of splicing. Our study substantially extends the current knowledge of RNA processing by SLTS in S. mansoni, and provide basis for future studies on the trans-splicing mechanism in other eukaryotes.

Purification, crystallization and preliminary crytallographic analysis of phosphoglucose isomerase from the hyperthermophilic archaeon Pyrococcus furiosus

NARCIS (Netherlands)

Akerboom, A.P.; Turnbull, A.P.; Hargreaves, D.; Fischer, M.; Geus, de D.; Sedelnikova, S.E.; Berrisford, J.M.; Baker, P.J.; Verhees, C.H.; Oost, van der J.; Rice, D.W.

2003-01-01

The glycolytic enzyme phosphoglucose isomerase catalyses the reversible isomerization of glucose 6-phosphate to fructose 6-phosphate. The phosphoglucose isomerase from the hyperthermophilic archaeon Pyrococcus furiosus, which shows no sequence similarity to any known bacterial or eukaryotic

Structure of ribose 5-phosphate isomerase from the probiotic bacterium Lactobacillus salivarius UCC118

International Nuclear Information System (INIS)

Lobley, Carina M. C.; Aller, Pierre; Douangamath, Alice; Reddivari, Yamini; Bumann, Mario; Bird, Louise E.; Nettleship, Joanne E.; Brandao-Neto, Jose; Owens, Raymond J.; O’Toole, Paul W.; Walsh, Martin A.

2012-01-01

The crystal structure of ribose 5-phosphate isomerase has been determined to 1.72 Å resolution and is presented with a brief comparison to other known ribose 5-phosphate isomerase A structures. The structure of ribose 5-phosphate isomerase from the probiotic bacterium Lactobacillus salivarius UCC188 has been determined at 1.72 Å resolution. The structure was solved by molecular replacement, which identified the functional homodimer in the asymmetric unit. Despite only showing 57% sequence identity to its closest homologue, the structure adopted the typical α and β d-ribose 5-phosphate isomerase fold. Comparison to other related structures revealed high homology in the active site, allowing a model of the substrate-bound protein to be proposed. The determination of the structure was expedited by the use of in situ crystallization-plate screening on beamline I04-1 at Diamond Light Source to identify well diffracting protein crystals prior to routine cryocrystallography

Thermal decomposition and isomerization of cis-permethrin and beta-cypermethrin in the solid phase.

Science.gov (United States)

González Audino, Paola; Licastro, Susana A; Zerba, Eduardo

2002-02-01

The stability to heart of cis-permethrin and beta-cypermethrin in the solid phase was studied and the decomposition products identified. Samples heated at 210 degrees C in an oven in the dark showed that, in the absence of potassium chlorate (the salt present in smoke-generating formulations of these pyrethroids), cis-permethrin was not isomerized, although in the presence of that salt, decomposition was greater and thermal isomerization occurred. Other salts of the type KXO3 or NaXO3, with X being halogen or nitrogen, also led to a considerable thermal isomerization. Heating the insecticides in solution in the presence of potassium chlorate did not produce isomerization in any of the solvents assayed. Salt-catalysed thermal cis-trans isomerization was also found for other pyrethroids derived from permethrinic or deltamethrinic acid but not for those derived from chrysanthemic acid. The main thermal degradation processes of cis-permethrin and beta-cypermethrin decomposition when potassium chlorate was present were cyclopropane isomerization, ester cleavage and subsequent oxidation of the resulting products. Permethrinic acid, 3-phenoxybenzyle chloride, alcohol, aldehyde and acid were identified in both cases, as well as 3-phenoxybenzyl cyanide from beta-cypermethrin. A similar decomposition pattern occurred after combustion of pyrethroid fumigant formulations.

Mixed-mode solid-phase extraction followed by acetylation and gas chromatography mass spectrometry for the reliable determination of trans-resveratrol in wine samples

Energy Technology Data Exchange (ETDEWEB)

Montes, R.; Garcia-Lopez, M. [Departamento de Quimica Analitica, Nutricion y Bromatologia, Instituto de Investigacion y Analisis Alimentario, Universidad de Santiago de Compostela, Santiago de Compostela 15782 (Spain); Rodriguez, I., E-mail: isaac.rodriguez@usc.es [Departamento de Quimica Analitica, Nutricion y Bromatologia, Instituto de Investigacion y Analisis Alimentario, Universidad de Santiago de Compostela, Santiago de Compostela 15782 (Spain); Cela, R. [Departamento de Quimica Analitica, Nutricion y Bromatologia, Instituto de Investigacion y Analisis Alimentario, Universidad de Santiago de Compostela, Santiago de Compostela 15782 (Spain)

2010-07-12

This work presents an advantageous analytical procedure for the accurate determination of free trans-resveratrol in red and white wines. The proposed method involves solid-phase extraction (SPE), acetylation of the analyte in aqueous media and further determination by gas chromatography (GC) with mass spectrometry detection (MS). The use of a mixed-mode SPE sorbent provides an improvement in the selectivity of the extraction step; moreover, the presence of several intense ions in the electron impact mass spectra of its acetyl derivative guarantees the unambiguous identification of trans-resveratrol. Considering a sample intake of 10 mL, the method provides a limit of quantification (LOQ) of 0.8 ng mL{sup -1} and linear responses for concentrations up to 2.5 {mu}g mL{sup -1}, referred to wine samples. The average recovery, estimated with samples fortified at different concentrations in the above range, was 99.6% and the inter-day precision stayed below 8%. Trans-resveratrol levels in the analyzed wines varied from 3.4 to 1810 ng mL{sup -1}. Cis-resveratrol was also found in all samples. In most cases, equal or higher responses were measured for this latter form than for the trans-isomer. The reduced form of resveratrol, dihydro-resveratrol, was systematically identified in red wines.

Mixed-mode solid-phase extraction followed by acetylation and gas chromatography mass spectrometry for the reliable determination of trans-resveratrol in wine samples

International Nuclear Information System (INIS)

Montes, R.; Garcia-Lopez, M.; Rodriguez, I.; Cela, R.

2010-01-01

This work presents an advantageous analytical procedure for the accurate determination of free trans-resveratrol in red and white wines. The proposed method involves solid-phase extraction (SPE), acetylation of the analyte in aqueous media and further determination by gas chromatography (GC) with mass spectrometry detection (MS). The use of a mixed-mode SPE sorbent provides an improvement in the selectivity of the extraction step; moreover, the presence of several intense ions in the electron impact mass spectra of its acetyl derivative guarantees the unambiguous identification of trans-resveratrol. Considering a sample intake of 10 mL, the method provides a limit of quantification (LOQ) of 0.8 ng mL -1 and linear responses for concentrations up to 2.5 μg mL -1 , referred to wine samples. The average recovery, estimated with samples fortified at different concentrations in the above range, was 99.6% and the inter-day precision stayed below 8%. Trans-resveratrol levels in the analyzed wines varied from 3.4 to 1810 ng mL -1 . Cis-resveratrol was also found in all samples. In most cases, equal or higher responses were measured for this latter form than for the trans-isomer. The reduced form of resveratrol, dihydro-resveratrol, was systematically identified in red wines.

Preparation of fluorescence quenched libraries containing interchain disulphide bonds for studies of protein disulphide isomerases

DEFF Research Database (Denmark)

Spetzler, J C; Westphal, V; Winther, Jakob R.

1998-01-01

Protein disulphide isomerase is an enzyme that catalyses disulphide redox reactions in proteins. In this paper, fluorogenic and interchain disulphide bond containing peptide libraries and suitable substrates, useful in the study of protein disulphide isomerase, are described. In order to establish...... the quenching chromophore (Tyr(NO2)) and Cys(pNpys) activated for reaction with a second thiol. The formation and cleavage of the interchain disulphide bonds in the library were monitored under a fluorescence microscope. Substrates to investigate the properties of protein disulphide isomerase in solution were...

Evaluating cis-2,6-Dimethylpiperidide (cis-DMP) as a Base Component in Lithium-Mediated Zincation Chemistry

Science.gov (United States)

Armstrong, David R; Garden, Jennifer A; Kennedy, Alan R; Leenhouts, Sarah M; Mulvey, Robert E; O'Keefe, Philip; O'Hara, Charles T; Steven, Alan

2013-01-01

-DMP)tBu2] and the post-metallation complex [(TMEDA)Li(cis-DMP){2-[1-C(=O)N(iPr)2]C6H4}Zn(tBu)], shed valuable light on the structures and mechanisms involved in these alkali-metal-mediated zincation reactions. Aspects of these reactions are also modelled by DFT calculations. PMID:23955639

Functional differences in yeast protein disulfide isomerases

DEFF Research Database (Denmark)

Nørgaard, P; Westphal, V; Tachibana, C

2001-01-01

PDI1 is the essential gene encoding protein disulfide isomerase in yeast. The Saccharomyces cerevisiae genome, however, contains four other nonessential genes with homology to PDI1: MPD1, MPD2, EUG1, and EPS1. We have investigated the effects of simultaneous deletions of these genes. In several...

An optimized method for fatty acid analysis, including quantification of trans fatty acids, in human adipose tissue by gas-liquid chromatography

DEFF Research Database (Denmark)

Bysted, Anette; Cold, S; Hølmer, Gunhild Kofoed

1999-01-01

Considering the need for a quick direct method for measurement of the fatty acid composition including trans isomers ofhuman adipose tissue we have developed a procedure using gas-liquid chromatography (GLC) alone, which is thussuitable for validation of fatty acid status in epidemiological studies...... for 25 min, and finally raised at 25 degrees C/min to 225 degrees C. The trans and cis isomers of18:1 were well separated from each other, as shown by silver-ion thin-layer chromatography. Verification by standardsshowed that the trans 18:1 isomers with a double bond in position 12 or lower were...

Cis-drivers and trans-drivers of bovine leukemia virus oncogenesis.

Science.gov (United States)

Safari, Roghaiyeh; Hamaidia, Malik; de Brogniez, Alix; Gillet, Nicolas; Willems, Luc

2017-10-01

The bovine leukemia virus (BLV) is a retrovirus inducing an asymptomatic and persistent infection in ruminants and leading in a minority of cases to the accumulation of B-lymphocytes (lymphocytosis, leukemia or lymphoma). Although the mechanisms of oncogenesis are still largely unknown, there is clear experimental evidence showing that BLV infection drastically modifies the pattern of gene expression of the host cell. This alteration of the transcriptome in infected B-lymphocytes results first, from a direct activity of viral proteins (i.e. transactivation of gene promoters, protein-protein interactions), second, from insertional mutagenesis by proviral integration (cis-activation) and third, from gene silencing by microRNAs. Expression of viral proteins stimulates a vigorous immune response that indirectly modifies gene transcription in other cell types (e.g. cytotoxic T-cells, auxiliary T-cells, macrophages). In principle, insertional mutagenesis and microRNA-associated RNA interference can modify the cell fate without inducing an antiviral immunity. Despite a tight control by the immune response, the permanent attempts of the virus to replicate ultimately induce mutations in the infected cell. Accumulation of these genomic lesions and Darwinian selection of tumor clones are predicted to lead to cancer. Copyright © 2017 Elsevier B.V. All rights reserved.

Comparing the xylose reductase/xylitol dehydrogenase and xylose isomerase pathways in arabinose and xylose fermenting Saccharomyces cerevisiae strains

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Hahn-Hägerdal Bärbel

2008-10-01

Full Text Available Abstract Background Ethanolic fermentation of lignocellulosic biomass is a sustainable option for the production of bioethanol. This process would greatly benefit from recombinant Saccharomyces cerevisiae strains also able to ferment, besides the hexose sugar fraction, the pentose sugars, arabinose and xylose. Different pathways can be introduced in S. cerevisiae to provide arabinose and xylose utilisation. In this study, the bacterial arabinose isomerase pathway was combined with two different xylose utilisation pathways: the xylose reductase/xylitol dehydrogenase and xylose isomerase pathways, respectively, in genetically identical strains. The strains were compared with respect to aerobic growth in arabinose and xylose batch culture and in anaerobic batch fermentation of a mixture of glucose, arabinose and xylose. Results The specific aerobic arabinose growth rate was identical, 0.03 h-1, for the xylose reductase/xylitol dehydrogenase and xylose isomerase strain. The xylose reductase/xylitol dehydrogenase strain displayed higher aerobic growth rate on xylose, 0.14 h-1, and higher specific xylose consumption rate in anaerobic batch fermentation, 0.09 g (g cells-1 h-1 than the xylose isomerase strain, which only reached 0.03 h-1 and 0.02 g (g cells-1h-1, respectively. Whereas the xylose reductase/xylitol dehydrogenase strain produced higher ethanol yield on total sugars, 0.23 g g-1 compared with 0.18 g g-1 for the xylose isomerase strain, the xylose isomerase strain achieved higher ethanol yield on consumed sugars, 0.41 g g-1 compared with 0.32 g g-1 for the xylose reductase/xylitol dehydrogenase strain. Anaerobic fermentation of a mixture of glucose, arabinose and xylose resulted in higher final ethanol concentration, 14.7 g l-1 for the xylose reductase/xylitol dehydrogenase strain compared with 11.8 g l-1 for the xylose isomerase strain, and in higher specific ethanol productivity, 0.024 g (g cells-1 h-1 compared with 0.01 g (g cells-1 h-1

Targeting Pin1 by inhibitor API-1 regulates microRNA biogenesis and suppresses hepatocellular carcinoma development.

Science.gov (United States)

Pu, Wenchen; Li, Jiao; Zheng, Yuanyuan; Shen, Xianyan; Fan, Xin; Zhou, Jian-Kang; He, Juan; Deng, Yulan; Liu, Xuesha; Wang, Chun; Yang, Shengyong; Chen, Qiang; Liu, Lunxu; Zhang, Guolin; Wei, Yu-Quan; Peng, Yong

2018-01-30

Hepatocellular carcinoma (HCC) is a leading cause of cancer death worldwide, but there are few effective treatments. Aberrant microRNA (miRNA) biogenesis is correlated with HCC development. We previously demonstrated that peptidyl-prolyl cis-trans isomerase NIMA-interacting 1 (Pin1) participates in miRNA biogenesis and is a potential HCC treatment target. However, how Pin1 modulates miRNA biogenesis remains obscure. Here, we present in vivo evidence that Pin1 overexpression is directly linked to the development of HCC. Administration with the Pin1 inhibitor (API-1), a specific small molecule targeting Pin1 peptidyl-prolyl isomerase domain and inhibiting Pin1 cis-trans isomerizing activity, suppresses in vitro cell proliferation and migration of HCC cells. But API-1-induced Pin1 inhibition is insensitive to HCC cells with low Pin1 expression and/or low exportin-5 (XPO5) phosphorylation. Mechanistically, Pin1 recognizes and isomerizes the phosphorylated serine-proline motif of phosphorylated XPO5 and passivates phosphorylated XPO5. Pin1 inhibition by API-1 maintains the active conformation of phosphorylated XPO5 and restores XPO5-driven precursor miRNA nuclear-to-cytoplasm export, activating anticancer miRNA biogenesis and leading to both in vitro HCC suppression and HCC suppression in xenograft mice. Experimental evidence suggests that Pin1 inhibition by API-1 up-regulates miRNA biogenesis by retaining active XPO5 conformation and suppresses HCC development, revealing the mechanism of Pin1-mediated miRNA biogenesis and unequivocally supporting API-1 as a drug candidate for HCC therapy, especially for Pin1-overexpressing, extracellular signal-regulated kinase-activated HCC. (Hepatology 2018). © 2018 by the American Association for the Study of Liver Diseases.

Thiolato-technetium complexes. 5. Synthesis, characterization, and electrochemical properties of bis(o-phenylenebis(dimethylarsine))technetium(II) and -technetium(III) complexes with thiolato ligands. Single-crystal structural analyses of trans-[Tc(SCH3)2(DIARS)2]PF6 and trans-[Tc(SC6H5)2(DIARS)2]0

International Nuclear Information System (INIS)

Konno, Takumi; Heineman, W.R.; Deutsch, E.; Kirchhoff, J.R.; Heeg, M.J.; Stuckey, J.A.

1992-01-01

Three different thiols have been brought into reaction with trans-[Tc(OH)(O)(DIARS) 2 ] 2+ to produce initially the Tc(II) complex, [Tc(SR) 2 (DIARS) 2 ] 0 , which can be oxidized to the Tc(III) complex, [Tc(SR) 2 (DIARS) 2 ] + (DIARS = o-phenylenebis(dimethylarsine)). In the case of SR = SCH 3 and SCH 2 C 6 H 5 , the Tc(II) and Tc(III) products were found to be in the trans geometry, while for SR = SC 6 H 5 , both cis and trans isomers were generated. Two of the complexes were structurally characterized by X-ray diffraction. trans-[Tc(SCH 3 ) 2 (DIARS) 2 ]PF 6 , chemical formula TcAs 4 S 2 PF 6 C 22 H 38 , crystallizes in the monoclinic space group. The Tc atom occupies an inversion center. Representative elemental analyses, FAB mass spectra, and visible-UV spectra are reported. Electrochemical and spectroelectrochemical measurements were taken on trans-[Tc(SCH 3 ) 2 (DIARS) 2 ] + , trans-[Tc(SCH 2 C 6 H 5 ) 2 (DIARS) 2 ] + , and cis-[Tc(SC 6 H 5 ) 2 (DIARS) 2 ] + , which exhibit a reversible Tc(III/II) redox couple in the range -0.32 to -0.47 V vs. Ag/AgCl. Another redox couple is present in the range -1.22 to -1.70 V; this is ascribed to Tc(II/I) and is reversible only for SR = SCH 2 C 6 H 5 at 20C. At room temperature, chemically irreversible couples are exhibited at ca. +1.0 V for Tc(IV/III)

An ethylene-responsive enhancer element is involved in the senescence-related expression of the carnation glutathione-S-transferase (GST1) gene.

OpenAIRE

Itzhaki, H; Maxson, J M; Woodson, W R

1994-01-01

The increased production of ethylene during carnation petal senescence regulates the transcription of the GST1 gene encoding a subunit of glutathione-S-transferase. We have investigated the molecular basis for this ethylene-responsive transcription by examining the cis elements and trans-acting factors involved in the expression of the GST1 gene. Transient expression assays following delivery of GST1 5' flanking DNA fused to a beta-glucuronidase receptor gene were used to functionally define ...

Effet d’un régime riche en acides gras ω3 et en CLA 9-cis, 11-trans sur l’insulinorésistance et les paramètres du diabète de type 2

Directory of Open Access Journals (Sweden)

Schmitt Bernard

2006-01-01

Full Text Available The prevalence of type 2 diabetes, a pathology mainly induced by nutrition is increasing. In vivo studies on rat have demonstrated the interest of n-3 long chains polyunsaturated fatty acids (n-3 LC PUFA and conjugated linoleic acids (CLA in the diet to improve insulin sensibility. This study investigates the effect of a diet with products (linseed enriched livestock diet products and linseed bread naturally enriched in n-3 PUFA and CLA 9-cis, 11-trans on glycemic parameters of type 2 diabetics. 44 type 2 diabetics were randomised in three parallel groups and followed a particular diet during 100 days. The three diets: diet A (n = 13, enriched in n-3 PUFA via bread, eggs and pastas, diet B (n = 13, enriched in n-3 PUFA and richer in conjugated linoleic acids (CLA via bread, eggs, pastas, beef meat and dairy products and diet T (n = 18, standard, were otherwise similar in energy (1970 kcal per day and type of food. The serum value of the ALA is significantly higher for group A and B and the CLA serum value is significantly higher for the group B only at the end of the study. At the end of the study, fasting insulinemia is lower in group B compared with group A (p = 0,06 and T (p < 0,05 while glycemia does not differ between groups. Insulin resistance is also lower in group B compared with groups A and T, but the differences do not reach significance (p = 0,08 and p = 0,1 respectively. These results suggest the potential implication of CLA 9-cis, 11-trans in a diet rich in ALA in the improvement of insulin sensitivity.

Characterization of a mutated Geobacillus stearothermophilus L-arabinose isomerase that increases the production rate of D-tagatose.

Science.gov (United States)

Kim, H-J; Kim, J-H; Oh, H-J; Oh, D-K

2006-07-01

Characterization of a mutated Geobacillus stearothermophilus L-arabinose isomerase used to increase the production rate of D-tagatose. A mutated gene was obtained by an error-prone polymerase chain reaction using L-arabinose isomerase gene from G. stearothermophilus as a template and the gene was expressed in Escherichia coli. The expressed mutated L-arabinose isomerase exhibited the change of three amino acids (Met322-->Val, Ser393-->Thr, and Val408-->Ala), compared with the wild-type enzyme and was then purified to homogeneity. The mutated enzyme had a maximum galactose isomerization activity at pH 8.0, 65 degrees C, and 1.0 mM Co2+, while the wild-type enzyme had a maximum activity at pH 8.0, 60 degrees C, and 1.0-mM Mn2+. The mutated L-arabinose isomerase exhibited increases in D-galactose isomerization activity, optimum temperature, catalytic efficiency (kcat/Km) for D-galactose, and the production rate of D-tagatose from D-galactose. The mutated L-arabinose isomerase from G. stearothermophilus is valuable for the commercial production of D-tagatose. This work contributes knowledge on the characterization of a mutated L-arabinose isomerase, and allows an increased production rate for D-tagatose from D-galactose using the mutated enzyme.

Molecular Characterization and Analysis of a Novel Protein Disulfide Isomerase-Like Protein of Eimeria tenella

OpenAIRE

Han, Hongyu; Dong, Hui; Zhu, Shunhai; Zhao, Qiping; Jiang, Lianlian; Wang, Yange; Li, Liujia; Wu, Youlin; Huang, Bing

2014-01-01

Protein disulfide isomerase (PDI) and PDI-like proteins are members of the thioredoxin superfamily. They contain thioredoxin-like domains and catalyze the physiological oxidation, reduction and isomerization of protein disulfide bonds, which are involved in cell function and development in prokaryotes and eukaryotes. In this study, EtPDIL, a novel PDI-like gene of Eimeria tenella, was cloned using rapid amplification of cDNA ends (RACE) according to the expressed sequence tag (EST). The EtPDI...

A canonical discriminant analysis to study the association between milk fatty acids of ruminal origin and milk fat depression in dairy cows.

Science.gov (United States)

Conte, G; Dimauro, C; Serra, A; Macciotta, N P P; Mele, M

2018-04-04

Although milk fat depression (MFD) has been observed and described since the beginning of the last century, all the molecular and biochemical mechanisms involved are still not completely understood. Some fatty acids (FA) originating during rumen biohydrogenation have been proposed as causative elements of MFD. However, contradictory results were obtained when studying the effect of single FA on MFD. An alternative could be the simultaneous evaluation of the effect of many FA using a multivariate approach. The aim of this study was to evaluate the relationship between individual milk FA of ruminal origin and MFD using canonical discriminant analysis, a multivariate technique able to distinguish 2 or more groups on the basis of a pool of variables. In a commercial dairy herd, a diet containing 26% starch on a DM basis induced an unintentional MFD syndrome in 14 cows out of 40. Milk yielded by these 14 animals showed a fat content lower than 50% of the ordinary value, whereas milk production and protein content were normal. The remaining 26 cows secreted typical milk fat content and therefore were considered the control group, even though they ate the same diet. The stepwise discriminant analysis selected 14 milk FA of ruminal origin most able to distinguish the 2 groups. This restricted pool of FA was used, as variables, in a run of the canonical discriminant analysis that was able to significantly discriminate between the 2 groups. Out of the 14 FA, 5 conjugated linoleic acid isomers (C18:2 trans-10,trans-12, C18:2 trans-8,trans-10, C18:2 trans-11,cis-13, C18:2 cis-9,cis-11, C18:2 cis-10,cis-12) and C15:0 iso were more related to the control group, whereas C18:2 trans-10,cis-12, C16:1 trans-6-7, C16:1 trans-9, C18:1 trans-6-8, C18:1 trans-9, C18:1 trans-10, C18:1 cis-11, and C18:3n-3 were positively associated with the MFD group, allowing a complete discrimination. On the basis of these results, we can conclude that (1) the shift of ruminal biohydrogenation from C18

trans-[Pt(BCat')Me(PCy3)2]: an experimental case study of reductive elimination processes in Pt-Boryls through associative mechanisms.

Science.gov (United States)

Braunschweig, Holger; Bertermann, Rüdiger; Brenner, Peter; Burzler, Michael; Dewhurst, Rian D; Radacki, Krzysztof; Seeler, Fabian

2011-10-10

A stable trans-(alkyl)(boryl) platinum complex trans-[Pt(BCat')Me(PCy(3))(2)] (Cat'=Cat-4-tBu; Cy=cyclohexyl=C(6)H(11)) was synthesised by salt metathesis reaction of trans-[Pt(BCat')Br(PCy(3))(2)] with LiMe and was fully characterised. Investigation of the reactivity of the title compound showed complete reductive elimination of Cat'BMe at 80 °C within four weeks. This process may be accelerated by the addition of a variety of alkynes, thereby leading to the formation of the corresponding η(2) -alkyne platinum complexes, of which [Pt(η(2)-MeCCMe)(PCy(3))(2)] was characterised by X-ray crystallography. Conversion of the trans-configured title compound to a cis derivative remained unsuccessful due to an instantaneous reductive elimination process during the reaction with chelating phosphines. Treatment of trans-[Pt(BCat')Me(PCy(3))(2)] with Cat(2)B(2) led to the formation of CatBMe and Cat'BMe. In the course of further investigations into this reaction, indications for two indistinguishable reaction mechanisms were found: 1) associative formation of a six-coordinate platinum centre prior to reductive elimination and 2) σ-bond metathesis of B-B and C-Pt bonds. Mechanism 1 provides a straightforward explanation for the formation of both methylboranes. Scrambling of diboranes(4) Cat(2)B(2) and Cat'(2)B(2) in the presence of [Pt(PCy(3))(2)], fully reductive elimination of CatBMe or Cat'BMe from trans-[Pt(BCat')Me(PCy(3))(2)] in the presence of sub-stoichiometric amounts of Cat(2)B(2), and evidence for the reversibility of the oxidative addition of Cat(2)B(2) to [Pt(PCy(3))(2)] all support mechanism 2, which consists of sequential equilibria reactions. Furthermore, the solid-state molecular structure of cis-[Pt(BCat)(2)(PCy(3))(2)] and cis-[Pt(BCat')(2)(PCy(3))(2)] were investigated. The remarkably short B-B separations in both bis(boryl) complexes suggest that the two boryl ligands in each case are more loosely bound to the Pt(II) centre than in related bis

Treating hepatitis C: can you teach old dogs new tricks?

Science.gov (United States)

Rice, Charles M; You, Shihyun

2005-12-01

Viruses depend on host-derived factors for their efficient genome replication. Here, we demonstrate that a cellular peptidyl-prolyl cis-trans isomerase (PPIase), cyclophilin B (CyPB), is critical for the efficient replication of the hepatitis C virus genome. CyPB interacted with the HCV RNA polymerase NS5B to directly stimulate its RNA binding activity. Both the RNA interference (RNAi)-mediated reduction of endogenous CyPB expression and the induced loss of NS5B binding to CyPB decreased the levels of HCV replication. Thus, CyPB functions as a stimulatory regulator of NS5B in HCV replication machinery. This regulation mechanism for viral replication identifies CyPB as a target for antiviral therapeutic strategies.

Hybrid macrocycle formation and spiro annulation on cis-syn-cis-tricyclo[6.3.0.02,6]undeca-3,11-dione and its congeners via ring-closing metathesis

Directory of Open Access Journals (Sweden)

Sambasivarao Kotha

2015-07-01

Full Text Available We have developed a simple methodology to transform cis-syn-cis-triquinane derivative 2 into the diindole based macrocycle 6 involving Fischer indolization and ring-closing metathesis (RCM. Various spiro-polyquinane derivatives have been assembled via RCM as a key step.

Mapping the ER Interactome: The P Domains of Calnexin and Calreticulin as Plurivalent Adapters for Foldases and Chaperones.

Science.gov (United States)

Kozlov, Guennadi; Muñoz-Escobar, Juliana; Castro, Karla; Gehring, Kalle

2017-09-05

The lectin chaperones calreticulin (CRT) and calnexin (CNX) contribute to the folding of glycoproteins in the ER by recruiting foldases such as the protein disulfide isomerase ERp57 and the peptidyl prolyl cis-trans isomerase CypB. Recently, CRT was shown to interact with the chaperone ERp29. Here, we show that ERp29 directly binds to the P domain of CNX. Crystal structures of the D domain of ERp29 in complex with the P domains from CRT and calmegin, a tissue-specific CNX homolog, reveal a commonality in the mechanism of binding whereby the tip of the P domain functions as a plurivalent adapter to bind a variety of folding factors. We show that mutation of a single residue, D348 in CNX, abrogates binding to ERp29 as well as ERp57 and CypB. The structural diversity of the accessory factors suggests that these chaperones became specialized for glycoprotein folding through convergent evolution of their P-domain binding sites. Copyright © 2017 Elsevier Ltd. All rights reserved.

Studies on the aroma of five fresh tomato cultivars and the precursors of cis- and trans-4,5-epoxy-(E)-2-decenals and methional.

Science.gov (United States)

Mayer, Florian; Takeoka, Gary R; Buttery, Ron G; Whitehand, Linda C; Naim, Michael; Rabinowitch, Haim D

2008-05-28

Three tasty (BR-139, FA-624, and FA-612) and two less tasty (R-144 and R-175) fresh greenhouse tomato cultivars, which significantly differ in their flavor profiles, were screened for potent odorants using aroma extract dilution analysis (AEDA). On the basis of AEDA results, 19 volatiles were selected for quantification in those 5 cultivars using gas chromatography-mass spectrometry (GC-MS). Compounds such as 1-penten-3-one, ( E, E)- and ( E, Z)-2,4-decadienal, and 4-hydroxy-2,5-dimethyl-3(2 H)-furanone (Furaneol) had higher odor units in the more preferred cultivars, whereas methional, phenylacetaldehyde, 2-phenylethanol, or 2-isobutylthiazole had higher odor units in the less preferred cultivars. Simulation of the odor of the selected tomato cultivars by preparation of aroma models and comparison with the corresponding real samples confirmed that all important fresh tomato odorants were identified, that their concentrations were determined correctly in all five cultivars, and that differences in concentration, especially of the compounds mentioned above, make it possible to distinguish between them and are responsible for the differential preference. To help elucidate formation pathways of key odorants, labeled precursors were added to tomatoes. Biogenesis of cis- and trans-4,5-epoxy-( E)-2-decenals from linoleic acid and methional from methionine was confirmed.

The Osmium(VIII) Oxofluoro Cations OsO(2)F(3)(+) and F(cis-OsO(2)F(3))(2)(+): Syntheses, Characterization by (19)F NMR Spectroscopy and Raman Spectroscopy, X-ray Crystal Structure of F(cis-OsO(2)F(3))(2)(+)Sb(2)F(11)(-), and Density Functional Theory Calculations of OsO(2)F(3)(+), ReO(2)F(3), and F(cis-OsO(2)F(3))(2)(+).

Science.gov (United States)

Casteel, William J.; Dixon, David A.; Mercier, Hélène P. A.; Schrobilgen, Gary J.

