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61.
Kelley BD Booth J Tannatt M Wub QL Ladner R Yuc J Potter D Ley A 《Journal of chromatography. A》2004,1038(1-2):121-130
Polypeptides for use in affinity chromatography of factor VIII were identified using phage display technology. Phage libraries were designed to express polypeptide fusions containing five to seven residues flanked by two cysteines that form a disulfide bond. Individual bacteriophage were selected for the ability of these polypeptides to bind factor VIII, and then release the protein under mild elution conditions. Strong consensus sequences were observed that appear to be necessary for this reversible interaction. Chemically synthesized ligands identified by this screening were immobilized onto a chromatographic support and used for affinity purification of factor VIII from a complex feedstream. A chromatographic step was developed that provided a 10000-fold reduction in host cell proteins and DNA, while providing exceptional product recovery. 相似文献
62.
Superheated water eluent capillary liquid chromatography 总被引:4,自引:0,他引:4
A capillary scale reverse phase liquid chromatography (LC) system using a super hot water eluent is described. The system, constructed in-house from readily available components, has been shown to operate at temperatures as high as 370 °C and pressures in excess of 10 000 psi. The capability of the system is demonstrated with the separation of a mixture of polar and non-polar benzene derivatives on polybutadiene and elemental carbon modified zirconia packings with or without temperature gradients. Six benzene derivatives can be separated in 2 min. 相似文献
63.
One unit of S(IV) (SO2 or SHO3?) is oxidized per 2 units of [NiIII(cyclam)] species to obtain sulfate. Kinetic analyses have been done by varying the acidities (0.013 ? [H+] ? 1.0 M) and halide concentrations (0.000 ? [X?] ? 0.012 M; X=Cl and Br) at constant ionic strength (μ = 1.0 M). The rate law that incorporates the [X?] and [H+] dependence is ?d[NiIII]T/dt=2k[NiIII]T[S(IV)]T where 2k={ka[H+] + kbK + kK′X[H+] [X?] + kK′XK[X?]} {[H+] + K}?1 {1 + K′X[X?]}?1, here ka=87 ± 7 M?1 s?1, kb=(2.5 ± 0.5)×103 M?1 s?1 and pK = 1.8 ± 0.2. Rate constants ka and kb are attributed to the reactions of [NiIII(cyclam) (H2O)2]3+ with SO2 and SHO3?, respectively. Monohalo species apparent equilibrium constants K′Cl=(1600 ± 400) M?1 and K′Br=(190 ± 20) M?1 and rate constants k=80 ± 8 M?1 s?1 and k = 140 ± 15 M?1 s?1 are ascribed to the protonated pathway, involving the [NiIII(cyclam) (H2O)X]2+ and SO2(aq) reaction pairs. The other two rate constants of k=(5 ± 1)×103 M?1 s?1 and k=(3.1 ± 0.5)×104 M?1 s?1, refer to the deprotonated pathway and are assigned to the [NiIII(cyclam) (H2O)X]2+ /SHO3? redox couple. A deuterium H2O / D2O isotope effect of 2.1–2.8 can be attributed partially to an equilibrium isotope effect at low acidity though a small kinetic isotope (2.5 ± 0.5) effect is evident for the dihydrogen sulfito pathway, ka. The kinetic isotope effect and the absence of sulfite radical scavenging effects are explained by a mechanism entailing migration of a hydride from sulfur to the NiIII center to produce a NiIII—H species, which rapidly comproportionates, and S(VI). © 1993 John Wiley & Sons, Inc. 相似文献
64.
Applied Biochemistry and Biotechnology - Methods of achieving high-yield fermentation ofd-xylose to ethanol in shake flasks were investigated using the microaerophilic yeastPichia stipitis NRRL... 相似文献
65.
Scott Charles D. Woodward Charlene A. Thompson James E. Blankinship Stephen L. 《Applied biochemistry and biotechnology》1990,24(1):799-815
Applied Biochemistry and Biotechnology - Both oxidative and reductive enzymes can be utilized to enhance coal solubilization in aqueous and organic media. Aerobic solubilization was carried out... 相似文献
66.
Stulz E Scott SM Ng YF Bond AD Teat SJ Darling SL Feeder N Sanders JK 《Inorganic chemistry》2003,42(20):6564-6574
The synthesis of linear multiporphyrin arrays with mono- and bisphosphine-substituted porphyrins as ligand donors and ruthenium(II) or rhodium(III) porphyrins as ligand acceptors is described. With appropriate amounts of the building blocks mixed, linear dimeric and trimeric arrays have been synthesized and analyzed by (1)H NMR and (31)P NMR spectroscopy. The Ru/Rh acceptor porphyrins can be located either at the periphery or in the center of the array. Likewise, the monophosphine porphyrins can be positioned at the periphery, thus allowing a high degree of freedom in the overall composition of the arrays. This way, both donor and acceptor porphyrins can act as chain extenders or terminators. One of the trimeric complexes with two nickel and one ruthenium porphyrin has also been analyzed by X-ray crystallography. Attempts have also been made to synthesize higher order arrays by mixing appropriate amounts of the porphyrins; however, from the NMR data it cannot be concluded if monodisperse five, seven, or nine porphyrin arrays are present or if the solutions are composed of a statistical mixture of smaller and larger arrays. 相似文献
67.
Brian D. Hudson Ashley R. George Martyn G. Ford David J. Livingstone 《Journal of computer-aided molecular design》1992,6(2):191-201
Summary Molecular dynamics simulations have been performed on a number of conformationally flexible pyrethroid insecticides. The results indicate that molecular dynamics is a suitable tool for conformational searching of small molecules given suitable simulation parameters. The structures derived from the simulations are compared with the static conformation used in a previous study. Various physicochemical parameters have been calculated for a set of conformations selected from the simulations using multivariate analysis. The averaged values of the parameters over the selected set (and the factors derived from them) are compared with the single conformation values used in the previous study. 相似文献
68.
It is shown that a thiolamide antioxidant, 4-mercaptoacetamido diphenylamine (MADA) can be reacted with both polypropylene and polyethylene in a mechanochemical process. The resulting bound antioxidant concentrates (MADA-B) can be used for the thermal and photostabilisation of the parent polymers. The adduct is very stable to solvent extraction and is also very effective as a high temperature antioxidant for polypropylene subjected to water leaching.The uv stabilising mechanism of MADA-B is believed to be related to the regenerative process involved in the mechanism of stabilisation by hindered nitroxyl radicals. 相似文献
69.
70.