The Experts below are selected from a list of 105 Experts worldwide ranked by ideXlab platform
Nicolai V Bovin - One of the best experts on this subject based on the ideXlab platform.
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human antibodies eluted from ligand free Sepharose capable of binding bacterial polysaccharides and sulfated glycans
Molecular Immunology, 2019Co-Authors: Kira Dobrochaeva, Nailya Khasbiullina, Nadezhda Shilova, Polina Obukhova, Yuriy A Knirel, Yu A Nokel, Nicolai V BovinAbstract:Abstract Sepharose matrix without immobilized ligands binds antibodies from human blood serum or immunoglobulin preparations. The eluted antibodies bind bacterial polysaccharides having no structural similarity to agarose (Sepharose is a cross-linked polysaccharide agarose) with a high affinity. It is concluded that the identified antibodies are capable of recognizing spatial rather than linear epitopes of bacterial polysaccharides. This side activity of Sepharose matrix should be taken into account in isolating target antibodies and other proteins from human blood.
Kazuhiko Nakatani - One of the best experts on this subject based on the ideXlab platform.
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Analysis of mismatched DNA by mismatch binding ligand (MBL)-Sepharose affinity chromatography.
Analytical and bioanalytical chemistry, 2007Co-Authors: Yuki Goto, Hitoshi Suda, Akio Kobori, Kazuhiko NakataniAbstract:Mismatch binding molecules (MBLs), strongly and selectively bound to the mismatched base pair in duplex DNA, were immobilized on Sepharose. Three MBL-Sepharose columns were prepared with three MBLs, naphthyridine dimer (ND), naphthyridine-azaquinolone (NA), and aminonaphthyridine dimer (amND), which exhibited different binding profiles to the mismatched base pairs. These three MBL-Sepharose columns showed characteristic elution profiles for DNA duplexes containing mismatched base pairs. The ND-Sepharose column separated the G-G and G-A mismatched DNA from fully matched duplexes. The NA-Sepharose column separated the A-A and G-A mismatched DNA from other DNA duplexes. The amND-Sepharose column separated the C-C mismatched DNA. These chromatographic profiles were very consistent with the binding preference of each MBL. By changing the elution conditions from sodium hydroxide to sodium chloride, MBL-Sepharose columns were also able to separate the mismatched DNA that weakly bound to the MBL from fully matched DNA duplex. Figure MBL-Sepharose affinity chromatography successfully separates the mismatched duplex DNA from fully matched duplex.
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Analysis of mismatched DNA by mismatch binding ligand (MBL)-Sepharose affinity chromatography.
Analytical and Bioanalytical Chemistry, 2007Co-Authors: Yuki Goto, Hitoshi Suda, Akio Kobori, Kazuhiko NakataniAbstract:Mismatch binding molecules (MBLs), strongly and selectively bound to the mismatched base pair in duplex DNA, were immobilized on Sepharose. Three MBL–Sepharose columns were prepared with three MBLs, naphthyridine dimer (ND), naphthyridine–azaquinolone (NA), and aminonaphthyridine dimer (amND), which exhibited different binding profiles to the mismatched base pairs. These three MBL–Sepharose columns showed characteristic elution profiles for DNA duplexes containing mismatched base pairs. The ND–Sepharose column separated the G–G and G–A mismatched DNA from fully matched duplexes. The NA–Sepharose column separated the A–A and G–A mismatched DNA from other DNA duplexes. The amND–Sepharose column separated the C–C mismatched DNA. These chromatographic profiles were very consistent with the binding preference of each MBL. By changing the elution conditions from sodium hydroxide to sodium chloride, MBL–Sepharose columns were also able to separate the mismatched DNA that weakly bound to the MBL from fully matched DNA duplex.
Yan Sun - One of the best experts on this subject based on the ideXlab platform.