1996-07-17

Osmium dioxide tetrafluoride, cis-OsO(2)F(4), reacts with the strong fluoride ion acceptors AsF(5) and SbF(5) in anhydrous HF and SbF(5) solutions to form orange salts. Raman spectra are consistent with the formation of the fluorine-bridged diosmium cation F(cis-OsO(2)F(3))(2)(+), as the AsF(6)(-) and Sb(2)F(11)(-) salts, respectively. The (19)F NMR spectra of the salts in HF solution are exchange-averaged singlets occurring at higher frequency than those of the fluorine environments of cis-OsO(2)F(4). The F(cis-OsO(2)F(3))(2)(+)Sb(2)F(11)(-) salt crystallizes in the orthorhombic space group Imma. At -107 degrees C, a = 12.838(3) Å, b = 10.667(2) Å, c = 11.323(2) Å, V = 1550.7(8) Å(3), and Z = 4. Refinement converged with R = 0.0469 [R(w) = 0.0500]. The crystal structure consists of discrete fluorine-bridged F(cis-OsO(2)F(3))(2)(+) and Sb(2)F(11)(-) ions in which the fluorine bridge of the F(cis-OsO(2)F(3))(2)(+) cation is trans to an oxygen atom (Os-O 1.676 Å) of each OsO(2)F(3) group. The angle at the bridge is 155.2(8) degrees with a bridging Os---F(b) distance of 2.086(3) Å. Two terminal fluorine atoms (Os-F 1.821 Å) are cis to the two oxygen atoms (Os-O 1.750 Å), and two terminal fluorine atoms of the OsO(2)F(3) group are trans to one another (1.813 Å). The OsO(2)F(3)(+) cation was characterized by (19)F NMR and by Raman spectroscopy in neat SbF(5) solution but was not isolable in the solid state. The NMR and Raman spectroscopic findings are consistent with a trigonal bipyramidal cation in which the oxygen atoms and a fluorine atom occupy the equatorial plane and two fluorine atoms are in axial positions. Density functional theory calculations show that the crystallographic structure of F(cis-OsO(2)F(3))(2)(+) is the energy-minimized structure and the energy-minimized structures of the OsO(2)F(3)(+) cation and ReO(2)F(3) are trigonal bipyramidal having C(2)(v)() point symmetry. Attempts to prepare the OsOF(5)(+) cation by oxidative fluorination of cis

High production of D-tagatose, a potential sugar substitute, using immobilized L-arabinose isomerase.

Science.gov (United States)

Kim, P; Yoon, S H; Roh, H J; Choi, J H

2001-01-01

An L-arabinose isomerase of Escherichia coli was immobilized using covalent binding to agarose to produce D-tagatose, a bulking sweetener that can be economically used as a sugar substitute. The immobilized L-arabinose isomerase stably produced an average of 7.5 g-tagatose/L.day for 7 days with a productivity exceeding that of the free enzyme (0.47 vs 0.30 mg/U.day). Using a scaled-up immobilized enzyme system, 99.9 g-tagatose/L was produced from galactose with 20% equilibrium in 48 h. The process was repeated two more times with production of 104.1 and 103.5 g-tagatose/L. D-Tagatose production using an immobilized L-arabinose isomerase has a high potential for commercial application.

Bioproduction of D-Tagatose from D-Galactose Using Phosphoglucose Isomerase from Pseudomonas aeruginosa PAO1.

Science.gov (United States)

Patel, Manisha J; Patel, Arti T; Akhani, Rekha; Dedania, Samir; Patel, Darshan H

2016-07-01

Pseudomonas aeruginosa PAO1 phosphoglucose isomerase was purified as an active soluble form by a single-step purification using Ni-NTA chromatography that showed homogeneity on SDS-PAGE with molecular mass ∼62 kDa. The optimum temperature and pH for the maximum isomerization activity with D-galactose were 60 °C and 7.0, respectively. Generally, sugar phosphate isomerases show metal-independent activity but PA-PGI exhibited metal-dependent isomerization activity with aldosugars and optimally catalyzed the D-galactose isomerization in the presence of 1.0 mM MnCl2. The apparent Km and Vmax for D-galactose under standardized conditions were calculated to be 1029 mM (±31.30 with S.E.) and 5.95 U/mg (±0.9 with S.E.), respectively. Equilibrium reached after 180 min with production of 567.51 μM D-tagatose from 1000 mM of D-galactose. Though, the bioconversion ratio is low but it can be increased by immobilization and enzyme engineering. Although various L-arabinose isomerases have been characterized for bioproduction of D-tagatose, P. aeruginosa glucose phosphate isomerase is distinguished from the other L-arabinose isomerases by its optimal temperature (60 °C) for D-tagatose production being mesophilic bacteria, making it an alternate choice for bulk production.

Bacterial L-arabinose isomerases: industrial application for D-tagatose production.

Science.gov (United States)

Boudebbouze, Samira; Maguin, Emmanuelle; Rhimi, Moez

2011-12-01

D-tagatose is a natural monosaccharide with a low caloric value and has an anti-hyperglycemiant effect. This hexose has potential applications both in pharmaceutical and agro-food industries. However, the use of D-tagatose remains limited by its production cost. Many production procedures including chemical and biological processes were developed and patented. The most profitable production way is based on the use of L-arabinose isomerase which allows the manufacture of D-tagatose with an attractive rate. Future developments are focused on the generation of L-arabinose isomerases having biochemical properties satisfying the industrial applications. This report provides a brief review of the most recent patents that have been published relating to this area.

Trans and cis effects of axial fluoroalkyl ligands in vitamin B12 analogues: relationship between alkyl- and fluoroalkyl-cobalamins.

Science.gov (United States)

Randaccio, Lucio; Brancatelli, Giovanna; Demitri, Nicola; Dreos, Renata; Hickey, Neal; Siega, Patrizia; Geremia, Silvano

2013-12-02

CF2HCbl, CF3Cbl , and CF3CH2Cbl have been synthesized and characterized in solution by (1)H NMR and UV-vis spectroscopy, and their X-ray crystal structures have been determined using synchrotron radiation. The structure of CF3CH2Cbl is reported for the first time, whereas those of CF2HCbl and CF3Cbl are re-examined to obtain more precise structural data. Comparison of the structural data obtained with the alkylcobalamin analogues, MeCbl and EtCbl, indicates that the Co-C and Co-NB3 bond lengths are shorter in the fluoroalkylcobalamins. The structural data of the fluoroalkylcobalamins previously reported in the literature had been conflicting in this regard. Thus, a much less dramatic shortening of the two axial bonds was found for CF3Cbl, whereas in the case of CF2HCbl, the Co-NB3 bond length is shorter than in MeCbl. Direct comparison of the structures of CF3CH2Cbl and EtCbl indicates a large distortion of the axial fragment in the former case that can be attributed to steric effects. A number of previously reported correlations of the effect of the β-ligand on the structure and properties of cobalamins are re-examined in light of the present results. Particular emphasis is placed on the axial fragment. This analysis substantially confirms and, with the new data reported here, adjusts and expands the data set for correlations between trans and cis influences of the β-ligand of cobalamins and their structure (Co-X and Co-NB3 distances and corrin fold angle) and properties (UV-vis spectra, NMR spectra, and pK(base-off)).

Directed evolution of xylose isomerase for improved xylose catabolism and fermentation in the yeast Saccharomyces cerevisiae.

Science.gov (United States)

Lee, Sun-Mi; Jellison, Taylor; Alper, Hal S

2012-08-01

The heterologous expression of a highly functional xylose isomerase pathway in Saccharomyces cerevisiae would have significant advantages for ethanol yield, since the pathway bypasses cofactor requirements found in the traditionally used oxidoreductase pathways. However, nearly all reported xylose isomerase-based pathways in S. cerevisiae suffer from poor ethanol productivity, low xylose consumption rates, and poor cell growth compared with an oxidoreductase pathway and, additionally, often require adaptive strain evolution. Here, we report on the directed evolution of the Piromyces sp. xylose isomerase (encoded by xylA) for use in yeast. After three rounds of mutagenesis and growth-based screening, we isolated a variant containing six mutations (E15D, E114G, E129D, T142S, A177T, and V433I) that exhibited a 77% increase in enzymatic activity. When expressed in a minimally engineered yeast host containing a gre3 knockout and tal1 and XKS1 overexpression, the strain expressing this mutant enzyme improved its aerobic growth rate by 61-fold and both ethanol production and xylose consumption rates by nearly 8-fold. Moreover, the mutant enzyme enabled ethanol production by these yeasts under oxygen-limited fermentation conditions, unlike the wild-type enzyme. Under microaerobic conditions, the ethanol production rates of the strain expressing the mutant xylose isomerase were considerably higher than previously reported values for yeast harboring a xylose isomerase pathway and were also comparable to those of the strains harboring an oxidoreductase pathway. Consequently, this study shows the potential to evolve a xylose isomerase pathway for more efficient xylose utilization.

Methods of measuring Protein Disulfide Isomerase activity: a critical overview

Science.gov (United States)

Watanabe, Monica; Laurindo, Francisco; Fernandes, Denise

2014-09-01

Protein disulfide isomerase is an essential redox chaperone from the endoplasmic reticulum (ER) and is responsible for correct disulfide bond formation in nascent proteins. PDI is also found in other cellular locations in the cell, particularly the cell surface. Overall, PDI contributes to ER and global cell redox homeostasis and signaling. The knowledge about PDI structure and function progressed substantially based on in vitro studies using recombinant PDI and chimeric proteins. In these experimental scenarios, PDI reductase and chaperone activities are readily approachable. In contrast, assays to measure PDI isomerase activity, the hallmark of PDI family, are more complex. Assessment of PDI roles in cells and tissues mainly relies on gain- or loss-of-function studies. However, there is limited information regarding correlation of experimental readouts with the distinct types of PDI activities. In this mini-review, we evaluate the main methods described for measuring the different kinds of PDI activity: thiol reductase, thiol oxidase, thiol isomerase and chaperone. We emphasize the need to use appropriate controls and the role of critical interferents (e.g., detergent, presence of reducing agents). We also discuss the translation of results from in vitro studies with purified recombinant PDI to cellular and tissue samples, with critical comments on the interpretation of results.

Effect of pH on simultaneous saccharification and isomerization by glucoamylase and glucose isomerase.

Science.gov (United States)

Mishra, Abha; Debnath Das, Meera

2002-01-01

pH and temperature play critical roles in multistep enzymatic conversions. In such conversions, the optimal pH for individual steps differs greatly. In this article, we describe the production of glucoamylase (from Aspergillus oryzae MTCC152 in solid-state fermentation) and glucose isomerase (from Streptomyces griseus NCIM2020 in submerged fermentation), used in industries for producing high-fructose syrup. Optimum pH for glucoamylase was found to be 5.0. For glucose isomerase, the optimum pH ranged between 7.0 and 8.5, depending on the type of buffer used. Optimum temperature for glucoamylase and glucose isomerase was 50 and 60 degrees C, respectively. When both the enzymatic conversions were performed simultaneously at a compromised pH of 6.5, both the enzymes showed lowered activity. We also studied the kinetics at different pHs, which allows the two-step reaction to take place simultaneously. This was done by separating two steps by a thin layer of urease. Ammonia generated by the hydrolysis of urea consumed the hydrogen ions, thereby allowing optimal activity of glucose isomerase at an acidic pH of 5.0.

The effect of pomegranate seed oil and grapeseed oil on cis-9, trans-11 CLA (rumenic acid), n-3 and n-6 fatty acids deposition in selected tissues of chickens.

Science.gov (United States)

Białek, A; Białek, M; Lepionka, T; Kaszperuk, K; Banaszkiewicz, T; Tokarz, A

2018-04-23

The aim of this study was to determine whether diet modification with different doses of grapeseed oil or pomegranate seed oil will improve the nutritive value of poultry meat in terms of n-3 and n-6 fatty acids, as well as rumenic acid (cis-9, trans-11 conjugated linoleic acid) content in tissues diversified in lipid composition and roles in lipid metabolism. To evaluate the influence of applied diet modification comprehensively, two chemometric methods were used. Results of cluster analysis demonstrated that pomegranate seed oil modifies fatty acids profile in the most potent way, mainly by an increase in rumenic acid content. Principal component analysis showed that regardless of type of tissue first principal component is strongly associated with type of deposited fatty acid, while second principal component enables identification of place of deposition-type of tissue. Pomegranate seed oil seems to be a valuable feed additive in chickens' feeding. © 2018 Blackwell Verlag GmbH.

Organization of cis-acting regulatory elements in osmotic- and cold-stress-responsive promoters.

Science.gov (United States)

Yamaguchi-Shinozaki, Kazuko; Shinozaki, Kazuo

2005-02-01

cis-Acting regulatory elements are important molecular switches involved in the transcriptional regulation of a dynamic network of gene activities controlling various biological processes, including abiotic stress responses, hormone responses and developmental processes. In particular, understanding regulatory gene networks in stress response cascades depends on successful functional analyses of cis-acting elements. The ever-improving accuracy of transcriptome expression profiling has led to the identification of various combinations of cis-acting elements in the promoter regions of stress-inducible genes involved in stress and hormone responses. Here we discuss major cis-acting elements, such as the ABA-responsive element (ABRE) and the dehydration-responsive element/C-repeat (DRE/CRT), that are a vital part of ABA-dependent and ABA-independent gene expression in osmotic and cold stress responses.

Mediation Analysis Demonstrates That Trans-eQTLs Are Often Explained by Cis-Mediation : A Genome-Wide Analysis among 1,800 South Asians

NARCIS (Netherlands)

Pierce, Brandon L.; Tong, Lin; Chen, Lin S.; Rahaman, Ronald; Argos, Maria; Jasmine, Farzana; Roy, Shantanu; Paul-Brutus, Rachelle; Westra, Harm-Jan; Franke, Lude; Esko, Tonu; Zaman, Rakibuz; Islam, Tariqul; Rahman, Mahfuzar; Baron, John A.; Kibriya, Muhammad G.; Ahsan, Habibul

2014-01-01

A large fraction of human genes are regulated by genetic variation near the transcribed sequence (cis-eQTL, expression quantitative trait locus), and many cis-eQTLs have implications for human disease. Less is known regarding the effects of genetic variation on expression of distant genes

The secreted L-arabinose isomerase displays anti-hyperglycemic effects in mice.

Science.gov (United States)

Rhimi, Moez; Bermudez-Humaran, Luis G; Huang, Yuan; Boudebbouze, Samira; Gaci, Nadia; Garnier, Alexandrine; Gratadoux, Jean-Jacques; Mkaouar, Héla; Langella, Philippe; Maguin, Emmanuelle

2015-12-21

The L-arabinose isomerase is an intracellular enzyme which converts L-arabinose into L-ribulose in living systems and D-galactose into D-tagatose in industrial processes and at industrial scales. D-tagatose is a natural ketohexose with potential uses in pharmaceutical and food industries. The D-galactose isomerization reaction is thermodynamically equilibrated, and leads to secondary subproducts at high pH. Therefore, an attractive L-arabinose isomerase should be thermoactive and acidotolerant with high catalytic efficiency. While many reports focused on the set out of a low cost process for the industrial production of D-tagatose, these procedures remain costly. When compared to intracellular enzymes, the production of extracellular ones constitutes an interesting strategy to increase the suitability of the biocatalysts. The L-arabinose isomerase (L-AI) from Lactobacillus sakei was expressed in Lactococcus lactis in fusion with the signal peptide of usp45 (SP(Usp45)). The L-AI protein and activity were detected only in the supernatant of the induced cultures of the recombinant L. lactis demonstrating the secretion in the medium of the intracellular L. sakei L-AI in an active form. Moreover, we showed an improvement in the enzyme secretion using either (1) L. lactis strains deficient for their two major proteases, ClpP and HtrA, or (2) an enhancer of protein secretion in L. lactis fused to the recombinant L-AI with the SP(Usp45). Th L-AI enzyme secreted by the recombinant L. lactis strains or produced intracellularly in E. coli, showed the same functional properties than the native enzyme. Furthermore, when mice are fed with the L. lactis strain secreting the L-AI and galactose, tagatose was produced in vivo and reduced the glycemia index. We report for the first time the secretion of the intracellular L-arabinose isomerase in the supernatant of food grade L. lactis cultures with hardly display other secreted proteins. The secreted L-AI originated from the food

Structural insights from a novel invertebrate triosephosphate isomerase from Litopenaeus vannamei

Science.gov (United States)

Lopez-Zavala, Alonso A.; Carrasco-Miranda, Jesus S.; Ramirez-Aguirre, Claudia D.; López-Hidalgo, Marisol; Benitez-Cardoza, Claudia G.; Ochoa-Leyva, Adrian; Cardona-Felix, Cesar S.; Diaz-Quezada, Corina; Rudiño-Piñera, Enrique; Sotelo-Mundo, Rogerio R.; Brieba, Luis G.

2016-01-01

Triosephosphate isomerase (TIM; EC 5.3.1.1) is a key enzyme involved in glycolysis and gluconeogenesis. Glycolysis is one of the most regulated metabolic pathways, however little is known about the structural mechanisms for its regulation in non-model organisms, like crustaceans. To understand the structure and function of this enzyme in invertebrates, we obtained the crystal structure of triosephosphate isomerase from the marine Pacific whiteleg shrimp (Litopenaeus vannamei, LvTIM) in complex with its inhibitor 2-phosphogyceric acid (2-PG) at 1.7 Å resolution. LvTIM assembles as a homodimer with residues 166-176 covering the active site and residue Glu166 interacting with the inhibitor. We found that LvTIM is the least stable TIM characterized to date, with the lowest range of melting temperatures, and with the lowest activation enthalpy associated with the thermal unfolding process reported. In TIMs dimer stabilization is maintained by an interaction of loop 3 by a set of hydrophobic contacts between subunits. Within these contacts, the side chain of a hydrophobic residue of one subunit fits into a cavity created by a set of hydrophobic residues in the neighboring subunit, via a "ball and socket" interaction. LvTIM presents a Cys47 at the "ball" inter-subunit contact indicating that the character of this residue is responsible for the decrease in dimer stability. Mutational studies show that this residue plays a role in dimer stability but is not a solely determinant for dimer formation. PMID:27614148

Characteristics of chalcone isomerase promoter in crabapple leaves ...

African Journals Online (AJOL)

Anthocyanins are secondary metabolites found in higher plants that contribute to the colors of plants and chalcone isomerase (CHI) is one of the key enzymes in anthocyanin biosynthetic pathway. What characteristic is CHI promoter known as the regulation sequence of CHI gene, has been rarely investigated. We isolated A ...

Kinetics of photoirradiation-induced synthesis of soy oil-conjugated linoleic acid isomers.

Science.gov (United States)

Jain, Vishal P; Proctor, Andrew

2007-02-07

Photoirradiation of soy oil with UV/visible light has been shown to produce significant amounts of trans,trans conjugated linoleic acid (CLA) isomers through conversion of various synthesized intermediate cis,trans isomers. The objective of this study was to determine the kinetics of CLA isomers synthesis to better understand the production of various isomers. Soy oil was irradiated with UV/visible light for 144 h in the presence of an iodine catalyst and CLA isomers analyzed by gas chromatography (GC). Arrhenius plots were developed for the conversion of soy oil linoleic acid (A) to form cis-, trans/trans-, cis-CLA (B), conversion of cis-, trans/trans-, cis-CLA to form trans,trans-CLA (C) with respect to B, and formation of trans,trans-CLA isomers with respect to C. The kinetics of consumption of linoleic acid (LA) to form cis-, trans/trans-, cis-CLA was found to be of second-order with a rate constant of 9.01 x 10-7 L/mol s. The rate of formation of cis-, trans/trans-, cis-CLA isomers depends on the rate of formation from LA and its rate of consumption to form trans,trans-CLA isomers. The conversion of cis-, trans/trans-, cis-CLA isomers to trans,trans-CLA isomers was found to be of first-order with a rate constant of 2.75 x 10-6 s-1. However, the formation of thermodynamically stable trans,trans-CLA isomers (C) with respect to C was found to be a zero-order reaction with a rate constant of 10.66 x 10-7 mol/L s. The consumption of LA was found to be the rate-determining step in the CLA isomers formation reaction mechanism. The findings provide a better understanding of the mechanism of CLA isomers synthesis by photoirradiation and the factors controlling the ratio of various isomers.

Cyclophilin D links programmed cell death and organismal aging in Podospora anserina.

Science.gov (United States)

Brust, Diana; Daum, Bertram; Breunig, Christine; Hamann, Andrea; Kühlbrandt, Werner; Osiewacz, Heinz D

2010-10-01

Cyclophilin D (CYPD) is a mitochondrial peptidyl prolyl-cis,trans-isomerase involved in opening of the mitochondrial permeability transition pore (mPTP). CYPD abundance increases during aging in mammalian tissues and in the aging model organism Podospora anserina. Here, we show that treatment of the P. anserina wild-type with low concentrations of the cyclophilin inhibitor cyclosporin A (CSA) extends lifespan. Transgenic strains overexpressing PaCypD are characterized by reduced stress tolerance, suffer from pronounced mitochondrial dysfunction and are characterized by accelerated aging and induction of cell death. Treatment with CSA leads to correction of mitochondrial function and lifespan to that of the wild-type. In contrast, PaCypD deletion strains are not affected by CSA within the investigated concentration range and show increased resistance against inducers of oxidative stress and cell death. Our data provide a mechanistic link between programmed cell death (PCD) and organismal aging and bear implications for the potential use of CSA to intervene into biologic aging. © 2010 The Authors Aging Cell © 2010 Blackwell Publishing Ltd/Anatomical Society of Great Britain and Ireland.

Microwave discharge electrodeless lamps (MDEL). Part VII. Photo-isomerization of trans-urocanic acid in aqueous media driven by UV light from a novel Hg-free Dewar-like microwave discharge thermally-insulated electrodeless lamp (MDTIEL). Performance evaluation.

Science.gov (United States)

Horikoshi, Satoshi; Sato, Tatsuro; Sakamoto, Kazutami; Abe, Masahiko; Serpone, Nick

2011-07-01

A novel mercury-free Dewar-like (double-walled structure) microwave discharge thermally-insulated electrodeless lamp (MDTIEL) was fabricated and its performance evaluated using the photo-isomerization of trans-urocanic acid (trans-UA) in aqueous media as a test process driven by the emitted UV light when ignited with microwave radiation. The photo-isomerization processes trans-UA → cis-UA and cis-UA → trans-UA were re-visited using light emitted from a conventional high-pressure Hg light source and examined for the influence of UV light irradiance and solution temperature; the temperature dependence of the trans → cis process displayed a negative activation energy, E(a) = -1.3 cal mol(-1). To control the photo-isomerization of urocanic acid from the heat usually dissipated by a microwave discharge electrodeless lamp (single-walled MDEL), it was necessary to suppress the microwave-initiated heat. For comparison, the gas-fill in the MDEL lamp, which typically consists of a mixture of Hg and Ar, was changed to the more eco-friendly N(2) gas in the novel MDTIEL device. The dynamics of the photo-isomerization of urocanic acid driven by the UV wavelengths of the N(2)-MDTIEL light source were compared to those from the more conventional single-walled N(2)-MDEL and Hg/Ar-MDEL light sources, and with those from the Hg lamp used to irradiate, via a fiber optic, the photoreactor located in the wave-guide of the microwave apparatus. The heating efficiency of a solution with the double-walled N(2)-MDTIEL was compared to the efficiency from the single-walled N(2)-MDEL device. Advantages of N(2)-MDTIEL are described from a comparison of the dynamics of the trans-UA → cis-UA process on the basis of unit surface area of the lamp and unit power consumption. The considerably lower temperature on the external surface of the N(2)-MDTIEL light source should make it attractive in carrying out photochemical reactions that may be heat-sensitive such as the photothermochromic

The evolutionary landscape of intergenic trans-splicing events in insects

Science.gov (United States)

Kong, Yimeng; Zhou, Hongxia; Yu, Yao; Chen, Longxian; Hao, Pei; Li, Xuan

2015-01-01

To explore the landscape of intergenic trans-splicing events and characterize their functions and evolutionary dynamics, we conduct a mega-data study of a phylogeny containing eight species across five orders of class Insecta, a model system spanning 400 million years of evolution. A total of 1,627 trans-splicing events involving 2,199 genes are identified, accounting for 1.58% of the total genes. Homology analysis reveals that mod(mdg4)-like trans-splicing is the only conserved event that is consistently observed in multiple species across two orders, which represents a unique case of functional diversification involving trans-splicing. Thus, evolutionarily its potential for generating proteins with novel function is not broadly utilized by insects. Furthermore, 146 non-mod trans-spliced transcripts are found to resemble canonical genes from different species. Trans-splicing preserving the function of ‘breakup' genes may serve as a general mechanism for relaxing the constraints on gene structure, with profound implications for the evolution of genes and genomes. PMID:26521696

Finding a Trans-Affirmative Provider: Challenges Faced by Trans and Gender Diverse Psychologists and Psychology Trainees.

Science.gov (United States)

Dickey, Lore M; Singh, Anneliese A

2017-08-01

This article explores some of the challenges faced by trans and gender diverse (TGD) individuals who not only are attempting to access trans-affirmative care, but who are also members of the very profession from which they are seeking services. The authors explore challenges related to finding supervision, accessing care for assessment services, and finding a provider for personal counseling. With each example, the authors unpack the challenges and also address the implications for training for all involved. Based on these challenges that TGD psychologists and trainees face in attempting to access care, the authors provide recommendations related to trans-affirmative training for psychologists. © 2017 Wiley Periodicals, Inc.

Escherichia coli rpiA gene encoding ribose phosphate isomerase A

DEFF Research Database (Denmark)

Hove-Jensen, Bjarne; Maigaard, Marianne

1993-01-01

The rpiA gene encoding ribose phosphate isomerase A was cloned from phage 1A2(471) of the Kohara gene library. Subcloning, restriction, and complementation analyses revealed an 1,800-bp SspI-generated DNA fragment that contained the entire control and coding sequences. This DNA fragment was seque......The rpiA gene encoding ribose phosphate isomerase A was cloned from phage 1A2(471) of the Kohara gene library. Subcloning, restriction, and complementation analyses revealed an 1,800-bp SspI-generated DNA fragment that contained the entire control and coding sequences. This DNA fragment...

Trans*+ing Classrooms: The Pedagogy of Refusal as Mediator for Learning

Directory of Open Access Journals (Sweden)

sj Miller

2016-07-01

Full Text Available Gender and sexuality norms, conscribed under cis/heteropatriarchy, have established violent and unstable social and educational climates for the millennial generation of lesbian, gay, bisexual, transgender, intersex, agender/asexual, gender creative, and questioning youth. While strides have been made to make schools more supportive and queer inclusive, schools still struggle to include lesbian, gay, bisexual, transgender*+, intersex, agender/asexual, gender creative, queer and questioning (LGBT*+IAGCQQ-positive curricula. While extensive studies must be done on behalf of all queer youth, this work specifically focuses on how to support classroom teachers to uptake and apply a pedagogy of refusal that attends to the most vulnerabilized population of queer youth to date, those that are trans*+. A pedagogy of refusal will be explored through an evolving theory of trans*+ness, then demonstrated through a framework for classroom application, followed by recommendations for change.

Kinase-dead ATM protein is highly oncogenic and can be preferentially targeted by Topo-isomerase I inhibitors.

Science.gov (United States)

Yamamoto, Kenta; Wang, Jiguang; Sprinzen, Lisa; Xu, Jun; Haddock, Christopher J; Li, Chen; Lee, Brian J; Loredan, Denis G; Jiang, Wenxia; Vindigni, Alessandro; Wang, Dong; Rabadan, Raul; Zha, Shan

2016-06-15

Missense mutations in ATM kinase, a master regulator of DNA damage responses, are found in many cancers, but their impact on ATM function and implications for cancer therapy are largely unknown. Here we report that 72% of cancer-associated ATM mutations are missense mutations that are enriched around the kinase domain. Expression of kinase-dead ATM (Atm(KD/-)) is more oncogenic than loss of ATM (Atm(-/-)) in mouse models, leading to earlier and more frequent lymphomas with Pten deletions. Kinase-dead ATM protein (Atm-KD), but not loss of ATM (Atm-null), prevents replication-dependent removal of Topo-isomerase I-DNA adducts at the step of strand cleavage, leading to severe genomic instability and hypersensitivity to Topo-isomerase I inhibitors. Correspondingly, Topo-isomerase I inhibitors effectively and preferentially eliminate Atm(KD/-), but not Atm-proficientor Atm(-/-) leukemia in animal models. These findings identify ATM kinase-domain missense mutations as a potent oncogenic event and a biomarker for Topo-isomerase I inhibitor based therapy.

Cyclophilin B is a functional regulator of hepatitis C virus RNA polymerase.

Science.gov (United States)

Watashi, Koichi; Ishii, Naoto; Hijikata, Makoto; Inoue, Daisuke; Murata, Takayuki; Miyanari, Yusuke; Shimotohno, Kunitada

2005-07-01

Viruses depend on host-derived factors for their efficient genome replication. Here, we demonstrate that a cellular peptidyl-prolyl cis-trans isomerase (PPIase), cyclophilin B (CyPB), is critical for the efficient replication of the hepatitis C virus (HCV) genome. CyPB interacted with the HCV RNA polymerase NS5B to directly stimulate its RNA binding activity. Both the RNA interference (RNAi)-mediated reduction of endogenous CyPB expression and the induced loss of NS5B binding to CyPB decreased the levels of HCV replication. Thus, CyPB functions as a stimulatory regulator of NS5B in HCV replication machinery. This regulation mechanism for viral replication identifies CyPB as a target for antiviral therapeutic strategies.

Crystallization and preliminary X-ray characterization of phosphoglucose isomerase from Mycobacterium tuberculosis H37Rv

International Nuclear Information System (INIS)

Mathur, Divya; Anand, Kanchan; Mathur, Deepika; Jagadish, Nirmala; Suri, Anil; Garg, Lalit C.

2007-01-01

The phosphoglucose isomerase from Mycobacterium tuberculosis H37Rv was crystallized and diffraction data were collected to 2.8 Å resolution. Phosphoglucose isomerase is a ubiquitous enzyme that catalyzes the isomerization of d-glucopyranose-6-phosphate to d-fructofuranose-6-phosphate. The present investigation reports the expression, purification, crystallization and preliminary crystallographic studies of the phosphoglucose isomerase from Mycobacterium tuberculosis H37Rv, which shares 46% sequence identity with that of its human host. The recombinant protein, which was prepared using an Escherichia coli expression system, was crystallized by the hanging-drop vapour-diffusion method. The crystals diffracted to a resolution of 2.8 Å and belonged to the orthorhombic space group I2 1 2 1 2 1 , with unit-cell parameters a = 109.0, b = 119.8, c = 138.9 Å

Effect of silage type and concentrate level on conjugated linoleic acids, trans-C18 : 1 isomers and fat content in milk from dairy cows

DEFF Research Database (Denmark)

Nielsen, Torben Skov; Straarup, Ellen Marie; Jungersen, Mogens Vestergaard

2006-01-01

to one of four diets in a 2 x 2 factorial arrangement of treatments and a six week experimental period. Treatments were total mixed rations with maize (M) or grass (G) silage differing in polyunsaturated fatty acid (PUFA) profile and starch content, combined with a high (H) or a low (L) level......:1 and reduced cis9, trans11-CLA and trans11-C18:1 when maize but not grass silage was provided. The results suggest that high levels of concentrate (grain) do not significantly alter the pattern of PUFA biohydrogenation in the rumen, the concentration of CLA and trans-C18:1 isomers in milk or cause milk fat...

Arabidopsis Phosphomannose Isomerase 1, but Not Phosphomannose Isomerase 2, Is Essential for Ascorbic Acid Biosynthesis*S⃞

OpenAIRE

Maruta, Takanori; Yonemitsu, Miki; Yabuta, Yukinori; Tamoi, Masahiro; Ishikawa, Takahiro; Shigeoka, Shigeru

2008-01-01

We studied molecular and functional properties of Arabidopsis phosphomannose isomerase isoenzymes (PMI1 and PMI2) that catalyze reversible isomerization between d-fructose 6-phosphate and d-mannose 6-phosphate (Man-6P). The apparent Km and Vmax values for Man-6P of purified recombinant PMI1 were 41.3 ± 4.2 μm and 1.89 μmol/min/mg protein, respectively, whereas those of purified recombinant PMI2 were 372 ± 13 μm and 22.5 μmol/min/mg protein, respectively. Both PMI1 ...

