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991.
Qi Ye Ming Yan Lin Xu Hou Cao Zhenjiang Li Yong Chen Shuya Li Hanjie Ying 《Biotechnology letters》2009,31(4):537-542
An NADPH-dependent carbonyl reductase (PsCR) gene from Pichia stipitis was cloned. It contains an open reading frame of 849 bp encoding 283 amino acids whose sequence had less than 60% identity
to known reductases that produce ethyl (S)-4-chloro-3-hydroxybutanoates (S-CHBE). When expressed in Escherichia coli, the recombinant PsCR exhibited an activity of 27 U/mg using ethyl 4-chloro-3-oxobutanoate (COBE) as a substrate. Reduction
of COBE to (S)-CHBE by transformants in an aqueous mono-phase system for 18 h, gave a molar yield of 94% and an optical purity of the (S)-isomer of more than 99% enantiomeric excess. 相似文献
992.
Sharpening is a powerful method to restore the details from blurred electron density in crystals with high overall temperature factors (B-factors). This valuable technique is currently not optimally used because of the uncertainty in the scope of its application and ambiguities in practice. We performed an analysis of ~ 2000 crystal data sets deposited in the Protein Data Bank and show that sharpening improves the electron density map in many cases across all resolution ranges, often with dramatic enhancement for mid- and low-resolution structures. It is effective when used with either experimental or model phases without introducing additional bias. Our tests also provide a practical guide for optimal sharpening. We further show that anisotropic diffraction correction improves electron density in many cases but should be used with caution. Our study demonstrates that a routine practice of electron density sharpening may have a broad impact on the outcomes of structural biology studies. 相似文献
993.
Hualin Ma Yaojiong Wu Wanfan Zhang Yong Dai Furong Li Ying Xu Yunshuai Wang Huiying Tu Wuxian Li Xinzhou Zhang 《Cytotherapy》2013,15(6):703-711
Background aimsThe potential protective effects of mesenchymal stromal cells (MSCs) on some kidney diseases has been reported. However, the effect of MSCs on doxorubicin-induced nephropathy is still poorly understood.MethodsRats with doxorubicin-induced kidney injuries were treated with human cord-derived MSCs. Human MSCs were first labeled with 5-bromo-2′-deoxyuridine to track their homing in kidneys after infusion.ResultsAlleviation of proteinuria, decreased serum albumin, alleviation of lipid disorders and histologic alterations were found in rats 4 weeks after treatment with MSCs, particularly in rats that were given repeat doses. Decreases in serum levels of interleukin-6, tumor necrosis factor-α and prostaglandin E2 and decreases in messenger RNA levels of kidney tissue cylooxygenase-2 and EP4 were found in MSC-treated rats. MSC-treated rats also displayed an increase in serum interleukin-10 levels.ConclusionsThese results indicate that MSCs ameliorate doxorubicin-induced kidney injuries and inflammation, suggesting a potential clinical treatment for inflammatory kidney diseases. 相似文献
994.
995.
Dual targeting of organellar seryl-tRNA synthetase to maize mitochondria and chloroplasts 总被引:2,自引:0,他引:2
Aminoacyl-tRNA synthetases (AARSs) play a critical role in translation and are thus required in three plant protein-synthesizing compartments: cytosol, mitochondria and plastids. A systematic study had previously shown extensive sharing of organellar AARSs from Arabidopsis thaliana, mostly between mitochondria and chloroplasts. However, distribution of AARSs from monocot species, such as maize, has never been experimentally investigated. Here we demonstrate dual targeting of maize seryl-tRNA synthetase, SerZMo, into both mitochondria and chloroplasts using combination of complementary methods, including in vitro import assay, transient expression analysis of green fluorescent protein (GFP) fusions and immunodetection. We also show that SerZMo dual localization is established by the virtue of an ambiguous targeting peptide. Full-length SerZMo protein fused to GFP is targeted to chloroplast stromules, indicating that SerZMo protein performs its function in plastid stroma. The deletion mutant lacking N-terminal region of the ambiguous SerZMo targeting peptide was neither targeted into mitochondria nor chloroplasts, indicating the importance of this region in both mitochondrial and chloroplastic import. 相似文献
996.
997.
Nervous system tumors are one of the leading causes of cancer related death. Specific mechanisms facilitating the invasive
behavior of gliomas remain obscure. Advanced simulation models of the in vivo response to therapy conditions should potentially
improve malignant glioma treatment. Expressional profiling of vimentin––one of reliable pro-invasive tumor makers––in those
simulation models was the goal of this study, in order to estimate a pro-invasive response of surviving malignant glioma cells
under clinically relevant therapeutic conditions. Human U87-MG malignant glioma cells were used. These cells are characterized
by the wild p53-phenotype, which is relevant for the majority of primary malignant glioblastomas. Experimental design foresaw the cells to
undergo either irradiation or chemo-treatment with temozolomide alone, or combined treatment. Expression profiling of vimentin
was performed by quantitative “Real-Time”-PCR under all treatment conditions simulating diverse tumor regions. Here we demonstrated
that vimentin expression patterns in human malignant glioma cells strongly depend on cellular density, algorithms of drug
delivery and chemo/radio treatment. Substantial differences were recognized between immediate and late therapy effects. Significant
increase in vimentin expression levels was detected particularly in low-density cell cultures under durable treatment with
constant concentration levels of temezolomide. Simulation of variable intratumoral regional conditions (central intratumoral
regions vs. disseminated malignant cells in peripheral regions) demonstrated differential response of vimentin expression
in malignant glioma cell cultures treated under clinically relevant conditions. Slight ebbing of expression levels as late
effects of the treatment in confluent cultures may correspond to necrotic processes clinically observed in central intratumoral
regions. Contrary, in disseminated malignant cells of peripheral regions therapy resulted in vimentin-inducing effects. This
is in agreement with the clinical observations of an increased aggressiveness and malignancy grade of post-operatively chemo/radio-treated
malignant gliomas. 相似文献
998.
999.
Dawei Jiang Yunchao Liu Aiping Wang Gaiping Zhang Guoyu Yang Yumei Chen Pengchao Ji Chang Liu Yapeng Song Yunfang Su Guoqiang Wang Jucai Wang Baolei Zhao Ruiguang Deng 《Biotechnology letters》2016,38(6):901-908
Objectives
To improve the expression of soluble IBDV VP2 protein by using different tagged vectors in Escherichia coli.Results
Fusion tags, Grifin, MBP, SUMO, thioredoxin, γ-crystallin, ArsC and PpiB, enhanced the expression and solubility of VP2 protein. The fusion proteins were purified by Ni–NTA chromatography, MBP-VP2 showed the highest purity about 90 %. After removing the MBP tag, VP2 self-assembled into virus-like particles, ~25 nm diam. Results from AGP suggested the recombinant IBDV VP2 protein identified by reference serum like IBDV.Conclusion
All the seven tags enhanced the expression and solubility of IBDV VP2 protein. The recombinant protein self-assembly into virus like particles and possess antigenicity as reference IBDV.1000.