The Experts below are selected from a list of 1572 Experts worldwide ranked by ideXlab platform
Silvia Dibenedetto - One of the best experts on this subject based on the ideXlab platform.
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calcineurin a versus ns5a tp2 hd domain containing 2 a case study of site directed low frequency random mutagenesis for dissecting target specificity of Peptide Aptamers
Molecular & Cellular Proteomics, 2013Co-Authors: Silvia Dibenedetto, David Cluet, Pierre-nicolas Stebe, Véronique Baumlé, Jérémie Léault, Benoit De Chassey, Marc Bickle, Raphaël Terreux, Ivan MikaelianAbstract:We previously identified a Peptide Aptamer (named R5G42) via functional selection for its capacity to slow cell proliferation. A yeast two-hybrid screen of human cDNA libraries, using R5G42 as “bait,” allowed the identification of two binding proteins with very different functions: calcineurin A (CnA) (PP2B/PPP3CA), a protein phosphatase well characterized for its role in the immune response, and NS5A-TP2/HD domain containing 2, a much less studied protein induced subsequent to hepatitis C virus non-structural protein 5A expression in HepG2 hepatocellular carcinoma cells, with no known activity. Our objective in the present study was to dissect the dual target specificity of R5G42 in order to have tools with which to better characterize the actions of the Peptide Aptamers toward their individual targets. This was achieved through the selection of random mutants of the variable loop, derived from R5G42, evaluating their specificity toward CnA and NS5A-TP2 and analyzing their sequence. An interdisciplinary approach involving biomolecular computer simulations with integration of the sequence data and yeast two-hybrid binding phenotypes of these mutants yielded two structurally distinct conformers affording the potential molecular basis of the binding diversity of R5G42. Evaluation of the biological impact of CnA- versus NS5A-TP2-specific Peptide Aptamers indicated that although both contributed to the anti-proliferative effect of R5G42, CnA-binding was essential to stimulate the nuclear translocation of nuclear factor of activated T cells, indicative of the activation of endogenous CnA. By dissecting the target specificity of R5G42, we have generated novel tools with which to study each target individually. Apta-C8 is capable of directly activating CnA independent of binding to NS5A-TP2 and will be an important tool in studying the role of CnA activation in the regulation of different signaling pathways, whereas Apta-E1 will allow dissection of the function of NS5A-TP2, serving as an example of the usefulness of Peptide Aptamer technology for investigating signaling pathways.
Yuzuru Takamura - One of the best experts on this subject based on the ideXlab platform.
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Peptide Aptamer modified single walled carbon nanotube based transistors for high performance biosensors
Scientific Reports, 2017Co-Authors: Nguyen Thanh Tung, Truong Thi Ngoc Lien, Phan Trong Tue, Yasuhide Ohno, Kenzo Maehashi, Kazuhiko Matsumoto, Koichi Nishigaki, Manish Biyani, Yuzuru TakamuraAbstract:Biosensors employing single-walled carbon nanotube field-effect transistors (SWCNT FETs) offer ultimate sensitivity. However, besides the sensitivity, a high selectivity is critically important to distinguish the true signal from interference signals in a non-controlled environment. This work presents the first demonstration of the successful integration of a novel Peptide Aptamer with a liquid-gated SWCNT FET to achieve highly sensitive and specific detection of Cathepsin E (CatE), a useful prognostic biomarker for cancer diagnosis. Novel Peptide Aptamers that specifically recognize CatE are engineered by systemic in vitro evolution. The SWCNTs were firstly grown using the thermal chemical vapor deposition (CVD) method and then were employed as a channel to fabricate a SWCNT FET device. Next, the SWCNTs were functionalized by noncovalent immobilization of the Peptide Aptamer using 1-pyrenebutanoic acid succinimidyl ester (PBASE) linker. The resulting FET sensors exhibited a high selectivity (no response to bovine serum albumin and cathepsin K) and label-free detection of CatE at unprecedentedly low concentrations in both phosphate-buffered saline (2.3 pM) and human serum (0.23 nM). Our results highlight the use of Peptide Aptamer-modified SWCNT FET sensors as a promising platform for near-patient testing and point-of-care testing applications.
Masuki Kawamoto - One of the best experts on this subject based on the ideXlab platform.