Preparation and Characterization of cis- and trans-[Ir(tn)2Cl2]CF3SO3 and of [Ir(tn)3]Cl3 (tn=propane-1,3-diamine)

DEFF Research Database (Denmark)

Brorson, Michael; Galsbøl, Frode; Simonsen, Kim

1998-01-01

for the preparation of [Rh(tn)3]Cl3 in quantitative yield from Rh(thtp)3Cl3 is also given. The complexes were characterized by 1H and 13C NMR and by UV/VIS spectroscopy. The conformation of the six-membered chelate rings of [Ir(tn)3]3+ in the solid state was determined by single-crystal X-ray diffraction of [Ir(tn)3......Procedures are given for the preparation and isolation of cis- and trans-[Ir(tn)2Cl2]CF3SO3 and of [Ir(tn)3]Cl3, (tn=propane-1,3-diamine). The compounds were prepared by the use of Ir(thtp)3Cl3 (thtp=tetrahydrothiophene) as starting material, using either DMSO or neat tn as solvent. A procedure......] [Co(CN)6] x 5H2O. The three chelate rings all adopt the energetically favoured chair conformation; however, the overall idealized symmetry is C1. A comparative ligand field analysis, based on Gaussian resolution of the solution UV/VIS spectra for a number of homoleptic [M(N6)]3+ (M=CoIII, RhIII, Ir...

Epoxidation of the methamphetamine pyrolysis product, trans-phenylpropene, to trans-phenylpropylene oxide by CYP enzymes and stereoselective glutathione adduct formation

International Nuclear Information System (INIS)

Sanga, Madhu; Younis, Islam R.; Tirumalai, Padma S.; Bland, Tina M.; Banaszewska, Monica; Konat, Gregory W.; Tracy, Timothy S.; Gannett, Peter M.; Callery, Patrick S.

2006-01-01

Pyrolytic products of smoked methamphetamine hydrochloride are well established. Among the various degradation products formed, trans-phenylpropene (trans-β-methylstyrene) is structurally similar to styrene analogues known to be bioactivated by CYP enzymes. In human liver microsomes, trans-phenylpropene was converted to the epoxide trans-phenylpropylene oxide (trans-2-methyl-3-phenyloxirane) and cinnamyl alcohol. Incubation of trans-phenylpropene with microsomes in the presence of enzyme-specific P450 enzyme inhibitors indicated the involvement of CYP2E1, CYP1A2, and CYP3A4 enzymes. Both (R,R)-phenylpropylene oxide and (S,S)-phenylpropylene oxide were formed in human liver microsomal preparations. Enantiomers of trans-phenylpropylene oxide were stereoselectively and regioselectively conjugated in a Phase II drug metabolism reaction catalyzed by human liver cytosolic enzymes consisting of conjugation with glutathione. The structure of the phenylpropylene oxide-glutathione adduct is consistent with nucleophilic ring-opening by attack at the benzylic carbon. Exposure of cultured C6 glial cells to (S,S)-phenylpropylene oxide produced a cytotoxic response in a concentration-dependent manner based on cell degeneration and death

Effect of a trans fatty acid-enriched diet on biochemical and inflammatory parameters in Wistar rats.

Science.gov (United States)

Longhi, Rafael; Almeida, Roberto Farina; Machado, Letiane; Duarte, Maria Marta Medeiros Frescura; Souza, Débora Guerini; Machado, Priscila; de Assis, Adriano Martimbianco; Quincozes-Santos, André; Souza, Diogo Onofre

2017-04-01

Recent data regarding trans fatty acids (TFAs) have implicated these lipids as particularly deleterious to human health, causing systemic inflammation, endothelial dysfunction and possibly inflammation in the central nervous system (CNS). We aimed to clarify the impact of partially hydrogenated soybean oil (PHSO) with different TFA concentrations on cerebrospinal fluid (CSF), serum and hepatic parameters in adult Wistar rats. Wistar rats (n = 15/group) were fed either a normolipidic diet or a hyperlipidic diet for 90 days. The normolipidic and hyperlipidic diets had the same ingredients except for fat compositions, concentrations and calories. We used lard in the cis fatty acid group and PHSO in the trans fatty acid group. The intervention groups were as follows: (1) low lard (LL), (2) high lard (HL), (3) low partially hydrogenated soybean oil (LPHSO) and (4) high partially hydrogenated soybean oil (HPHSO). Body weight, lipid profiles and the inflammatory responses in the CSF, serum and liver tissue were analyzed. Surprisingly, with the PHSO diet we observed a worse metabolic response that was associated with oxidative stress in hepatic tissue as well as impaired serum and CSF fluid parameters at both PHSO concentrations. In many analyses, there were no significant differences between the LPHSO and HPHSO diets. Dietary supplementation with PHSO impaired inflammatory parameters in CSF and blood, induced insulin resistance, altered lipid profiles and caused hepatic damage. Overall, these findings suggest that fat composition is more important than the quantity of fat consumed in terms of cis and trans fatty acid diets.

Enantioselective disruption of the endocrine system by Cis-Bifenthrin in the male mice.

Science.gov (United States)

Jin, Yuanxiang; Wang, Jiangcong; Pan, Xiuhong; Miao, Wenyu; Lin, Xiaojian; Wang, Linggang; Fu, Zhengwei

2015-07-01

Bifenthrin (BF), as a chiral pyrethroid, is widely used to control field and household pests in China. At present, the commercial BF is a mixed compound containing cis isomers (cis-BF) including two enantiomers of 1R-cis-BF and 1S-cis-BF. In the present study, the two individual cis-BF enantiomers were separated by a preparative supercritical fluid chromatography. Then, four week-old adolescent male ICR mice were orally administered 1R-cis-BF and 1S-cis-BF separately daily for 3 weeks at doses of 0, 7.5 and 15 mg/kg/day, respectively. Results showed that the transcription status of some genes involved in cholesterol synthesis and transport as well as testosterone (T) synthesis in the testes were influenced by cis-BF enantiomers. Especially, we observed that the transcription status of key genes on the pathway of T synthesis including cytochrome P450 cholesterol side-chain cleavage enzyme (P450scc) and cytochrome P450 17α-hydroxysteroid dehydrogenase (P45017α)) were selectively altered in the testis of mice when treated with 1S-cis-BF, suggesting that it is the possible reason to explain why the lower serum T concentration in 1S-cis-BF treated group. Taken together, it concluded that both of the cis-BF enantiomers have the endocrine disruption activities, while 1S-cis-BF was higher than 1R-cis-BF in mice when exposed during the puberty. The data was helpful to understand the toxicity of cis-BF in mammals under enantiomeric level. © 2014 Wiley Periodicals, Inc.

Generation of Chimeric RNAs by cis-splicing of adjacent genes (cis-SAGe) in mammals.

Science.gov (United States)

Zhuo, Jian-Shu; Jing, Xiao-Yan; Du, Xin; Yang, Xiu-Qin

2018-02-20

Chimeric RNA molecules, possessing exons from two or more independent genes, are traditionally believed to be produced by chromosome rearrangement. However, recent studies revealed that cis-splicing of adjacent genes (cis- SAGe) is one of the major mechanisms underlying the formation of chimeric RNAs. cis-SAGe refers to intergenic splicing of directly adjacent genes with the same transcriptional orientation, resulting in read-through transcripts, termed chimeric RNAs, which contain sequences from two or more parental genes. cis-SAGe was first identified in tumor cells, since then its potential in carcinogenesis has attracted extensive attention. More and more scientists are focusing on it. With the development of research, cis-SAGe was found to be ubiquitous in various normal tissues, and might make a crucial contribution to the formation of novel genes in the evolution of genomes. In this review, we summarize the splicing pattern, expression characteristics, possible mechanisms, and significance of cis-SAGe in mammals. This review will be helpful for general understanding of the current status and development tendency of cis-SAGe.

Characterization of the Promoter Region of an Arabidopsis Gene for 9-cis-Epoxycarotenoid Dioxygenase Involved in Dehydration-Inducible Transcription

Science.gov (United States)

Behnam, Babak; Iuchi, Satoshi; Fujita, Miki; Fujita, Yasunari; Takasaki, Hironori; Osakabe, Yuriko; Yamaguchi-Shinozaki, Kazuko; Kobayashi, Masatomo; Shinozaki, Kazuo

2013-01-01

Plants respond to dehydration stress and tolerate water-deficit status through complex physiological and cellular processes. Many genes are induced by water deficit. Abscisic acid (ABA) plays important roles in tolerance to dehydration stress by inducing many stress genes. ABA is synthesized de novo in response to dehydration. Most of the genes involved in ABA biosynthesis have been identified, and they are expressed mainly in leaf vascular tissues. Of the products of such genes, 9-cis-epoxycarotenoid dioxygenase (NCED) is a key enzyme in ABA biosynthesis. One of the five NCED genes in Arabidopsis, AtNCED3, is significantly induced by dehydration. To understand the regulatory mechanism of the early stages of the dehydration stress response, it is important to analyse the transcriptional regulatory systems of AtNCED3. In the present study, we found that an overlapping G-box recognition sequence (5′-CACGTG-3′) at −2248 bp from the transcriptional start site of AtNCED3 is an important cis-acting element in the induction of the dehydration response. We discuss the possible transcriptional regulatory system of dehydration-responsive AtNCED3 expression, and how this may control the level of ABA under water-deficit conditions. PMID:23604098

Coexpression of β-D-galactosidase and L-arabinose isomerase in the production of D-tagatose: a functional sweetener.

Science.gov (United States)

Zhan, Yijing; Xu, Zheng; Li, Sha; Liu, Xiaoliu; Xu, Lu; Feng, Xiaohai; Xu, Hong

2014-03-19

The functional sweetener, d-tagatose, is commonly transformed from galactose by l-arabinose isomerase. To make use of a much cheaper starting material, lactose, hydrolization, and isomerization are required to take place collaboratively. Therefore, a single-step method involving β-d-galactosidase was explored for d-tagatose production. The two vital genes, β-d-galactosidase gene (lacZ) and l-arabinose isomerase mutant gene (araA') were extracted separately from Escherichia coli strains and incorporated into E. coli simultaneously. This gave us E. coli-ZY, a recombinant producing strain capable of coexpressing the two key enzymes. The resulted cells exhibited maximum d-tagatose producing activity at 34 °C and pH 6.5 and in the presence of borate, 10 mM Fe(2+), and 1 mM Mn(2+). Further monitoring showed that the recombinant cells could hydrolyze more than 95% lactose and convert 43% d-galactose into d-tagatose. This research has verified the feasibility of single-step d-tagatose fermentation, thereby laying down the foundation for industrial usage of lactose.

Structural and functional characterization of the interaction between cyclophilin B and a heparin-derived oligosaccharide.

Science.gov (United States)

Hanoulle, Xavier; Melchior, Aurélie; Sibille, Nathalie; Parent, Benjamin; Denys, Agnès; Wieruszeski, Jean-Michel; Horvath, Dragos; Allain, Fabrice; Lippens, Guy; Landrieu, Isabelle

2007-11-23

The chemotaxis and integrin-mediated adhesion of T lymphocytes triggered by secreted cyclophilin B (CypB) depend on interactions with both cell surface heparan sulfate proteoglycans (HSPG) and the extracellular domain of the CD147 membrane receptor. Here, we use NMR spectroscopy to characterize the interaction of CypB with heparin-derived oligosaccharides. Chemical shift perturbation experiments allowed the precise definition of the heparan sulfate (HS) binding site of CypB. The N-terminal extremity of CypB, which contains a consensus sequence for heparin-binding proteins was modeled on the basis of our experimental NMR data. Because the HS binding site extends toward the CypB catalytic pocket, we measured its peptidyl-prolyl cis-trans isomerase (PPIase) activity in the absence or presence of a HS oligosaccharide toward a CD147-derived peptide. We report the first direct evidence that CypB is enzymatically active on CD147, as it is able to accelerate the cis/trans isomerization of the Asp(179)-Pro(180) bond in a CD147-derived peptide. However, HS binding has no significant influence on this PPIase activity. We thus conclude that the glycanic moiety of HSPG serves as anchor for CypB at the cell surface, and that the signal could be transduced by CypB via its PPIase activity toward CD147.

Cyclosporin A Impairs the Secretion and Activity of ADAMTS13 (A Disintegrin and Metalloprotease with Thrombospondin Type 1 Repeat)*

Science.gov (United States)

Hershko, Klilah; Simhadri, Vijaya L.; Blaisdell, Adam; Hunt, Ryan C.; Newell, Jordan; Tseng, Sandra C.; Hershko, Alon Y.; Choi, Jae Won; Sauna, Zuben E.; Wu, Andrew; Bram, Richard J.; Komar, Anton A.; Kimchi-Sarfaty, Chava

2012-01-01

The protease ADAMTS13 (a disintegrin and metalloprotease with thrombospondin type 1 repeat) cleaves multimers of von Willebrand factor, thus regulating platelet aggregation. ADAMTS13 deficiency leads to the fatal disorder thrombotic thrombocytopenic purpura (TTP). It has been observed that cyclosporin A (CsA) treatment, particularly in transplant patients, may sometimes be linked to the development of TTP. Until now, the reason for such a link was unclear. Here we provide evidence demonstrating that cyclophilin B (CypB) activity plays an important role in the secretion of active ADAMTS13. We found that CsA, an inhibitor of CypB, reduces the secretion of ADAMTS13 and leads to conformational changes in the protein resulting in diminished ADAMTS13 proteolytic activity. A direct, functional interaction between CypB (which possesses peptidyl-prolyl cis-trans isomerase (PPIase) and chaperone functions) and ADAMTS13 is demonstrated using immunoprecipitation and siRNA knockdown of CypB. Finally, CypB knock-out mice were found to have reduced ADAMTS13 levels. Taken together, our findings indicate that cyclophilin-mediated activity is an important factor affecting secretion and activity of ADAMTS13. The large number of proline residues in ADAMTS13 is consistent with the important role of cis-trans isomerization in the proper folding of this protein. These results altogether provide a novel mechanistic explanation for CsA-induced TTP in transplant patients. PMID:23144461

Cyclosporin A impairs the secretion and activity of ADAMTS13 (a disintegrin and metalloprotease with thrombospondin type 1 repeat).

Science.gov (United States)

Hershko, Klilah; Simhadri, Vijaya L; Blaisdell, Adam; Hunt, Ryan C; Newell, Jordan; Tseng, Sandra C; Hershko, Alon Y; Choi, Jae Won; Sauna, Zuben E; Wu, Andrew; Bram, Richard J; Komar, Anton A; Kimchi-Sarfaty, Chava

2012-12-28

The protease ADAMTS13 (a disintegrin and metalloprotease with thrombospondin type 1 repeat) cleaves multimers of von Willebrand factor, thus regulating platelet aggregation. ADAMTS13 deficiency leads to the fatal disorder thrombotic thrombocytopenic purpura (TTP). It has been observed that cyclosporin A (CsA) treatment, particularly in transplant patients, may sometimes be linked to the development of TTP. Until now, the reason for such a link was unclear. Here we provide evidence demonstrating that cyclophilin B (CypB) activity plays an important role in the secretion of active ADAMTS13. We found that CsA, an inhibitor of CypB, reduces the secretion of ADAMTS13 and leads to conformational changes in the protein resulting in diminished ADAMTS13 proteolytic activity. A direct, functional interaction between CypB (which possesses peptidyl-prolyl cis-trans isomerase (PPIase) and chaperone functions) and ADAMTS13 is demonstrated using immunoprecipitation and siRNA knockdown of CypB. Finally, CypB knock-out mice were found to have reduced ADAMTS13 levels. Taken together, our findings indicate that cyclophilin-mediated activity is an important factor affecting secretion and activity of ADAMTS13. The large number of proline residues in ADAMTS13 is consistent with the important role of cis-trans isomerization in the proper folding of this protein. These results altogether provide a novel mechanistic explanation for CsA-induced TTP in transplant patients.

Fatty acid transport protein 1 regulates retinoid metabolism and photoreceptor development in mouse retina.

Directory of Open Access Journals (Sweden)

Aurélie Cubizolle

Full Text Available In retinal pigment epithelium (RPE, RPE65 catalyzes the isomerization of all-trans-retinyl fatty acid esters to 11-cis-retinol in the visual cycle and controls the rhodopsin regeneration rate. However, the mechanisms by which these processes are regulated are still unclear. Fatty Acid Transport Protein 1 (FATP1 is involved in fatty acid uptake and lipid metabolism in a variety of cell types. FATP1 co-localizes with RPE65 in RPE and inhibits its isomerase activity in vitro. Here, we further investigated the role of FATP1 in the visual cycle using transgenic mice that overexpress human FATP1 specifically in the RPE (hFATP1TG mice. The mice displayed no delay in the kinetics of regeneration of the visual chromophore 11-cis-retinal after photobleaching and had no defects in light sensitivity. However, the total retinoid content was higher in the hFATP1TG mice than in wild type mice, and the transgenic mice also displayed an age-related accumulation (up to 40% of all-trans-retinal and retinyl esters that was not observed in control mice. Consistent with these results, hFATP1TG mice were more susceptible to light-induced photoreceptor degeneration. hFATP1 overexpression also induced an ~3.5-fold increase in retinosome autofluorescence, as measured by two-photon microscopy. Interestingly, hFATP1TG retina contained ~25% more photoreceptor cells and ~35% longer outer segments than wild type mice, revealing a non-cell-autonomous effect of hFATP1 expressed in the RPE. These data are the first to show that FATP1-mediated fatty acid uptake in the RPE controls both retinoid metabolism in the outer retina and photoreceptor development.

Identifying Cis-Regulatory Changes Involved in the Evolution of Aerobic Fermentation in Yeasts

Science.gov (United States)

Lin, Zhenguo; Wang, Tzi-Yuan; Tsai, Bing-Shi; Wu, Fang-Ting; Yu, Fu-Jung; Tseng, Yu-Jung; Sung, Huang-Mo; Li, Wen-Hsiung

2013-01-01

Gene regulation change has long been recognized as an important mechanism for phenotypic evolution. We used the evolution of yeast aerobic fermentation as a model to explore how gene regulation has evolved and how this process has contributed to phenotypic evolution and adaptation. Most eukaryotes fully oxidize glucose to CO2 and H2O in mitochondria to maximize energy yield, whereas some yeasts, such as Saccharomyces cerevisiae and its relatives, predominantly ferment glucose into ethanol even in the presence of oxygen, a phenomenon known as aerobic fermentation. We examined the genome-wide gene expression levels among 12 different yeasts and found that a group of genes involved in the mitochondrial respiration process showed the largest reduction in gene expression level during the evolution of aerobic fermentation. Our analysis revealed that the downregulation of these genes was significantly associated with massive loss of binding motifs of Cbf1p in the fermentative yeasts. Our experimental assays confirmed the binding of Cbf1p to the predicted motif and the activator role of Cbf1p. In summary, our study laid a foundation to unravel the long-time mystery about the genetic basis of evolution of aerobic fermentation, providing new insights into understanding the role of cis-regulatory changes in phenotypic evolution. PMID:23650209

Protein Disulfide Isomerase and Host-Pathogen Interaction

Directory of Open Access Journals (Sweden)

Beatriz S. Stolf

2011-01-01

Full Text Available Reactive oxygen species (ROS production by immunological cells is known to cause damage to pathogens. Increasing evidence accumulated in the last decade has shown, however, that ROS (and redox signals functionally regulate different cellular pathways in the host-pathogen interaction. These especially affect (i pathogen entry through protein redox switches and redox modification (i.e., intra- and interdisulfide and cysteine oxidation and (ii phagocytic ROS production via Nox family NADPH oxidase enzyme and the control of phagolysosome function with key implications for antigen processing. The protein disulfide isomerase (PDI family of redox chaperones is closely involved in both processes and is also implicated in protein unfolding and trafficking across the endoplasmic reticulum (ER and towards the cytosol, a thiol-based redox locus for antigen processing. Here, we summarise examples of the cellular association of host PDI with different pathogens and explore the possible roles of pathogen PDIs in infection. A better understanding of these complex regulatory steps will provide insightful information on the redox role and coevolutional biological process, and assist the development of more specific therapeutic strategies in pathogen-mediated infections.

Combinatorial Cis-regulation in Saccharomyces Species

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Aaron T. Spivak

2016-03-01

Full Text Available Transcriptional control of gene expression requires interactions between the cis-regulatory elements (CREs controlling gene promoters. We developed a sensitive computational method to identify CRE combinations with conserved spacing that does not require genome alignments. When applied to seven sensu stricto and sensu lato Saccharomyces species, 80% of the predicted interactions displayed some evidence of combinatorial transcriptional behavior in several existing datasets including: (1 chromatin immunoprecipitation data for colocalization of transcription factors, (2 gene expression data for coexpression of predicted regulatory targets, and (3 gene ontology databases for common pathway membership of predicted regulatory targets. We tested several predicted CRE interactions with chromatin immunoprecipitation experiments in a wild-type strain and strains in which a predicted cofactor was deleted. Our experiments confirmed that transcription factor (TF occupancy at the promoters of the CRE combination target genes depends on the predicted cofactor while occupancy of other promoters is independent of the predicted cofactor. Our method has the additional advantage of identifying regulatory differences between species. By analyzing the S. cerevisiae and S. bayanus genomes, we identified differences in combinatorial cis-regulation between the species and showed that the predicted changes in gene regulation explain several of the species-specific differences seen in gene expression datasets. In some instances, the same CRE combinations appear to regulate genes involved in distinct biological processes in the two different species. The results of this research demonstrate that (1 combinatorial cis-regulation can be inferred by multi-genome analysis and (2 combinatorial cis-regulation can explain differences in gene expression between species.

Reasons for decision in the matter of Trans Mountain Pipeline Inc. (formerly Terasen Pipelines (Trans Mountain) Inc.) : tariffs

International Nuclear Information System (INIS)

2007-01-01

In 2006 and 2007 Terasen Pipelines (Trans Mountain) Inc. (now Trans Mountain Pipeline Inc.) submitted a series of applications to the National Energy Board for revisions to the Trans Mountain Tariffs. They were filed in response to apportionment concerns on the Trans Mountain pipeline. Four of the applications involved pronounced and contentious changes to the capacity allocation procedures on the pipeline system. For ease of reference, the Board amalgamated its 4 decisions on these applications into a single document. A map of the Trans Mountain pipeline system as a whole was presented along with a detailed map indicating the delivery locations served by the system in the lower mainland of British Columbia and the state of Washington. The issues considered by the Board in each of these decisions included capacity allocation for Westridge Dock; capacity allocations to export destinations; common carriage requirements; and the need for creating a new barge subcategory. Relevant sections of the National Energy Board Act referred to in the decisions were highlighted. This document also listed the Trans Mountain Tariffs that have introduced notable revisions to the capacity allocation procedures on the system since September 2003. 16 refs., 2 figs., 3 appendices

A novel begomovirus isolated from sida contains putative cis- and trans-acting replication specificity determinants that have evolved independently in several geographical lineages.

Science.gov (United States)

Mauricio-Castillo, J A; Torres-Herrera, S I; Cárdenas-Conejo, Y; Pastor-Palacios, G; Méndez-Lozano, J; Argüello-Astorga, G R

2014-09-01

A novel begomovirus isolated from a Sida rhombifolia plant collected in Sinaloa, Mexico, was characterized. The genomic components of sida mosaic Sinaloa virus (SiMSinV) shared highest sequence identity with DNA-A and DNA-B components of chino del tomate virus (CdTV), suggesting a vertical evolutionary relationship between these viruses. However, recombination analysis indicated that a short segment of SiMSinV DNA-A encompassing the plus-strand replication origin and the 5´-proximal 43 codons of the Rep gene was derived from tomato mottle Taino virus (ToMoTV). Accordingly, the putative cis- and trans-acting replication specificity determinants of SiMSinV were identical to those of ToMoTV but differed from those of CdTV. Modeling of the SiMSinV and CdTV Rep proteins revealed significant differences in the region comprising the small β1/β5 sheet element, where five putative DNA-binding specificity determinants (SPDs) of Rep (i.e., amino acid residues 5, 8, 10, 69 and 71) were previously identified. Computer-assisted searches of public databases led to identification of 33 begomoviruses from three continents encoding proteins with SPDs identical to those of the Rep encoded by SiMSinV. Sequence analysis of the replication origins demonstrated that all 33 begomoviruses harbor potential Rep-binding sites identical to those of SiMSinV. These data support the hypothesis that the Rep β1/β5 sheet region determines specificity of this protein for DNA replication origin sequences.

Obtaining mutants of Streptomyces griseoflavus strain 1339, producers of glucose isomerase, following gamma irradiation

International Nuclear Information System (INIS)

Dzhedzheva, G.; Stoeva, N.; Stojchev, M.

1990-01-01

A water suspension of Streptomyces griseoflavus strain 1339 spores of a density of 8.7.10 6 spores/cm 3 is gamma irradiated ( 60 Co, RHM-γ-20, 30.3 Gy/min). The survival of Streptomyces griseoflavus strain 1339 spores was determined depending on radiation doses, exposure times and incubation temperature. Five major morphological types of colonies were isolated, characterized by different levels of glucose isomerase activity. Maximum specific glucose isomerase activity (GIU/g) was attained after the third gamma irradiation step using a dose of 3000 Gy. 2 tabs., 3 figs., 7 refs

Effect of weaning status on lipids of Galician Blond veal: total fatty acids and 18:1 cis and trans isomers.

Science.gov (United States)

Bispo, Esperanza; Moreno, Teresa; Latorre, Alicia; González, Laura; Herradón, Pedro G; Franco, Daniel; Monserrat, Lorenzo

2010-10-01

The effect of weaning at different ages (NW=not weaned, W5=5.5 months and W2=2 months) on fatty acids (FA) of the Longissimus thoracis (LT) muscle was studied in 36 Galician Blond (GB) calves. Total FA (TFA) were determined by gas chromatography (GC) and 18:1 isomers by a combination of reversed-phase high performance liquid chromatography (HPLC) and GC. NW group showed higher (Pconjugated linoleic acid (CLA) and 18:1 trans-11 compared to LT from W5 and W2 calves. W2 calves showed the highest levels of n-6 PUFA (P<0.01), 18:1 trans-10 and 18:1 trans-6/7/8 (P<0.001). Generally, W5 calves had intermediate values for TFA and 18:1 isomers. As the suckling period was longer, GB milk and veal FA profiles became more similar, it seems that muscle FA were partially transmitted by the milk FA intake due to the persistence of the reticular grove closing reflex. Copyright (c) 2010 The American Meat Science Association. Published by Elsevier Ltd.. All rights reserved.

Comparison of two derivatization methods for the analysis of fatty acids and trans fatty acids in bakery products using gas chromatography.

Science.gov (United States)

Salimon, Jumat; Omar, Talal A; Salih, Nadia

2014-01-01

Two different procedures for the methylation of fatty acids (FAs) and trans fatty acids (TFAs) in food fats were compared using gas chromatography (GC-FID). The base-catalyzed followed by an acid-catalyzed method (KOCH3/HCl) and the base-catalyzed followed by (trimethylsilyl)diazomethane (TMS-DM) method were used to prepare FA methyl esters (FAMEs) from lipids extracted from food products. In general, both methods were suitable for the determination of cis/trans FAs. The correlation coefficients (r) between the methods were relatively small (ranging from 0.86 to 0.99) and had a high level of agreement for the most abundant FAs. The significant differences (P = 0.05) can be observed for unsaturated FAs (UFAs), specifically for TFAs. The results from the KOCH3/HCl method showed the lowest recovery values (%R) and higher variation (from 84% to 112%), especially for UFAs. The TMS-DM method had higher R values, less variation (from 90% to 106%), and more balance between variation and %RSD values in intraday and interday measurements (less than 4% and 6%, resp.) than the KOCH3/HCl method, except for C12:0, C14:0, and C18:0. Nevertheless, the KOCH3/HCl method required shorter time and was less expensive than the TMS-DM method which is more convenient for an accurate and thorough analysis of rich cis/trans UFA samples.

Comparison of Two Derivatization Methods for the Analysis of Fatty Acids and Trans Fatty Acids in Bakery Products Using Gas Chromatography

Science.gov (United States)

Salimon, Jumat; Omar, Talal A.; Salih, Nadia

2014-01-01

Two different procedures for the methylation of fatty acids (FAs) and trans fatty acids (TFAs) in food fats were compared using gas chromatography (GC-FID). The base-catalyzed followed by an acid-catalyzed method (KOCH3/HCl) and the base-catalyzed followed by (trimethylsilyl)diazomethane (TMS–DM) method were used to prepare FA methyl esters (FAMEs) from lipids extracted from food products. In general, both methods were suitable for the determination of cis/trans FAs. The correlation coefficients (r) between the methods were relatively small (ranging from 0.86 to 0.99) and had a high level of agreement for the most abundant FAs. The significant differences (P = 0.05) can be observed for unsaturated FAs (UFAs), specifically for TFAs. The results from the KOCH3/HCl method showed the lowest recovery values (%R) and higher variation (from 84% to 112%), especially for UFAs. The TMS-DM method had higher R values, less variation (from 90% to 106%), and more balance between variation and %RSD values in intraday and interday measurements (less than 4% and 6%, resp.) than the KOCH3/HCl method, except for C12:0, C14:0, and C18:0. Nevertheless, the KOCH3/HCl method required shorter time and was less expensive than the TMS-DM method which is more convenient for an accurate and thorough analysis of rich cis/trans UFA samples. PMID:24719581

Comparison of Two Derivatization Methods for the Analysis of Fatty Acids and Trans Fatty Acids in Bakery Products Using Gas Chromatography

Directory of Open Access Journals (Sweden)

Jumat Salimon

2014-01-01

Full Text Available Two different procedures for the methylation of fatty acids (FAs and trans fatty acids (TFAs in food fats were compared using gas chromatography (GC-FID. The base-catalyzed followed by an acid-catalyzed method (KOCH3/HCl and the base-catalyzed followed by (trimethylsilyldiazomethane (TMS–DM method were used to prepare FA methyl esters (FAMEs from lipids extracted from food products. In general, both methods were suitable for the determination of cis/trans FAs. The correlation coefficients (r between the methods were relatively small (ranging from 0.86 to 0.99 and had a high level of agreement for the most abundant FAs. The significant differences (P=0.05 can be observed for unsaturated FAs (UFAs, specifically for TFAs. The results from the KOCH3/HCl method showed the lowest recovery values (%R and higher variation (from 84% to 112%, especially for UFAs. The TMS-DM method had higher R values, less variation (from 90% to 106%, and more balance between variation and %RSD values in intraday and interday measurements (less than 4% and 6%, resp. than the KOCH3/HCl method, except for C12:0, C14:0, and C18:0. Nevertheless, the KOCH3/HCl method required shorter time and was less expensive than the TMS-DM method which is more convenient for an accurate and thorough analysis of rich cis/trans UFA samples.

Human triose-phosphate isomerase deficiency: a single amino acid substitution results in a thermolabile enzyme.

OpenAIRE

Daar, I O; Artymiuk, P J; Phillips, D C; Maquat, L E

1986-01-01

Triose-phosphate isomerase (TPI; D-glyceraldehyde-3-phosphate ketol-isomerase, EC 5.3.1.1) deficiency is a recessive disorder that results in hemolytic anemia and neuromuscular dysfunction. To determine the molecular basis of this disorder, a TPI allele from two unrelated patients homozygous for TPI deficiency was compared with an allele from a normal individual. Each disease-associated sequence harbors a G X C----C X G transversion in the codon for amino acid-104 and specifies a structurally...

