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1.
Han Z Karatan E Scholle MD McCafferty J Kay BK 《Combinatorial chemistry & high throughput screening》2004,7(1):55-62
When using multiple targets and libraries, selection of affinity reagents from phage-displayed libraries is a relatively time-consuming process. Herein, we describe an automation-amenable approach to accelerate the process by using alkaline phosphatase (AP) fusion proteins in place of the phage ELISA screening and subsequent confirmation steps with purified protein. After two or three rounds of affinity selection, the open reading frames that encode the affinity selected molecules (i.e., antibody fragments, engineered scaffold proteins, combinatorial peptides) are amplified from the phage or phagemid DNA molecules by PCR and cloned en masse by a Ligation Independent Cloning (LIC) method into a plasmid encoding a highly active variant of E. coli AP. This time-saving process identifies affinity reagents that work out of context of the phage and that can be used in various downstream enzyme linked binding assays. The utility of this approach was demonstrated by analyzing single-chain antibodies (scFvs), engineered fibronectin type III domains (FN3), and combinatorial peptides that were selected for binding to the Epsin N-terminal Homology (ENTH) domain of epsin 1, the c-Src SH3 domain, and the appendage domain of the gamma subunit of the clathrin adaptor complex, AP-1, respectively. 相似文献
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New 3,3‐diphenylpropoxyphthalonitrile (5) was obtained from 3,3‐diphenylpropanol (3) and 4‐nitrophthalonitrile (4) with K2CO3 in DMF at 50 °C. The novel cobalt(II) phthalocyanine complexes, tetrakis‐[2‐(1,4‐dioxa‐8‐azaspiro[4.5]dec‐8‐yl)ethoxy] phthalocyaninato cobalt(II) (2) and tetrakis‐(3,3‐diphenylpropoxy)phthalocyaninato cobalt(II) (6) were prepared by the reaction of the phthalonitrile derivatives 1 and 5 with CoCl2 by microwave irradiation in 2‐(dimethylamino)ethanol for at 175 °C, 350 W for 7 and 10 min, respectively. These new cobalt(II)phthalocyanine complexes were characterized by spectroscopic methods (IR, UV–visible and mass spectroscopy) as well as elemental analysis. Complexes 2 and 6 are employed as catalyst for the oxidation of cyclohexene using tert‐butyl hydroperoxide (TBHP), m‐chloroperoxybenzoic acid (m‐CPBA), aerobic oxygen and hydrogen peroxide (H2O2) as oxidant. It is observed that both complexes can selectively oxidize cyclohexene to give 2‐cyclohexene‐1‐ol as major product, and 2‐cyclohexen‐1‐one and cyclohexene oxide as minor products. TBHP was found to be the best oxidant since minimal destruction of the catalyst, higher selectivity and conversion were observed in the products. Copyright © 2012 John Wiley & Sons, Ltd. 相似文献
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Anthracene Substituted Co (II) and Cu (II) phthalocyanines; Preparations,Investigation of Catalytical and Electrochemical Behaviors
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An approach to investigation of catalytical behaviors of Co (II) and Cu (II) phthalocyanines is reported that is based on changing any parameter to effect these behaviors. Towards this end, new anthracene substituted Co (II) and Cu (II) phthalocyanines were prepared and characterized spectroscopic methods. New cobalt (II) and copper (II) phthalocyanines were used as catalyst for oxidation of different phenolic compounds (such as 2,3‐dichlorophenol, 4‐methoxyphenol, 4‐nitrophenol, 2,3,6‐trimethylphenol) with different oxidants. Then, electrochemical characterization of cobalt (II) and copper (II) phthallocyanines were determined by using cyclic voltammetry (CV) and square wave voltammetry (SWV) techniques. Although copper (II) phthalocyanine showed similar Pc based electron transfer processes, cobalt (II) phthalocyanine showed metal and ligand based reduction reactions as expected. 相似文献
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In the case of disruption of Hcy metabolism, the blood level of Hcy increases and it causes particularly the cardiovascular diseases, cancer, dementia and Parkinson’s disease. Thus, the sensitive analysis of Hcy levels in biological fluids is very important. Hcy analysis was performed herein using very practical and cost‐effective protocol using differential pulse voltammetry and graphite electrode. Detection limit of Hcy was found to be 1.21 µM in the linear range from 2 µM to 20 µM. The electrochemical Hcy detection in artificial urine medium was also successfully performed even in the presence of L ‐Cysteine, L ‐Methionine and Glutathione. 相似文献
6.
