bluuebunny/crossref_metadata_2025_split huggingface dataset:
Identification of a ligand for IgG‐Fc derived from a soluble peptide library based on fusion proteins secreted by S. cerevisiae
Authors: Mersich Christa , Billes Werner , Jungbauer Alois 
Published: May 2007

AbstractBiological libraries are important tools in the development of new peptide‐based compounds. Here, we describe the use of a soluble peptide library system as a complementary tool in the field of ligand development. Random peptides were expressed in S. cerevisiae as carboxy‐terminal extensions of the eukaryotic initiation factor 5a (eIF5a) and secreted into the culture supernatant. Expression and screening of this library were performed in a microwell format. As an example of this versatile approach, we describe the identification of a ligand for the human IgG‐Fc fragment. Ligands binding IgG‐Fc show great potential in a wide variety of applications including development of therapeutics, streamlining the large‐scale purification of antibodies, and applications in diagnostic tests. We demonstrated the utility of this system. After screening only 6160 clones, we identified a ligand with the peptide sequence of TRRRTCSPPTWPRARARSTPSGCSSTGPSANRG. An affinity constant of 3.9 x 105 M‐1 was determined by a biosensor method. Handling and maintenance of this library is conceptually simple and highly applicable for automated high‐throughput systems.
High‐throughput protein purification under denaturating conditions by the use of cation exchange chromatography
Authors: Alm Tove , Steen Johanna , Ottosson Jenny , Hober Sophia 
Published: May 2007

AbstractA high‐throughput protein purification strategy using the polycationic Zbasic tag has been developed. In order for the strategy to be useful both for soluble and less soluble proteins, a denaturating agent, urea, was used in all purification steps. First, four target proteins were genetically fused to the purification tag, Zbasic. These protein constructs were purified by cation exchange chromatography and eluted using a salt gradient. From the data achieved, a purification strategy was planned including stepwise elution to enable parallel protein purification using a laboratory robot. A protocol that includes all steps, equilibration of the chromatography resin, load of sample, wash, and elution, all without any manual handling steps, was handled by the laboratory robot. The program allows automated purification giving milligram amounts of pure recombinant protein of up to 60 cell lysates. In this study 22 different protein constructs, with different characteristics regarding pI and solubility, were successfully purified by the laboratory robot. The data show that Zbasic can be used as a general purification tag also under denaturating conditions. Moreover, the strategy enables purification of proteins with different pI and solubility using ion exchange chromatography (IEXC). The procedure is highly reproducible and allows for high protein yield and purity and is therefore a good complement to the commonly used His6‐tag.
Electron donor effect on nitrate reduction pathway and kinetics in a mixed methanogenic culture
Authors: Tugtas A. Evren , Pavlostathis Spyros G. 
Published: May 2007

AbstractThe effect of different electron donors on the pathway and kinetics of nitrate reduction in a sulfide‐acclimated mixed, mesophilic (35°C) methanogenic culture was investigated. A mixture of dextrin and peptone, glucose, propionate, acetate, and H2/CO2 were used as substrates at an initial chemical oxygen demand of 1,500 mg/L and the initial nitrate concentration ranged between 0 and 300 mg N/L. The fastest nitrate reduction was observed in the H2/CO2 and acetate‐fed cultures. In the case of propionate, nitrate reduction was the slowest followed by partial recovery of methanogenesis and accumulation of volatile fatty acids due to inhibition as a result of accumulation of denitrification intermediates. Similarly, accumulation of nitrite and nitric oxide and partial or complete inhibition of methanogenesis was observed in the H2/CO2‐fed cultures. Methanogenesis completely recovered in the dextrin/peptone‐, glucose‐, and acetate‐fed cultures at all nitrate levels. Denitrification was the dominant pathway of nitrate reduction in the propionate‐, acetate‐, and H2/CO2‐fed cultures regardless of the COD/N value. However, both denitrification and dissimilatory nitrate reduction to ammonia (DNRA) were observed in the dextrin/peptone‐ and glucose‐fed cultures and the degree of predominance of either of the two pathways was a function of the COD/N value. Therefore, the type of electron donor used affected both the nitrate reduction pathway and kinetics, as well as the recovery of fermentation and/or methanogenesis in the mixed methanogenic culture. Biotechnol. Biotechnol. Bioeng. 2007;98: 756–763. © 2007 Wiley Periodicals, Inc.
Penetration of the Antimicrobial Peptide Dicynthaurin into Phospholipid Monolayers at the Liquid–Air Interface
Authors: Bringezu Frank , Majerowicz Monika , Maltseva Elena , Wen Shaoying , Brezesinski Gerald , Waring Alan J. 
Published: May 2007

