排序方式: 共有55条查询结果,搜索用时 15 毫秒
31.
Sabo MC Luca VC Prentoe J Hopcraft SE Blight KJ Yi M Lemon SM Ball JK Bukh J Evans MJ Fremont DH Diamond MS 《Journal of virology》2011,85(14):7005-7019
The E2 glycoprotein of hepatitis C virus (HCV) mediates viral attachment and entry into target hepatocytes and elicits neutralizing antibodies in infected patients. To characterize the structural and functional basis of HCV neutralization, we generated a novel panel of 78 monoclonal antibodies (MAbs) against E2 proteins from genotype 1a and 2a HCV strains. Using high-throughput focus-forming reduction or luciferase-based neutralization assays with chimeric infectious HCV containing structural proteins from both genotypes, we defined eight MAbs that significantly inhibited infection of the homologous HCV strain in cell culture. Two of these bound E2 proteins from strains representative of HCV genotypes 1 to 6, and one of these MAbs, H77.39, neutralized infection of strains from five of these genotypes. The three most potent neutralizing MAbs in our panel, H77.16, H77.39, and J6.36, inhibited infection at an early postattachment step. Receptor binding studies demonstrated that H77.39 inhibited binding of soluble E2 protein to both CD81 and SR-B1, J6.36 blocked attachment to SR-B1 and modestly reduced binding to CD81, and H77.16 blocked attachment to SR-B1 only. Using yeast surface display, we localized epitopes for the neutralizing MAbs on the E2 protein. Two of the strongly inhibitory MAbs, H77.16 and J6.36, showed markedly reduced binding when amino acids within hypervariable region 1 (HVR1) and at sites ~100 to 200 residues away were changed, suggesting binding to a discontinuous epitope. Collectively, these studies help to define the structural and functional complexity of antibodies against HCV E2 protein with neutralizing potential. 相似文献
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Lena Feuerer Susanne Lamm Ingmar Henz Melanie Kappelmann‐Fenzl Sebastian Haferkamp Svenja Meierjohann Claus Hellerbrand Silke Kuphal Anja Katrin Bosserhoff 《Pigment cell & melanoma research》2019,32(6):777-791
The protein melanoma inhibitory activity (MIA) is known to be expressed in melanoma and to support melanoma progression. Interestingly, previous studies also observed the expression of MIA in nevi. Concentrating on these findings, we revealed that MIA expression is correlated with a senescent state in melanocytes. Induction of replicative or oncogene‐induced senescence resulted in increased MIA expression in vitro. Notably, MIA knockdown in senescent melanocytes reduced the percentage of senescence‐associated beta‐Gal‐positive cells and enhanced proliferation. Using the melanoma mouse model Tg(Grm1), MIA‐deficient mice supported the impact of MIA on senescence by showing a significantly earlier tumor onset compared to controls. In melanocytes, MIA knockdown led to a downregulation of the cell cycle inhibitor p21 in vitro and in vivo. In contrast, after induction of hTERT in human melanoma cells, p21 regulation by MIA was lost. In summary, our data show for the first time that MIA is a regulator of cellular senescence in human and murine melanocytes. 相似文献
33.
Parallelized disruption of prokaryotic and eukaryotic cells via miniaturized and automated bead mill
Roman P. Jansen Moritz Fabian Müller Sophie Edith Schrter Jannick Kappelmann Bianca Klein Marco Oldiges Stephan Noack 《Engineering in Life Science》2020,20(8):350-356
The application of integrated microbioreactor systems is rapidly becoming of more interest to accelerate strain characterization and bioprocess development. However, available high‐throughput screening capabilities are often limited to target extracellular compounds only. Consequently, there is a great demand for automated technologies allowing for miniaturized and parallel cell disruption providing access to intracellular measurements. In this study, a fully automated bead mill workflow was developed and validated for four different industrial platform organisms: Escherichia coli, Corynebacterium glutamicum, Saccharomyces cerevisiae, and Aspergillus niger. The workflow enables up to 48 parallel cell disruptions in microtiter plates and is applicable at‐line to running lab‐scale cultivations. The resulting cell extracts form the basis for quantitative omics studies where no rapid metabolic quenching is required (e.g., genomics and proteomics). 相似文献
34.