Genomic analysis of a xylose operon and characterization of novel xylose isomerase and xylulokinase from Bacillus coagulans NL01.

Science.gov (United States)

Zheng, Zhaojuan; Lin, Xi; Jiang, Ting; Ye, Weihua; Ouyang, Jia

2016-08-01

To investigate the xylose operon and properties of xylose isomerase and xylulokinase in Bacillus coagulans that can effectively ferment xylose to lactic acid. The xylose operon is widely present in B. coagulans. It is composed of four putative ORFs. Novel xylA and xylB from B. coagulans NL01 were cloned and expressed in Escherichia coli. Sequence of xylose isomerase was more conserved than that of xylulokinase. Both the enzymes exhibited maximum activities at pH 7-8 but with a high temperature maximum of 80-85 °C, divalent metal ion was prerequisite for their activation. Xylose isomerase and xylulokinase were most effectively activated by Ni(2+) and Co(2+), respectively. Genomic analysis of xylose operon has contributed to understanding xylose metabolism in B. coagulans and the novel xylose isomerase and xylulokinase might provide new alternatives for metabolic engineering of other strains to improve their fermentation performance on xylose.

Histochemical study of trans-polyisoprene accumulation by spectral confocal laser scanning microscopy and a specific dye showing fluorescence solvatochromism in the rubber-producing plant, Eucommia ulmoides Oliver.

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Nakazawa, Yoshihisa; Takeda, Tsuyoshi; Suzuki, Nobuaki; Hayashi, Tatsushi; Harada, Yoko; Bamba, Takeshi; Kobayashi, Akio

2013-09-01

A microscopic technique combining spectral confocal laser scanning microscopy with a lipophilic fluorescent dye, Nile red, which can emit trans-polyisoprene specific fluorescence, was developed, and unmixed images of synthesized trans-polyisoprene in situ in Eucommia ulmoides were successfully obtained. The images showed that trans-polyisoprene was initially synthesized as granules in non-articulated laticifers that changed shape to fibers during laticifer maturation. Non-articulated laticifers are developed from single laticiferous cells, which are differentiated from surrounding parenchyma cells in the cambium. Therefore, these observations suggested that trans-polyisoprene biosynthesis first started in laticifer cells as granules and then the granules accumulated and fused in the inner space of the laticifers over time. Finally, laticifers were filled with the synthesized trans-polyisoprene, which formed a fibrous structure fitting the laticifers shape. Both trans- and cis-polyisoprene are among the most important polymers naturally produced by plants, and this microscopic technique combined with histological study should provide useful information in the fields of plant histology, bioindustry and phytochemistry.

Study of the UV Light Conversion of Feruloyl Amides from Portulaca oleracea and Their Inhibitory Effect on IL-6-Induced STAT3 Activation.

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Hwang, Joo Tae; Kim, Yesol; Jang, Hyun-Jae; Oh, Hyun-Mee; Lim, Chi-Hwan; Lee, Seung Woong; Rho, Mun-Chual

2016-06-30

Two new feruloyl amides, N-cis-hibiscusamide (5) and (7'S)-N-cis-feruloylnormetanephrine (9), and eight known feruloyl amides were isolated from Portulaca oleracea L. and the geometric conversion of the ten isolated feruloyl amides by UV light was verified. The structures of the feruloyl amides were determined based on spectroscopic data and comparison with literature data. The NMR data revealed that the structures of the isolated compounds showed cis/trans-isomerization under normal laboratory light conditions. Therefore, cis and trans-isomers of feruloyl amides were evaluated for their convertibility and stability by UV light of a wavelength of 254 nm. After 96 h of UV light exposure, 23.2%-35.0% of the cis and trans-isomers were converted to trans-isomers. Long-term stability tests did not show any significant changes. Among all compounds and conversion mixtures collected, compound 6 exhibited the strongest inhibition of IL-6-induced STAT3 activation in Hep3B cells, with an IC50 value of 0.2 μM. This study is the first verification of the conversion rates and an equilibrium ratio of feruloyl amides. These results indicate that this natural material might provide useful information for the treatment of various diseases involving IL-6 and STAT3.

The immunosuppressives FK 506 and cyclosporin A inhibit the generation of protein factors binding to the two purine boxes of the interleukin 2 enhancer.

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Brabletz, T; Pietrowski, I; Serfling, E

1991-01-11

Like Cyclosporin A (CsA), the macrolide FK 506 is a potent immunosuppressive that inhibits early steps of T cell activation, including the synthesis of Interleukin 2 (II-2) and numerous other lymphokines. The block of II-2 synthesis occurs at the transcriptional level. At concentrations that block T cell activation, FK 506 and CsA inhibit the proto-enhancer activity of Purine boxes of the II-2 promoter and the generation of lymphocyte-specific factors binding to the Purine boxes. Under the same conditions, the DNA binding of other II-2 enhancer factors remains unaffected by both compounds. These results support the view that FK 506 and CsA, which both inhibit the activity of peptidylprolyl cis/trans isomerases, suppress T cell activation by a similar, if not identical mechanism.

Primary photochemical processes for Pt(iv) diazido complexes prospective in photodynamic therapy of tumors.

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Shushakov, Anton A; Pozdnyakov, Ivan P; Grivin, Vjacheslav P; Plyusnin, Victor F; Vasilchenko, Danila B; Zadesenets, Andrei V; Melnikov, Alexei A; Chekalin, Sergey V; Glebov, Evgeni M

2017-07-25

Diazide diamino complexes of Pt(iv) are considered as prospective prodrugs in oxygen-free photodynamic therapy (PDT). Primary photophysical and photochemical processes for cis,trans,cis-[Pt(N 3 ) 2 (OH) 2 (NH 3 ) 2 ] and trans,trans,trans-[Pt(N 3 ) 2 (OH) 2 (NH 3 ) 2 ] complexes were studied by means of stationary photolysis, nanosecond laser flash photolysis and ultrafast kinetic spectroscopy. The process of photolysis is multistage. The first stage is the photosubstitution of an azide ligand to a water molecule. This process was shown to be a chain reaction involving redox stages. Pt(iv) and Pt(iii) intermediates responsible for the chain propagation were recorded using ultrafast kinetic spectroscopy and nanosecond laser flash photolysis. The mechanism of photosubstitution is proposed.

Eucalyptus ESTs involved in the production of 9-cis epoxycarotenoid dioxygenase, a regulatory enzyme of abscisic acid production

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Iraê A. Guerrini

2005-01-01

Full Text Available Abscisic acid (ABA regulates stress responses in plants, and genomic tools can help us to understand the mechanisms involved in that process. FAPESP, a Brazilian research foundation, in association with four private forestry companies, has established the FORESTs database (https://forests.esalq.usp.br. A search was carried out in the Eucalyptus expressed sequence tag database to find ESTs involved with 9-cis epoxycarotenoid dioxygenase (NCED, the regulatory enzyme for ABA biosynthesis, using the basic local BLAST alignment tool. We found four clusters (EGEZLV2206B11.g, EGJMWD2252H08.g, EGBFRT3107F10.g, and EGEQFB1200H10.g, which represent similar sequences of the gene that produces NCED. Data showed that the EGBFRT3107F10.g cluster was similar to the maize (Zea mays NCED enzyme, while EGEZLV2206B11.g and EGJMWD2252H08.g clusters were similar to the avocado (Persea americana NCED enzyme. All Eucalyptus clusters were expressed in several tissues, especially in flower buds, where ABA has a special participation during the floral development process.

Transmutation of human glutathione transferase A2-2 with peroxidase activity into an efficient steroid isomerase.

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Pettersson, Par L; Johansson, Ann-Sofie; Mannervik, Bengt

2002-08-16

A major goal in protein engineering is the tailor-making of enzymes for specified chemical reactions. Successful attempts have frequently been based on directed molecular evolution involving libraries of random mutants in which variants with desired properties were identified. For the engineering of enzymes with novel functions, it would be of great value if the necessary changes of the active site could be predicted and implemented. Such attempts based on the comparison of similar structures with different substrate selectivities have previously met with limited success. However, the present work shows that the knowledge-based redesign restricted to substrate-binding residues in human glutathione transferase A2-2 can introduce high steroid double-bond isomerase activity into the enzyme originally characterized by glutathione peroxidase activity. Both the catalytic center activity (k(cat)) and catalytic efficiency (k(cat)/K(m)) match the values of the naturally evolved glutathione transferase A3-3, the most active steroid isomerase known in human tissues. The substrate selectivity of the mutated glutathione transferase was changed 7000-fold by five point mutations. This example demonstrates the functional plasticity of the glutathione transferase scaffold as well as the potential of rational active-site directed mutagenesis as a complement to DNA shuffling and other stochastic methods for the redesign of proteins with novel functions.

Involvement of polyphosphate kinase in virulence and stress tolerance of uropathogenic Proteus mirabilis.

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Peng, Liang; Jiang, Qiao; Pan, Jia-Yun; Deng, Cong; Yu, Jing-Yi; Wu, Xiao-Man; Huang, Sheng-He; Deng, Xiao-Yan

2016-04-01

Proteus mirabilis (P. mirabilis), a gram-negative enteric bacterium, frequently causes urinary tract infections. Many virulence factors of uropathogenic P. mirabilis have been identified, including urease, flagella, hemolysin and fimbriae. However, the functions of polyphosphate kinase (PPK), which are related to the pathogenicity of many bacteria, remain entirely unknown in P. mirabilis. In this study, a ppk gene encoding the PPK insertional mutant in P. mirabilis strain HI4320 was constructed, and its biological functions were examined. The results of survival studies demonstrated that the ppk mutant was deficient in resistance to oxidative, hyperosmotic and heat stress. The swarming and biofilm formation abilities of P. mirabilis were also attenuated after the ppk interruption. In vitro and in vivo experiments suggested that ppk was required for P. mirabilis to invade the bladder. The negative phenotypes of the ppk mutant could be restored by ppk gene complementation. Furthermore, two-dimensional gel electrophoresis and liquid chromatography-mass spectrometry were used to analyze the proteomes of the wild-type strain and the ppk mutant. Compared with the wild-type strain, seven proteins including TonB-dependent receptor, universal stress protein G, major mannose-resistant/Proteus-like fimbrial protein (MR/P fimbriae), heat shock protein, flagellar capping protein, putative membrane protein and multidrug efflux protein were down-regulated, and four proteins including exported peptidase, repressor protein for FtsI, FKBP-type peptidyl-prolyl cis-trans isomerase and phosphotransferase were up-regulated in the ppk mutant. As a whole, these results indicate that PPK is an important regulator and plays a crucial role in stress tolerance and virulence in uropathogenic P. mirabilis.

Effects of pyrethroid pesticide cis-bifenthrin on lipogenesis in hepatic cell line.

Science.gov (United States)

Xiang, Dandan; Chu, Tianyi; Li, Meng; Wang, Qiangwei; Zhu, Guonian

2018-06-01

Mounting evidence suggests there is a link between exposure to synthetic pyrethroids (SPs) and the development of obesity. The information presented in this study suggests that cis-bifenthrin (cis-BF) could activate pregnane X receptor (PXR) mediated pathway and lead to the lipid accumulation of human hepatoma (HepG2) cells. Cells were incubated in the control or different concentrations of cis-BF for 24 h. The 1 × 10 -7  M and 1 × 10 -6  M cis-BF exposure were found to induce cellular triglyceride (TG) accumulation significantly. This phenomenon was further supported by Oil Red O Staining assay. The cis-BF exposure caused upregulation of PXR gene and protein. Correspondingly, we also observed the increased expression of downstream genes involved in lipid formation and the inhibition of the expression of β-oxidation. As chiral pesticide，cis-BF was further conformed to behave enantioselectivity in the lipid metabolism. Rather than 1R-cis-BF, HepG2 cells incubated with 1S-cis-BF exhibited a significant TG accumulation. 1S-cis-BF also showed a higher binding level, of which the KD value was 9.184 × 10 -8  M in the SPR assay, compared with 1R-cis-BF (3.463 × 10 -6  M). In addition, the molecular docking simulation analyses correlated well with the KD values measured by the SPR, indicating that 1S-cis-BF showed a better binding affinity with PXR. The results in this study also elucidates the differences between the two enantiomers of pyrethroid-induced toxicity in lipid metabolism of non-target organism. Copyright © 2018 Elsevier Ltd. All rights reserved.

Asymmetrically doped one-dimensional trans-polymers

International Nuclear Information System (INIS)

Caldas, Heron

2009-01-01

More than 30 years ago [H. Shirakawa, E.J. Louis, A.G. MacDiarmid, C.K. Chiang, A.J. Heeger, J. Chem. Soc. Chem. Comm. 578 (1977); S. Etemad, A.J. Heeger, Ann. Rev. Phys. Chem. 33 (1982) 443] it was discovered that doped trans-polyacetylene (CH) x , a one-dimensional (1D) conjugated polymer, exhibits electrical conductivity. In this work we show that an asymmetrically doped 1D trans-polymer has non-conventional properties, as compared to symmetrically doped systems. Depending on the level of asymmetry between the chemical potentials of the two involved fermionic species, the polymer can be in a partially or fully spin polarized state. Some possible experimental consequences of doped 1D trans-polymers used as 1D organic polarized conductors are discussed.

[Deficiency of triosephosphate isomerase. Apropos of 2 new cases].

Science.gov (United States)

Delso Martínez, M C; Uriel Miñana, P; Pérez Lugmus, G; Giménez Mas, J A; Baldellou Vázquez, A

1983-08-01

Two siblings, born of a no consanguineous couple, a female and a male, affected by a severe and progressive neurological disease and chronic hemolytic anemia are presented. Their clinical, hematological, biochemical and pathological studies are discussed. One of the patients showed a triosephosphate isomerase deficiency and the carrier condition of their parents was tested. Commentaries about physiopathology of this disease are made.

Understanding the complexity of trans fatty acid reduction in the American diet: American Heart Association Trans Fat Conference 2006: report of the Trans Fat Conference Planning Group.

Science.gov (United States)

Eckel, Robert H; Borra, Susan; Lichtenstein, Alice H; Yin-Piazza, Shirley Y

2007-04-24

A 2-day forum was convened to discuss the current status and future implications of reducing trans fatty acids without increasing saturated fats in the food supply while maintaining functionality and consumer acceptance of packaged, processed, and prepared foods. Attendees represented the agriculture and oilseed industry and oil processing, food manufacturing, food service, government, food technology, and health and nutrition disciplines. Presentations included food science behind fatty acid technology, the health science of dietary fatty acids, alternatives to trans fatty acids, and the use of alternatives in food manufacturing and food service. The reduction of trans fatty acids in the food supply is a complex issue involving interdependent and interrelated stakeholders. Actions to reduce trans fatty acids need to carefully consider both intended and unintended consequences related to nutrition and public health. The unintended consequence of greatest concern is that fats and oils high in saturated fats, instead of the healthier unsaturated fats, might be used to replace fats and oils with trans fatty acids. Many different options of alternative oils and fats to replace trans fatty acids are available or in development. Decisions on the use of these alternatives need to consider availability, health effects, research and development investments, reformulated food quality and taste, supply-chain management, operational modifications, consumer acceptance, and cost. The conference demonstrated the value of collaboration between the food industry and health and nutrition professionals, and this conference model should be used to address other food development, processing, and/or technology issues.

Strand-specific RNA-seq reveals widespread occurrence of novel cis-natural antisense transcripts in rice

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Lu Tingting

2012-12-01

Full Text Available Abstract Background Cis-natural antisense transcripts (cis-NATs are RNAs transcribed from the antisense strand of a gene locus, and are complementary to the RNA transcribed from the sense strand. Common techniques including microarray approach and analysis of transcriptome databases are the major ways to globally identify cis-NATs in various eukaryotic organisms. Genome-wide in silico analysis has identified a large number of cis-NATs that may generate endogenous short interfering RNAs (nat-siRNAs, which participate in important biogenesis mechanisms for transcriptional and post-transcriptional regulation in rice. However, the transcriptomes are yet to be deeply sequenced to comprehensively investigate cis-NATs. Results We applied high-throughput strand-specific complementary DNA sequencing technology (ssRNA-seq to deeply sequence mRNA for assessing sense and antisense transcripts that were derived under salt, drought and cold stresses, and normal conditions, in the model plant rice (Oryza sativa. Combined with RAP-DB genome annotation (the Rice Annotation Project Database build-5 data set, 76,013 transcripts corresponding to 45,844 unique gene loci were assembled, in which 4873 gene loci were newly identified. Of 3819 putative rice cis-NATs, 2292 were detected as expressed and giving rise to small RNAs from their overlapping regions through integrated analysis of ssRNA-seq data and small RNA data. Among them, 503 cis-NATs seemed to be associated with specific conditions. The deep sequence data from isolated epidermal cells of rice seedlings further showed that 54.0% of cis-NATs were expressed simultaneously in a population of homogenous cells. Nearly 9.7% of rice transcripts were involved in one-to-one or many-to-many cis-NATs formation. Furthermore, only 17.4-34.7% of 223 many-to-many cis-NAT groups were all expressed and generated nat-siRNAs, indicating that only some cis-NAT groups may be involved in complex regulatory networks. Conclusions

Changes in cis-regulatory elements of a key floral regulator are associated with divergence of inflorescence architectures.

Science.gov (United States)

Kusters, Elske; Della Pina, Serena; Castel, Rob; Souer, Erik; Koes, Ronald

2015-08-15

Higher plant species diverged extensively with regard to the moment (flowering time) and position (inflorescence architecture) at which flowers are formed. This seems largely caused by variation in the expression patterns of conserved genes that specify floral meristem identity (FMI), rather than changes in the encoded proteins. Here, we report a functional comparison of the promoters of homologous FMI genes from Arabidopsis, petunia, tomato and Antirrhinum. Analysis of promoter-reporter constructs in petunia and Arabidopsis, as well as complementation experiments, showed that the divergent expression of leafy (LFY) and the petunia homolog aberrant leaf and flower (ALF) results from alterations in the upstream regulatory network rather than cis-regulatory changes. The divergent expression of unusual floral organs (UFO) from Arabidopsis, and the petunia homolog double top (DOT), however, is caused by the loss or gain of cis-regulatory promoter elements, which respond to trans-acting factors that are expressed in similar patterns in both species. Introduction of pUFO:UFO causes no obvious defects in Arabidopsis, but in petunia it causes the precocious and ectopic formation of flowers. This provides an example of how a change in a cis-regulatory region can account for a change in the plant body plan. © 2015. Published by The Company of Biologists Ltd.

Useful Bicistronic Reporter System for Studying Poly(A Site-Defining cis Elements and Regulation of Alternative Polyadenylation

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Zhongyuan Deng

2018-01-01

Full Text Available The link between polyadenylation (pA and various biological, behavioral, and pathological events of eukaryotes underlines the need to develop in vivo polyadenylation assay methods for characterization of the cis-acting elements, trans-acting factors and environmental stimuli that affect polyadenylation efficiency and/or relative usage of two alternative polyadenylation (APA sites. The current protein-based CAT or luciferase reporter systems can measure the polyadenylation efficiency of a single pA site or candidate cis element but not the choice of two APA sites. To address this issue, we developed a set of four new bicistronic reporter vectors that harbor either two luciferase or fluorescence protein open reading frames connected with one Internal Ribosome Entry Site (IRES. Transfection of single or dual insertion constructs of these vectors into mammalian cells demonstrated that they could be utilized not only to quantify the strength of a single candidate pA site or cis element, but also to accurately measure the relative usage of two APA sites at both the mRNA (qRT-PCR and protein levels. This represents the first reporter system that can study polyadenylation efficiency of a single pA site or element and regulation of two APA sites at both the mRNA and protein levels.

First characterization of three cyclophilin family proteins in the oyster, Crassostrea ariakensis Gould.

Science.gov (United States)

Xu, Ting; Xie, Jiasong; Yang, Shoubao; Ye, Shigen; Luo, Ming; Wu, Xinzhong

2016-08-01

Cyclophilins (CyPs) are a family of proteins that bind the immunosuppressive agent cyclosporin A (CsA) with high-affinity and belong to one of the three superfamilies of peptidyl-prolyl cis-trans isomerases (PPIase). In this report, three cyclophilin genes (Ca-CyPs), including Ca-CyPA, Ca-CyPB and Ca-PPIL3, were identified from oyster, Crassostrea ariakensis Gould in which Ca-CyPA encodes a protein with 165 amino acid sequences, Ca-CyPB encodes a protein with 217 amino acid sequences and Ca-PPIL3 encodes a protein with 162 amino acid sequences. All of the three Ca-CyPs genes contain a typical CyP-PPIase domain with its signature sequences and Ca-CyPB contains an N-signal peptide sequences. Tissue distribution study revealed that Ca-CyPs were ubiquitously expressed in all examined tissues and the highest levels were observed in hemocytes. RLO incubation upregulated the mRNA expression levels of Ca-CyPs, indicating that three Ca-CyPs might be involved in oyster immune response against RLO infection. Copyright © 2016 Elsevier Ltd. All rights reserved.

Alterations in cholesterol metabolism restrict HIV-1 trans infection in nonprogressors.

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Rappocciolo, Giovanna; Jais, Mariel; Piazza, Paolo; Reinhart, Todd A; Berendam, Stella J; Garcia-Exposito, Laura; Gupta, Phalguni; Rinaldo, Charles R

2014-04-29

ABSTRACT HIV-1-infected nonprogressors (NP) inhibit disease progression for years without antiretroviral therapy. Defining the mechanisms for this resistance to disease progression could be important in determining strategies for controlling HIV-1 infection. Here we show that two types of professional antigen-presenting cells (APC), i.e., dendritic cells (DC) and B lymphocytes, from NP lacked the ability to mediate HIV-1 trans infection of CD4(+) T cells. In contrast, APC from HIV-1-infected progressors (PR) and HIV-1-seronegative donors (SN) were highly effective in mediating HIV-1 trans infection. Direct cis infection of T cells with HIV-1 was comparably efficient among NP, PR, and SN. Lack of HIV-1 trans infection in NP was linked to lower cholesterol levels and an increase in the levels of the reverse cholesterol transporter ABCA1 (ATP-binding cassette transporter A1) in APC but not in T cells. Moreover, trans infection mediated by APC from NP could be restored by reconstitution of cholesterol and by inhibiting ABCA1 by mRNA interference. Importantly, this appears to be an inherited trait, as it was evident in APC obtained from NP prior to their primary HIV-1 infection. The present study demonstrates a new mechanism wherein enhanced lipid metabolism in APC results in remarkable control of HIV-1 trans infection that directly relates to lack of HIV-1 disease progression. IMPORTANCE HIV-1 can be captured by antigen-presenting cells (APC) such as dendritic cells and transferred to CD4 helper T cells, which results in greatly enhanced viral replication by a mechanism termed trans infection. A small percentage of HIV-1-infected persons are able to control disease progression for many years without antiretroviral therapy. In our study, we linked this lack of disease progression to a profound inability of APC from these individuals to trans infect T cells. This effect was due to altered lipid metabolism in their APC, which appears to be an inherited trait. These

Isomer-specific regulation of metabolism and PPARgamma signaling by CLA in human preadipocytes

DEFF Research Database (Denmark)

Brown, J Mark; Boysen, Maria Sandberg; Jensen, Søren Skov

2003-01-01

Trans-10,cis-12 conjugated linoleic acid (CLA) has previously been shown to be the CLA isomer responsible for CLA-induced reductions in body fat in animal models, and we have shown that this isomer, but not the cis-9,trans-11 CLA isomer, specifically decreased triglyceride (TG) accumulation...... transporter 4 gene expression. Furthermore, trans-10,cis-12 CLA reduced oleic acid uptake and oxidation when compared with all other treatments. In parallel to CLA's effects on metabolism, trans-10,cis-12 CLA decreased, whereas cis-9,trans-11 CLA increased, the expression of peroxisome proliferator...

Binge-type behavior in rats consuming trans-fat-free shortening.

Science.gov (United States)

Wojnicki, F H E; Charny, G; Corwin, R L W

2008-07-05

Studies from this and another laboratory involving an animal model of binge-type behavior have used vegetable shortening containing trans-fats. Due to reformulations by vegetable shortening manufacturers to remove trans-fats from their products, only trans-fat-free shortenings are now available. The goal of the present study was to assess binge-type behavior in rats with trans-fat and trans-free vegetable shortening. Trans-fat-free shortening was provided to three different groups of non-food-deprived male Sprague Dawley rats on different schedules of access: continuous access (24 h/day-7 days/week), daily access (1 h every day), and intermittent access (1 h on Mondays, Wednesdays, Fridays). Trans-fat shortening was provided to a fourth group on the intermittent access schedule. A fifth group had no shortening access (chow only). Both intermittent groups (trans-fat-free and trans-fat) consumed significantly more shortening during the 1-h period of availability than did the daily group, and there was no difference in shortening intakes between the intermittent groups. These results are identical to previous reports of binge-type behavior in rats using this model. Thus, binge-type behavior in the present behavioral model depends upon the schedule of access, not the presence of trans-fats in the shortening.

Conjugated Linoleic Acid (CLA) content in different tissues of ruminants fed with CLA supplementation

OpenAIRE

Pellattiero, Erika

2014-01-01

Conjugated Linoleic Acid (CLA) are a group of positional and geometric isomers of Linoleic Acid characterized by a carbon chain containing 18 carbon atoms and two double bonds, not in the classic position (cis), but conjugated from the carbons atoms 9, 10 or 11. Double bonds have different position in the carbon chain ([7,9], [8,10], [9,11], [10,12], [11,13] and [12,14]) and four different geometric distribution (cis/trans, trans/cis, cis/cis and trans/trans). In total 24 possible isomers are...

A generalized allosteric mechanism for cis-regulated cyclic nucleotide binding domains.

Directory of Open Access Journals (Sweden)

Alexandr P Kornev

2008-04-01

Full Text Available Cyclic nucleotides (cAMP and cGMP regulate multiple intracellular processes and are thus of a great general interest for molecular and structural biologists. To study the allosteric mechanism of different cyclic nucleotide binding (CNB domains, we compared cAMP-bound and cAMP-free structures (PKA, Epac, and two ionic channels using a new bioinformatics method: local spatial pattern alignment. Our analysis highlights four major conserved structural motifs: 1 the phosphate binding cassette (PBC, which binds the cAMP ribose-phosphate, 2 the "hinge," a flexible helix, which contacts the PBC, 3 the beta(2,3 loop, which provides precise positioning of an invariant arginine from the PBC, and 4 a conserved structural element consisting of an N-terminal helix, an eight residue loop and the A-helix (N3A-motif. The PBC and the hinge were included in the previously reported allosteric model, whereas the definition of the beta(2,3 loop and the N3A-motif as conserved elements is novel. The N3A-motif is found in all cis-regulated CNB domains, and we present a model for an allosteric mechanism in these domains. Catabolite gene activator protein (CAP represents a trans-regulated CNB domain family: it does not contain the N3A-motif, and its long range allosteric interactions are substantially different from the cis-regulated CNB domains.

The first astrophysical detection, terahertz spectrum, and database for the monodeuterated species of methyl formate HCOOCH2D

International Nuclear Information System (INIS)

Coudert, L. H.; Drouin, B. J.; Tercero, B.; Cernicharo, J.; Guillemin, J.-C.; Motiyenko, R. A.; Margulès, L.

2013-01-01

Based on new measurements carried out in the laboratory from 0.77 to 1.2 THz and on a line-frequency analysis of these new data, along with previously published data, we build a line list for HCOOCH 2 D that leads to its first detection in the Orion KL nebula. The observed lines, both in space and in the laboratory, involve the cis D-in-plane and trans D-out-of-plane conformations of HCOOCH 2 D and the two tunneling states arising from the large-amplitude motion connecting the two trans configurations. The model used in the line position calculation accounts for both cis and trans conformations, as well as the large-amplitude motion.

The first astrophysical detection, terahertz spectrum, and database for the monodeuterated species of methyl formate HCOOCH{sub 2}D

Energy Technology Data Exchange (ETDEWEB)

Coudert, L. H. [LISA, UMR 7583 CNRS-Universités Paris Est Créteil et Paris Diderot, 61 Avenue du Général de Gaulle, F-94010 Créteil (France); Drouin, B. J. [Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA 91109 (United States); Tercero, B.; Cernicharo, J. [Centro de Astrobiologia (CSIC-INTA), Laboratory of Molecular Astrophysics, Department of Astrophysics, Ctra de Ajalvir, Km 4, E-28850 Torrejón de Ardoz, Madrid (Spain); Guillemin, J.-C. [Institut des Sciences Chimiques de Rennes, UMR 6226 CNRS-ENSCR, 11 Allée de Beaulieu, CS 50837, F-35708 Rennes Cedex 7 (France); Motiyenko, R. A.; Margulès, L., E-mail: laurent.coudert@lisa.u-pec.fr [Laboratoire de Physique des Lasers, Atomes et Molécules, UMR 8523 CNRS-Université Lille I, Bât. P5, F-59655 Villeneuve d' Ascq Cedex (France)

2013-12-20

Based on new measurements carried out in the laboratory from 0.77 to 1.2 THz and on a line-frequency analysis of these new data, along with previously published data, we build a line list for HCOOCH{sub 2}D that leads to its first detection in the Orion KL nebula. The observed lines, both in space and in the laboratory, involve the cis D-in-plane and trans D-out-of-plane conformations of HCOOCH{sub 2}D and the two tunneling states arising from the large-amplitude motion connecting the two trans configurations. The model used in the line position calculation accounts for both cis and trans conformations, as well as the large-amplitude motion.

Mechanism of cis- and trans-substrate interactions at the tetraethylammonium/H+ exchanger of rabbit renal brush-border membrane vesicles

International Nuclear Information System (INIS)

Wright, S.H.; Wunz, T.M.

1988-01-01

The kinetic basis for trans-effects of intravesicular substrates on the uptake of the organic cation, tetraethylammonium (TEA), into rabbit renal brush-border membrane vesicles (BBMV) was studied. Preloading BBMV with 1, 2, or 4 mM TEA stimulated the initial rate of uptake and the total net accumulation of 0.1 mM [ 3 H]TEA. The stimulatory effect of intravesicular TEA on the initial rate of uptake was a saturable function of the trans-TEA concentration, with a half-maximal effect noted at an intravesicular concentration of 0.28 mM. A 1 mM trans-concentration of TEA increased the Jmax of [ 3 H]TEA uptake (from 4.3 to 6.8 nmol.mg-1.min-1) without affecting the apparent Kt. An outwardly directed H+ gradient also increased Jmax (to 10.7 nmol.mg-1.min-1), although the addition of an outwardly directed TEA gradient did not produce further increases in the rate of TEA uptake. External H+ acted as a competitive inhibitor of TEA uptake, and an increase in external [H+] (from 32 nM to 100 nM) produced an increase in the apparent Kt for TEA transport (from 0.12 to 0.26 mM) without affecting the Jmax. The results suggested that TEA and H+ compete for a common site or set of mutually exclusive sites on the cytoplasmic and luminal aspects of TEA/H+ exchanger in the renal brush border, and that these sites have a similar affinity for TEA

Formic acid dimers in a nitrogen matrix

Science.gov (United States)

Lopes, Susy; Fausto, Rui; Khriachtchev, Leonid

2018-01-01

Formic acid (HCOOH) dimers are studied by infrared spectroscopy in a nitrogen matrix and by ab initio calculations. We benefit from the use of a nitrogen matrix where the lifetime of the higher-energy (cis) conformer is very long (˜11 h vs. 7 min in an argon matrix). As a result, in a nitrogen matrix, a large proportion of the cis conformer can be produced by vibrational excitation of the lower-energy (trans) conformer. Three trans-trans, four trans-cis, and three cis-cis dimers are found in the experiments. The spectroscopic information on most of these dimers is enriched compared to the previous studies in an argon matrix. The cis-cis dimers of ordinary formic acid (without deuteration) are reported here for the first time. Several conformational processes are obtained using selective excitation by infrared light, some of them also for the first time. In particular, we report on the formation of cis-cis dimers upon vibrational excitation of trans-cis dimers. Tunneling decays of several dimers have been detected in the dark. The tunneling decay of cis-cis dimers of formic acid as well as the stabilization of cis units in cis-cis dimers is also observed for the first time.