AbstractThis work focuses on the adsorption kinetics of dicynthaurin with lipid monolayers, the effect of peptide adsorption on the structure of the lipid condensed chain lattice, peptide orientation and secondary structure in the adsorbed state. The studies with DPPG as model system revealed strong adsorption and massive incorporation of the peptide into the monolayer. Infrared reflection absorption spectroscopy (IRRAS) experiments showed that the secondary structure of the peptide is maintained upon adsorption. Specular X‐ray reflectivity showed the destabilization of the condensed phase of the pure lipid monolayer and revealed a tilted orientation of the long axis of the peptide helix of about 40° from the surface normal. Incorporation of the peptide was found to be pressure dependent, and at high pressure a “squeeze‐out” was observed; however, the peptide remained localized to the interface, as suggested by infrared data. These findings were supported by optical fluorescence microscopy measurements which showed the squeeze‐out of the peptide on water, but not under physiological conditions. The results suggest that dicynthaurin is able to adsorb to the phosphatidylglycerol‐rich inner cytoplasmic membrane of bacteria and alter membrane integrity. To identify and interact with membrane motifs that are characteristic of microbes, but which are absent in eukaryotic cells, might be an intrinsic ability of peptide antibiotics.
Closure of extracardiac Fontan fenestration by using the covered Cheatham Platinum stent
Authors: Marini D. , Boudjemline Y. , Agnoletti G. 
Published: May 2007

AbstractObjective: The purpose of this study was to describe our experience concerning the use of covered Cheatham Platinum (CP) stent in patients with fenestrated total cavopulmonary connection (TCPC). Background: Closure of TCPC fenestrations has been achieved by utilizing different devices designed to close intra‐cardiac or aorto‐pulmonary communications. Methods: We used the covered CP stent in 6 patients with fenestrated TCPC. Median age and weight were 11 years and 38 Kg, respectively. Femoral approach was used in all but 1 patient having bilateral thrombosis of femoral veins. The CP stent was crimped on a BiB balloon in 5 patients and on a simple balloon in 1 patient. The balloon's diameter was the same size or 1–2 mm larger than the TCPT conduit, according to angiographic diameter. Results: Mean procedural and fluoroscopy time were 41 ± 8 and 8 ± 2 min, respectively. Immediate full occlusion of fenestration was obtained in all patients. Mean central venous pressure was not significantly increased from 10.8 ± 2.5 to 11.8 ± 2.8 mm Hg and oxygen saturation significantly increased from (91.5 ± 4.4)% to (98.5 ± 1.9)% (P = 0.003). No procedural or intra‐hospital complications occurred. In particular, no arrhythmias, systemic embolism, or acute venous thrombosis were observed. At a median follow‐up of 2.8 months all patients have normal oxygen saturation and are symptom‐free. Conclusions: The covered CP stent can be easily and effectively used for closure of TCPC fenestrations. This method has the advantage to avoid protrusion of prosthetic material into the left atrium and to prevent early or late embolism. © 2007 Wiley‐Liss, Inc.
Increased incidence of stent thrombosis in patients with cocaine use
Authors: Karlsson Gudjon , Rehman Jalees , Kalaria Vijay , Breall Jeffrey A. 
Published: May 2007

AbstractIntroduction: Coronary stent thrombosis is a rare occurrence in the era of dual‐antiplatelet therapy. It is not known whether patients who use cocaine have a higher risk of thrombosis following coronary stent placement. Methods: We studied 247 consecutive patients who underwent coronary stent placement at an inner‐city hospital. Results: Twelve patients (4.9%) were actively using cocaine at the time of PCI. Of these twelve patients, four patients presented with stent thrombosis (33%) at a mean of 51 ± 40 days (median 45 days), after the index revascularization procedure. Only 2 of the 235 patients without documented cocaine use (0.85%) had stent thrombosis during the same period (P < 0.0001). Conclusion: The patients who actively use cocaine have a markedly higher risk of stent thrombosis when compared with patients without a documented history of cocaine use. We discuss various factors that potentially predispose cocaine users to stent thrombosis. © 2007 Wiley‐Liss, Inc.
Modeling Promiscuity Based on in vitro Safety Pharmacology Profiling Data
Authors: Azzaoui Kamal , Hamon Jacques , Faller Bernard , Whitebread Steven , Jacoby Edgar , Bender Andreas , Jenkins Jeremy L. , Urban Laszlo 
Published: May 2007

