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Ebitani K Ide M Mitsudome T Mizugaki T Kaneda K 《Chemical communications (Cambridge, England)》2002,(7):690-691
A chain-like Fe3+ species containing an Fe-O-Fe unit has been prepared within the interlayer space of a montmorillonite, which showed a very high catalytic activity (turnover frequency 386 h-1 and turnover number 23,200) for the oxidation of cyclohexane with H2O2, affording cyclohexyl hydroperoxide as a major product. 相似文献
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We have reported in the previous paper (Colloids Surf. B (2006) in press) a marked increase in the rate of gluconic acid production at a very high cell concentration (40 g/l) of filamentous fungus (Aspergillus niger IFO 31012) which was immobilized with polyelectrolyte complex consisting of potassium poly(vinyl alcohol) sulfate and trimethylammonium glycol chitosan iodide [6-O-(2-hydroxyethyl)-2-(trimethylammonio)-chitosan iodide]. The present study was carried out to look at what factors play a crucial role in this enhancement. We measured viscosity of broth, mass-transfer coefficient (k(L)a) for oxygen and diffusion coefficient of glucose (substrate). It has become apparent that there is only a difference in the diffusion coefficient of glucose between the free and immobilized cells. Therefore, we believe that the diffusion limitation by substrates as a problem in submerged mycelial processes is improved by immobilization based on polyelectrolyte complexes. 相似文献
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Suda M Ishii T Sootome H King AJ Shibahara M Noro N Yamashita K Noumi T 《Analytical and bioanalytical chemistry》2008,390(1):343-348
No universal approach has been reported for specific monitoring of the catalytic activity of a wide range of kinases in cells.
The present study describes an original platform for detecting the autonomous activity of serine/threonine kinases in cells
through the introduction of expression vectors encoding modified substrate kinase fusion proteins. The surrogate substrate
used consists of the p53 tumor suppressor protein fused with individual kinase domains (Chk1, DYRK3, and Cdk5) at its carboxy-terminal
through four tandem Gly-Gly-Gly-Gly-Ser repeats. After transfection into cells, phosphorylation of the p53 moiety could be
specifically induced by the catalytic activity of kinases contained in the fusion protein. Moreover, p53 phosphorylation was
significantly blocked when a kinase-inactive mutant was used as the fusion partner instead of the active kinase. Using this
system, the cell-based evaluation of several Cdk5 inhibitors was demonstrated. Thus, this approach provides a novel platform
for the specific, cell-based screening of inhibitors of a wide prospective range of protein kinases and is of tremendous potential
for drug discovery efforts. 相似文献
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Takuzo Aida Masakatsu Kuroki Hiroshi Sugimoto Tsuyoshi Watanabe Takato Adachi Chikara Kawamura Shohei Inoue 《Macromolecular Symposia》1993,67(1):125-135
Living anionic polymerization of methacrylic esters initiated with aluminum porphyrins ( 1 ) was found to be dramatically accelerated (e.g., 46 000 times) upon addition of bulky Lewis acids such as alkylaluminum diphenolates ( 3 ). Under appropriate conditions, a narrow MWD poly(methyl methacrylate) with Mn exceeding a million could be synthesized. The key conception of this high speed living polymerization is the coexistence of nucleophile ( 2 ) and Lewis acid ( 3 ) realized by steric repulsion. 相似文献
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