Luk Fojt Bohumír Grüner Jan Nekvinda Ece Zeynep Tzn Ludk Havran Miroslav Fojta 《Molecules (Basel, Switzerland)》2022,27(6)
In this study we explore the effect on the electrochemical signals in aqueous buffers of the presence of hydrophilic alkylhydroxy and carboxy groups on the carbon atoms of cobalta bis(dicarbollide) ions. The oxygen-containing exo-skeletal substituents of cobalta bis(dicarbollide) ions belong to the perspective building blocks that are considered for bioconjugation. Carbon substitution provides wider versatility and applicability in terms of the flexibility of possible chemical pathways. However, until recently, the electrochemistry of compounds substituted only on boron atoms could be studied, due to the unavailability of carbon-substituted congeners. In the present study, electrochemistry in aqueous phosphate buffers is considered along with the dependence of electrochemical response on pH and concentration. The compounds used show electrochemical signals around −1.3 and +1.1 V of similar or slightly higher intensities than in the parent cobalta bis(dicarbollide) ion. The signals at positive electrochemical potential correspond to irreversible oxidation of the boron cage (the C2B9 building block) and at negative potential correspond to the reversible redox process of (CoIII/CoII) at the central atom. Although the first signal is typically sharp and its potential can be altered by a number of substituents, the second signal is complex and is composed of three overlapping peaks. This signal shows sigmoidal character at higher concentrations and may be used as a diagnostic tool for aggregation in solution. Surprisingly enough, the observed effects of the site of substitution (boron or carbon) and between individual groups on the electrochemical response were insignificant. Therefore, the substitutions would preserve promising properties of the parent cage for redox labelling, but would not allow for the further tuning of signal position in the electrochemical window. 相似文献
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Cobalt-modified nickel-zinc catalyst CuNi(Zn)Co is prepared on a copper substrate by using electrodeposition. Its catalytic efficiency for methanol oxidation is studied with cyclic voltammetry, chronoamperometry, and chronopotentiometry techniques. The surface morphology and chemical composition of catalyst are characterized by scanning electron microscopy and energy dispersive X-ray spectroscopy. The oxidation kinetic parameters activation energy (Ea), active species on the surface (Γ), and rate constant (k) are determined from cyclic voltammograms which are performed at different methanol concentrations and temperatures. The results show that Ni(Zn)Co catalyst has higher catalytic activity than Ni, Co, and NiZn coatings as a composite catalyst for a promising choice of methanol electrooxidation in the alkaline medium. 相似文献
8.
Urea dimethacrylates functionalized with bisphosphonate/bisphosphonic acid for improved dental materials
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Melek Naz Guven Ece Akyol Fatma Demir Duman Havva Yagci Acar Ozlem Karahan Duygu Avci 《Journal of polymer science. Part A, Polymer chemistry》2017,55(19):3195-3204
Incorporation of bisphosphonate/bisphosphonic acid groups in dental monomer structures should increase interaction of these monomers with dental tissue as these groups have strong affinity for hydroxyapatite. Therefore, new urea dimethacrylates functionalized with bisphosphonate (1a, 1b) and bisphosphonic acid (2a, 2b) groups are synthesized and evaluated for dental applications. Monomers 1a and 1b are synthesized from 2‐isocyanatoethyl methacrylate (IEM) and two bisphosphonated amines (BPA1 and BPA2), prepared as reported elsewhere. Selective dealkylation of the bisphosphonate ester groups of 1a and 1b using trimethylsilyl bromide (TMSBr) gives monomers (2a and 2b) with bisphosphonic acid functionality. X‐ray diffractometer (XRD), Raman spectroscopy, and X‐ray photoelectron spectroscopy (XPS) analyses of monomer‐treated HAP particles show that 2a induces formation of stable monomer‐calcium salts, similar to 10‐methacryloyloxydecyl dihydrogen phosphate (MDP), with higher chemical interaction than 2b. The photopolymerization studies indicate good copolymerizability with commercial dental monomers. In vitro studies on NIH 3T3 mouse embryonic fibroblast cells have clearly shown that the tested monomers (1b and 2b) are not toxic according to the MTT standards. All these properties make these monomers suitable as biocompatible cross‐linkers/adhesives for dental applications. © 2017 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2017 , 55, 3195–3204 相似文献
9.
Multiwalled Carbon Nanotubes‐Chitosan Modified Single‐Use Biosensors for Electrochemical Monitoring of Drug‐DNA Interactions
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A multiwalled carbon nanotubes (CNT)‐chitosan (CHIT) modified pencil graphite electrode (CNT‐CHIT/PGE) was developed for the first time herein for electrochemical monitoring of the interaction of an anticancer drug, mitomycin C (MC) and DNA. The characterization of unmodified PGE, CHIT/PGE, CNT/PGE and CHIT‐CNT/PGE were performed by scanning electron microscopy and cyclic voltammetry techniques. The oxidation signals of MC and guanine were measured before and after interaction at the surface of CNT‐CHIT/PGEs using differential pulse voltammetry. Electrochemical impedance spectroscopy technique was also successfully utilized for monitoring of the interaction process at the surface of CNT‐CHIT/PGEs in different interaction times. 相似文献
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Ali Osman Ayaş Mustafa Akyol Selda Kılıç Çetin Melike Kaya İlker Dinçer Ahmet Ekicibil 《哲学杂志》2013,93(9):671-682
AbstractIn this work, we have studied on double-layered perovskite (Ruddlesden–Popper) manganite structure in Pr1.75Sr1.25Mn2O7 synthesised by sol–gel method. The crystal structure of the double-layered perovskite is found as tetragonal from the X-ray diffraction analysis with I4/mmm space group. A high Curie temperature, TC = 305 K is observed from the temperature dependence of magnetisation measurement. The isothermal magnetisation curves showed that magnetic phase transition is second order due to the positive slope of the Arrott plots. Maximum magnetic entropy change (ΔSM) and adiabatic temperature change (ΔTad) values are calculated as 3.99 J kg?1 K?1 and 2.1 K under external magnetic field of 70 kOe, respectively. Since our double-layered perovskite manganite sample has desired TC value and relatively high ΔSM, it can be a potential candidate as a magnetocaloric material for room temperature magnetic cooling systems. 相似文献