AbstractThis study describes a method for mining and modeling binding data obtained from a large panel of targets (in vitro safety pharmacology) to distinguish differences between promiscuous and selective compounds. Two naïve Bayes models for promiscuity and selectivity were generated and validated on a test set as well as publicly available drug databases. The model shows a higher score (lower promiscuity) for marketed drugs than for compounds in early development or compounds that failed during clinical development. Such models can be used in triaging high‐throughput screening data or for lead optimization.
Single Dibenzoterrylene Molecules in an Anthracene Crystal: Spectroscopy and Photophysics
Authors: Nicolet Aurélien A. L. , Hofmann Clemens , Kol'chenko Mikhail A. , Kozankiewicz Boleslaw , Orrit Michel 
Published: May 2007

AbstractWe study single dibenzoterrylene molecules in an anthracene single crystal at 1.4 K in two insertion sites at 785.1 and 794.3 nm. The single‐molecule zero‐phonon lines are narrow (about 30 MHz), intense (the detected fluorescence rates at saturation reach 100,000 counts s−1), and very photostable. The intersystem‐crossing yield is extremely low (10−7 or lower). All of these features are hallmarks of an excellent system for high‐resolution spectroscopy and nanoscale probing at cryogenic temperatures.
Intermolecular Interactions between Halothane and Dimethyl Ether: A Cryosolution Infrared and Ab Initio Study
Authors: Michielsen Bart , Herrebout Wouter A. , van der Veken Benjamin J. 
Published: May 2007

AbstractThe complex of halothane (CHClBrCF3) and dimethyl ether has been investigated experimentally in solutions of liquid krypton using infrared spectroscopy and theoretically using ab initio calculations at the MP2/6‐311++G(d,p) level. The formation of a 1:1 complex was experimentally detected. The most stable ab initio geometry found is the one in which the CH bond of halothane interacts with the oxygen atom of dimethyl ether. The complexes in which the chlorine or the bromine atom of halothane interacts with the oxygen atom of the ether were found to be local energy minima and were less stable by 14.5 and 9.3 kJ mol−1, respectively, than the global minimum. The formation of a single complex species was observed in the infrared spectra; the standard complexation enthalpy of this complex was determined to be −12.3(8) kJ mol−1. Analysis of the observed complexation shifts supports the identification of the complex as the hydrogen‐bonded species. The CH stretching vibration of halothane was found to show a redshift upon complexation of 19(2) cm−1. The infrared intensity ratios εcomplex/εmonomer for the fundamental and its first overtone were measured to be 6.5(1) and 0.31(1). The frequency shift was analyzed using Morokuma‐type analysis, and the infrared intensity ratios were rationalized using a model including the mechanical and electric anharmonicity of the CH stretching fundamental.
A novel triple fusion reporter system for use in gene trap mutagenesis
Authors: Tsakiridis Anestis , Tzouanacou Elena , Larralde Osmany , Watts Tim M. , Wilson Valerie , Forrester Lesley , Brickman Joshua M. 
Published: May 2007

AbstractGene trapping is an insertional mutagenesis strategy that allows for simultaneous gene identification and mutation in embryonic stem (ES) cells. Gene trap vectors both disrupt coding sequence and report on the genes' endogenous expression. The most popular gene trap reporter to date combines β‐galactosidase expression with neomycin resistance in a fusion protein known as β‐geo. Here we describe a refinement to this reporter that also incorporates real time fluorescent readouts. We have constructed a series of gene trap vectors incorporating a novel tripartite fusion protein consisting of EGFP, β‐galactosidase, and the neomycin or hygromycin resistance activities. Our results indicate that these triple fusions can function efficiently as reporters of endogenous trapped gene expression and subcellular localization. We show that these fusion proteins constitute versatile gene trap reporters whose activity can be detected in real time by fluorescence and in fixed tissue with a sensitive enzymatic activity. genesis 45:353–360, 2007. © 2007 Wiley‐Liss, Inc.
Drosophila female sterile mutation spoonbill interferes with multiple pathways in oogenesis
Authors: Neuman‐Silberberg F. Shira 
Published: May 2007