Løkke Søren Schmidt Jannick H. Lyhne Ivar Kørnøv Lone Revsbeck Rasmus 《The International Journal of Life Cycle Assessment》2020,25(10):2086-2092
The International Journal of Life Cycle Assessment - ‘Green’ business models1 have received considerable political and financial support, which for the public is a validation of the... 相似文献
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36.
Phylogenetic and functional analysis of the bacteriophage P1 single-stranded DNA-binding protein
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Bacteriophage P1 encodes a single-stranded DNA-binding protein (SSB-P1), which shows 66% amino acid sequence identity to the SSB protein of the host bacterium Escherichia coli. A phylogenetic analysis indicated that the P1 ssb gene coexists with its E. coli counterpart as an independent unit and does not represent a recent acquisition of the phage. The P1 and E. coli SSB proteins are fully functionally interchangeable. SSB-P1 is nonessential for phage growth in an exponentially growing E. coli host, and it is sufficient to promote bacterial growth in the absence of the E. coli SSB protein. Expression studies showed that the P1 ssb gene is transcribed only, in an rpoS-independent fashion, during stationary-phase growth in E. coli. Mixed infection experiments demonstrated that a wild-type phage has a selective advantage over an ssb-null mutant when exposed to a bacterial host in the stationary phase. These results reconciled the observed evolutionary conservation with the seemingly redundant presence of ssb genes in many bacteriophages and conjugative plasmids. 相似文献
37.
Becker F Schnorr K Wilting R Tolstrup N Bendtsen JD Olsen PB 《Journal of microbiological methods》2004,57(1):123-133
To identify genes encoding extracytosolic proteins, a minitransposon, TnSig, containing a signal-less beta-lactamase ('bla) as reporter gene, was constructed and used for in vitro transposition of genomic libraries made in Escherichia coli. The 'bla gene was cloned into a bacteriophage Mu minitransposon enabling translational fusions between 'bla and target genes. Fusion of TnSig in the correct reading frame to a protein carrying transmembrane domains or signal peptides resulted in ampicillin resistance of the corresponding clone. Prokaryotic gene libraries from the alkaliphilic bacterium Bacillus halodurans C125 and the hyperthermophilic archaeon Sulfolobus solfataricus P2 were tagged with TnSig. The genomic sequences, which are publicly available (EMBL and EMBL ), were used for rapid open reading frame (ORF) identification and prediction of protein localisation in the cell. Genes for secreted proteins, transmembrane proteins and lipoproteins were successfully identified by this method. In contrast to previous transposon based identification strategies, the method described here is fast and versatile and essentially enables any selectable marker compatible library to be tagged. It is suited for identifying genes encoding extracytosolic proteins in gene libraries of a wide range of prokaryotic organisms. 相似文献
38.
Jannick?D?Bendtsen Lars?Kiemer Anders?Fausb?ll S?ren?BrunakEmail author 《BMC microbiology》2005,5(1):58
Background
We present an overview of bacterial non-classical secretion and a prediction method for identification of proteins following signal peptide independent secretion pathways. We have compiled a list of proteins found extracellularly despite the absence of a signal peptide. Some of these proteins also have known roles in the cytoplasm, which means they could be so-called "moon-lightning" proteins having more than one function. 相似文献39.
Salvador A Dubreuil D Denouel J Millerioux L 《Journal of chromatography. B, Analytical technologies in the biomedical and life sciences》2005,820(2):237-242
A sensitive LC-MS-MS assay for the quantitative determination of bromocriptine has been developed and validated and is described in this work. The assay involved the extraction of the analyte from 1 ml of human plasma using a solid phase extraction on Oasis MCX cartridges. Chromatography was performed on a Symmetry C18 (2.1 mm x 100 mm, 3.5 microm) column using a mobile phase consisting of 25:75:01 acetonitrile-water-formic acid with a flow rate of 250 microl/min. The linearity was within the concentration range of 2-500 pg/ml. The lower limit of quantification was 2 pg/ml. This method has been demonstrated to be an improvement over existing methods due to its greater sensitivity and specificity. 相似文献
40.
Ivan Muñoz Jannick H. Schmidt 《The International Journal of Life Cycle Assessment》2016,21(8):1069-1075