The Experts below are selected from a list of 261 Experts worldwide ranked by ideXlab platform
Stefan Ståhl - One of the best experts on this subject based on the ideXlab platform.
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A novel affinity Protein Selection system based on staphylococcal cell surface display and flow cytometry
Protein Engineering Design & Selection, 2008Co-Authors: Nina Kronqvist, Henrik Wernérus, Andreas Jonsson, John Löfblom, Stefan StåhlAbstract:Here we describe the first reported use of a Gram-positive bacterial system for the Selection of affinity Proteins from large combinatorial libraries displayed on the surface of Staphylococcus carn ...
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A novel affinity Protein Selection system based on staphylococcal cell surface display and flow cytometry
Protein Engineering Design and Selection, 2008Co-Authors: Nina Kronqvist, Henrik Wernérus, Andreas Jonsson, John Löfblom, Stefan StåhlAbstract:Here we describe the first reported use of a Gram-positive bacterial system for the Selection of affinity Proteins from large combinatorial libraries displayed on the surface of Staphylococcus carnosus. An affibody library of 3 x 10(9) variants, based on a 58 residue domain from staphylococcal Protein A, was pre-enriched for binding to human tumor necrosis factor-alpha (TNF-alpha) using one cycle of phage display and thereafter transferred to the staphylococcal host ( approximately 10(6) variants). The staphylococcal-displayed library was subjected to three rounds of flow-cytometric sorting, and the selected clones were screened and ranked by on-cell analysis for binding to TNF-alpha and further characterized using biosensor analysis and circular dichroism spectroscopy. The successful sorting yielded three different high-affinity binders (ranging from 95 pM to 2.2 nM) and constitutes the first Selection of a novel affinity Protein using Gram-positive bacterial display. The method combines the simplicity of working with a bacterial host with the advantages of displaying recombinant Proteins on robust Gram-positive bacteria as well as using powerful flow cytometry in the Selection and characterization process.
Catharina Svanborg - One of the best experts on this subject based on the ideXlab platform.
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mechanism of pathogen specific tlr4 activation in the mucosa fimbriae recognition receptors and adaptor Protein Selection
European Journal of Immunology, 2006Co-Authors: Hans Fischer, Masahiro Yamamoto, Shizuo Akira, Bruce Beutler, Catharina SvanborgAbstract:The mucosal host defence discriminates pathogens from commensals, and prevents infection while allowing the normal flora to persist. Paradoxically, Toll-like receptors (TLR) control the mucosal defence against pathogens, even though the TLR recognise conserved molecules like LPS, which are shared between pathogens and commensals. This study proposes a mechanism of pathogen-specific mucosal TLR4 activation, involving adhesive ligands and their host cell receptors. TLR4 signalling was activated in CD14-negative, LPS-unresponsive epithelial cells by P fimbriated, uropathogenic Escherichia coli but not by a mutant lacking fimbriae. Epithelial TLR4 signalling in vivo involved the glycosphingolipid receptors for P fimbriae and the adaptor Proteins Toll/IL-1R (TIR) domain-containing adaptor inducing IFN-beta (TRIF)/TRIF-related adaptor molecule (TRAM), but myeloid differentiation Protein 88 (MyD88)/TIR domain-containing adaptor Protein were not required for the epithelial response. Substituting the P fimbriae with type 1 fimbriae changed TLR4 signalling from the TRIF to the MyD88 adaptor pathway. In addition, the adaptor Proteins and the fimbrial type were found to influence bacterial clearance. Trif(-/-) and Tram(-/-) mice remained infected with P fimbriated E. coli but cleared the type 1 fimbriated strain, while Myd88(-/-) mice became carriers of both the P and the type 1 fimbriated bacteria. Thus, TLR4 maybe engaged specifically by pathogens, when the proper cell surface receptors are engaged by virulence ligands. (Less)
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Mechanism of pathogen‐specific TLR4 activation in the mucosa: Fimbriae, recognition receptors and adaptor Protein Selection
European Journal of Immunology, 2006Co-Authors: Hans Fischer, Masahiro Yamamoto, Shizuo Akira, Bruce Beutler, Catharina SvanborgAbstract:The mucosal host defence discriminates pathogens from commensals, and prevents infection while allowing the normal flora to persist. Paradoxically, Toll-like receptors (TLR) control the mucosal defence against pathogens, even though the TLR recognise conserved molecules like LPS, which are shared between pathogens and commensals. This study proposes a mechanism of pathogen-specific mucosal TLR4 activation, involving adhesive ligands and their host cell receptors. TLR4 signalling was activated in CD14-negative, LPS-unresponsive epithelial cells by P fimbriated, uropathogenic Escherichia coli but not by a mutant lacking fimbriae. Epithelial TLR4 signalling in vivo involved the glycosphingolipid receptors for P fimbriae and the adaptor Proteins Toll/IL-1R (TIR) domain-containing adaptor inducing IFN-beta (TRIF)/TRIF-related adaptor molecule (TRAM), but myeloid differentiation Protein 88 (MyD88)/TIR domain-containing adaptor Protein were not required for the epithelial response. Substituting the P fimbriae with type 1 fimbriae changed TLR4 signalling from the TRIF to the MyD88 adaptor pathway. In addition, the adaptor Proteins and the fimbrial type were found to influence bacterial clearance. Trif(-/-) and Tram(-/-) mice remained infected with P fimbriated E. coli but cleared the type 1 fimbriated strain, while Myd88(-/-) mice became carriers of both the P and the type 1 fimbriated bacteria. Thus, TLR4 maybe engaged specifically by pathogens, when the proper cell surface receptors are engaged by virulence ligands. (Less)
Richard W Roberts - One of the best experts on this subject based on the ideXlab platform.
