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The list of LDL receptor superfamily relatives is still growing. The two most recently discovered family branches are (1) a set of receptors characterized by expression in brain and a very close relationship to the LDL and VLDL receptors, and (2) highly cross-species (man, mouse, rabbit, chicken) conserved complex mosaic receptors which contain structural domains so far not found in the superfamily. At present, we know very little about the physiological function(s) of these molecules. They can be safely assumed, based on the presence of seven, eight or 11 clustered LDL receptor ligand binding repeats, to recognize mammalian apolipoprotein E but, based on the absence of apolipoprotein E in birds, they may exhibit interactions quite different from and/or in addition to typical lipoprotein receptors in vivo.  相似文献   
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The singular perturbation technique is used for the dynamic extension of the RGA (relative gain array) based on the state-space model. The dynamic interaction measure derived serves as a means of pairing input and output variables for the systems having substantially different time scales.  相似文献   
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The moderately thermophilic bacterium Bacillus subtilis WU-S2B desulfurized dibenzothiophene (DBT) at 50 degrees C through the selective cleavage of carbon-sulfur bonds. In this study, three enzymes involved in the microbial DBT desulfurization were purified and characterized. The first two enzymes, DBT monooxygenase (BdsC) and DBT sulfone monooxygenase (BdsA), were purified from the wild-type strain, and the last one, 2'-hydroxybiphenyl 2-sulfinic acid desulfinase (BdsB), was purified from the recombinant Escherichia coli overexpressing the gene, bdsB, with chaperonin genes, groEL/ES. The genes of BdsC and BdsA were also overexpressed. The molecular weights of BdsC and BdsA were determined to be 200 and 174 kDa, respectively, by gel filtration chromatography, suggesting that both enzymes had four identical subunits. BdsB had a monomeric structure of 40 kDa. The three enzymes were characterized and compared with the corresponding enzymes (DszC, DszA, and DszB) of mesophilic desulfurization bacteria. The specific activities of BdsC, BdsA, and BdsB were 84.2, 855, and 280 units/mg, respectively, and the latter two activities were higher than those of DszA and DszB. The heat stability and optimum temperature of BdsC, BdsA, and BdsB were higher than those of DszC, DszA, and DszB. Other enzymatic properties were investigated in detail.  相似文献   
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Enantioselective Friedel–Crafts alkylations of a variety of indoles with ethyl 3,3,3‐trifluoropyruvate catalyzed by novel chiral m‐phenylenebis(imidazoline)‐copper(II) complexes or the bis(imidazoline)‐achiral acid combination afforded products with high enantioselectivity. Both enantiomers of indole derivatives can be prepared with high enantioselectivities by tuning the N‐substituents of the imidazoline.  相似文献   
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Two kinds of stilbene-type fluorescent whitening agents (i.e., DSBP and DAS1), minor components of laundry detergents, were analyzed in surface waters of Tokyo Bay and adjacent rivers and in sewage effluents to examine their usefulness as molecular markers in the marine environment. Sensitive determination using HPLC (high performance liquid chromatography) with fluorescence detection with postcolumn UV radiator was employed. DSBP and DAS1 were found in Tokyo rivers at concentrations of a few microg/L and approximately 1 microg/L, respectively. DSBP and DAS1 were widely distributed in Tokyo Bay waters at concentrations in the range of 0.019-0.264 microg/L and 0.021-0.127 microg/L, respectively. Comparison of these concentrations with those in sewage effluents (DSBP: 8 microg/L and DAS1: 2.5 microg/L on average) yielded sewage dilutions in Tokyo Bay on the order of 10(2). FWAs-salinity diagram in the Tamagawa Estuary showed fairly conservative behaviors of the FWAs with approximately 20% and approximately 10% removal of DSBP and DAS1, respectively. This is thought to be caused by photodegradation. The persistent nature of FWAs and their widespread distribution in coastal environments demonstrates the utility of FWAs in tracing the behavior of water from rivers and sewage outfalls. The DSBP/DAS1 ratio showed a decreasing trend from sewage effluents, to rivers, to Tokyo Bay, indicating selective photodegradation of DSBP. The DSBP/DAS1 ratio is proposed as an index of the degree of photodegradation and residence time and freshness of water mass in coastal environments.  相似文献   
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