Abstractspoonbill is a Drosophila female‐sterile mutation, which displays a range of eggshell and egg chamber patterning defects. Previous analysis has shown that the mutation interfered with the function of two major signaling pathways, GRK/EGFR and DPP. In this report, the nature of spoonbill was further investigated to examine whether it was associated with additional pathways in oogenesis. Clonal analysis, presented here, demonstrated that most of the aberrant phenotypes associated with spoonbill were dependent on a mutant germline. Nevertheless, SPOONBILL may function also in the soma to ensure proper polarization and migration of the border‐cell‐cluster. Further, genetic interaction studies implicated spoonbill in additional unrelated pathways such as the one(s) involved in actin polymerization/depolymerization. Based on the previous data and the results presented here, it is anticipated that spoonbill may encode a multifunctional protein that perhaps coordinately regulated the activity of multiple signaling pathways during oogenesis. genesis 45:369–381, 2007. © 2007 Wiley‐Liss, Inc.
The Role of Equatorial and Axial Ligands in Promoting the Activity of Non‐Heme Oxidoiron(IV) Catalysts in Alkane Hydroxylation
Authors: Bernasconi Leonardo , Louwerse Manuel J. , Baerends Evert Jan 
Published: May 2007

AbstractThe key electronic structural feature of the FeO2+ moiety, which determines its activity as an alkane hydroxylation catalyst, is the presence of low‐lying acceptor orbitals, namely the 3σ* 3d–2pz antibonding orbital. Both the energetic position of this orbital and the spin state of the system (which in turn also affects the 3σ* energy) depend on the surrounding ligands. We present results of density functional theory (DFT) calculations performed on a series of gas‐phase complexes of composition [FeO(H2O)n(L)5–n]2+ (n = 4, 1, 0) derived from the recently characterised aqueous [FeO(H2O)5]2+ by substitution of ligand water molecules with L = NH3, CH3CN, H2S and BF3. The calculations reveal that the high‐spin (quintet) state is favoured by the weaker σ‐donating equatorial ligands, which is consistent with the literature. The high‐spin configuration is more reactive because of significant exchange stabilisation of the crucial 3σ*↑ orbital. Once the quintet state is formed by a judicious choice of equatorial ligands, the reactivity can be fine‐tuned by modulating the energy of the 3σ* orbital by varying the nature of the axial ligand. A linear relation between the σ‐donor properties of the axial ligand (estimated from the magnitude of the orbital interaction between the σ lone pair and the 3σ* orbital) and the activation barrier for the abstraction reaction is observed, and is related to a “push effect” of the σ donors that destabilises the 3σ* orbital. We propose that species with enhanced activation properties for hydrogen abstraction relative to [FeO(H2O)5]2+ might be obtainable by either replacing the axial ligand with a σ donor weaker than H2O or by preventing ligands from coordinating to iron in an axial position. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2007)
Boron Dipyrromethene Dyes Bearing Ancillary 2,2′:6′,2″‐Terpyridine Coordination Sites
Authors: Harriman Anthony , Mallon Laura J. , Stewart Beverly , Ulrich Gilles , Ziessel Raymond 
Published: May 2007

AbstractTwo new boron‐dipyrromethene dyes have been synthesised and their photophysical properties have been investigated by steady‐state and time‐resolved fluorescence spectroscopy. These dyes are equipped with ancillary 2,2′:6′,2″‐terpyridine (terpy) residues, attached either at the B centre or at the meso position of the organic framework; in this latter case two ethynylated pyrene units are bound to the B atom. Under most experimental conditions, the absorption and emission spectral properties are typical of this class of dye. Complexation of zinc(II) cations to the terpy units attached at the B centre causes complete extinction of the fluorescence due to intramolecular electron transfer from the excited state dye to the resultant zinc(II) bis‐terpy complex. Similar behaviour is noted when the terpy is attached at the meso site, although the rate of electron transfer is slower due to the weaker driving force. A most unusual feature of the pyrene‐substituted dye is its facile self association in acetonitrile solution. This results in the reversible formation of a fluorescent associate, believed to be a symmetric dimer, that absorbs and emits to the red of the monomer. Self association is considered to be driven by a solvophobic effect in which the pyrene units seek to minimize surface contact with the surrounding solvent molecules.(© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2007)
Asymmetric Homoaldol Reactions with Cyclohex‐2‐enyl N,N‐Diisopropylcarbamate: Kinetic Resolution, Elucidation of the Stereochemical Course and Applications in the Synthesis of Hexahydroisobenzofuran‐4‐(1H)‐ones
Authors: Becker Jochen , Fröhlich Roland , Salorinne Kirsi , Hoppe Dieter 
Published: May 2007