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Context and conformation dictate function of a transcription antitermination switch
Nature Structural & Molecular Biology, 2003Co-Authors: Adam Frankel, Terry T. Takahashi, Richard W RobertsAbstract:In bacteriophage λ, transcription elongation is regulated by the N Protein, which binds a nascent mRNA hairpin (termed boxB) and enables RNA polymerase to read through distal terminators. We have examined the structure, energetics and in vivo function of a number of N−boxB complexes derived from in vitro Protein Selection. Trp18 fully stacks on the RNA loop in the wild-type structure, and can become partially or completely unstacked when the sequence context is changed three or four residues away, resulting in a recognition interface in which the best binding residues depend on the sequence context. Notably, in vivo antitermination activity correlates with the presence of a stacked aromatic residue at position 18, but not with N−boxB binding affinity. Our work demonstrates that RNA polymerase responds to subtle conformational changes in cis-acting regulatory complexes and that approximation of components is not sufficient to generate a fully functional transcription switch.
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mRNA display: ligand discovery, interaction analysis and beyond
Trends in Biochemical Sciences, 2003Co-Authors: Terry T. Takahashi, Ryan J. Austin, Richard W RobertsAbstract:Abstract In vitro peptide and Protein Selection using mRNA display enables the discovery and directed evolution of new molecules from combinatorial libraries. These selected molecules can serve as tools to control and understand biological processes, enhance our understanding of molecular interactions and potentially treat disease in therapeutic applications. In mRNA display, mRNA molecules are covalently attached to the peptide or Protein they encode. These mRNA–Protein fusions enable in vitro Selection of peptide and Protein libraries of >10 13 different sequences. mRNA display has been used to discover novel peptide and Protein ligands for RNA, small molecules and Proteins, as well as to define cellular interaction partners of Proteins and drugs. In addition, several unique applications are possible with mRNA display, including self-assembling Protein chips and library construction with unnatural amino acids and chemically modified peptides.
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totally in vitro Protein Selection using mrna Protein fusions and ribosome display
Current Opinion in Chemical Biology, 1999Co-Authors: Richard W RobertsAbstract:Both chemists and biochemists have great interest in creating peptides and Proteins with desired structure, recognition and catalytic properties. Recently, two techniques have been developed that afford functional Selection of Proteins entirely in vitro : mRNA-Protein fusions, and ribosome display. Improvements in both methods have allowed peptide and Protein libraries of unprecedented size (10 11 –10 13 different members) to be generated and screened for function.
Fei Wang - One of the best experts on this subject based on the ideXlab platform.
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gold nanoprobe functionalized with specific fusion Protein Selection from phage display and its application in rapid selective and sensitive colorimetric biosensing of staphylococcus aureus
Biosensors and Bioelectronics, 2016Co-Authors: Fei Wang, Valery A PetrenkoAbstract:Abstract Staphylococcus aureus (S. aureus) is one of the most ubiquitous pathogens in public healthcare worldwide. It holds great insterest in establishing robust analytical method for S. aureus. Herein, we report a S. aureus-specific recognition element, isolated from phage monoclone GQTTLTTS, which was selected from f8/8 landscape phage library against S. aureus in a high-throughput way. By functionalizing cysteamine (CS)-stabilized gold nanoparticles (CS-AuNPs) with S. aureus-specific pVIII fusion Protein (fusion-pVIII), a bifunctional nanoprobe (CS-AuNPs@fusion-pVIII) for S. aureus was developed. In this strategy, the CS-AuNPs@fusion-pVIII could be induced to aggregate quickly in the presence of target S. aureus, resulting in a rapid colorimetric response of gold nanoparticles. More importantly, the as-designed probe exhibited excellent selectivity over other bacteria. Thus, the CS-AuNPs@fusion-pVIII could be used as the indicator of target S. aureus. This assay can detect as low as 19 CFU mL−1 S. aureus within 30 min. Further, this approach can be applicable to detect S. aureus in real water samples. Due to its sensitivity, specificity and rapidness, this proposed method is promising for on-site testing of S. aureus without using any costly instruments.