SAXS-WAXS studies of the low-resolution structure in solution of xylose/glucose isomerase from Streptomyces rubiginosus

Science.gov (United States)

Kozak, Maciej; Taube, Michał

2009-10-01

The structure and conformation of molecule of xylose/glucose isomerase from Streptomyces rubiginosus in solution (at pH 6 and 7.6; with and without the substrate) has been studied by small- and wide-angle scattering of synchrotron radiation (SAXS-WAXS). On the basis of the SAXS-WAXS data, the low-resolution structure in solution has been reconstructed using ab inito methods. A comparison of the models of glucose isomerase shows only small differences between the model in solution and the crystal structure.

Footprints of a trypanosomatid RNA world: pre-small subunit rRNA processing by spliced leader addition trans-splicing

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Mario Gustavo Mayer

2012-06-01

Full Text Available The addition of a capped mini-exon [spliced leader (SL] through trans-splicing is essential for the maturation of RNA polymerase (pol II-transcribed polycistronic pre-mRNAs in all members of the Trypanosomatidae family. This process is an inter-molecular splicing reaction that follows the same basic rules of cis-splicing reactions. In this study, we demonstrated that mini-exons were added to precursor ribosomal RNA (pre-rRNA are transcribed by RNA pol I, including the 5' external transcribed spacer (ETS region. Additionally, we detected the SL-5'ETS molecule using three distinct methods and located the acceptor site between two known 5'ETS rRNA processing sites (A' and A1 in four different trypanosomatids. Moreover, we detected a polyadenylated 5'ETS upstream of the trans-splicing acceptor site, which also occurs in pre-mRNA trans-splicing. After treatment with an indirect trans-splicing inhibitor (sinefungin, we observed SL-5'ETS decay. However, treatment with 5-fluorouracil (a precursor of RNA synthesis that inhibits the degradation of pre-rRNA led to the accumulation of SL-5'ETS, suggesting that the molecule may play a role in rRNA degradation. The detection of trans-splicing in these molecules may indicate broad RNA-joining properties, regardless of the polymerase used for transcription.

trans-11 18:1 Vaccenic Acid (TVA Has a Direct Anti-Carcinogenic Effect on MCF-7 Human Mammary Adenocarcinoma Cells

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Ji-Na Lim

2014-02-01

Full Text Available Trans vaccenic acid (TVA; trans-11 18:1 is a positional and geometric isomer of oleic acid and it is the predominant trans isomer found in ruminant fats. TVA can be converted into cis-9, trans-11 conjugated linoleic acid (c9, t11-CLA, a CLA isomer that has many beneficial effects, by stearoyl CoA desaturase 1 (SCD1 in the mammary gland. The health benefits associated with CLA are well documented, but it is unclear whether trans fatty acids (TFAs from ruminant products have healthy effects. Therefore, the effects of TVA on the proliferation of MCF-7 human breast adenocarcinoma cells and MCF-10A human breast epithelial cells were investigated in the present study. Results showed that TVA inhibited the proliferation of MCF-7 cells but not MCF-10A cells by down-regulating the expression of Bcl-2 as well as procaspase-9. In addition, the suppressive effect of TVA was confirmed in SCD1-depleted MCF-7 cells. Our results suggested that TVA exerts a direct anti-carcinogenic effect on MCF-7 cells. These findings provided a better understanding of the research on the anti-carcinogenic effects of TVA and this may facilitate the manufacture of TVA/c9, t11-CLA fortified ruminant products.

Deviation from the trans -Effect in Ligand-Exchange Reactions of Zeise’s Ions PtCl₃(C₂H₄)^- with Heavier Halides (Br^–, I^- )

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Hou, Gao-Lei [Physical; Govind, Niranjan [Environmental; Xantheas, Sotiris S. [Advanced; Department; Wang, Xue-Bin [Physical

2018-01-16

Four new Zeise’s family ions with mixed-halide ligands, i.e., PtCl_nX_3-n(C₂H₄)^- (X = Br, I; n = 1, 2), were synthesized via ligand-exchange reactions of KX salts with KPtCl₃(C₂H₄) in aqueous solutions, and were detected in vacuum via electrospray ionization mass spectrometry. Their photoelectron spectra reveal a series of well-resolved spectral peaks with their electron binding energies (EBEs) decreasing with increasing halide size, with I having a much stronger effect than Br, i.e., 4.57 (–Cl₃) > 4.56 (–Cl₂Br) > 4.53 (–ClBr₂) > 4.34 (–Cl₂I) > 4.30 eV (–ClI₂). Ab initio electronic structure calculations including spin-orbit coupling (SOC) predict that the cis- and trans-isomers are nearly isoenergetic with the cis-isomer for –Cl₂X, and the trans-isomer for –ClX₂ slightly favored, respectively. Excited-state spectra calculated with time-dependent density functional theory (TDDFT), and their comparison with the observed ones, suggest that for each species, both the cis- and trans-configurations coexist in the experiments and contribute to the observed spectra, a fact that clearly violates the prediction of the widely accepted trans-effect, which suggests that only one isomer would have formed.

cis-Stilbene and (1 alpha,2 beta,3 alpha)-(2-ethenyl-3-methoxycyclopropyl)benzene as mechanistic probes in the Mn(III)(salen)-catalyzed epoxidation: influence of the oxygen source and the counterion on the diastereoselectivity of the competitive concerted and radical-type oxygen transfer.

Science.gov (United States)

Adam, Waldemar; Roschmann, Konrad J; Saha-Möller, Chantu R; Seebach, Dieter

2002-05-08

cis-Stilbene (1) has been epoxidized by a set of diverse oxygen donors [OxD], catalyzed by the Mn(III)(salen)X complexes 3 (X = Cl, PF(6)), to afford a mixture of cis- and trans-epoxides 2. The cis/trans ratios range from 29:71 (extensive isomerization) to 92:8, which depends both on the oxygen source [OxD] and on the counterion X of the catalyst. When (1 alpha,2 beta,3 alpha)-(2-ethenyl-3-methoxycyclopropyl)-benzene (4) is used as substrate, a mechanistic probe which differentiates between radical and cationic intermediates, no cationic ring-opening products are found in this epoxidation reaction; thus, isomerized epoxide product arises from intermediary radicals. The dependence of the diastereoselectivity on the oxygen source is rationalized in terms of a bifurcation step in the catalytic cycle, in which concerted Lewis-acid-activated oxygen transfer competes with stepwise epoxidation by the established Mn(V)(oxo) species. The experimental counterion effect is attributed to the computationally assessed ligand-dependent reaction profiles and stereoselectivities of the singlet, triplet, and quintet spin states available to the manganese species.

cis sequence effects on gene expression

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Jacobs Kevin

2007-08-01

Full Text Available Abstract Background Sequence and transcriptional variability within and between individuals are typically studied independently. The joint analysis of sequence and gene expression variation (genetical genomics provides insight into the role of linked sequence variation in the regulation of gene expression. We investigated the role of sequence variation in cis on gene expression (cis sequence effects in a group of genes commonly studied in cancer research in lymphoblastoid cell lines. We estimated the proportion of genes exhibiting cis sequence effects and the proportion of gene expression variation explained by cis sequence effects using three different analytical approaches, and compared our results to the literature. Results We generated gene expression profiling data at N = 697 candidate genes from N = 30 lymphoblastoid cell lines for this study and used available candidate gene resequencing data at N = 552 candidate genes to identify N = 30 candidate genes with sufficient variance in both datasets for the investigation of cis sequence effects. We used two additive models and the haplotype phylogeny scanning approach of Templeton (Tree Scanning to evaluate association between individual SNPs, all SNPs at a gene, and diplotypes, with log-transformed gene expression. SNPs and diplotypes at eight candidate genes exhibited statistically significant (p cis sequence effects in our study, respectively. Conclusion Based on analysis of our results and the extant literature, one in four genes exhibits significant cis sequence effects, and for these genes, about 30% of gene expression variation is accounted for by cis sequence variation. Despite diverse experimental approaches, the presence or absence of significant cis sequence effects is largely supported by previously published studies.

Turkic Communities in South Trans-Urals in the 15th–17th centuries: National, Administrative, Territorial, Ethnosocial Transformations.

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D.N. Maslyuzhenko

2017-06-01

Full Text Available Research objectives: The article reads on the settlement on and the economic use of the south Trans-Urals territories by Turkic communities. Research materials: Published and unpublished sources: books of official orders in the Russian state, chronicles, acts, diplomatic documents, archaeological data, etc. Results and novelty of the research: Traditionally, administrative divisions of Ural and Trans-Urals are considered to be a sort of a naturally emerged structure. Having analyzed the sources, we may conclude: the system of counties’ (uyezd division, as introduced by the Russian state, did not consider the allocation of the communities and their economic management mode. Cattle breeding practices of the local Turks determined the specifity of their economic activities. Many Turks’ volosts (ancestral territories were compound and consisted of two parts: the winter part and the summer one. These two parts could be quite long-distance, divided by the Urals and upon being included into the Russian state they were designated to different uyezds. For instance, one part of Tersyak volost was assigned to Verkhoturskiy uyezd and the second – to Tyumensky uyezd; the western part of the Myakotinskaya (Bakatin volost was located in Ufimsky uyezd and the eastern – in Tyumensky uyezd, which was in the lower reach of the Iset and Pyshma rivers. Consequently, by the moment of being merged into the Russian state, the territories indicated below were economically managed by the local Turks: South Trans-Urals and a part of Cis-Urals, including the territories in the upperstreams of the Ufa and Chusovaya rivers, along the Pyshma and Iset rivers, partially the Tura river, and Tobol between the outflows of the Miass and Tura. The given practice arose in the late Middle Ages and was intimately connected with Shibanids’ claims who ruled in Tyumen and Siberian Khanates. They claimed not only to the territories in the south of West Siberia, Aral Sea region

Improved separation of conjugated fatty acid methyl esters by silver ion-high-performance liquid chromatography.

Science.gov (United States)

Sehat, N; Rickert, R; Mossoba, M M; Kramer, J K; Yurawecz, M P; Roach, J A; Adlof, R O; Morehouse, K M; Fritsche, J; Eulitz, K D; Steinhart, H; Ku, Y

1999-04-01

Operating from one to six silver ion-high-performance liquid chromatography (Ag+-HPLC) columns in series progressively improved the resolution of the methyl esters of conjugated linoleic acid (CLA) isomeric mixtures from natural and commercial products. In natural products, the 8 trans, 10 cis-octadecadienoic (18:2) acid was resolved from the more abundant 7 trans, 9 cis-18:2, and the 10 trans, 12 cis-18:2 was separated from the major 9 cis, 11 trans-18:2 peak. In addition, both 11 trans, 13 cis-18:2 and 11 cis, 13 trans-18:2 isomers were found in natural products and were separated; the presence of the latter, 11 cis, 13 trans-18:2, was established in commercial CLA preparations. Three Ag+-HPLC columns in series appeared to be the best compromise to obtain satisfactory resolution of most CLA isomers found in natural products. A single Ag+-HPLC column in series with one of several normal-phase columns did not improve the resolution of CLA isomers as compared to that of the former alone. The 20:2 conjugated fatty acid isomers 11 cis, 13 trans-20:2 and 12 trans, 14 cis-20:2, which were synthesized by alkali isomerization from 11 cis, 14 cis-20:2, eluted in the same region of the Ag+-HPLC chromatogram just before the corresponding geometric CLA isomers. Therefore, CLA isomers will require isolation based on chain length prior to Ag+-HPLC separation. The positions of conjugated double bonds in 20:2 and 18:2 isomers were established by gas chromatography-electron ionization mass spectrometry as their 4,4-dimethyloxazoline derivatives. The double-bond geometry was determined by gas chromatography-direct deposition-Fourier transform infrared spectroscopy and by the Ag+-HPLC relative elution order.

Differential Potency of 2,6-Dimethylcyclohexanol Isomers for Positive Modulation of GABAA Receptor Currents.

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Chowdhury, Luvana; Croft, Celine J; Goel, Shikha; Zaman, Naina; Tai, Angela C-S; Walch, Erin M; Smith, Kelly; Page, Alexandra; Shea, Kevin M; Hall, C Dennis; Jishkariani, D; Pillai, Girinath G; Hall, Adam C

2016-06-01

GABAA receptors meet all of the pharmacological requirements necessary to be considered important targets for the action of general anesthetic agents in the mammalian brain. In the following patch-clamp study, the relative modulatory effects of 2,6-dimethylcyclohexanol diastereomers were investigated on human GABAA (α1β3γ2s) receptor currents stably expressed in human embryonic kidney cells. Cis,cis-, trans,trans-, and cis,trans-isomers were isolated from commercially available 2,6-dimethylcyclohexanol and were tested for positive modulation of submaximal GABA responses. For example, the addition of 30 μM cis,cis-isomer resulted in an approximately 2- to 3-fold enhancement of the EC20 GABA current. Coapplications of 30 μM 2,6-dimethylcyclohexanol isomers produced a range of positive enhancements of control GABA responses with a rank order for positive modulation: cis,cis > trans,trans ≥ mixture of isomers > > cis,trans-isomer. In molecular modeling studies, the three cyclohexanol isomers bound with the highest binding energies to a pocket within transmembrane helices M1 and M2 of the β3 subunit through hydrogen-bonding interactions with a glutamine at the 224 position and a tyrosine at the 220 position. The energies for binding to and hydrogen-bond lengths within this pocket corresponded with the relative potencies of the agents for positive modulation of GABAA receptor currents (cis,cis > trans,trans > cis,trans-2,6-dimethylcyclohexanol). In conclusion, the stereochemical configuration within the dimethylcyclohexanols is an important molecular feature in conferring positive modulation of GABAA receptor activity and for binding to the receptor, a consideration that needs to be taken into account when designing novel anesthetics with enhanced therapeutic indices. Copyright © 2016 by The American Society for Pharmacology and Experimental Therapeutics.

Contribution of two ζ-carotene desaturases to the poly-cis desaturation pathway in the cyanobacterium Nostoc PCC 7120.

Science.gov (United States)

Breitenbach, Jürgen; Bruns, Marius; Sandmann, Gerhard

2013-07-01

The presence of two completely unrelated ζ-carotene desaturases CrtQa and CrtQb in some Nostoc strains is unique. CrtQb is the ζ-carotene desaturase, which was acquired by almost all cyanobacteria. The additional CrtQa can be regarded as an evolutionary relict of the CrtI desaturase present in non-photosynthetic bacteria. By reconstruction of the carotene desaturation pathway, we showed that both enzymes from Nostoc PCC 7120 were active. However, they differed in their preferred utilization of ζ-carotene Z isomers. CrtQa converted ζ-carotene isomers that were poorly metabolized by CrtQb. In this respect, CrtQa complemented the reactions of CrtQb, which is an advantage avoiding dead ends in the poly-cis desaturation pathway. In addition to ζ-carotene desaturation, CrtQa still possesses the Z to E isomerase function of the ancestral desaturase CrtI. Biochemical characterization showed that CrtQb is an enzyme with one molecule of tightly bound FAD and acts as a dehydrogenase transferring hydrogen to oxidized plastoquinone.

Single d(ApG)/cis-diamminedichloroplatinum(II) adduct-induced mutagenesis in Escherichia coli

International Nuclear Information System (INIS)

Burnouf, D.; Fuchs, R.P.P.; Gauthier, C.; Chottard, J.C.

1990-01-01

The mutation spectrum induced by the widely used antitumor drug cis-diamminedichloroplatinum(II) (cis-DDP) showed that cisDDP[d(ApG)] adducts, although they account for only 25% of the lesions formed are ∼5 times more mutagenic than the major GG adduct. The authors report the construction of vectors bearing a single cisDDP[d(ApG)] lesion and their use in mutagenesis experiments in Escherichia coli. The mutagenic processing of the lesion is found to depend strictly on induction of the SOS system of the bacterial host cells. In SOS-induced cells, mutation frequencies of 1-2% were detected. All these mutations are targeted to the 5' base of the adduct. Single A → T transversions are mainly observed (80%), whereas A → G transitions account for 10% of the total mutations. Tandem base-pair substitutions involving the adenine residue and the thymine residue immediately 5' to the adduct occur at a comparable frequency (10%). No selective loss of the strand bearing the platinum adduct was seen, suggesting that, in vivo, cisDDP[d(ApG)] adducts are not blocking lesions. The high mutation specificity of cisDDP-[d(ApG)]-induced mutagenesis is discussed in relation to structural data

Affinity labeling and characterization of the active site histidine of glucosephosphate isomerase

International Nuclear Information System (INIS)

Gibson, D.R.; Gracy, R.W.; Hartman, F.C.

1980-01-01

N-bromoacetylethanolamine phosphate was found to act as a specific affinity label for the active center of glucosephosphate isomerase. The inactivation process followed pseudo-first order kinetics, was irreversible, and exhibited rate saturation kinetics with minimal half-lives of inactivation of 4.5 and 6.3 min for the enzyme isolated from human placenta and rabbit muscle, respectively. The pH dependence of the inactivation process closely paralleled the pH dependence of the overall catalytic process with pK/sub a/ values at pH 6.4 and 9.0. The stoichiometry of labeling of either enzyme, as determined with N-bromo[ 14 C 2 ]acetylethanolamine phosphate, was 1 eq of the affinity label/subunit of enzyme. After acid hydrolysis and amino acid analysis of the radioactive affinity-labeled human enzyme, only radioactive 3-carboxymethyl histidine was found. In the case of the rabbit enzyme, the only radioactive derivative obtained was 1-carboxymethyl histidine. Active site tryptic peptides were isolated by solvent extraction, thin layer peptide fingerprinting, and ion exchange chromatography before and after removal of the phosphate from the active site peptide. Amino acid analysis of the labeled peptides from the two species were very similar. Using high sensitivity methods for sequence analysis, the primary structure of the active site was established as Val-Leu-His-Ala-Glu-Asn-Val-Asp (Gly,Thr,Ser) Glu-Ile (Thr-Gly-His-Lys-Glx)-Tyr-Phe. Apparent sequence homology between the catalytic center of glucosephosphate isomerase and triosephosphate isomerase suggest that the two enzymes may have evolved from a common ancestral gene

Molecular phylogenetics and comparative modeling of HEN1, a methyltransferase involved in plant microRNA biogenesis

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Obarska Agnieszka

2006-01-01

Full Text Available Abstract Background Recently, HEN1 protein from Arabidopsis thaliana was discovered as an essential enzyme in plant microRNA (miRNA biogenesis. HEN1 transfers a methyl group from S-adenosylmethionine to the 2'-OH or 3'-OH group of the last nucleotide of miRNA/miRNA* duplexes produced by the nuclease Dicer. Previously it was found that HEN1 possesses a Rossmann-fold methyltransferase (RFM domain and a long N-terminal extension including a putative double-stranded RNA-binding motif (DSRM. However, little is known about the details of the structure and the mechanism of action of this enzyme, and about its phylogenetic origin. Results Extensive database searches were carried out to identify orthologs and close paralogs of HEN1. Based on the multiple sequence alignment a phylogenetic tree of the HEN1 family was constructed. The fold-recognition approach was used to identify related methyltransferases with experimentally solved structures and to guide the homology modeling of the HEN1 catalytic domain. Additionally, we identified a La-like predicted RNA binding domain located C-terminally to the DSRM domain and a domain with a peptide prolyl cis/trans isomerase (PPIase fold, but without the conserved PPIase active site, located N-terminally to the catalytic domain. Conclusion The bioinformatics analysis revealed that the catalytic domain of HEN1 is not closely related to any known RNA:2'-OH methyltransferases (e.g. to the RrmJ/fibrillarin superfamily, but rather to small-molecule methyltransferases. The structural model was used as a platform to identify the putative active site and substrate-binding residues of HEN and to propose its mechanism of action.

A Role of a Newly Identified Isomerase From Yarrowia lipolytica in Erythritol Catabolism

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Aleksandra M. Mirończuk

2018-05-01

Full Text Available Erythritol is a natural sweetener produced by microorganisms as an osmoprotectant. It belongs to the group of polyols and it can be utilized by the oleaginous yeast Yarrowia lipolytica. Despite the recent identification of the transcription factor of erythritol utilization (EUF1, the metabolic pathway of erythritol catabolism remains unknown. In this study we identified a new gene, YALI0F01628g, involved in erythritol assimilation. In silico analysis showed that YALI0F01628g is a putative isomerase and it is localized in the same region as EUF1. qRT-PCR analysis of Y. lipolytica showed a significant increase in YALI0F01628g expression during growth on erythritol and after overexpression of EUF1. Moreover, the deletion strain ΔF01628 showed significantly impaired erythritol assimilation, whereas synthesis of erythritol remained unchanged. The results showed that YALI0F1628g is involved in erythritol assimilation; thus we named the gene EYI1. Moreover, we suggest the metabolic pathway of erythritol assimilation in yeast Y. lipolytica.

Peel Region TransHelp's experience

Energy Technology Data Exchange (ETDEWEB)

NONE

2009-09-15

TransHelp was founded in the Peel Region of Ontario in 1981 to provide paratransit service to individuals unable to use conventional transit. The TransHelp vehicle fleet consists of 40 buses that make over 220,000 one way trips annually. Each vehicle has a typical life span of between 375,000 and 425,000 km. TransHelp vehicles spend much of their time idling in emissions-sensitive areas, such as outside hospitals. In order to reduce fuel costs, TransHelp adopted the use of propane to fuel its vehicles. However, difficulties were experienced with this technology, particularly on V-10 engines where increased maintenance was a problem. SFI Technologies Inc. provided a solution with their SEQUIN System which allows seamless transitioning between gasoline and propane under all conditions without any operator involvement in fuel selection. The technology favours propane as the fuel of choice and automatically switches between propane and gasoline based on the ideal conditions at the time of operation. The technology has received certification from the Environmental Protection Agency in the United States and the Canadian Standards Association. The use of the SEQUIN System has proven to successful for TransHelp. It has allowed the use of propane to be continued, meaning that vehicle emissions are greatly reduced relative to gasoline or diesel fuelled vehicles. TransHelp has realized a fuel savings of 15-20 per cent over gasoline and receives an additional federal transit rebate of 15 per cent for the conversion cost.

Studies on the production of glucose isomerase by Bacillus licheniformis

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Nwokoro Ogbonnaya

2015-09-01

Full Text Available This work reports the effects of some culture conditions on the production of glucose isomerase by Bacillus licheniformis. The bacterium was selected based on the release of 3.62 mg/mL fructose from the fermentation of glucose. Enzyme was produced using a variety of carbon substrates but the highest enzyme activity was detected in a medium containing 0.5% xylose and 1% glycerol (specific activity = 6.88 U/mg protein. Media containing only xylose or glucose gave lower enzyme productivies (specific activities= 4.60 and 2.35 U/mg protein respectively. The effects of nitrogen substrates on glucose isomerase production showed that yeast extract supported maximum enzyme activity (specific activity = 5.24 U/mg protein. Lowest enzyme activity was observed with sodium trioxonitrate (specific activity = 2.44 U/mg protein. In general, organic nitrogen substrates supported higher enzyme productivity than inorganic nitrogen substrates. Best enzyme activity was observed in the presence of Mg2+ (specific activity = 6.85 U/mg protein while Hg2+ was inhibitory (specific activity = 1.02 U/mg protein. The optimum pH for best enzyme activity was 6.0 while optimum temperature for enzyme production was 50ºC.

Structure of ribose 5-phosphate isomerase from the probiotic bacterium Lactobacillus salivarius UCC118.

Science.gov (United States)

Lobley, Carina M C; Aller, Pierre; Douangamath, Alice; Reddivari, Yamini; Bumann, Mario; Bird, Louise E; Nettleship, Joanne E; Brandao-Neto, Jose; Owens, Raymond J; O'Toole, Paul W; Walsh, Martin A

2012-12-01

The structure of ribose 5-phosphate isomerase from the probiotic bacterium Lactobacillus salivarius UCC188 has been determined at 1.72 Å resolution. The structure was solved by molecular replacement, which identified the functional homodimer in the asymmetric unit. Despite only showing 57% sequence identity to its closest homologue, the structure adopted the typical α and β D-ribose 5-phosphate isomerase fold. Comparison to other related structures revealed high homology in the active site, allowing a model of the substrate-bound protein to be proposed. The determination of the structure was expedited by the use of in situ crystallization-plate screening on beamline I04-1 at Diamond Light Source to identify well diffracting protein crystals prior to routine cryocrystallography.

Conjugated Linoleic Acid Production by Bifidobacteria: Screening, Kinetic, and Composition

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Stefano Raimondi

2016-01-01

Full Text Available Conjugated linoleic acids (CLA are positional and geometric isomers of linoleic acid involved in a number of health aspects. In humans, CLA production is performed by gut microbiota, including some species of potential probiotic bifidobacteria. 128 strains of 31 Bifidobacterium species were screened with a spectrophotometric assay to identify novel CLA producers. Most species were nonproducers, while producers belonged to B. breve and B. pseudocatenulatum. GC-MS revealed that CLA producer strains yielded 9cis,11trans-CLA and 9trans,11trans-CLA, without any production of other isomers. Hydroxylated forms of LA were absent in producer strains, suggesting that the myosin-cross-reactive antigen (MCRA protein that exerts hydratase activity is not involved in LA isomerization. Moreover, both CLA producer and nonproducer species bear a MCRA homologue. The strain B. breve WC 0421 was the best CLA producer, converting LA into 68.8% 9cis,11trans-CLA and 25.1% 9trans,11trans-CLA. Production occurred mostly during the lag and the exponential phase. For the first time, production and incorporation of CLA in biomass were assessed. B. breve WC 0421 stored CLA in the form of free fatty acids, without changing the composition of the esterified fatty acids, which mainly occurred in the plasmatic membrane.

Cis-Lunar Base Camp

Science.gov (United States)

Merrill, Raymond G.; Goodliff, Kandyce E.; Mazanek, Daniel D.; Reeves, John D., Jr.

2012-01-01

Historically, when mounting expeditions into uncharted territories, explorers have established strategically positioned base camps to pre-position required equipment and consumables. These base camps are secure, safe positions from which expeditions can depart when conditions are favorable, at which technology and operations can be tested and validated, and facilitate timely access to more robust facilities in the event of an emergency. For human exploration missions into deep space, cis-lunar space is well suited to serve as such a base camp. The outer regions of cis-lunar space, such as the Earth-Moon Lagrange points, lie near the edge of Earth s gravity well, allowing equipment and consumables to be aggregated with easy access to deep space and to the lunar surface, as well as more distant destinations, such as near-Earth Asteroids (NEAs) and Mars and its moons. Several approaches to utilizing a cis-lunar base camp for sustainable human exploration, as well as some possible future applications are identified. The primary objective of the analysis presented in this paper is to identify options, show the macro trends, and provide information that can be used as a basis for more detailed mission development. Compared within are the high-level performance and cost of 15 preliminary cis-lunar exploration campaigns that establish the capability to conduct crewed missions of up to one year in duration, and then aggregate mass in cis-lunar space to facilitate an expedition from Cis-Lunar Base Camp. Launch vehicles, chemical propulsion stages, and electric propulsion stages are discussed and parametric sizing values are used to create architectures of in-space transportation elements that extend the existing in-space supply chain to cis-lunar space. The transportation options to cis-lunar space assessed vary in efficiency by almost 50%; from 0.16 to 0.68 kg of cargo in cis-lunar space for every kilogram of mass in Low Earth Orbit (LEO). For the 15 cases, 5-year campaign

Glucose(xylose isomerase production by Streptomyces sp. CH7 grown on agricultural residues

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Kankiya Chanitnun

2012-09-01

Full Text Available Streptomyces sp. CH7 was found to efficiently produce glucose(xylose isomerase when grown on either xylan or agricultural residues. This strain produced a glucose(xylose isomerase activity of roughly 1.8 U/mg of protein when it was grown in medium containing 1% xylose as a carbon source. Maximal enzymatic activities of about 5 and 3 U/mg were obtained when 1% xylan and 2.5% corn husks were used, respectively. The enzyme was purified from a mycelial extract to 16-fold purity with only two consecutive column chromatography steps using Macro-prep DEAE and Sephacryl-300, respectively. The approximate molecular weight of the purified enzyme is 170 kDa, and it has four identical subunits of 43.6 kDa as estimated by SDS-PAGE. Its Km values for glucose and xylose were found to be 258.96 and 82.77 mM, respectively, and its Vmax values are 32.42 and 63.64 μM/min/mg, respectively. The purified enzyme is optimally active at 85ºC and pH 7.0. It is stable at pH 5.5-8.5 and at temperatures up to 60ºC after 30 min. These findings indicate that glucose(xylose isomerase from Streptomyces sp. CH7 has the potential for industrial applications, especially for high-fructose syrup production and bioethanol fermentation from hemicellulosic hydrolysates by Saccharomyces cerevisiae.

Mapping Discrimination Experienced by Indonesian Trans* FtM Persons.

Science.gov (United States)

Gordon, Danny; Pratama, Mario Prajna

2017-01-01

This work sought to document how Indonesian trans* FtM persons experienced discrimination across the interlinked domains of social networks, religious and educational institutions, employment and the workplace, and health care institutions. Objectives were (1) to map the discrimination experienced by trans* FtM individuals in Indonesia, and (2) to establish the specific priorities of the Indonesian trans* FtM community. In-depth interviews, focus groups, and participant observation was used involving 14 respondents. Findings revealed that respondents experienced othering through rejection, misidentification, harassment, "correction," and bureaucratic discrimination across the five preestablished domains. Health care and a lack of information emerged as areas of particular concern for respondents. This work calls for health care that is sensitive to the needs of trans* FtM people coupled with high-quality information to alleviate the cycles through which discrimination is sustained.

Optimization of extraction of high purity all-trans-lycopene from tomato pulp waste.

Science.gov (United States)

Poojary, Mahesha M; Passamonti, Paolo

2015-12-01

The aim of this work was to optimize the extraction of pure all-trans-lycopene from the pulp fractions of tomato processing waste. A full factorial design (FFD) consisting of four independent variables including extraction temperature (30-50 °C), time (1-60 min), percentage of acetone in n-hexane (25-75%, v/v) and solvent volume (10-30 ml) was used to investigate the effects of process variables on the extraction. The absolute amount of lycopene present in the pulp waste was found to be 0.038 mg/g. The optimal conditions for extraction were as follows: extraction temperature 20 °C, time 40 min, a solvent composition of 25% acetone in n-hexane (v/v) and solvent volume 40 ml. Under these conditions, the maximal recovery of lycopene was 94.7%. The HPLC-DAD analysis demonstrated that, lycopene was obtained in the all-trans-configuration at a very high purity grade of 98.3% while the amount of cis-isomers and other carotenoids were limited. Copyright © 2015 Elsevier Ltd. All rights reserved.

