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61.
An approach for the improved immobilization of penicillin G acylase onto macroporous poly(glycidyl methacrylate‐co‐ethylene glycol dimethacrylate) as a potential industrial biocatalyst 下载免费PDF全文
Zorica D. Knežević‐Jugović Milena G. Žuža Sonja M. Jakovetić Andrea B. Stefanović Enis S. Džunuzović Katarina B. Jeremić Slobodan M. Jovanović 《Biotechnology progress》2016,32(1):43-53
The use of penicillin G acylase (PGA) covalently linked to insoluble carrier is expected to produce major advances in pharmaceutical processing industry and the enzyme stability enhancement is still a significant challenge. The objective of this study was to improve catalytic performance of the covalently immobilized PGA on a potential industrial carrier, macroporous poly(glycidyl methacrylate‐co‐ethylene glycol dimethacrylate) [poly(GMA‐co‐EGDMA)], by optimizing the copolymerization process and the enzyme attachment procedure. This synthetic copolymer could be a very promising alternative for the development of low‐cost, easy‐to‐prepare, and stable biocatalyst compared to expensive commercially available epoxy carriers such as Eupergit or Sepabeads. The PGA immobilized on poly(GMA‐co‐EGDMA) in the shape of microbeads obtained by suspension copolymerization appeared to have higher activity yield compared to copolymerization in a cast. Optimal conditions for the immobilization of PGA on poly(GMA‐co‐EGDMA) microbeads were 1 mg/mL of PGA in 0.75 mol/L phosphate buffer pH 6.0 at 25°C for 24 h, leading to the active biocatalyst with the specific activity of 252.7 U/g dry beads. Chemical amination of the immobilized PGA could contribute to the enhanced stability of the biocatalyst by inducing secondary interactions between the enzyme and the carrier, ensuring multipoint attachment. The best balance between the activity yield (51.5%), enzyme loading (25.6 mg/g), and stability (stabilization factor 22.2) was achieved for the partially modified PGA. © 2015 American Institute of Chemical Engineers Biotechnol. Prog., 32:43–53, 2016 相似文献
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Environmental and spatial characterisation of an unknown fauna using DNA sequencing – an example with Himalayan Hydropsychidae (Insecta: Trichoptera) 下载免费PDF全文
Felicitas Hoppeler Ram Devi Tachamo Shah Deep Narayan Shah Sonja C. Jähnig Jonathan D. Tonkin Subodh Sharma Steffen U. Pauls 《Freshwater Biology》2016,61(11):1905-1920
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Hong‐Mei Liu Libor Ekrt Petr Koutecky Jaume Pellicer Oriane Hidalgo Jeannine Marquardt Fatima Pustahija Atsushi Ebihara Sonja Siljak‐Yakovlev Mary Gibby Ilia Leitch Harald Schneider 《植物分类学报:英文版》2019,57(4):418-430
Recent studies investigating the evolution of genome size diversity in ferns have shown that they have a distinctive genome profile compared with other land plants. Ferns are typically characterized by possessing medium‐sized genomes, although a few lineages have evolved very large genomes. Ferns are different from other vascular plant lineages as they are the only group to show evidence for a correlation between genome size and chromosome number. In this study, we aim to explore whether the evolution of fern genome sizes is not only shaped by chromosome number changes arising from polyploidy but also by constraints on the average amount of DNA per chromosome. We selected the genus Asplenium L. as a model genus to study the question because of the unique combination of a highly conserved base chromosome number and a high frequency of polyploidy. New genome size data for Asplenium taxa were combined with existing data and analyzed within a phylogenetic framework. Genome size varied substantially between diploid species, resulting in overlapping genome sizes among diploid and tetraploid spleenworts. The observed additive pattern indicates the absence of genome downsizing following polyploidy. The genome size of diploids varied non‐randomly and we found evidence for clade‐specific trends towards larger or smaller genomes. The 578‐fold range of fern genome sizes have arisen not only from repeated cycles of polyploidy but also through clade‐specific constraints governing accumulation and/or elimination of DNA. 相似文献
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Nicola Vannini Vasco Campos Mukul Girotra Vincent Trachsel Shanti Rojas-Sutterlin Josefine Tratwal Simone Ragusa Evangelos Stefanidis Dongryeol Ryu Pernille Y. Rainer Gena Nikitin Sonja Giger Terytty Y. Li Aikaterini Semilietof Aurelien Oggier Yannick Yersin Loïc Tauzin Eija Pirinen Olaia Naveiras 《Cell Stem Cell》2019,24(3):405-418.e7
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Interleukin-13 interferes with CFTR and AQP5 expression and localization during human airway epithelial cell differentiation 总被引:1,自引:0,他引:1
Skowron-zwarg M Boland S Caruso N Coraux C Marano F Tournier F 《Experimental cell research》2007,313(12):2695-2702
Interleukin-13 (IL-13) is a central regulator of Th2-dominated respiratory disorders such as asthma. Lesions of the airway epithelial barrier frequently observed in chronic respiratory inflammatory diseases are repaired through proliferation, migration and differentiation of epithelial cells. Our work is focused on the effects of IL-13 in human cellular models of airway epithelial cell regeneration. We have previously shown that IL-13 altered epithelial cell polarity during mucociliary differentiation of human nasal epithelial cells. In particular, the cytokine inhibited ezrin expression and interfered with its apical localization during epithelial cell differentiation in vitro. Here we show that CFTR expression is enhanced in the presence of the cytokine, that two additional CFTR protein isoforms are expressed in IL-13-treated cells and that part of the protein is retained within the endoplasmic reticulum. We further show that aquaporin 5 expression, a water channel localized within the apical membrane of epithelial cells, is completely abolished in the presence of the cytokine. These results show that IL-13 interferes with ion and water channel expression and localization during epithelial regeneration and may thereby influence mucus composition and hydration. 相似文献
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Posttranslational modifications of histones are involved in regulation of chromatin structure and gene activity. Whereas the modifications of the core histones H2A, H2B, H3, and H4 have been extensively studied, our knowledge of H1 modifications remained mainly limited to its phosphorylation. Here we analyzed the composition of histone H1 variants and their modifications in two human cell lines and nine mouse tissues. Use of a hybrid linear ion trap-orbitrap mass spectrometer facilitated assignment of modifications by high resolution and low ppm mass accuracy for both the precursor and product mass spectra. Across different tissues we identified a range of phosphorylation, acetylation, and methylation sites. We also mapped sites of ubiquitination and report identification of formylated lysine residues. Interestingly many of the mapped modifications are located within the globular domain of the histones at sites that are thought to be involved in binding to nucleosomal DNA. Investigation of mouse tissue in addition to cell lines uncovered a number of interesting differences. For example, whereas methylation sites are frequent in tissues, this type of modification was much less abundant in cultured cells and escaped detection. Our study significantly extends the known spectrum of linker histone variability. 相似文献