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gold nanoprobe functionalized with specific fusion Protein Selection from phage display and its application in rapid selective and sensitive colorimetric biosensing of staphylococcus aureus
Biosensors and Bioelectronics, 2016Co-Authors: Pei Liu, Lei Han, Fei Wang, Valery A Petrenko, Aihua LiuAbstract:Staphylococcus aureus (S. aureus) is one of the most ubiquitous pathogens in public healthcare worldwide. It holds great insterest in establishing robust analytical method for S. aureus. Herein, we report a S. aureus-specific recognition element, isolated from phage monoclone GQTTLITS, which was selected from f8/8 landscape phage library against S. aureus in a high-throughput way. By fiinctionalizing cysteamine (CS)-stabilized gold nanoparticles (CS-AuNPs) with S. aureus-specific pVIII fusion Protein (fusion-pVIII), a bifunctional nanoprobe (CS-AuNPs@fusion-pVIII) for S. aureus was developed. In this strategy, the CS-AuNPs@fusion-pVIII could be induced to aggregate quickly in the presence of target S. aureus, resulting in a rapid colorimetric response of gold nanoparticles. More importantly, the as-designed probe exhibited excellent selectivity over other bacteria. Thus, the CS-AuNPs@fusion-pVIII could be used as the indicator of target S. aureus. This assay can detect as low as 19 CFU mL(-1) S. aureus within 30 min. Further, this approach can be applicable to detect S. aureus in real water samples. Due to its sensitivity, specificity and rapidness, this proposed method is promising for on-site testing of S. aureus without using any costly instruments. (C) 2016 Elsevier B.V. All rights reserved.
Valery A Petrenko - One of the best experts on this subject based on the ideXlab platform.
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gold nanoprobe functionalized with specific fusion Protein Selection from phage display and its application in rapid selective and sensitive colorimetric biosensing of staphylococcus aureus
Biosensors and Bioelectronics, 2016Co-Authors: Fei Wang, Valery A PetrenkoAbstract:Abstract Staphylococcus aureus (S. aureus) is one of the most ubiquitous pathogens in public healthcare worldwide. It holds great insterest in establishing robust analytical method for S. aureus. Herein, we report a S. aureus-specific recognition element, isolated from phage monoclone GQTTLTTS, which was selected from f8/8 landscape phage library against S. aureus in a high-throughput way. By functionalizing cysteamine (CS)-stabilized gold nanoparticles (CS-AuNPs) with S. aureus-specific pVIII fusion Protein (fusion-pVIII), a bifunctional nanoprobe (CS-AuNPs@fusion-pVIII) for S. aureus was developed. In this strategy, the CS-AuNPs@fusion-pVIII could be induced to aggregate quickly in the presence of target S. aureus, resulting in a rapid colorimetric response of gold nanoparticles. More importantly, the as-designed probe exhibited excellent selectivity over other bacteria. Thus, the CS-AuNPs@fusion-pVIII could be used as the indicator of target S. aureus. This assay can detect as low as 19 CFU mL−1 S. aureus within 30 min. Further, this approach can be applicable to detect S. aureus in real water samples. Due to its sensitivity, specificity and rapidness, this proposed method is promising for on-site testing of S. aureus without using any costly instruments.
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gold nanoprobe functionalized with specific fusion Protein Selection from phage display and its application in rapid selective and sensitive colorimetric biosensing of staphylococcus aureus
Biosensors and Bioelectronics, 2016Co-Authors: Pei Liu, Lei Han, Fei Wang, Valery A Petrenko, Aihua LiuAbstract:Staphylococcus aureus (S. aureus) is one of the most ubiquitous pathogens in public healthcare worldwide. It holds great insterest in establishing robust analytical method for S. aureus. Herein, we report a S. aureus-specific recognition element, isolated from phage monoclone GQTTLITS, which was selected from f8/8 landscape phage library against S. aureus in a high-throughput way. By fiinctionalizing cysteamine (CS)-stabilized gold nanoparticles (CS-AuNPs) with S. aureus-specific pVIII fusion Protein (fusion-pVIII), a bifunctional nanoprobe (CS-AuNPs@fusion-pVIII) for S. aureus was developed. In this strategy, the CS-AuNPs@fusion-pVIII could be induced to aggregate quickly in the presence of target S. aureus, resulting in a rapid colorimetric response of gold nanoparticles. More importantly, the as-designed probe exhibited excellent selectivity over other bacteria. Thus, the CS-AuNPs@fusion-pVIII could be used as the indicator of target S. aureus. This assay can detect as low as 19 CFU mL(-1) S. aureus within 30 min. Further, this approach can be applicable to detect S. aureus in real water samples. Due to its sensitivity, specificity and rapidness, this proposed method is promising for on-site testing of S. aureus without using any costly instruments. (C) 2016 Elsevier B.V. All rights reserved.