Crystal Structure and Substrate Specificity of D-Galactose-6-Phosphate Isomerase Complexed with Substrates

Science.gov (United States)

Lee, Jung-Kul; Pan, Cheol-Ho

2013-01-01

D-Galactose-6-phosphate isomerase from Lactobacillus rhamnosus (LacAB; EC 5.3.1.26), which is encoded by the tagatose-6-phosphate pathway gene cluster (lacABCD), catalyzes the isomerization of D-galactose-6-phosphate to D-tagatose-6-phosphate during lactose catabolism and is used to produce rare sugars as low-calorie natural sweeteners. The crystal structures of LacAB and its complex with D-tagatose-6-phosphate revealed that LacAB is a homotetramer of LacA and LacB subunits, with a structure similar to that of ribose-5-phosphate isomerase (Rpi). Structurally, LacAB belongs to the RpiB/LacAB superfamily, having a Rossmann-like αβα sandwich fold as has been identified in pentose phosphate isomerase and hexose phosphate isomerase. In contrast to other family members, the LacB subunit also has a unique α7 helix in its C-terminus. One active site is distinctly located at the interface between LacA and LacB, whereas two active sites are present in RpiB. In the structure of the product complex, the phosphate group of D-tagatose-6-phosphate is bound to three arginine residues, including Arg-39, producing a different substrate orientation than that in RpiB, where the substrate binds at Asp-43. Due to the proximity of the Arg-134 residue and backbone Cα of the α6 helix in LacA to the last Asp-172 residue of LacB with a hydrogen bond, a six-carbon sugar-phosphate can bind in the larger pocket of LacAB, compared with RpiB. His-96 in the active site is important for ring opening and substrate orientation, and Cys-65 is essential for the isomerization activity of the enzyme. Two rare sugar substrates, D-psicose and D-ribulose, show optimal binding in the LacAB-substrate complex. These findings were supported by the results of LacA activity assays. PMID:24015281

Crystal structure and substrate specificity of D-galactose-6-phosphate isomerase complexed with substrates.

Directory of Open Access Journals (Sweden)

Woo-Suk Jung

Full Text Available D-Galactose-6-phosphate isomerase from Lactobacillus rhamnosus (LacAB; EC 5.3.1.26, which is encoded by the tagatose-6-phosphate pathway gene cluster (lacABCD, catalyzes the isomerization of D-galactose-6-phosphate to D-tagatose-6-phosphate during lactose catabolism and is used to produce rare sugars as low-calorie natural sweeteners. The crystal structures of LacAB and its complex with D-tagatose-6-phosphate revealed that LacAB is a homotetramer of LacA and LacB subunits, with a structure similar to that of ribose-5-phosphate isomerase (Rpi. Structurally, LacAB belongs to the RpiB/LacAB superfamily, having a Rossmann-like αβα sandwich fold as has been identified in pentose phosphate isomerase and hexose phosphate isomerase. In contrast to other family members, the LacB subunit also has a unique α7 helix in its C-terminus. One active site is distinctly located at the interface between LacA and LacB, whereas two active sites are present in RpiB. In the structure of the product complex, the phosphate group of D-tagatose-6-phosphate is bound to three arginine residues, including Arg-39, producing a different substrate orientation than that in RpiB, where the substrate binds at Asp-43. Due to the proximity of the Arg-134 residue and backbone Cα of the α6 helix in LacA to the last Asp-172 residue of LacB with a hydrogen bond, a six-carbon sugar-phosphate can bind in the larger pocket of LacAB, compared with RpiB. His-96 in the active site is important for ring opening and substrate orientation, and Cys-65 is essential for the isomerization activity of the enzyme. Two rare sugar substrates, D-psicose and D-ribulose, show optimal binding in the LacAB-substrate complex. These findings were supported by the results of LacA activity assays.

Direct production of D-arabinose from D-xylose by a coupling reaction using D-xylose isomerase, D-tagatose 3-epimerase and D-arabinose isomerase.

Science.gov (United States)

Sultana, Ishrat; Mizanur, Rahman Md; Takeshita, Kei; Takada, Goro; Izumori, Ken

2003-01-01

Klebsiella pneumoniae 40bXX, a mutant strain that constitutively produces D-arabinose isomerase (D-AI), was isolated through a series of repeated subcultures from the parent strain on a mineral salt medium supplemented with L-Xylose as the sole carbon source. D-AI could be efficiently immobilized on chitopearl beads. The optimum temperature for the activity of the immobilized enzyme was 40 degrees C and the enzyme was stable up to 50 degrees C. The D-Al was active at pH 10.0 and was stable in the range of pH 6.0-11.0. The enzyme required manganese ions for maximum activity. Three immobilized enzymes, D-xylose isomerase (D-XI), D-tagatose 3-epimerase (D-TE and D-AI were used for the preparation of D-arabinose from D-xylose in a coupling reaction. After completion of the reaction, degradation of D-xylulose was carried out by Saccharomyces cerevisiae. The reaction mixture containing D-Xylose, D-ribulose and the product was then separated by ion exchange column chromatography. After crystallization, the product was checked by HPLC, IR spectroscopy, NMR spectroscopy and optical rotation measurements. Finally, 2.0 g of D-arabinose could be obtained from 5 g of the substrate.

Trans10,cis12 conjugated linoleic acid inhibits proliferation and migration of ovarian cancer cells by inducing ER stress, autophagy, and modulation of Src.

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Mian M K Shahzad

Full Text Available The goal of this study was to investigate the anti-cancer effects of Trans10,cis12 conjugated linoleic acid (t10,c12 CLA. MTT assays and QCM™ chemotaxis 96-wells were used to test the effect of t10,c12 CLA on the proliferation and migration and invasion of cancer cells. qPCR and Western Blotting were used to determine the expression of specific factors. RNA sequencing was conducted using the Illumina platform and apoptosis was measured using a flow cytometry assay. t10,c12 CLA (IC50, 7 μM inhibited proliferation of ovarian cancer cell lines SKOV-3 and A2780. c9,t11 CLA did not attenuate the proliferation of these cells. Transcription of 165 genes was significantly repressed and 28 genes were elevated. Genes related to ER stress, ATF4, CHOP, and GADD34 were overexpressed whereas EDEM2 and Hsp90, genes required for proteasomal degradation of misfolded proteins, were downregulated upon treatment. While apoptosis was not detected, t10,c12 CLA treatment led to 9-fold increase in autophagolysosomes and higher levels of LC3-II. G1 cell cycle arrest in treated cells was correlated with phosphorylation of GSK3β and loss of β-catenin. microRNA miR184 and miR215 were upregulated. miR184 likely contributed to G1 arrest by downregulating E2F1. miR215 upregulation was correlated with increased expression of p27/Kip-1. t10,c12 CLA-mediated inhibition of invasion and migration correlated with decreased expression of PTP1b and decreased Src activation by inhibiting phosphorylation at Tyr416. Due to its ability to inhibit proliferation and migration, t10,c12 CLA should be considered for treatment of ovarian cancer.

Trans10,cis12 conjugated linoleic acid inhibits proliferation and migration of ovarian cancer cells by inducing ER stress, autophagy, and modulation of Src.

Science.gov (United States)

Shahzad, Mian M K; Felder, Mildred; Ludwig, Kai; Van Galder, Hannah R; Anderson, Matthew L; Kim, Jong; Cook, Mark E; Kapur, Arvinder K; Patankar, Manish S

2018-01-01

The goal of this study was to investigate the anti-cancer effects of Trans10,cis12 conjugated linoleic acid (t10,c12 CLA). MTT assays and QCM™ chemotaxis 96-wells were used to test the effect of t10,c12 CLA on the proliferation and migration and invasion of cancer cells. qPCR and Western Blotting were used to determine the expression of specific factors. RNA sequencing was conducted using the Illumina platform and apoptosis was measured using a flow cytometry assay. t10,c12 CLA (IC50, 7 μM) inhibited proliferation of ovarian cancer cell lines SKOV-3 and A2780. c9,t11 CLA did not attenuate the proliferation of these cells. Transcription of 165 genes was significantly repressed and 28 genes were elevated. Genes related to ER stress, ATF4, CHOP, and GADD34 were overexpressed whereas EDEM2 and Hsp90, genes required for proteasomal degradation of misfolded proteins, were downregulated upon treatment. While apoptosis was not detected, t10,c12 CLA treatment led to 9-fold increase in autophagolysosomes and higher levels of LC3-II. G1 cell cycle arrest in treated cells was correlated with phosphorylation of GSK3β and loss of β-catenin. microRNA miR184 and miR215 were upregulated. miR184 likely contributed to G1 arrest by downregulating E2F1. miR215 upregulation was correlated with increased expression of p27/Kip-1. t10,c12 CLA-mediated inhibition of invasion and migration correlated with decreased expression of PTP1b and decreased Src activation by inhibiting phosphorylation at Tyr416. Due to its ability to inhibit proliferation and migration, t10,c12 CLA should be considered for treatment of ovarian cancer.

Trans-10, cis-12 conjugated linoleic acid decreases de novo lipid synthesis in human adipocytes

DEFF Research Database (Denmark)

Obsen, Thomas; Faergeman, Nils J; Chung, Soonkyu

2012-01-01

7-12 h, respectively. The mRNA levels of liver X receptor (LXR)α and sterol regulatory element binding protein (SREBP)-1c, transcription factors that regulate SCD-1, were decreased by 10,12 CLA within 5 h. These data suggest that the isomer-specific decrease in de novo lipid synthesis by 10,12 CLA......]-oleic or [(14)C]-linoleic acids. When using [(14)C]-acetic acid and [(14)C]-pyruvic acid as substrates, 30 μM 10,12 CLA, but not 9,11 CLA, decreased de novo synthesis of triglyceride, free FA, diacylglycerol, cholesterol esters, cardiolipin, phospholipids and ceramides within 3-24 h. Treatment with 30 μM 10...... is due, in part, to the rapid repression of lipogenic transcription factors that regulate MUFA synthesis, suggesting an anti-obesity mechanism unique to this trans FA....

Filaggrin compound heterozygous patients carry mutations in trans position

DEFF Research Database (Denmark)

Carlsen, Berit C; Meldgaard, Michael; Johansen, Jeanne D

2013-01-01

by means of allele-specific PCR amplification and analysis of PCR products by agarose gel electrophoresis. All R501X/2282del4 compound heterozygous samples collected over a 4-year period of routine FLG mutation testing were investigated. In total, 37 samples were tested. All thirty-seven R501X/2282del4......More than 40 null mutations in the filaggrin (FLG) gene are described. It is therefore possible to find two different null mutations in one individual (compound heterozygosity). It has been generally perceived that homozygous and compound heterozygous individuals were genotypically comparable......; however, this has not been scientifically investigated. Two different FLG null mutations in the same individual may be in trans position, meaning that each mutation locates to a different allele functionally equivalent to homozygosity, or may be in cis position, meaning that both mutations locate...

Indirect approach to C-3 branched 1,2-cis-glycofuranosides: synthesis of aceric acid glycoside analogues.

Science.gov (United States)

de Oliveira, Marcelo T; Hughes, David L; Nepogodiev, Sergey A; Field, Robert A

2008-02-04

Aceric acid (3-C-carboxy-5-deoxy-alpha-l-xylofuranose) residues are present in pectic polysaccharide rhamnogalacturonan II (RG II) in the form of synthetically challenging 1,2-cis-glycofuranosides. To access synthetic fragments of RG II incorporating aceric acid, a four-step procedure based on C-2 epimerisation of initially prepared 1,2-trans-glycofuranoside was developed. Readily available derivatives of branched-chain l-lyxofuranose bearing a 3-C-vinyl group as a masked 3-C-carboxyl group were investigated as potential precursors of aceric acid units. In the first step of the procedure, installation of a participating group at C-2 of the furanose ring ensured stereocontrol of the O-glycosylation, which was carried out with the thioglycoside of 2-O-acetyl-3,5-di-O-benzyl-3-C-vinyl-L-lyxofuranose. After the glycosylation step, the 2-O-acetyl group was removed, the free 2-OH group was oxidised and the resulting ketone was finally reduced to form the C-3-vinyl-L-xylofuranoside. The use of L-Selectride in the key reduction reaction was essential to achieve the required stereoselectivity to generate 1,2-cis-furanoside.

Bioconversion of D-galactose into D-tagatose by expression of L-arabinose isomerase.

Science.gov (United States)

Roh, H J; Kim, P; Park, Y C; Choi, J H

2000-02-01

D-Tagatose is a potential bulking agent in food as a non-calorific sweetener. To produce D-tagatose from cheaper resources, plasmids harbouring the L-arabinose isomerase gene (araA) from Escherichia coli, Bacillus subtilis and Salmonella typhimurium were constructed because L-arabinose isomerase was suggested previously as an enzyme that mediates the bioconversion of galactose into tagatose as well as that of arabinose to ribulose. The constructed plasmids were named pTC101, pTC105 and pTC106, containing araA from E. coli, B. subtilis and S. typhimurium respectively. In the cultures of recombinant E. coli with pTC101, pTC105 and pTC106, tagatose was produced from galactose in 9.9, 7.1 and 6.9% yields respectively. The enzyme extract of E. coli with the plasmid pTC101 also converted galactose into tagatose with a 96.4% yield.

Trans fatty acid isomers and the trans-9/trans-11 index in fat containing foods

Science.gov (United States)

Kuhnt, Katrin; Baehr, Melanie; Rohrer, Carsten; Jahreis, Gerhard

2011-01-01

To determine trans fatty acid (TFA) distribution of contemporary foods, especially regarding individual trans octadecenoic acids (trans C18:1), 339 German foods of six categories (semi-solid fats, deep-fried potato products, bakery products, confectioneries, instant products and butter) were analysed using two GC methods. Results showed a high variation of TFA content between and within the categories containing between 0 and 40.5% of FAME except in butter, which is a source of natural TFA. The mean TFA values were below 2.0% of FAME, however, bakery products contained 4.5% and butter fat 3.2%, respectively. In addition, the distribution of individual trans C18:1 differed. In samples containing ruminant fat (butter and various confectioneries), vaccenic acid (t11-C18:1, t11) predominated, while in foods containing industrially hydrogenated fats, elaidic acid (trans-9, t9-) and t10-C18:1 were the major trans isomers.. This was reflected by a low t9/t11 index of 0.3 and 0.5 in butter and ruminant fat containing confectioneries, respectively, whilst the highest index was observed in shortenings and deep-fried potato products at 5.2 and 6.8, respectively. In conclusion, the TFA content of foods available on the German market is generally declining, but substantial variations are present. The t9/t11 index could be used as an indicator to determine ruminant fat. Practical applications: A number of studies provide evidence that a high TFA intake, particularly of industrial origin, adversely affects human health. The TFA content of foods could be reduced due to the introduction of several mandatory regulations and modifications regarding the hydrogenation process of oils. The most abundant dietary TFA are the isomers of trans C18:1. Unfortunately, the differentiation of these isomers is not yet very common, though the trans C18:1 profile differs depending on its origin (bacterial hydrogenation in the rumen or industrial hydrogenation). To date, data for TFA content

Differential trypanosome surface coat regulation by a CCCH protein that co-associates with procyclin mRNA cis-elements.

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Pegine Walrad

2009-02-01

Full Text Available The genome of Trypanosoma brucei is unusual in being regulated almost entirely at the post-transcriptional level. In terms of regulation, the best-studied genes are procyclins, which encode a family of major surface GPI-anchored glycoproteins (EP1, EP2, EP3, GPEET that show differential expression in the parasite's tsetse-fly vector. Although procyclin mRNA cis-regulatory sequences have provided the paradigm for post-transcriptional control in kinetoplastid parasites, trans-acting regulators of procyclin mRNAs are unidentified, despite intensive effort over 15 years. Here we identify the developmental regulator, TbZFP3, a CCCH-class predicted RNA binding protein, as an isoform-specific regulator of Procyclin surface coat expression in trypanosomes. We demonstrate (i that endogenous TbZFP3 shows sequence-specific co-precipitation of EP1 and GPEET, but not EP2 and EP3, procyclin mRNA isoforms, (ii that ectopic overexpression of TbZFP3 does not perturb the mRNA abundance of procyclin transcripts, but rather that (iii their protein expression is regulated in an isoform-specific manner, as evidenced by mass spectrometric analysis of the Procyclin expression signature in the transgenic cell lines. The TbZFP3 mRNA-protein complex (TbZFP3mRNP is identified as a trans-regulator of differential surface protein expression in trypanosomes. Moreover, its sequence-specific interactions with procyclin mRNAs are compatible with long-established predictions for Procyclin regulation. Combined with the known association of TbZFP3 with the translational apparatus, this study provides a long-sought missing link between surface protein cis-regulatory signals and the gene expression machinery in trypanosomes.

10 points about buying C.I.S

International Nuclear Information System (INIS)

Anon.

1993-01-01

On October 16, 1992, the U.S. Department of Commerce (DOC) settled the antidumping case against the CIS republics by imposing price and volume quotas on CIS uranium imported into the United States. Bound by a suspension agreement, each of the six uranium-producing CIS republics is responsible for restricting the flow of imports to the US-either directly or indirectly. (As the NUKEM Market Report went to press, the Ukraine government notified the DOC of its intent not to terminate the suspension agreement.) This action is to prevent undercutting price levels in the US domestic uranium markets. What follows are ten points about everything you should know about importing uranium from the uranium-producing CIS republics- Kazakhstan, Kyrgyzstan, Russian Federation, Tajikistan, Ukraine and Uzbekistan. Newcomers to the CIS scene should follow this simple roadmap and be aware of the issues they face as importers in terms of Commerce/Customs requirements and documentation and where to get them, when to buy the material and how to transport it, how to deal effectively with CIS exporters, and how to avoid unnecessary complications when buying CIS

Chemometric deconvolution of gas chromatographic unresolved conjugated linoleic acid isomers triplet in milk samples.

Science.gov (United States)

Blasko, Jaroslav; Kubinec, Róbert; Ostrovský, Ivan; Pavlíková, Eva; Krupcík, Ján; Soják, Ladislav

2009-04-03

A generally known problem of GC separation of trans-7;cis-9; cis-9,trans-11; and trans-8,cis-10 CLA (conjugated linoleic acid) isomers was studied by GC-MS on 100m capillary column coated with cyanopropyl silicone phase at isothermal column temperatures in a range of 140-170 degrees C. The resolution of these CLA isomers obtained at given conditions was not high enough for direct quantitative analysis, but it was, however, sufficient for the determination of their peak areas by commercial deconvolution software. Resolution factors of overlapped CLA isomers determined by the separation of a model CLA mixture prepared by mixing of a commercial CLA mixture and CLA isomer fraction obtained by the HPLC semi-preparative separation of milk fatty acids methyl esters were used to validate the deconvolution procedure. Developed deconvolution procedure allowed the determination of the content of studied CLA isomers in ewes' and cows' milk samples, where dominant isomer cis-9,trans-11 is eluted between two small isomers trans-7,cis-9 and trans-8,cis-10 (in the ratio up to 1:100).

Cis-regulatory somatic mutations and gene-expression alteration in B-cell lymphomas.

Science.gov (United States)

Mathelier, Anthony; Lefebvre, Calvin; Zhang, Allen W; Arenillas, David J; Ding, Jiarui; Wasserman, Wyeth W; Shah, Sohrab P

2015-04-23

With the rapid increase of whole-genome sequencing of human cancers, an important opportunity to analyze and characterize somatic mutations lying within cis-regulatory regions has emerged. A focus on protein-coding regions to identify nonsense or missense mutations disruptive to protein structure and/or function has led to important insights; however, the impact on gene expression of mutations lying within cis-regulatory regions remains under-explored. We analyzed somatic mutations from 84 matched tumor-normal whole genomes from B-cell lymphomas with accompanying gene expression measurements to elucidate the extent to which these cancers are disrupted by cis-regulatory mutations. We characterize mutations overlapping a high quality set of well-annotated transcription factor binding sites (TFBSs), covering a similar portion of the genome as protein-coding exons. Our results indicate that cis-regulatory mutations overlapping predicted TFBSs are enriched in promoter regions of genes involved in apoptosis or growth/proliferation. By integrating gene expression data with mutation data, our computational approach culminates with identification of cis-regulatory mutations most likely to participate in dysregulation of the gene expression program. The impact can be measured along with protein-coding mutations to highlight key mutations disrupting gene expression and pathways in cancer. Our study yields specific genes with disrupted expression triggered by genomic mutations in either the coding or the regulatory space. It implies that mutated regulatory components of the genome contribute substantially to cancer pathways. Our analyses demonstrate that identifying genomically altered cis-regulatory elements coupled with analysis of gene expression data will augment biological interpretation of mutational landscapes of cancers.

Open reading frame 176 in the photosynthesis gene cluster of Rhodobacter capsulatus encodes idi, a gene for isopentenyl diphosphate isomerase.

OpenAIRE

Hahn, F M; Baker, J A; Poulter, C D

1996-01-01

Isopentenyl diphosphate (IPP) isomerase catalyzes an essential activation step in the isoprenoid biosynthetic pathway. A database search based on probes from the highly conserved regions in three eukaryotic IPP isomerases revealed substantial similarity with ORF176 in the photosynthesis gene cluster in Rhodobacter capsulatus. The open reading frame was cloned into an Escherichia coli expression vector. The encoded 20-kDa protein, which was purified in two steps by ion exchange and hydrophobic...

Crystal structure of Pyrococcus furiosus phosphoglucose isomerase: Implications for substrate binding and catalysis

NARCIS (Netherlands)

Berrisford, J.M.; Akerboom, A.P.; Turnbull, A.P.; Geus, de D.; Sedelnikova, S.E.; Staton, I.; McLeod, C.W.; Verhees, C.H.; Oost, van der J.; Rice, D.W.; Baker, P.J.

2003-01-01

Phosphoglucose isomerase (PGI) catalyzes the reversible isomerization between D-fructose 6-phosphate and D-glucose 6-phosphate as part of the glycolytic pathway. PGI from the Archaea Pyrococcus furiosus (Pfu) was crystallized, and its structure was determined by x-ray diffraction to a 2-Angstrom

Trans-Planckian wimpzillas

CERN Document Server

Kolb, E W; Tkachev, I I

2007-01-01

Two previously proposed conjectures--gravitational trans-Planckian particle creation in the expanding universe, and the existence of ultra-heavy stable particles with masses up to the Planck scale (wimpzillas)--are combined in a proposal for trans-Planckian particle creation of wimpzillas. It is shown that the trans-Planckian particle creation parameter should be rather small to avoid overproduction of such particles. This ensures that wimpzillas are mainly created at the end of primordial inflation. Conditions under which trans-Planckian wimpzillas can constitute the present dark matter are determined.

Effect of Trans, Trans-Farnesol on Pseudogymnoascus destructans and Several Closely Related Species.

Science.gov (United States)

Raudabaugh, Daniel B; Miller, Andrew N

2015-12-01

Bat white-nose syndrome, caused by the psychrophilic fungus Pseudogymnoascus destructans, has dramatically reduced the populations of many hibernating North American bat species. The search for effective biological control agents targeting P. destructans is of great importance. We report that the sesquiterpene trans, trans-farnesol, which is also a Candida albicans quorum sensing compound, prevented in vitro conidial germination for at least 14 days and inhibited growth of preexisting hyphae of five P. destructans isolates in filtered potato dextrose broth at 10 °C. Depending on the inoculation concentrations, both spore and hyphal inhibition occurred upon exposure to concentrations as low as 15-20 µM trans, trans-farnesol. In contrast, most North American Pseudogymnoascus isolates were more tolerant to the exposure of trans, trans-farnesol. Our results suggest that some Candida isolates may have the potential to inhibit the growth of P. destructans and that the sesquiterpene trans, trans-farnesol has the potential to be utilized as a biological control agent.

MYC cis-Elements in PsMPT Promoter Is Involved in Chilling Response of Paeonia suffruticosa.

Directory of Open Access Journals (Sweden)

Yuxi Zhang

Full Text Available The MPT transports Pi to synthesize ATP. PsMPT, a chilling-induced gene, was previously reported to promote energy metabolism during bud dormancy release in tree peony. In this study, the regulatory elements of PsMPT promoter involved in chilling response were further analyzed. The PsMPT transcript was detected in different tree peony tissues and was highly expressed in the flower organs, including petal, stigma and stamen. An 1174 bp of the PsMPT promoter was isolated by TAIL-PCR, and the PsMPT promoter::GUS transgenic Arabidopsis was generated and analyzed. GUS staining and qPCR showed that the promoter was active in mainly the flower stigma and stamen. Moreover, it was found that the promoter activity was enhanced by chilling, NaCl, GA, ACC and NAA, but inhibited by ABA, mannitol and PEG. In transgenic plants harboring 421 bp of the PsMPT promoter, the GUS gene expression and the activity were significantly increased by chilling treatment. When the fragment from -421 to -408 containing a MYC cis-element was deleted, the chilling response could not be observed. Further mutation analysis confirmed that the MYC element was one of the key motifs responding to chilling in the PsMPT promoter. The present study provides useful information for further investigation of the regulatory mechanism of PsMPT during the endo-dormancy release.

Effect of CLA and other C18 unsaturated fatty acids on DGAT in bovine milk fat biosynthetic systems.

Science.gov (United States)

Sørensen, Brent M; Chris Kazala, E; Murdoch, Gordon K; Keating, Aileen F; Cruz-Hernandez, Cristina; Wegner, Jochen; Kennelly, John J; Okine, Erasmus K; Weselake, Randall J

2008-10-01

Production of dairy products with increased amounts of nutraceutic FA such as conjugated linoleic acid (CLA) represents a recent approach for dairy producers and processors to increase the value of their products. The effect of CLA and other FA on the expression of diacylglycerol acyltransferase-1 (DGAT-1) and DGAT-2, and DGAT activity were investigated in bovine mammary gland epithelial (MAC-T) cells. DGAT gene expression analyses were also conducted using bovine mammary gland tissue from dairy cows. In the studies with MAC-T cells, there were no significant effects of CLA isomers or other FA on DGAT1 expression, whereas all FA tested showed enhanced DGAT2 expression (P < 0.05 to P < 0.001), with alpha-linolenic acid (alpha-18:3) having the greatest effect. Additionally, DGAT2 expression was co-ordinated with expression of lysophosphatidic acid acyltransferase (LPAAT), an observation that was also apparent in mammary gland from lactating dairy cows. In contrast, treatment of MAC-T cells with trans-10, cis-12 18:2 or alpha-18:3 resulted in a significant (P < 0.05) decrease in overall DGAT enzyme activity, although the mechanisms resulting in these effects are unclear. Competition assays using microsomes from bovine mammary gland tissue and 1-[(14)C]oleoyl-CoA suggested that DGAT activity was more selective for oleoyl (cis-9 18:1)-CoA than cis-9, trans-11 18:2-, trans-10, cis-12 18:2- or cis-9, cis-12 18:2-CoA. Collectively, the results suggest the relationship between trans-10, cis-12 18:2 and reduced TAG production in bovine milk is not linked to the production of DGAT1 or DGAT2 transcripts, but probably involves effects of this CLA isomer at events beyond transcription, such as post-translational and/or enzyme activity effects.

Overexpressed cyclophilin B suppresses aldosterone-induced proximal tubular cell injury both in vitro and in vivo.

Science.gov (United States)

Wang, Bin; Lin, Lilu; Wang, Haidong; Guo, Honglei; Gu, Yong; Ding, Wei

2016-10-25

The renin-angiotensin-aldosterone system (RAAS) is overactivated in patients with chronic kidney disease. Oxidative stress and endoplasmic reticulum stress (ERS) are two major mechanisms responsible for aldosterone-induced kidney injury. Cyclophilin (CYP) B is a chaperone protein that accelerates the rate of protein folding through its peptidyl-prolyl cis-trans isomerase (PPIase) activity. We report that overexpression of wild-type CYPB attenuated aldosterone-induced oxidative stress (evidenced by reduced production of reactive oxygen species and improved mitochondrial dysfunction), ERS (indicated by reduced expression of the ERS markers glucose-regulated protein 78 [GRP78] and C/-EBP homologous protein [CHOP]), and tubular cell apoptosis in comparison with aldosterone-induced human kidney-2 (HK-2) cells. The in vivo study also yielded similar results. Hence, CYPB performs a crucial function in protecting cells against aldosterone-induced oxidative stress, ERS, and tubular cell injury via its PPIase activity.

Genetic manipulation of carotenoid biosynthesis in the green sulfur bacterium Chlorobium tepidum

DEFF Research Database (Denmark)

Frigaard, Niels-Ulrik; Maresca, Julia A; Yunker, Colleen E

2004-01-01

The green sulfur bacterium Chlorobium tepidum is a strict anaerobe and an obligate photoautotroph. On the basis of sequence similarity with known enzymes or sequence motifs, nine open reading frames encoding putative enzymes of carotenoid biosynthesis were identified in the genome sequence of C....... tepidum, and all nine genes were inactivated. Analysis of the carotenoid composition in the resulting mutants allowed the genes encoding the following six enzymes to be identified: phytoene synthase (crtB/CT1386), phytoene desaturase (crtP/CT0807), zeta-carotene desaturase (crtQ/CT1414), gamma......-carotene desaturase (crtU/CT0323), carotenoid 1',2'-hydratase (crtC/CT0301), and carotenoid cis-trans isomerase (crtH/CT0649). Three mutants (CT0180, CT1357, and CT1416 mutants) did not exhibit a discernible phenotype. The carotenoid biosynthetic pathway in C. tepidum is similar to that in cyanobacteria and plants...

cis-Bifenthrin enantioselectively induces hepatic oxidative stress in mice.

Science.gov (United States)

Jin, Yuanxiang; Wang, Jiangcong; Pan, Xiuhong; Wang, Linggang; Fu, Zhengwei

2013-09-01

Bifenthrin (BF), as a chiral synthetic pyrethroid, is widely used to control field and household pests. In China, the commercial cis-BF contained two enantiomers including 1R-cis-BF and 1S-cis-BF. However, the difference in oxidative stress induced by the two enantiomers in mice still remains unclear. In the present study, 4 week-old adolescent male ICR mice were orally administered cis-BF, 1R-cis-BF or 1S-cis-BF daily for 2, 4 and 6 weeks at doses of 5 mg/kg/day, respectively. We found that the hepatic reactive oxygen species (ROS) levels, as well as the malondialdehyde (MDA) and glutathione (GSH) content both in the serum and liver increased significantly in the 4 or 6 weeks 1S-cis-BF treated groups. The activities of superoxide dismutase (SOD) and catalase (CAT) also changed significantly in the serum and liver of 1S-cis-BF treated mice. More importantly, the significant differences in MDA content and CAT activity both in the serum and liver, and the activities of total antioxidant capacity (T-AOC) and SOD in serum were also observed between the 1S-cis-BF and 1R-cis-BF treated groups. Moreover, the transcription of oxidative stress response related genes including Sod1, Cat and heme oxygenase-1(Ho-1) in the liver of 1S-cis-BF treated groups were also significant higher than those in 1R-cis-BF treated group. Thus, it was concluded that cis-BF induced hepatic oxidative stress in an enantiomer specific manner in mice when exposed during the puberty, and that 1S-cis-BF showed much more toxic in hepatic oxidative stress than 1R-cis-BF. Copyright © 2013 Elsevier Inc. All rights reserved.

CisLunar Habitat Internal Architecture Design Criteria

Science.gov (United States)

Jones, R.; Kennedy, K.; Howard, R.; Whitmore, M.; Martin, C.; Garate, J.