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solubilization of single walled carbon nanotubes using a Peptide Aptamer in water below the critical micelle concentration
Langmuir, 2015Co-Authors: Zha Li, Tomoshi Kameda, Takashi Isoshima, Eiry Kobatake, Takeshi Tanaka, Masuki KawamotoAbstract:The solubilizing ability of single-walled carbon nanotubes (SWCNTs) in water with several dispersants was investigated. Among the dispersants, including low-molecular-weight surfactants, Peptides, DNA, and a water-soluble polymer, the Peptide Aptamer, A2 (IFRLSWGTYFS), exhibited the highest dispersion capability below the critical micelle concentration at a concentration of 0.02 w/v%. The dispersion of supernatant aqueous solution of SWCNTs containing Aptamer A2 was essentially unchanged for several months after high-speed ultracentrifugation and gave rise to an efficient and stable dispersion of the SWCNTs in water. From the results of isothermal titration calorimetry and molecular dynamics simulations, the effective binding capability of A2 was due to π–π interaction between aromatic groups in the Peptide Aptamer and the side walls of SWCNTs. Interestingly, the Peptide Aptamer showed the possibility of diameter separation of semiconducting SWCNTs using a uniform density gradient ultracentrifuge. These p...
Koichi Nishigaki - One of the best experts on this subject based on the ideXlab platform.
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Peptide Aptamer modified single walled carbon nanotube based transistors for high performance biosensors
Scientific Reports, 2017Co-Authors: Nguyen Thanh Tung, Truong Thi Ngoc Lien, Phan Trong Tue, Yasuhide Ohno, Kenzo Maehashi, Kazuhiko Matsumoto, Koichi Nishigaki, Manish Biyani, Yuzuru TakamuraAbstract:Biosensors employing single-walled carbon nanotube field-effect transistors (SWCNT FETs) offer ultimate sensitivity. However, besides the sensitivity, a high selectivity is critically important to distinguish the true signal from interference signals in a non-controlled environment. This work presents the first demonstration of the successful integration of a novel Peptide Aptamer with a liquid-gated SWCNT FET to achieve highly sensitive and specific detection of Cathepsin E (CatE), a useful prognostic biomarker for cancer diagnosis. Novel Peptide Aptamers that specifically recognize CatE are engineered by systemic in vitro evolution. The SWCNTs were firstly grown using the thermal chemical vapor deposition (CVD) method and then were employed as a channel to fabricate a SWCNT FET device. Next, the SWCNTs were functionalized by noncovalent immobilization of the Peptide Aptamer using 1-pyrenebutanoic acid succinimidyl ester (PBASE) linker. The resulting FET sensors exhibited a high selectivity (no response to bovine serum albumin and cathepsin K) and label-free detection of CatE at unprecedentedly low concentrations in both phosphate-buffered saline (2.3 pM) and human serum (0.23 nM). Our results highlight the use of Peptide Aptamer-modified SWCNT FET sensors as a promising platform for near-patient testing and point-of-care testing applications.
Ivan Mikaelian - One of the best experts on this subject based on the ideXlab platform.
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calcineurin a versus ns5a tp2 hd domain containing 2 a case study of site directed low frequency random mutagenesis for dissecting target specificity of Peptide Aptamers
Molecular & Cellular Proteomics, 2013Co-Authors: Silvia Dibenedetto, David Cluet, Pierre-nicolas Stebe, Véronique Baumlé, Jérémie Léault, Benoit De Chassey, Marc Bickle, Raphaël Terreux, Ivan MikaelianAbstract:We previously identified a Peptide Aptamer (named R5G42) via functional selection for its capacity to slow cell proliferation. A yeast two-hybrid screen of human cDNA libraries, using R5G42 as “bait,” allowed the identification of two binding proteins with very different functions: calcineurin A (CnA) (PP2B/PPP3CA), a protein phosphatase well characterized for its role in the immune response, and NS5A-TP2/HD domain containing 2, a much less studied protein induced subsequent to hepatitis C virus non-structural protein 5A expression in HepG2 hepatocellular carcinoma cells, with no known activity. Our objective in the present study was to dissect the dual target specificity of R5G42 in order to have tools with which to better characterize the actions of the Peptide Aptamers toward their individual targets. This was achieved through the selection of random mutants of the variable loop, derived from R5G42, evaluating their specificity toward CnA and NS5A-TP2 and analyzing their sequence. An interdisciplinary approach involving biomolecular computer simulations with integration of the sequence data and yeast two-hybrid binding phenotypes of these mutants yielded two structurally distinct conformers affording the potential molecular basis of the binding diversity of R5G42. Evaluation of the biological impact of CnA- versus NS5A-TP2-specific Peptide Aptamers indicated that although both contributed to the anti-proliferative effect of R5G42, CnA-binding was essential to stimulate the nuclear translocation of nuclear factor of activated T cells, indicative of the activation of endogenous CnA. By dissecting the target specificity of R5G42, we have generated novel tools with which to study each target individually. Apta-C8 is capable of directly activating CnA independent of binding to NS5A-TP2 and will be an important tool in studying the role of CnA activation in the regulation of different signaling pathways, whereas Apta-E1 will allow dissection of the function of NS5A-TP2, serving as an example of the usefulness of Peptide Aptamer technology for investigating signaling pathways.