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protein adsorption to poly ethylenimine modified Sepharose ff v complicated effects of counterions
Journal of Chromatography A, 2015Co-Authors: Na Liu, Yan SunAbstract:Abstract In the previous studies on protein adsorption to poly(ethylenimine) (PEI)-grafted Sepharose FF resins, a critical ionic capacity (600 mmol/L) of PEI-Sepharose resins was found for the adsorption of bovine serum albumin (BSA), above which both protein capacity and uptake rate increased drastically. In this work, the influence of counterions on the PEI-Sepharose resin with an ionic capacity of 683 mmol/L (FF-PEI-L680) was investigated with sodium salts of SCN − , Cl − , HPO 4 2− and SO 4 2− . Linear gradient elution, batch adsorption and breakthrough experiments showed that counterion preference, effective pore diffusion coefficient ( D e ) and dynamic binding capacity (DBC) values increased in the order of SCN − , Cl − , HPO 4 2− and SO 4 2− , while static adsorption capacity decreased in this order. It is considered that higher counterion preference of the ion exchange groups resulted in lower protein binding strength and adsorption capacity, while the D e value increased due to the enhanced “chain delivery” effect (a kind of surface diffusion). Besides, the DBC value was mainly dependent on D e value. In particular, SO 4 2− was the most favorable counterion for the PEI-Sepharose resin, which gave rise to the highest D e value ( D e / D 0 = 1.17, D 0 is protein diffusivity in free solution) and DBC value (118 mg/mL at a residence time of 2 min). Moreover, the effects of counterions on BSA adsorption to DEAE Sepharose FF and Q Sepharose FF, which were non-grafted resins, were also studied for comparisons. It was found that the counterion preferences of the two non-grafted resins were different from each other and also different from that of FF-PEI-L680. The different counterion preferences were attributed to the differences in the ion-exchange ligand chemistries. In addition, the D e values for DEAE Sepharose FF and Q Sepharose FF kept unchanged. The low counterion sensitivity of D e values could be interpreted as the lack of “chain delivery” effect for the non-grafted resins. The results indicate that protein adsorption and chromatographic performance with PEI-Sepharose can be improved by proper counterions. For the four counterions tested, SO 4 2− was the most favorable for providing the best adsorption and elution outcomes with FF-PEI-L680.
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protein adsorption to poly ethylenimine modified Sepharose ff ii effect of ionic strength
Journal of Chromatography A, 2013Co-Authors: Yan SunAbstract:Abstract In Part I of this work, we have studied the effect of ionic capacity (IC) on bovine serum albumin (BSA) adsorption equilibria and kinetics to poly(ethylenimine) (PEI)-grafted Sepharose FF, and found a critical IC (cIC, 600 mmol/L), above which both protein capacity and uptake rate increased drastically. In this work, five PEI-Sepharose FF resins of typical ICs reported earlier were selected to explore the effect of ionic strength (IS) on the adsorption equilibria and kinetics of BSA. Commercially available DEAE (IC = 160 mmol/L) and Q Sepharose FF (IC = 269 mmol/L) resins were used for comparisons. It is found that at similar ionic capacities, protein adsorption capacities on both the PEI-Sepharose FF resins and the commercial resins decreased with increasing IS, but on the capacity sensitivity to salt concentration, the former was lower than the latter. In addition, the effective diffusivities ( D e ) of the former were smaller than the latter in the entire IS range studied. The low IS sensitivity of adsorption capacity of the PEI-Sepharose FF resins could be interpreted by the increase of pore accessibility with increasing IS; the smaller D e values in the PEI-Sepharose FF resins were considered due to the lack of surface diffusion in the PEI-Sepharose FF resins of low PEI densities. For the PEI-Sepharose FF resins of high ICs (520, 740 and 1220 mmol/L), both protein capacity and D e values increased first and then decreased with increasing IS. The increasing trend of protein capacity in the low IS range was considered due to the increase of accessible pores for BSA. The rise–fall trend of D e was attributed to the dependencies of the “chain delivery” effect on protein capacity and binding strength, both of which are related to IS. Moreover, the IS sensitivity of the D e for the resins of ICs > cIC (740 and 1220 mmol/L) was much higher than those of ICs cIC. Furthermore, the two PEI-Sepharose FF resins of ICs > cIC kept high adsorption capacities and D e values up to 200–300 mmol/L NaCl. Therefore, the operating IS ranges for these two PEI-Sepharose FF resins can be much broader than the traditional ion-exchange media.