2017-01-01

BACKGROUND: In preparation for human exploration to Mars, there is a need to define the development and test program that will validate deep space operations and systems. In that context, a Proving Grounds CisLunar habitat spacecraft is being defined as the next step towards this goal. This spacecraft will operate differently from the ISS or other spacecraft in human history. The performance envelope of this spacecraft (mass, volume, power, specifications, etc.) is being defined by the Future Capabilities Study Team. This team has recognized the need for a human-centered approach for the internal architecture of this spacecraft and has commissioned a CisLunar Phase-1 Habitat Internal Architecture Study Team to develop a NASA reference configuration, providing the Agency with a "smart buyer" approach for future acquisition. THE CISLUNAR HABITAT INTERNAL ARCHITECTURE STUDY: Overall, the CisLunar Habitat Internal Architecture study will address the most significant questions and risks in the current CisLunar architecture, habitation, and operations concept development. This effort is achieved through definition of design criteria, evaluation criteria and process, design of the CisLunar Habitat Phase-1 internal architecture, and the development and fabrication of internal architecture concepts combined with rigorous and methodical Human-in-the-Loop (HITL) evaluations and testing of the conceptual innovations in a controlled test environment. The vision of the CisLunar Habitat Internal Architecture Study is to design, build, and test a CisLunar Phase-1 Habitat Internal Architecture that will be used for habitation (e.g. habitability and human factors) evaluations. The evaluations will mature CisLunar habitat evaluation tools, guidelines, and standards, and will interface with other projects such as the Advanced Exploration Systems (AES) Program integrated Power, Avionics, Software (iPAS), and Logistics for integrated human-in-the-loop testing. The mission of the Cis

Crystal structure of {2,2′-[N,N′-bis(pyridin-2-ylmethylcyclohexane-trans-1,2-diyldi(nitrilo]diacetato}cobalt(III hexafluoridophosphate

Directory of Open Access Journals (Sweden)

Craig C. McLauchlan

2015-04-01

Full Text Available The title compound [Co(C22H26N4O4]PF6, commonly known as [Co(bpcd]PF6, where bpcd2− is derived from the historical ligand name N,N′-bis(2-pyridylmethyl-trans-1,2-diaminocyclohexane-N,N′-diacetate, crystallized by slow evaporation of a saturated acetonitrile solution in air. The cation of the hexafluoridophosphate salt has the CoIII atom in a distorted octahedral coordination geometry provided by an N4O2 donor atom set. The acetate groups, which are oriented trans with respect to each other, exhibit monodentate coordination whereas the pyridyl N atoms are coordinating in a cis configuration. The geometry of the cation is compared to the geometries of other diamino diacetate complexes with CoIII.

Filling the Gaps in the Kirromycin Biosynthesis: Deciphering the Role of Genes Involved in Ethylmalonyl-CoA Supply and Tailoring Reactions

DEFF Research Database (Denmark)

Robertsen, Helene L.; Musiol-Kroll, Ewa M.; Ding, Ling

2018-01-01

Kirromycin is the main product of the soil-dwelling Streptomyces collinus Tü 365. The elucidation of the biosynthetic pathway revealed that the antibiotic is synthesised via a unique combination of trans-/cis-AT type I polyketide synthases and non-ribosomal peptide synthetases (PKS I/NRPS). This ...

Cyclophilin B protects SH-SY5Y human neuroblastoma cells against MPP(+)-induced neurotoxicity via JNK pathway.

Science.gov (United States)

Oh, Yoojung; Jeong, Kwon; Kim, Kiyoon; Lee, Young-Seok; Jeong, Suyun; Kim, Sung Soo; Yoon, Kyung-Sik; Ha, Joohun; Kang, Insug; Choe, Wonchae

2016-09-23

Parkinson's disease (PD) is the second most common neurodegenerative disorder of aging. PD involves a progressive loss of dopaminergic neurons in the substantia nigra pars compacta. 1-Methyl-4-phenyl-1, 2, 3, 6-tetrahydropyidine (MPTP) and its toxic metabolite 1-methyl-4-phenylpyridinium ion (MPP+) inhibit the complex I of the mitochondrial electron transport chain, and have been widely used to construct PD models. Cyclophilin B (CypB) is an endoplasmic reticulum protein that binds to cyclosporine A as a cyclophilin family member. CypB has peptidyl-prolyl cis-trans isomerase (PPIase) activity. We investigated the protective effects of overexpressed CypB on MPP+-induced neurocytotoxicity in SH-SY5Y human neuroblastoma cells. Overexpressed CypB decreased MPP(+)-induced oxidative stress through the modulation of antioxidant enzymes including manganese superoxide dismutase and catalase, and prevented neurocytotoxicity via mitogen-activated protein kinase, especially the c-Jun N-terminal kinase pathway. In addition, CypB inhibited the activation of MPP(+)-induced the pro-apoptotic molecules poly (ADP-ribose) polymerase, Bax, and Bcl-2, and attenuated MPP(+)-induced mitochondrial dysfunction. The data suggest that overexpressed CypB protects neuronal cells from MPP+-induced dopaminergic neuronal cell death. Copyright © 2016 Elsevier Inc. All rights reserved.

Enzymatic conversion of D-galactose to D-tagatose: heterologous expression and characterisation of a thermostable L-arabinose isomerase from Thermoanaerobacter mathranii.

Science.gov (United States)

Jørgensen, F; Hansen, O C; Stougaard, P

2004-06-01

The ability to convert D-galactose into D-tagatose was compared among a number of bacterial L-arabinose isomerases ( araA). One of the most efficient enzymes, from the anaerobic thermophilic bacterium Thermoanaerobacter mathranii, was produced heterologously in Escherichia coli and characterised. Amino acid sequence comparisons indicated that this enzyme is only distantly related to the group of previously known araA sequences in which the sequence similarity is evident. The substrate specificity and the Michaelis-Menten constants of the enzyme determined with L-arabinose, D-galactose and D-fucose also indicated that this enzyme is an unusual, versatile L-arabinose isomerase which is able to isomerise structurally related sugars. The enzyme was immobilised and used for production of D-tagatose at 65 degrees C. Starting from a 30% solution of D-galactose, the yield of D-tagatose was 42% and no sugars other than D-tagatose and D-galactose were detected. Direct conversion of lactose to D-tagatose in a single reactor was demonstrated using a thermostable beta-galactosidase together with the thermostable L-arabinose isomerase. The two enzymes were also successfully combined with a commercially available glucose isomerase for conversion of lactose into a sweetening mixture comprising lactose, glucose, galactose, fructose and tagatose.

A library of fluorescent peptides for exploring the substrate specificities of prolyl isomerases

NARCIS (Netherlands)

Zoldak, G.; Aumuller, T.; Lucke, C.; Hritz, J.; Oostenbrink, C.; Fischer, G.; Schmid, F.X.

2009-01-01

To fully explore the substrate specificities of prolyl isomerases, we synthesized a library of 20 tetrapeptides that are labeled with a 2-aminobenzoyl (Abz) group at the amino terminus and a p-nitroanilide (pNA) group at the carboxy terminus. In this peptide library of the general formula

9-cis-retinoic acid represses estrogen-induced expression of the very low density apolipoprotein II gene.

Science.gov (United States)

Schippers, I J; Kloppenburg, M; Snippe, L; Ab, G

1994-11-01

The chicken very low density apolipoprotein II (apoVLDLII) gene is estrogen-inducible and specifically expressed in liver. We examined the possible involvement of the retinoid X receptor (RXR) and its ligand 9-cis-retinoic acid (9-cis-RA) in the activation of the apoVLDLII promoter. We first concentrated on a potential RXR recognition site, which deviates at only one position from a perfect direct A/GGGTCA repeat spaced by one nucleotide (DR-1) and was earlier identified as a common HNF-4/COUP-TF recognition site. However, band shift analysis revealed that this imperfect DR-1 motif does not interact with RXR alpha-homodimers. In accordance with this observation we found that this regulatory element does not mediate transactivation through RXR alpha in the presence of 9-cis-RA. However, our experiments revealed another, unexpected, effect of 9-cis-RA. Instead of stimulating, 9-cis-RA attenuated estrogen-induced expression of transfected estrogen-responsive VLDL-CAT reporter plasmids. This repression appeared to take place through the main estrogen response element (ERE) of the gene. Importantly, 9-cis-RA also strongly repressed the estrogen-induced expression of the endogenous apoVLDLII gene in cultured chicken hepatoma cells.

Expression of the helix-loop-helix protein inhibitor of DNA binding-1 (ID-1) is activated by all-trans retinoic acid in normal human keratinocytes

International Nuclear Information System (INIS)

Villano, C.M.; White, L.A.

2006-01-01

The ID (inhibitor of differentiation or DNA binding) helix-loop-helix proteins are important mediators of cellular differentiation and proliferation in a variety of cell types through regulation of gene expression. Overexpression of the ID proteins in normal human keratinocytes results in extension of culture lifespan, indicating that these proteins are important for epidermal differentiation. Our hypothesis is that the ID proteins are targets of the retinoic acid signaling pathway in keratinocytes. Retinoids, vitamin A analogues, are powerful regulators of cell growth and differentiation and are widely used in the prevention and treatment of a variety of cancers in humans. Furthermore, retinoic acid is necessary for the maintenance of epithelial differentiation and demonstrates an inhibitory action on skin carcinogenesis. We examined the effect of all-trans retinoic acid on expression of ID-1, -2, -3, and -4 in normal human keratinocytes and found that exposure of these cells to all-trans retinoic acid causes an increase in both ID-1 and ID-3 gene expression. Furthermore, our data show that this increase is mediated by increased transcription involving several cis-acting elements in the distal portion of the promoter, including a CREB-binding site, an Egr1 element, and an YY1 site. These data demonstrate that the ID proteins are direct targets of the retinoic acid signaling pathway. Given the importance of the ID proteins to epidermal differentiation, these results suggest that IDs may be mediating some of the effects of all-trans retinoic acid in normal human keratinocytes

Compartmental and noncompartmental modeling of ¹³C-lycopene absorption, isomerization, and distribution kinetics in healthy adults.

Science.gov (United States)

Moran, Nancy E; Cichon, Morgan J; Riedl, Kenneth M; Grainger, Elizabeth M; Schwartz, Steven J; Novotny, Janet A; Erdman, John W; Clinton, Steven K

2015-12-01

Lycopene, which is a red carotenoid in tomatoes, has been hypothesized to mediate disease-preventive effects associated with tomato consumption. Lycopene is consumed primarily as the all-trans geometric isomer in foods, whereas human plasma and tissues show greater proportions of cis isomers. With the use of compartmental modeling and stable isotope technology, we determined whether endogenous all-trans-to-cis-lycopene isomerization or isomeric-bioavailability differences underlie the greater proportion of lycopene cis isomers in human tissues than in tomato foods. Healthy men (n = 4) and women (n = 4) consumed (13)C-lycopene (10.2 mg; 82% all-trans and 18% cis), and plasma was collected over 28 d. Unlabeled and (13)C-labeled total lycopene and lycopene-isomer plasma concentrations, which were measured with the use of high-performance liquid chromatography-mass spectrometry, were fit to a 7-compartment model. Subjects absorbed a mean ± SEM of 23% ± 6% of the lycopene. The proportion of plasma cis-(13)C-lycopene isomers increased over time, and all-trans had a shorter half-life than that of cis isomers (5.3 ± 0.3 and 8.8 ± 0.6 d, respectively; P lycopene bioavailability and endogenous trans-to-cis-lycopene isomerization was predictive of plasma (13)C and unlabeled cis- and all-trans-lycopene concentrations. Although the bioavailability of cis (24.5% ± 6%) and all-trans (23.2% ± 8%) isomers did not differ, endogenous isomerization (0.97 ± 0.25 μmol/d in the fast-turnover tissue lycopene pool) drove tissue and plasma isomeric profiles. (13)C-Lycopene combined with physiologic compartmental modeling provides a strategy for following complex in vivo metabolic processes in humans and reveals that postabsorptive trans-to-cis-lycopene isomerization, and not the differential bioavailability of isomers, drives tissue and plasma enrichment of cis-lycopene. This trial was registered at clinicaltrials.gov as NCT01692340. © 2015 American Society for Nutrition.

Compartmental and noncompartmental modeling of 13C-lycopene absorption, isomerization, and distribution kinetics in healthy adults123

Science.gov (United States)

Moran, Nancy E; Cichon, Morgan J; Riedl, Kenneth M; Grainger, Elizabeth M; Schwartz, Steven J; Novotny, Janet A; Erdman, John W; Clinton, Steven K

2015-01-01

Background: Lycopene, which is a red carotenoid in tomatoes, has been hypothesized to mediate disease-preventive effects associated with tomato consumption. Lycopene is consumed primarily as the all-trans geometric isomer in foods, whereas human plasma and tissues show greater proportions of cis isomers. Objective: With the use of compartmental modeling and stable isotope technology, we determined whether endogenous all-trans-to-cis-lycopene isomerization or isomeric-bioavailability differences underlie the greater proportion of lycopene cis isomers in human tissues than in tomato foods. Design: Healthy men (n = 4) and women (n = 4) consumed 13C-lycopene (10.2 mg; 82% all-trans and 18% cis), and plasma was collected over 28 d. Unlabeled and 13C-labeled total lycopene and lycopene-isomer plasma concentrations, which were measured with the use of high-performance liquid chromatography–mass spectrometry, were fit to a 7-compartment model. Results: Subjects absorbed a mean ± SEM of 23% ± 6% of the lycopene. The proportion of plasma cis-13C-lycopene isomers increased over time, and all-trans had a shorter half-life than that of cis isomers (5.3 ± 0.3 and 8.8 ± 0.6 d, respectively; P lycopene bioavailability and endogenous trans-to-cis-lycopene isomerization was predictive of plasma 13C and unlabeled cis- and all-trans-lycopene concentrations. Although the bioavailability of cis (24.5% ± 6%) and all-trans (23.2% ± 8%) isomers did not differ, endogenous isomerization (0.97 ± 0.25 μmol/d in the fast-turnover tissue lycopene pool) drove tissue and plasma isomeric profiles. Conclusion: 13C-Lycopene combined with physiologic compartmental modeling provides a strategy for following complex in vivo metabolic processes in humans and reveals that postabsorptive trans-to-cis-lycopene isomerization, and not the differential bioavailability of isomers, drives tissue and plasma enrichment of cis-lycopene. This trial was registered at clinicaltrials.gov as NCT01692340. PMID

Trans-suppression of host CDH3 and LOXL4 genes during Cryptosporidium parvum infection involves nuclear delivery of parasite Cdg7_FLc_1000 RNA.

Science.gov (United States)

Ming, Zhenping; Gong, Ai-Yu; Wang, Yang; Zhang, Xin-Tian; Li, Min; Li, Yao; Pang, Jing; Dong, Stephanie; Strauss-Soukup, Juliane K; Chen, Xian-Ming

2018-05-01

Intestinal infection by Cryptosporidium parvum causes significant alterations in the gene expression profile in host epithelial cells. Previous studies demonstrate that a panel of parasite RNA transcripts of low protein-coding potential are delivered into infected host cells and may modulate host gene transcription. Using in vitro models of human intestinal cryptosporidiosis, we report here that trans-suppression of the cadherin 3 (CDH3) and lysyl oxidase like 4 (LOXL4) genes in human intestinal epithelial cells following C. parvum infection involves host delivery of the Cdg7_FLc_1000 RNA, a C. parvum RNA that has been previously demonstrated to be delivered into the nuclei of infected host cells. Downregulation of CDH3 and LOXL4 genes was detected in host epithelial cells following C. parvum infection or in cells expressing the parasite Cdg7_FLc_1000 RNA. Knockdown of Cdg7_FLc_1000 attenuated the trans-suppression of CDH3 and LOXL4 genes in host cells induced by infection. Interestingly, Cdg7_FLc_1000 was detected to be recruited to the promoter regions of both CDH3 and LOXL4 gene loci in host cells following C. parvum infection. Host delivery of Cdg7_FLc_1000 promoted the PH domain zinc finger protein 1 (PRDM1)-mediated H3K9 methylation associated with trans-suppression in the CDH3 gene locus, but not the LOXL4 gene. Therefore, our data suggest that host delivery of Cdg7_FLc_1000 causes CDH3 trans-suppression in human intestinal epithelial cells following C. parvum infection through PRDM1-mediated H3K9 methylation in the CDH3 gene locus, whereas Cdg7_FLc_1000 induces trans-suppression of the host LOXL4 gene through H3K9/H3K27 methylation-independent mechanisms. Copyright © 2018 Australian Society for Parasitology. Published by Elsevier Ltd. All rights reserved.

Crystallization and preliminary X-ray diffraction studies of l-rhamnose isomerase from Pseudomonas stutzeri

International Nuclear Information System (INIS)

Yoshida, Hiromi; Wayoon, Poonperm; Takada, Goro; Izumori, Ken; Kamitori, Shigehiro

2006-01-01

Recombinant l-rhamnose isomerase from P. stutzeri has been crystallized. Diffraction data have been collected to 2.0 Å resolution. l-Rhamnose isomerase from Pseudomonas stutzeri (P. stutzeril-RhI) catalyzes not only the reversible isomerization of l-rhamnose to l-rhamnulose, but also isomerization between various rare aldoses and ketoses. Purified His-tagged P. stutzeril-RhI was crystallized by the hanging-drop vapour-diffusion method. The crystals belong to the monoclinic space group P2 1 , with unit-cell parameters a = 74.3, b = 104.0, c = 107.0 Å, β = 106.8°. Diffraction data have been collected to 2.0 Å resolution. The molecular weight of the purified P. stutzeril-RhI with a His tag at the C-terminus was confirmed to be 47.7 kDa by MALDI–TOF mass-spectrometric analysis and the asymmetric unit is expected to contain four molecules

Dilemmas of compliance in the CIS

International Nuclear Information System (INIS)

Vorobyev, A.

1996-01-01

The objective of this paper is to examine some of the difficulties faced by Russia and other Common Independent States (CIS) in the field of compliance with disarmament treaties and non-proliferation regimes, as well as ways and means, particularly with regard to the legal framework, designed to overcome these difficulties. Naturally, the fate and pace of overcoming the existing problems will depend only partially on development of CIS States. A large variety of international factors and the general security will be essential for progress in resolving disarmament and arms control issues in the CIS

Photoelastic studies of some polybutadiene networks

Energy Technology Data Exchange (ETDEWEB)

Mark, J E; Llorente, M A [Cincinnati Univ., OH (USA). Dept. of Chemistry

1981-06-01

Two butadiene polymers were used in this investigation, one with 98.5% cis-1,4 units and the other with an approximately equibinary mixture of cis and trans units. Elastomeric networks prepared from these polymers were studied in elongation, in both the swollen and unswollen states over the temperature range -30 to 95/sup 0/C. There is evidence for crystallization in these networks, particularly as manifested by marked increases in birefringence at relatively low elongation and at temperatures as high as 40/sup 0/C. As expected, the birefringence and related quantities were found to be more sensitive to crystallization than the force, with the optical-configuration parameter and the stress-optical coefficient showing the greatest sensitivity. In the case of the cis-trans copolymer, the crystallization involves trans sequences, which are of relatively high melting point, and thus occurs at a temperature higher than for the lower melting cis sequences in the high-cis networks. The results which were free from the effects of network crystallization were used to calculate values of the temperature coefficient of the unperturbed dimensions of the chains, and values of the optical-configuration parameter. These configuration-dependent properties were found to be in satisfactory agreement with previously published theoretical results based on a rotational isomeric state model of these chain molecules.

Catalase Induced by All-Trans Retinoic Acid Is Involved in Antiproliferation of 36B10 Cells

International Nuclear Information System (INIS)

Park, Woo Yoon; Yu, Jae Ran

2010-01-01

All-trans retinoic acid (ATRA) has antiproliferative effects against brain tumor cells. Recently, ATRA has been reported to induce catalase. We investigated whether catalase induction by ATRA is associated with its antiproliferative effects. 36B10 cells were exposed to 0-50μM ATRA for 24 or 48 hours and mRNA, protein, and activity of catalase were measured. Reactive oxygen species (ROS) were measured using 2',7'-dichlorofluorescin diacetate. A clonogenic assay was used to confirm the cytotoxic effect. The mRNA, protein, and activity of catalase were found to increase in a concentration- and incubation- time-dependent manner. The increase in catalase activity induced by ATRA was decreased by the addition of 3-amino-1,2,4-triazole (ATZ). ROS was also increased with ATRA and decreased by the addition of ATZ. The decrease in cell survival induced by ATRA was partly rescued by ATZ. Catalase induction by ATRA is involved in ROS overproduction and thus inhibits the proliferation of 36B10 cells.

Synthesis and structural and photoswitchable properties of novel chiral host molecules: axis chiral 2,2'-dihydroxy-1,1'-binaphthyl-appended stiff-stilbene.

Science.gov (United States)

Shimasaki, Toshiaki; Kato, Shin-ichiro; Ideta, Keiko; Goto, Kenta; Shinmyozu, Teruo

2007-02-16

Novel photoswitchable chiral hosts having an axis chiral 2,2'-dihydroxy-1,1'-binaphthyl (BINOL)-appended stiff-stilbene, trans-(R,R)- and -(S,S)-1, were synthesized by palladium-catalyzed Suzuki-Miyaura coupling and low-valence titanium-catalyzed McMurry coupling as key steps, and they were fully characterized by various NMR spectral techniques. The enantiomers of trans-1 showed almost complete mirror images in the CD spectra, where two split Cotton effects (exciton coupling) were observed in the beta-transitions of the naphthyl chromophore at 222 and 235 nm, but no Cotton effect was observed in the stiff-stilbene chromophore at 365 nm. The structures of (R)-10 and trans-(R,R)-1 were confirmed by X-ray structural analysis. The optimized structure of cis-1 by MO calculations has a wide chiral cavity of 7-8 A in diameter, whereas trans-1 cannot form an intramolecular cavity based on the X-ray data. Irradiation of (R,R)-trans-1 with black light (lambda = 365 nm) in CH3CN or benzene at 23 degrees C led to the conversion to the corresponding cis-isomer, as was monitored by 1H NMR, UV-vis, and CD spectra. At the photostationary state, the cis-1/trans-1 ratio was 86/14 in benzene or 75/25 in CH3CN. On the other hand, irradiation of the cis-1/trans-1 (75/25) mixture in CH3CN with an ultra-high-pressure Hg lamp at 23 degrees C (lambda = 410 nm) led to the photostationary state, where the cis-1/trans-1 ratio was estimated to be 9/91 on the basis of the 1H NMR spectra. The cis-trans and trans-cis interconversions could be repeated 10 times without decomposition of the C=C double bond. Thus, a new type of photoswitchable molecule has been developed, and trans-1 and cis-1 were quite durable under irradiation conditions. The guest binding properties of the BINOL moieties of trans- and cis-(R,R)-1 with F-, Cl-, and H2PO4- were examined by 1H NMR titration in CDCl3. Similar interaction with F- and Cl- was observed in trans-1 (host/guest = 1/1, Kassoc = (1.0 +/- 0.13) x 103 for F

FACTS ABOUT TRANS FATTY ACIDS

Directory of Open Access Journals (Sweden)

Sedighe Asgary

2010-12-01

trans fatty acid on blood lipids are still incompletely understood, but may involve opposite effects on ApoA-I and LDL ApoB-100 catabolism.14 N.R. Matthan et al, Dietary hydrogenated fat increases high-density lipoprotein apoA-I catabolism and decreases low-density lipoprotein apoB-100 catabolism in hypercholesterolemic women.17,18      Consumption of TFA predicts higher risk of coronary heart disease, sudden death, cancer and possibly diabetes mellitus.19-22 Additionally, the high consumption of TFA during pregnancy has been associated with effects on intrauterine development.23 TFA may have adverse effects on growth and development by interfering with essential fatty acid metabolism, direct effects on membrane structures or metabolism, or secondary to reducing the intakes of the cis essential fatty acids in either mother or child. TFA are transported across the placenta and secreted in human milk in amounts that depend on the maternal dietary intake.24-26 Inverse associations have been shown between TFA and the essential n − 6 and n − 3 fatty acids in newborn infants, human milk and preschool children. It supports the need to reduce industrially produced TFA and improve dietary fat quality, particularly by increasing intake of n − 3 fatty acids. The use of partially hydrogenated fats and oils by industry, particularly in baked and processed foods that are widely consumed by women and children result in exposure to TFA in amounts shown to have adverse health effects on blood lipids and inflammatory markers in adults. In addition, high exposure to TFA is consistently related to lower levels of Docosahexaenoic acid, a fatty acid that is crucial for normal neural development and function.24,27-29      It has also been observed a rise in allergic diseases upon the high ingestion of this fatty acid.30 These associations are greater than would be predicted by effects of TFA on serum lipoproteins alone. Systemic inflammation and endothelial dysfunction may

Trans-1,4 selective polymerization of 1,3-butadiene with symmetry pincer chromium complexes activated by MMAO

KAUST Repository

Gong, Dirong; Jia, Xiaoyu; Wang, Baolin; Zhang, Xuequan; Huang, Kuo-Wei

2014-01-01

Tridentate chromium complexes (Cr1-Cr7) incorporated with symmetrical pincer ligand bis(arylimino)pyridine and bis(pyrzaolyl)pyridine have been synthesized and characterized by elemental analyis, FT-IR as well as ESI-MS. X-ray diffraction reveals solids-state structures of Cr2, Cr4 and Cr6 all adopt pseudo-octahedral coordination environment with respect to metal center. All complexes have been tested in stereoregulated polymerization of butadiene under various polymerization conditions. The trans-1,4 and cis-1,4 enchainment of resultant polymer are found to be dependent on the structure of ligand and amount of activator used. Under the optimized condition, free ortho-substitutes Cr catalysts Cr1, Cr3, Cr4 and Cr6 are capable of initiating high trans-1,4 selectivity (trans-1,4: 89.2%-92.0%) with good polymer yields (71.5%-78.0%), while counterparts with ortho-positioned alkyl groups Cr2, Cr5 and Cr7 display mixed selectivities with moderate polymer yields. The sterical effect of ligand and amount of MMAO on the catalytic performance, in particular, the stereoselectivity and polymer yield, has been also elucidated by conjugated diene polymerization mechanism. © 2014 Elsevier B.V. All rights reserved.

Trans-1,4 selective polymerization of 1,3-butadiene with symmetry pincer chromium complexes activated by MMAO

KAUST Repository

Gong, Dirong

2014-09-01

Tridentate chromium complexes (Cr1-Cr7) incorporated with symmetrical pincer ligand bis(arylimino)pyridine and bis(pyrzaolyl)pyridine have been synthesized and characterized by elemental analyis, FT-IR as well as ESI-MS. X-ray diffraction reveals solids-state structures of Cr2, Cr4 and Cr6 all adopt pseudo-octahedral coordination environment with respect to metal center. All complexes have been tested in stereoregulated polymerization of butadiene under various polymerization conditions. The trans-1,4 and cis-1,4 enchainment of resultant polymer are found to be dependent on the structure of ligand and amount of activator used. Under the optimized condition, free ortho-substitutes Cr catalysts Cr1, Cr3, Cr4 and Cr6 are capable of initiating high trans-1,4 selectivity (trans-1,4: 89.2%-92.0%) with good polymer yields (71.5%-78.0%), while counterparts with ortho-positioned alkyl groups Cr2, Cr5 and Cr7 display mixed selectivities with moderate polymer yields. The sterical effect of ligand and amount of MMAO on the catalytic performance, in particular, the stereoselectivity and polymer yield, has been also elucidated by conjugated diene polymerization mechanism. © 2014 Elsevier B.V. All rights reserved.

Up front in the CIS

International Nuclear Information System (INIS)

Grey, C.A.

1994-01-01

A picture is drawn of the current supply side of the front-end fuel cycle production capacities in the CIS. Uranium production has been steadily declining, as in the West. Market realities have been reflected in local costs of production since the break-up of the former Soviet Union and some uneconomic mines have been closed. In terms of actual production, Kazakhstan, Russia and Uzbekistan, remain among the top five uranium producers in the world. Western government action has been taken to restrict the market access for natural uranium from the CIS. Reactors in the CIS continue to be supplied with fabricated fuel solely by Russian, though Western fuel fabricators have reduced Russian supplies to Eastern Europe. Russia's current dominance in conversion and enrichment services in both the CIS and Eastern Europe is likely to continue as long as the present surplus low enriched uranium stocks last and surplus production capacity exists. Market penetration in the West has been limited by government action but Russia in 1993 still held about 20% of the world's conversion market and nearly 19% of the enrichment market. (6 figures, 2 tables, 4 references) (UK)

Trans-Cultural, Trans-Language Practices: Potentialities for Rethinking Doctoral Education Pedagogies

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Sarojni Choy

2017-01-01

Full Text Available Over the last decade, there has been a rapid increase in doctoral enrolments of Asian international students in Australian universities. While policies have been developed to meet the needs of these students, there seems to be some confusion around the terms internationalisation, globalisation, bi-cultural, inter-cultural, multi-cultural, and trans-cultural within these policies. In this paper, we define these terms and advocate for a policy position which orients to a futurist definition of culture. We then review the work of Michael Singh and his research team at Western Sydney University who have responded to this rapid increase in Asian international student doctoral enrolments in Australian universities by developing pedagogic principles around notions of trans-language and trans-cultural practices. In the final section of the paper, we then draw on our own experiences of doctoral supervision in Australian universities to reflect on our positioning within the pedagogic principles around trans-language and trans-cultural practices.

Conjugated linoleic acid in ewe milk fat.

Science.gov (United States)

Luna, Pilar; Fontecha, Javier; Juárez, Manuela; de la Fuente, Miguel Angel

2005-11-01

Ewe milk fat from five different herds was studied to determine the content of conjugated linoleic acid (CLA) isomers. Research was carried out by combining gas chromatography-mass spectrometry (GC-MS) of fatty acid methyl esters (FAME) and 4,4-dimethyloxazolyne derivatives (DMOX) with silver ion-high performance liquid chromatography (Ag+-HPLC). Reconstructed mass spectral profiles of CLA characteristic ions from DMOX were used to identify positional isomers and Ag+-HPLC to quantify them. Total CLA content varied from 0.57 to 0.97 g/100 g of total fatty acids. FAME and DMOX were separated into a complex mixture of minor isomers and major rumenic acid (9-cis 11-trans C18:2) by GC-MS using a 100-m polar capillary column. Rumenic acid would represent more than 75% of total CLA. 11-trans 13-trans, 11-13 cis/trans plus trans/cis and 7-9 cis/trans plus trans/cis were the main CLA isomers after rumenic acid. Minor amounts of 8-10 and 10-12 C18:2 isomers were also found. Although most of the isomers were present in each herd's milk, differences in content were observed for some CLA species.

Photoinduced gelation by stilbene oxalyl amide compounds.

Science.gov (United States)

Miljanić, Snezana; Frkanec, Leo; Meić, Zlatko; Zinić, Mladen

2005-03-29

Oxalyl amide derivatives bearing 4-dodecyloxy-stilbene as a cis-trans photoisomerizing unit were synthesized. The trans derivative acted as a versatile gelator of various organic solvents, whereas the corresponding cis derivative showed a poor gelation ability or none at all. In diluted solution (c = 2.0 x10(-5) mol dm(-3), ethanol), the cis isomer was photochemically converted into the trans isomer within 4 min. Depending on the radiation wavelength, the trans isomer was stable or liable to photodecomposition. When exposed to irradiation, a concentrated solution of the cis isomer (c = 2.0 x 10(-2) mol dm(-3), ethanol) turned into a gel. The FT-Raman, FT-IR, and 1H NMR spectra demonstrated that the gelation process occurred because of a rapid cis --> trans photoisomerization followed by a self-assembly of the trans molecules. Apart from the formation of hydrogen bonding between the oxalyl amide parts of the molecules, confirmed by FT-IR spectroscopy, it was assumed that the pi-pi stacking between the trans-stilbene units of the molecule and a lipophilic interaction between long alkyl chains were the interactions responsible for gelation.

Mutation of cis-proline 207 in mitochondrial creatine kinase to alanine leads to increased acid stability.