AbstractEnantio‐enriched cyclohex‐2‐enyl N,N‐diisopropylcarbamate (5) is stereospecifically deprotonated by sec‐butyllithium/(–)‐sparteine (9) to form the configurationally stable lithium complex 7·9. A kinetic resolution of rac‐5 by n‐butyllithium/(–)‐sparteine (9) yielded (R)‐5 with up to 99 % ee. Electrophilic substitution with tin electrophiles proceeds in a anti‐SE′ fashion as shown by chemical correlations. The synthesized allylstannanes 10 undergo a highly stereospecific TiCl4‐mediated homoaldol reaction with various aldehydes, yielding syn‐configured homoaldol products 12. These were transferred into all‐cis‐configured hexahydroisobenzofuran‐4(1H)‐ones 22 by BF3·OEt2‐mediated reactions with aldehydes. The configurations of several products were determined by X‐ray structure analysis. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2007)
Mass distribution, polydispersity and focusing properties of carrier ampholytes for IEF. IV: pH 6–8 intervals
Authors: Simó Carolina , Citterio Attilio , Righetti Pier Giorgio 
Published: May 2007

AbstractFour commercial brands of carrier ampholytes (Ampholine, Pharmalyte, Servalyt, Bio‐Lyte), in the pH 6–8 range, have been analyzed by a 2‐D technique based on preparative Rotofor fractionation followed by CE‐MS of 10 out of 20 fractions harvested, in the second dimension. The findings: Ampholine (pH 6–8) contains 80 differentMrcompounds, in theMrinterval 216–979 Da, for a total of 326 isoforms. Bio‐Lyte (pH 6–8) consists of 62 differentMrspecies, in theMrrange 341–1048 Da, for a total of 237 isoforms. Servalyt (pH 6–8) is made of 126 differentMrcompounds, in theMrinterval 240–785 Da, for a total of 703 isoforms. Pharmalyte (pH 5–8) comprises 123 amphoteres, in theMrrange of 221–992 Da, for a total of 476 isoforms. Pharmalyte appears to be the best brand, with a good proportion of species focusing sharply at their pIposition and relatively few ’︁poor' species, distributed along the entire pH gradient. General conclusions are drawn on the properties of all the pH intervals explored in this series of investigations and some guidelines for possible synthetic routes ameliorating the neutral and alkaline pH intervals are discussed.
Genomic and functional evidence for an ARID1A tumor suppressor role
Authors: Huang Jianmin , Zhao Yan‐Ling , Li Yu , Fletcher Jonathan A. , Xiao Sheng 
Published: May 2007

AbstractARID1A is located in 1p36.11, a region frequently deleted in human cancers. Using a novel method to screen for tumorigenic cDNA sequences, we have identified ARID1A as a presumptive tumor suppressor gene. The transforming ARID1A sequence was an antisense cDNA, and was the product of a genomic rearrangement, as corroborated in the primary breast carcinoma from which the cDNA had been obtained. In further screening, we identified a lung adenocarcinoma cell line with a highly localized homozygous genomic deletion involving the 5′ end of ARID1A. These studies provide strong evidence that ARID1A is a tumor suppressor gene. © 2007 Wiley‐Liss, Inc.
New founder germline mutations of CDKN2A in melanoma‐prone families and multiple primary melanoma development in a patient receiving levodopa treatment
Authors: Kannengiesser Caroline , Dalle Stéphane , Leccia Marie‐Thérèse , Avril Marie Françoise , Bonadona Valerie , Chompret Agnès , Lasset Christine , Leroux Dominique , Thomas Luc , Lesueur Fabienne , Lenoir Gilbert , Sarasin Alain , Bressac‐de Paillerets Brigitte 
Published: May 2007

AbstractGermline mutations in the CDKN2A gene have been shown to predispose individuals to cutaneous malignant melanoma. Here, we describe three melanoma‐prone families and one isolated patient affected by multiple melanoma who carried a tandem germline mutation of CDKN2A at the nucleotide level, [c.339G>C;c.340C>T], [p.Leu113Leu;p.Pro114Ser]. We also describe three other melanoma‐prone families that carried a missense germline CDKN2A mutation, c.167G>T, p.Ser56Ile. All these families and patients resided in southeast France. We analyzed six 9p21 markers where the CDKN2A gene is located and found that carrier haplotypes for both mutations were consistent with two respective common founder ancestors. In one family, we identified two fourth‐degree relatives homozygous for the Ser56Ile mutation, indicating a possible consanguinity. Furthermore, we observed that a carrier of the founder CDKN2A [p.Leu113Leu;p.Pro114Ser] mutation as well as two MC1R moderate‐risk variants, [p.Arg151Cys(+)p.Arg163Gln] developed 22 primary melanomas in the three years that followed initiation of levodopa therapy for Parkinson's disease. This observation suggests that there is a need for reconsideration of the hypothesis that levodopa may play a role in melanoma development, at least when in the context of a high‐risk genetic background. © 2007 Wiley‐Liss, Inc.