Yuki Goto - One of the best experts on this subject based on the ideXlab platform.
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Analysis of mismatched DNA by mismatch binding ligand (MBL)-Sepharose affinity chromatography.
Analytical and bioanalytical chemistry, 2007Co-Authors: Yuki Goto, Hitoshi Suda, Akio Kobori, Kazuhiko NakataniAbstract:Mismatch binding molecules (MBLs), strongly and selectively bound to the mismatched base pair in duplex DNA, were immobilized on Sepharose. Three MBL-Sepharose columns were prepared with three MBLs, naphthyridine dimer (ND), naphthyridine-azaquinolone (NA), and aminonaphthyridine dimer (amND), which exhibited different binding profiles to the mismatched base pairs. These three MBL-Sepharose columns showed characteristic elution profiles for DNA duplexes containing mismatched base pairs. The ND-Sepharose column separated the G-G and G-A mismatched DNA from fully matched duplexes. The NA-Sepharose column separated the A-A and G-A mismatched DNA from other DNA duplexes. The amND-Sepharose column separated the C-C mismatched DNA. These chromatographic profiles were very consistent with the binding preference of each MBL. By changing the elution conditions from sodium hydroxide to sodium chloride, MBL-Sepharose columns were also able to separate the mismatched DNA that weakly bound to the MBL from fully matched DNA duplex. Figure MBL-Sepharose affinity chromatography successfully separates the mismatched duplex DNA from fully matched duplex.
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Analysis of mismatched DNA by mismatch binding ligand (MBL)-Sepharose affinity chromatography.
Analytical and Bioanalytical Chemistry, 2007Co-Authors: Yuki Goto, Hitoshi Suda, Akio Kobori, Kazuhiko NakataniAbstract:Mismatch binding molecules (MBLs), strongly and selectively bound to the mismatched base pair in duplex DNA, were immobilized on Sepharose. Three MBL–Sepharose columns were prepared with three MBLs, naphthyridine dimer (ND), naphthyridine–azaquinolone (NA), and aminonaphthyridine dimer (amND), which exhibited different binding profiles to the mismatched base pairs. These three MBL–Sepharose columns showed characteristic elution profiles for DNA duplexes containing mismatched base pairs. The ND–Sepharose column separated the G–G and G–A mismatched DNA from fully matched duplexes. The NA–Sepharose column separated the A–A and G–A mismatched DNA from other DNA duplexes. The amND–Sepharose column separated the C–C mismatched DNA. These chromatographic profiles were very consistent with the binding preference of each MBL. By changing the elution conditions from sodium hydroxide to sodium chloride, MBL–Sepharose columns were also able to separate the mismatched DNA that weakly bound to the MBL from fully matched DNA duplex.
Kira Dobrochaeva - One of the best experts on this subject based on the ideXlab platform.
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human antibodies eluted from ligand free Sepharose capable of binding bacterial polysaccharides and sulfated glycans
Molecular Immunology, 2019Co-Authors: Kira Dobrochaeva, Nailya Khasbiullina, Nadezhda Shilova, Polina Obukhova, Yuriy A Knirel, Yu A Nokel, Nicolai V BovinAbstract:Abstract Sepharose matrix without immobilized ligands binds antibodies from human blood serum or immunoglobulin preparations. The eluted antibodies bind bacterial polysaccharides having no structural similarity to agarose (Sepharose is a cross-linked polysaccharide agarose) with a high affinity. It is concluded that the identified antibodies are capable of recognizing spatial rather than linear epitopes of bacterial polysaccharides. This side activity of Sepharose matrix should be taken into account in isolating target antibodies and other proteins from human blood.