Science.gov (United States)

Forstner, M; Müller, A; Rognan, D; Kriechbaum, M; Wallimann, T

1998-07-01

We show that the mutation of an uncharged residue far from the active site to another uncharged residue can have effects on the active site without disturbing the overall structure of the protein. Cis-proline 207 of mitochondrial creatine kinase was mutated to alanine. The mutant showed a decrease in the pH-optimum for ATP synthesis by 1.5 units while the maximum relative activity was lowered to 53% of the wild-type enzyme. In the direction of ATP consumption, the pH optimum was lowered by 1.3 units and the maximum relative activity was 49% of the wild-type enzyme. The enzyme kinetic parameters Km and Kd for the substrates did not change dramatically, indicating a largely unperturbed active site. Small-angle X-ray scattering was used to investigate the structural change concomitant with the mutation, yielding a scattering profile only slightly different from that of the wild-type enzyme. Neither the radius of gyration nor the molecular mass showed any significant differences, leading to the conclusion that quarternary organization and fold of the mutant and the wild-type enzymes were similar. Theoretical analysis suggests the most probable primary source of structural change to be a transition of residue 207 peptide bond torsional angle co from the cis to the trans configuration.

cisMEP: an integrated repository of genomic epigenetic profiles and cis-regulatory modules in Drosophila.

Science.gov (United States)

Yang, Tzu-Hsien; Wang, Chung-Ching; Hung, Po-Cheng; Wu, Wei-Sheng

2014-01-01

Cis-regulatory modules (CRMs), or the DNA sequences required for regulating gene expression, play the central role in biological researches on transcriptional regulation in metazoan species. Nowadays, the systematic understanding of CRMs still mainly resorts to computational methods due to the time-consuming and small-scale nature of experimental methods. But the accuracy and reliability of different CRM prediction tools are still unclear. Without comparative cross-analysis of the results and combinatorial consideration with extra experimental information, there is no easy way to assess the confidence of the predicted CRMs. This limits the genome-wide understanding of CRMs. It is known that transcription factor binding and epigenetic profiles tend to determine functions of CRMs in gene transcriptional regulation. Thus integration of the genome-wide epigenetic profiles with systematically predicted CRMs can greatly help researchers evaluate and decipher the prediction confidence and possible transcriptional regulatory functions of these potential CRMs. However, these data are still fragmentary in the literatures. Here we performed the computational genome-wide screening for potential CRMs using different prediction tools and constructed the pioneer database, cisMEP (cis-regulatory module epigenetic profile database), to integrate these computationally identified CRMs with genomic epigenetic profile data. cisMEP collects the literature-curated TFBS location data and nine genres of epigenetic data for assessing the confidence of these potential CRMs and deciphering the possible CRM functionality. cisMEP aims to provide a user-friendly interface for researchers to assess the confidence of different potential CRMs and to understand the functions of CRMs through experimentally-identified epigenetic profiles. The deposited potential CRMs and experimental epigenetic profiles for confidence assessment provide experimentally testable hypotheses for the molecular mechanisms

L-Arabinose isomerase and its use for biotechnological production of rare sugars.

Science.gov (United States)

Xu, Zheng; Li, Sha; Feng, Xiaohai; Liang, Jinfeng; Xu, Hong

2014-11-01

L-Arabinose isomerase (AI), a key enzyme in the microbial pentose phosphate pathway, has been regarded as an important biological catalyst in rare sugar production. This enzyme could isomerize L-arabinose into L-ribulose, as well as D-galactose into D-tagatose. Both the two monosaccharides show excellent commercial values in food and pharmaceutical industries. With the identification of novel AI family members, some of them have exhibited remarkable potential in industrial applications. The biological production processes for D-tagatose and L-ribose (or L-ribulose) using AI have been developed and improved in recent years. Meanwhile, protein engineering techniques involving rational design has effectively enhanced the catalytic properties of various AIs. Moreover, the crystal structure of AI has been disclosed, which sheds light on the understanding of AI structure and catalytic mechanism at molecular levels. This article reports recent developments in (i) novel AI screening, (ii) AI-mediated rare sugar production processes, (iii) molecular modification of AI, and (iv) structural biology study of AI. Based on previous reports, an analysis of the future development has also been initiated.

Effects of Lactation Stage and Individual Performance on Milk -9, -11 Conjugated Linoleic Acids Content in Dairy Cows

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T. Wang

2013-02-01

Full Text Available The goal of this study was to evaluate the effects of lactation stage and individual performance on milk cis-9, trans-11 conjugated linoleic acid (CLA content in dairy cows. In experiment 1, the milk cis-9, trans-11 CLA content from dairy cows in early (0.33±0.014%, middle (0.37±0.010%, and late stages (0.44±0.020% showed significant differences (p<0.05; and the individual contents of the major fatty acids, especially cis-9, trans-11 CLA in cows of the same lactation were also variable. In the second experiment design as a validation test, our results once again showed that the individual contents of cis-9, trans-11 CLA were various, and a difference of about 2-fold (0.55% vs 0.95% was observed, although the animals were offered same diet. These data demonstrated that lactation stage and individual performance have considerable effects on milk cis-9, trans-11 CLA contents.

Trans* Leadership.

Science.gov (United States)

Jourian, T J; Simmons, Symone L

2017-06-01

Focusing on emerging literature on trans* and gender-nonconforming students and their leadership, this chapter outlines the ways trans* students are engaged in leadership in educational institutions and outside of them and discusses implications for staff and faculty regarding how to support and engage these students and their leadership. © 2017 Wiley Periodicals, Inc., A Wiley Company.

The acid-tolerant L-arabinose isomerase from the mesophilic Shewanella sp. ANA-3 is highly active at low temperatures

Science.gov (United States)

2011-01-01

Background L-arabinose isomerases catalyse the isomerization of L-arabinose into L-ribulose at insight biological systems. At industrial scale of this enzyme is used for the bioconversion of D-galactose into D-tagatose which has many applications in pharmaceutical and agro-food industries. The isomerization reaction is thermodynamically equilibrated, and therefore the bioconversion rates is shifted towards tagatose when the temperature is increased. Moreover, to prevent secondary reactions it will be of interest to operate at low pH. The profitability of this D-tagatose production process is mainly related to the use of lactose as cheaper raw material. In many dairy products it will be interesting to produce D-tagatose during storage. This requires an efficient L-arabinose isomerase acting at low temperature and pH values. Results The gene encoding the L-arabinose isomerase from Shewanella sp. ANA-3 was cloned and overexpressed in Escherichia coli. The purified protein has a tetrameric arrangement composed by four identical 55 kDa subunits. The biochemical characterization of this enzyme showed that it was distinguishable by its maximal activity at low temperatures comprised between 15-35°C. Interestingly, this biocatalyst preserves more than 85% of its activity in a broad range of temperatures from 4.0 to 45°C. Shewanella sp. ANA-3 L-arabinose isomerase was also optimally active at pH 5.5-6.5 and maintained over 80% of its activity at large pH values from 4.0 to 8.5. Furthermore, this enzyme exhibited a weak requirement for metallic ions for its activity evaluated at 0.6 mM Mn2+. Stability studies showed that this protein is highly stable mainly at low temperature and pH values. Remarkably, T268K mutation clearly enhances the enzyme stability at low pH values. Use of this L-arabinose isomerase for D-tagatose production allows the achievement of attractive bioconversion rates of 16% at 4°C and 34% at 35°C. Conclusions Here we reported the purification and the

The acid-tolerant L-arabinose isomerase from the mesophilic Shewanella sp. ANA-3 is highly active at low temperatures

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Rhimi Moez

2011-11-01

Full Text Available Abstract Background L-arabinose isomerases catalyse the isomerization of L-arabinose into L-ribulose at insight biological systems. At industrial scale of this enzyme is used for the bioconversion of D-galactose into D-tagatose which has many applications in pharmaceutical and agro-food industries. The isomerization reaction is thermodynamically equilibrated, and therefore the bioconversion rates is shifted towards tagatose when the temperature is increased. Moreover, to prevent secondary reactions it will be of interest to operate at low pH. The profitability of this D-tagatose production process is mainly related to the use of lactose as cheaper raw material. In many dairy products it will be interesting to produce D-tagatose during storage. This requires an efficient L-arabinose isomerase acting at low temperature and pH values. Results The gene encoding the L-arabinose isomerase from Shewanella sp. ANA-3 was cloned and overexpressed in Escherichia coli. The purified protein has a tetrameric arrangement composed by four identical 55 kDa subunits. The biochemical characterization of this enzyme showed that it was distinguishable by its maximal activity at low temperatures comprised between 15-35°C. Interestingly, this biocatalyst preserves more than 85% of its activity in a broad range of temperatures from 4.0 to 45°C. Shewanella sp. ANA-3 L-arabinose isomerase was also optimally active at pH 5.5-6.5 and maintained over 80% of its activity at large pH values from 4.0 to 8.5. Furthermore, this enzyme exhibited a weak requirement for metallic ions for its activity evaluated at 0.6 mM Mn2+. Stability studies showed that this protein is highly stable mainly at low temperature and pH values. Remarkably, T268K mutation clearly enhances the enzyme stability at low pH values. Use of this L-arabinose isomerase for D-tagatose production allows the achievement of attractive bioconversion rates of 16% at 4°C and 34% at 35°C. Conclusions Here we

Carotenoids from Foods of Plant, Animal and Marine Origin: An Efficient HPLC-DAD Separation Method

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Irini F. Strati

2012-12-01

Full Text Available Carotenoids are important antioxidant compounds, present in many foods of plant, animal and marine origin. The aim of the present study was to describe the carotenoid composition of tomato waste, prawn muscle and cephalothorax and avian (duck and goose egg yolks through the use of a modified gradient elution HPLC method with a C30 reversed-phase column for the efficient separation and analysis of carotenoids and their cis-isomers. Elution time was reduced from 60 to 45 min without affecting the separation efficiency. All-trans lycopene predominated in tomato waste, followed by all-trans-β-carotene, 13-cis-lutein and all-trans lutein, while minor amounts of 9-cis-lutein, 13-cis-β-carotene and 9-cis-β-carotene were also detected. Considering the above findings, tomato waste is confirmed to be an excellent source of recovering carotenoids, especially all-trans lycopene, for commercial use. Xanthophylls were the major carotenoids of avian egg yolks, all-trans lutein and all-trans zeaxanthin in duck and goose egg yolk, respectively. In the Penaeus kerathurus prawn, several carotenoids (zeaxanthin, all-trans-lutein, canthaxanthin, cryptoxanthin, optical and geometrical astaxanthin isomers were identified in considerable amounts by the same method. A major advantage of this HPLC method was the efficient separation of carotenoids and their cis-isomers, originating from a wide range of matrices.

Synthesis, characterization, and monoamine transporter activity of the new psychoactive substance 3',4'-methylenedioxy-4-methylaminorex (MDMAR).

Science.gov (United States)

McLaughlin, Gavin; Morris, Noreen; Kavanagh, Pierce V; Power, John D; Twamley, Brendan; O'Brien, John; Talbot, Brian; Dowling, Geraldine; Mahony, Olivia; Brandt, Simon D; Patrick, Julian; Archer, Roland P; Partilla, John S; Baumann, Michael H

2015-07-01

The recent occurrence of deaths associated with the psychostimulant cis-4,4'-dimethylaminorex (4,4'-DMAR) in Europe indicated the presence of a newly emerged psychoactive substance on the market. Subsequently, the existence of 3,4-methylenedioxy-4-methylaminorex (MDMAR) has come to the authors' attention and this study describes the synthesis of cis- and trans-MDMAR followed by extensive characterization by chromatographic, spectroscopic, mass spectrometric platforms and crystal structure analysis. MDMAR obtained from an online vendor was subsequently identified as predominantly the cis-isomer (90%). Exposure of the cis-isomer to the mobile phase conditions (acetonitrile/water 1:1 with 0.1% formic acid) employed for high performance liquid chromatography analysis showed an artificially induced conversion to the trans-isomer, which was not observed when characterized by gas chromatography. Monoamine release activities of both MDMAR isomers were compared with the non-selective monoamine releasing agent (+)-3,4-methylenedioxymethamphetamine (MDMA) as a standard reference compound. For additional comparison, both cis- and trans-4,4'-DMAR, were assessed under identical conditions. cis-MDMAR, trans-MDMAR, cis-4,4'-DMAR and trans-4,4'-DMAR were more potent than MDMA in their ability to function as efficacious substrate-type releasers at the dopamine (DAT) and norepinephrine (NET) transporters in rat brain tissue. While cis-4,4'-DMAR, cis-MDMAR and trans-MDMAR were fully efficacious releasing agents at the serotonin transporter (SERT), trans-4,4'-DMAR acted as a fully efficacious uptake blocker. Currently, little information is available about the presence of MDMAR on the market but the high potency of ring-substituted methylaminorex analogues at all three monoamine transporters investigated here might be relevant when assessing the potential for serious side-effects after high dose exposure. Copyright © 2014 John Wiley & Sons, Ltd.

Reprogramming the Dynamin 2 mRNA by Spliceosome-mediated RNA Trans-splicing

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Delphine Trochet

2016-01-01

Full Text Available Dynamin 2 (DNM2 is a large GTPase, ubiquitously expressed, involved in membrane trafficking and regulation of actin and microtubule cytoskeletons. DNM2 mutations cause autosomal dominant centronuclear myopathy which is a rare congenital myopathy characterized by skeletal muscle weakness and histopathological features including nuclear centralization in absence of regeneration. No curative treatment is currently available for the DNM2-related autosomal dominant centronuclear myopathy. In order to develop therapeutic strategy, we evaluated here the potential of Spliceosome-Mediated RNA Trans-splicing technology to reprogram the Dnm2-mRNA in vitro and in vivo in mice. We show that classical 3′-trans-splicing strategy cannot be considered as accurate therapeutic strategy regarding toxicity of the pre-trans-splicing molecules leading to low rate of trans-splicing in vivo. Thus, we tested alternative strategies devoted to prevent this toxicity and enhance frequency of trans-splicing events. We succeeded to overcome the toxicity through a 5′-trans-splicing strategy which also allows detection of trans-splicing events at mRNA and protein levels in vitro and in vivo. These results suggest that the Spliceosome-Mediated RNA Trans-splicing strategy may be used to reprogram mutated Dnm2-mRNA but highlight the potential toxicity linked to the molecular tools which have to be carefully investigated during preclinical development.

Two negative cis-regulatory regions involved in fruit-specific promoter activity from watermelon (Citrullus vulgaris S.).

Science.gov (United States)

Yin, Tao; Wu, Hanying; Zhang, Shanglong; Lu, Hongyu; Zhang, Lingxiao; Xu, Yong; Chen, Daming; Liu, Jingmei

2009-01-01

A 1.8 kb 5'-flanking region of the large subunit of ADP-glucose pyrophosphorylase, isolated from watermelon (Citrullus vulgaris S.), has fruit-specific promoter activity in transgenic tomato plants. Two negative regulatory regions, from -986 to -959 and from -472 to -424, were identified in this promoter region by fine deletion analyses. Removal of both regions led to constitutive expression in epidermal cells. Gain-of-function experiments showed that these two regions were sufficient to inhibit RFP (red fluorescent protein) expression in transformed epidermal cells when fused to the cauliflower mosaic virus (CaMV) 35S minimal promoter. Gel mobility shift experiments demonstrated the presence of leaf nuclear factors that interact with these two elements. A TCCAAAA motif was identified in these two regions, as well as one in the reverse orientation, which was confirmed to be a novel specific cis-element. A quantitative beta-glucuronidase (GUS) activity assay of stable transgenic tomato plants showed that the activities of chimeric promoters harbouring only one of the two cis-elements, or both, were approximately 10-fold higher in fruits than in leaves. These data confirm that the TCCAAAA motif functions as a fruit-specific element by inhibiting gene expression in leaves.

Further delineation of FKBP14-related Ehlers-Danlos syndrome: A patient with early vascular complications and non-progressive kyphoscoliosis, and literature review.

Science.gov (United States)

Dordoni, Chiara; Ciaccio, Claudia; Venturini, Marina; Calzavara-Pinton, Piergiacomo; Ritelli, Marco; Colombi, Marina

2016-08-01

FKBP14-related Ehlers-Danlos syndrome (EDS) is an extremely rare recessive connective tissue disorder described for the first time in 2012 by Baumann and coworkers. The causal gene, FKBP14, encodes a member of the F506-binding family of peptidyl-prolyl cis-trans isomerases. The paucity of patients described so far makes this disorder poorly defined at clinical level. Here, we report an additional pediatric patient, who is compound heterozygous for a recurrent and a novel FKBP14 mutation, and compare his phenotype with those available in literature. This evaluation confirms that kyphoscoliosis (either progressive or non-progressive), myopathy, joint hypermobility, and congenital hearing loss (sensorineural, conductive, or mixed) are the typical features of the syndrome. Since the patient showed a severe cardiovascular event in childhood and atlantoaxial instability, this report expands the phenotype of the disorder and the allelic repertoire of FKBP14. © 2016 Wiley Periodicals, Inc. © 2016 Wiley Periodicals, Inc.

The foldase CYPB is a component of the secretory pathway of Aspergillus niger and contains the endoplasmic reticulum retention signal HEEL.

Science.gov (United States)

Derkx, P M; Madrid, S M

2001-12-01

Here we report the isolation and characterization of the cypB gene from Aspergillus niger. The cypB gene encodes a protein with a predicted molecular weight of 20.7 kDa, which shows a high degree of identity to the cyclophilin family of peptidyl prolyl cis-trans isomerases (PPIases) from other eukaryotes. The 5' untranslated region of cypB includes three sequences resembling UPREs (unfolded protein response elements). The expression of cypB is upregulated by tunicamycin and DTT, suggesting that at least one UPRE is functional. The CYPB protein also has a 23-amino acid sequence which serves to target the protein to the endoplasmic reticulum (ER), and the ER retention sequence HEEL. CYPB-(His)(6) was expressed in Escherichia coli; the purified protein is capable of isomerizing a substrate peptide in vitro. This is also the first report to show that C-terminal addition of the sequence HEEL is sufficient to ensure retention of the green fluorescent protein (GFP) within the ER.

Long-term inhibition of cyclophilin D results in intracellular translocation of calcein AM from mitochondria to lysosomes.

Science.gov (United States)

Shinohe, Daisuke; Kobayashi, Asuka; Gotoh, Marina; Tanaka, Kotaro; Ohta, Yoshihiro

2017-01-01

Cyclophilin D is a peptidyl-prolyl cis-trans isomerase localized in the mitochondrial matrix. Although its effects on mitochondrial characteristics have been well studied, its relation to the uptake of molecules by mitochondria remains unknown. Here, we demonstrated the effects of cyclophilin D on the intracellular translocation of calcein AM. Following addition of calcein AM to control cells or cells overexpressing wild-type cyclophilin D, calcein fluorescence was observed in mitochondria. However, long-term inhibition of cyclophilin D in these cells altered the localization of calcein fluorescence from mitochondria to lysosomes without changing mitochondrial esterase activity. In addition, depletion of glucose from the medium recovered calcein localization from lysosomes to mitochondria. This is the first demonstration of the effects of cyclophilin D on the intracellular translocation of molecules other than proteins and suggests that cyclophilin D may modify mitochondrial features by inducing the translocation of molecules to the mitochondria through the mechanism associated with cellular energy metabolism. Copyright © 2016 Elsevier Inc. All rights reserved.

A proteomics analysis for certain signature proteins of rabbit lacrimal passages after 125I seeds brachytherapy

International Nuclear Information System (INIS)

Li Dandan; Liu Lin; Gao Shi; Qi Liangchen; Ma Qingjie; Jin Longyun

2010-01-01

To search for certain signature proteins and the expression profiles in lacrimal passage stenosis, rabbit models of lacrimal passage stenosis were treated by 125 I seed brachytherapy. All the signature proteins were separated by two-dimensional electrophoresis, and identified by mass spectrometry. The results show that the up-regulated proteins are peptidyl-prolyl cis-trans isomerase A (PPIase A), and epidermal fatty acid-binding protein (E-FABP), while the down-regulated proteins are myosin light chain 1 (isomer of skeletal muscle), myosin light polypeptide 6 (isomer 1 of smooth muscle and non-muscle), myosin light chain 1 (isomer of slow-twitch muscle A), isomer 2 of ERC protein 2, and α-crystalline family protein. The proteins may play a role in healing the wound and regulating synaptic active zone of neurons due to correlation to cell apoptosis, proliferation and migration of smooth muscle cell. These provide molecular mechanism for preventing stenosis and restenosis of lacrimal passage. (authors)

Biotransformation of trans-1-chloro-3,3,3-trifluoropropene (trans-HCFO-1233zd)

International Nuclear Information System (INIS)

Schmidt, Tobias; Bertermann, Rüdiger; Rusch, George M.; Tveit, Ann; Dekant, Wolfgang

2013-01-01

trans-1-Chloro-3,3,3-trifluoropropene (trans-HCFO-1233zd) is a novel foam blowing and precision cleaning agent with a very low impact for global warming and ozone depletion. trans-HCFO-1233zd also has a low potential for toxicity in rodents and is negative in genotoxicity testing. The biotransformation of trans-HCFO-1233zd and kinetics of metabolite excretion with urine were assessed in vitro and in animals after inhalation exposures. For in vitro characterization, liver microsomes from rats, rabbits and humans were incubated with trans-HCFO-1233zd. Male Sprague Dawley rats and female New Zealand White rabbits were exposed to 2,000, 5,000 and 10,000 ppm for 6 h and urine was collected for 48 h after the end of the exposure. Study specimens were analyzed for metabolites using 19 F NMR, LC-MS/MS and GC/MS. S-(3,3,3-trifluoro-trans-propenyl)-glutathione was identified as predominant metabolite of trans-HCFO-1233zd in all microsomal incubation experiments in the presence of glutathione. Products of the oxidative biotransformation of trans-HCFO-1233zd were only minor metabolites when glutathione was present. In rats, both 3,3,3-trifluorolactic acid and N-acetyl-(3,3,3-trifluoro-trans-propenyl)-L-cysteine were observed as major urinary metabolites. 3,3,3-Trifluorolactic acid was not detected in the urine of rabbits. Quantitation showed rapid excretion of both metabolites in both species (t 1/2 1/2 < 6 h). ► Glutathione adduct as predominant in vitro metabolite in all tested species. ► Toxic metabolites could not be detected in any great extent

The content of conjugated linoleic acid (CLA) isomer groups in milk of two Polish sheep breeds determined by silver ion liquid chromatography (Ag(+)-HPLC).

Science.gov (United States)

Rozbicka-Wieczorek, Agnieszka; Radzik-Rant, Aurelia; Rant, Witold; Czauderna, Marian

2013-01-01

Sheep milk is rich in CLA isomers which are biologically active components influencing human health. There are four geometric CLA isomer pairs: cis, trans; trans, cis; trans, trans and cis, cis. The aim of the present study was the analysis of CLA isomer groups content by Ag+-HPLC in milk fat of Zelazneńska (ZS) and Wrzosówka (WS) sheep breeds. The ewes of both breeds were kept under the same environmental and nutritional conditions. Milk samples were collected from 60 suckling ewes (30 from each breed), at the age of 3-4 years and in their 4th week of lactation. A higher total amount of all CLA isomer groups was obtained in milk of ZS ewes, however, this result was statistically insignificant. The percentage of the main c9, t11 isomer in total CLA was higher in Wrzosówka milk (68% vs. 74%). The content of the trans, trans isomer group in milk fat of the studied breeds was similar. The percentage of this group in total CLA in milk of WS and ZS constitutes 7.2% and 7.7%, respectively. The amount of cis,cis isomers in milk fat of ZS was higher thanWS (P < or = 0.01).

Ready access to functionally embellished cis-hydrindanes and cis-decalins: protecting group-free total syntheses of (±)-Nootkatone and (±)-Noreremophilane.

Science.gov (United States)

Handore, Kishor L; Seetharamsingh, B; Reddy, D Srinivasa

2013-08-16

A simple and efficient synthesis of functionalized cis-hydrindanes and cis-decalins was achieved using a sequential Diels-Alder/aldol approach in a highly diastereoselective manner. The scope of this method was tested with a variety of substrates and was successfully applied to the synthesis of two natural products in racemic form. The highlights of the present work provide ready access to 13 new cis-hydrindanes/cis-decalins, a protecting group-free total synthesis of an insect repellent Nootkatone, and the first synthesis of a Noreremophilane using the shortest sequence.

Biotransformation of trans-1-chloro-3,3,3-trifluoropropene (trans-HCFO-1233zd)

Energy Technology Data Exchange (ETDEWEB)

Schmidt, Tobias [Institut für Toxikologie, Universität Würzburg, Versbacher Str. 9, 97078 Würzburg (Germany); Bertermann, Rüdiger [Institut für Anorganische Chemie, Universität Würzburg, Am Hubland, 97074 Würzburg (Germany); Rusch, George M.; Tveit, Ann [Honeywell, P.O. Box 1057, Morristown, NJ 07962-1057 (United States); Dekant, Wolfgang, E-mail: dekant@toxi.uni-wuerzburg.de [Institut für Toxikologie, Universität Würzburg, Versbacher Str. 9, 97078 Würzburg (Germany)

2013-05-01

trans-1-Chloro-3,3,3-trifluoropropene (trans-HCFO-1233zd) is a novel foam blowing and precision cleaning agent with a very low impact for global warming and ozone depletion. trans-HCFO-1233zd also has a low potential for toxicity in rodents and is negative in genotoxicity testing. The biotransformation of trans-HCFO-1233zd and kinetics of metabolite excretion with urine were assessed in vitro and in animals after inhalation exposures. For in vitro characterization, liver microsomes from rats, rabbits and humans were incubated with trans-HCFO-1233zd. Male Sprague Dawley rats and female New Zealand White rabbits were exposed to 2,000, 5,000 and 10,000 ppm for 6 h and urine was collected for 48 h after the end of the exposure. Study specimens were analyzed for metabolites using {sup 19}F NMR, LC-MS/MS and GC/MS. S-(3,3,3-trifluoro-trans-propenyl)-glutathione was identified as predominant metabolite of trans-HCFO-1233zd in all microsomal incubation experiments in the presence of glutathione. Products of the oxidative biotransformation of trans-HCFO-1233zd were only minor metabolites when glutathione was present. In rats, both 3,3,3-trifluorolactic acid and N-acetyl-(3,3,3-trifluoro-trans-propenyl)-L-cysteine were observed as major urinary metabolites. 3,3,3-Trifluorolactic acid was not detected in the urine of rabbits. Quantitation showed rapid excretion of both metabolites in both species (t{sub 1/2} < 6 h) and the extent of biotransformation of trans-HCFO-1233zd was determined as approximately 0.01% of received dose in rabbits and approximately 0.002% in rats. trans-HCFO-1233zd undergoes both oxidative biotransformation and glutathione conjugation at very low rates. The low extent of biotransformation and the rapid excretion of metabolites formed are consistent with the very low potential for toxicity of trans-HCFO-1233zd in mammals. - Highlights: ► No lethality and clinical signs were observed. ► Glutathione S-transferase and cytochrome P-450 dependent

Pathogenic adaptation of intracellular bacteria by rewiring a cis-regulatory input function.

Science.gov (United States)

Osborne, Suzanne E; Walthers, Don; Tomljenovic, Ana M; Mulder, David T; Silphaduang, Uma; Duong, Nancy; Lowden, Michael J; Wickham, Mark E; Waller, Ross F; Kenney, Linda J; Coombes, Brian K

2009-03-10

The acquisition of DNA by horizontal gene transfer enables bacteria to adapt to previously unexploited ecological niches. Although horizontal gene transfer and mutation of protein-coding sequences are well-recognized forms of pathogen evolution, the evolutionary significance of cis-regulatory mutations in creating phenotypic diversity through altered transcriptional outputs is not known. We show the significance of regulatory mutation for pathogen evolution by mapping and then rewiring a cis-regulatory module controlling a gene required for murine typhoid. Acquisition of a binding site for the Salmonella pathogenicity island-2 regulator, SsrB, enabled the srfN gene, ancestral to the Salmonella genus, to play a role in pathoadaptation of S. typhimurium to a host animal. We identified the evolved cis-regulatory module and quantified the fitness gain that this regulatory output accrues for the bacterium using competitive infections of host animals. Our findings highlight a mechanism of pathogen evolution involving regulatory mutation that is selected because of the fitness advantage the new regulatory output provides the incipient clones.

Effects of polybrominated diphenyl ethers (PBDEs) and their derivatives on protein disulfide isomerase activity and growth hormone release of GH3 cells.

Science.gov (United States)

Hashimoto, Shoko; Yoshimura, Hiromi; Okada, Kazushi; Uramaru, Naoto; Sugihara, Kazumi; Kitamura, Shigeyuki; Imaoka, Susumu

2012-03-19

Polybrominated diphenyl ethers (PBDEs) have been used in a variety of consumer products such as flame retardants and recently have been known to be widespread environmental pollutants, which probably affect biological functions of mammalian cells. However, the risk posed by PBDE metabolites has not been clarified. Our previous study suggested that bisphenol A (BPA), an endocrine-disrupting chemical, binds to protein disulfide isomerase (PDI) and inhibits its activity. PDI is an isomerase enzyme in the endoplasmic reticulum and facilitates the formation or cleavage of disulfide bonds. PDI consists of a, b, b', and a' domains and the c region, with the a and a' domains having isomerase active sites. In the present study, we tested the effects of 10 kinds of PBDE compounds and their metabolites on PDI. OH-PBDEs specifically inhibited the isomerase activity of PDI, with 4'-OH-PBDE more effective than 2' (or 2)-OH-PBDEs. 4'-OH-PBDE inhibited the isomerase activity of the b'a'c fragment but not that of ab and a'c, suggesting that the b' domain of PDI is essential for the inhibition by 4'-OH-PBDE. We also investigated the effects of these chemicals on the production of growth hormone (GH) in GH3 cells. In GH3 cells, levels of mRNA and protein of GH stimulated by T(3) were reduced by 4'-OH-PBDE and 4'-MeO-PBDE. The reduction in GH expression caused by these compounds was not changed by the overexpression or knockdown of PDI in GH3 cells, while these manipulations of PDI levels significantly suppressed the expression of GH. These results suggest that the biological effects of PBDEs differed depending on their brominated and hydroxylated positions. © 2011 American Chemical Society

Powdered activated carbon adsorption of two fishy odorants in water: Trans,trans-2,4-heptadienal and trans,trans-2,4-decadienal.

Science.gov (United States)

Li, Xin; Wang, Jun; Zhang, Xiaojian; Chen, Chao

2015-06-01

Powdered activated carbon (PAC) adsorption of two fishy odorants, trans,trans-2,4-heptadienal (HDE) and trans,trans-2,4-decadienal (DDE), was investigated. Both the pseudo first-order and the pseudo second-order kinetic models well described the kinetics curves, and DDE was more readily removed by PAC. In isotherm tests, both Freundlich and Modified Freundlich isotherms fitted the experimental data well. PAC exhibited a higher adsorption capacity for DDE than for HDE, which could be ascribed to the difference in their hydrophobicity. The calculated thermodynamic parameters (ΔG0, ΔH0, and ΔS0) indicated an exothermic and spontaneous adsorption process. PAC dosage, pH, and natural organic matter (NOM) presence were found to influence the adsorption process. With increasing PAC dosage, the pseudo first-order and pseudo second-order rate constants both increased. The value of pH had little influence on HDE or DDE molecules but altered the surface charge of PAC, and the maximum adsorption capacity occurred at pH9. The presence of NOM, especially the fraction with molecular weight less than 1k Dalton, hindered the adsorption. The study showed that preloaded NOM impaired the adsorption capacity of HDE or DDE more severely than simultaneously fed NOM did. Copyright © 2015. Published by Elsevier B.V.

Optimization of Pseudomonas putida KT2440 as host for the production of cis, cis-muconate from benzoate

NARCIS (Netherlands)

Duuren, van J.B.J.H.

2011-01-01

Optimization of Pseudomonas putida KT2440 as host for the production of cis, cis-muconate