The Experts below are selected from a list of 102 Experts worldwide ranked by ideXlab platform
Robert C. Woodworth - One of the best experts on this subject based on the ideXlab platform.
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Differences in absorption and emission properties of Conalbumin and metal‐saturated Conalbumin
Journal of Polymer Science Part C: Polymer Symposia, 2007Co-Authors: A. T. Tan, Robert C. WoodworthAbstract:The stabilities of Conalbumin and transition metal-Conalbumin complexes toward denaturants were studied by UV absorption and emission spectroscopy. The difference spectra of Conalbumin and metal-Conalbumins in buffer, pH 8.0 vs. the same species in buffered 8 M urea were similar in shape with maxima at 286- and 292-mμ and a negative absorption near 260-mμ. The Δe292 for colored Fe-, Cr-, Cu-, and Mn-Conalbumins was 5 × 103 less than that for Conalbumin and colorless Co-, Zn-, Cd-, Ni-, and Mn-Conalbumins, indicating that two tryptophanyl residues were bound to or protected by metal ions in the former but not the latter cases. The F350 of Conalbumin was quenched up to 65% on formation of the colored complexes, but not on formation of colorless complexes. The F350 of Conalbumin was strongly quenched by increasing temperature (0 to 70°) or pH (5 to 12.5), whereas that of Fe+3-Conalbumin was essentially independent of these variables. These results indicate the presence of tryptophanyl residues, in addition to the known tyrosyl and histidyl residues, in Conalbumin-metal binding sites, and suggest that charge-transfer interactions between these tryptophanyl residues and the bound metals is probably responsible, at least in part, for color formation, as well as for the marked increase in stability of these colored complexes.
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differences in absorption and emission properties of Conalbumin and metal saturated Conalbumin
Journal of Polymer Science Part C: Polymer Symposia, 2007Co-Authors: A. T. Tan, Robert C. WoodworthAbstract:The stabilities of Conalbumin and transition metal-Conalbumin complexes toward denaturants were studied by UV absorption and emission spectroscopy. The difference spectra of Conalbumin and metal-Conalbumins in buffer, pH 8.0 vs. the same species in buffered 8 M urea were similar in shape with maxima at 286- and 292-mμ and a negative absorption near 260-mμ. The Δe292 for colored Fe-, Cr-, Cu-, and Mn-Conalbumins was 5 × 103 less than that for Conalbumin and colorless Co-, Zn-, Cd-, Ni-, and Mn-Conalbumins, indicating that two tryptophanyl residues were bound to or protected by metal ions in the former but not the latter cases. The F350 of Conalbumin was quenched up to 65% on formation of the colored complexes, but not on formation of colorless complexes. The F350 of Conalbumin was strongly quenched by increasing temperature (0 to 70°) or pH (5 to 12.5), whereas that of Fe+3-Conalbumin was essentially independent of these variables. These results indicate the presence of tryptophanyl residues, in addition to the known tyrosyl and histidyl residues, in Conalbumin-metal binding sites, and suggest that charge-transfer interactions between these tryptophanyl residues and the bound metals is probably responsible, at least in part, for color formation, as well as for the marked increase in stability of these colored complexes.
John B. Vincent - One of the best experts on this subject based on the ideXlab platform.
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immobilization of Conalbumin onto polystyrene divinylbenzene co polymers towards finding the best support for mamc
Journal of Molecular Recognition, 1996Co-Authors: Enrique Gonzalezvergara, John B. VincentAbstract:Immediately after the successful immobilization of Conalbumin onto CNBr-activated Sepharose, efforts were begun to find a less expensive support and a more benign chemistry of activation. The potential of the Sepharose-Conalbumin conjugate for decontamination of several metal-containing waste-waters has been established, and a new method of chromatography has emerged, named metalloprotein affinity metal chromatography (MAMC). Efforts to immobilize Conalbumin onto polystyrene/divinylbenzene co-polymers, using the well known and commercially available Merrifield, aminomethyl and plain polystyrene resins are presented here. Immobilizations of Conalbumin were carried out on the Merrifield and Aminomethyl resins, but the procedures were time consuming and complicated by polymer aggregation. Because of high cost of these materials, research was directed towards the activation and functionalization of plain polystyrene/divinylbenzene co-polymers. Chlorosulfonation followed by sulfonamide formation was attempted on three commercially available polymers. Successful polysulfonamide formation was achieved with bislysine copper(II) acting as a diamine. Removal of the copper allows the unblocking of the alpha amino group of the immobilized lysine which in turn is treated with glutaraldehyde, affording an activated support for immobilization of proteins. To date, approximately 46 mg transferrin/g dry matrix have been successfully immobilized. The chemical and biological inertness of this support makes it a good candidate to scale up the procedure and continue the optimization of MAMC.
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silica Conalbumin conjugate as an inexpensive alternative for metalloprotein affinity metal chromatography
Journal of Environmental Science and Health Part A-toxic\ hazardous Substances & Environmental Engineering, 1996Co-Authors: Enrique Gonzalezvergara, John B. VincentAbstract:Abstract A newly developed method of chromatography based on the affinity of metal ions for the apometalloprotein Conalbumin (ovotransferrin, OT) has the potential to decontaminate and selectively recover metal ions from wastewater [1, 2]. The presence of inorganic contaminants in surface water is perhaps one of the most important environmental issues of our time. Thus, efforts to solve this problem by applying our recent understanding of metal‐protein interactions has lead us to the search for different apometalloproteins that could be affixed to inert supports to act as affinity media for a variety of heavy metal ions. The successful immobilization of Conalbumin onto sepharose has served as an entry into this chemistry; however, the ability to apply this methodology away from the laboratory environment is highly dependent on the cost and robustness of the support employed, as well as the cost of the reagents and methods utilized to achieve a functional metal affinity column. Results in the direction of ...
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Immobilization of Conalbumin onto polystyrene/divinylbenzene co‐polymers: Towards finding the best support for MAMC
Journal of molecular recognition : JMR, 1996Co-Authors: Enrique González-vergara, John B. VincentAbstract:Immediately after the successful immobilization of Conalbumin onto CNBr-activated Sepharose, efforts were begun to find a less expensive support and a more benign chemistry of activation. The potential of the Sepharose-Conalbumin conjugate for decontamination of several metal-containing waste-waters has been established, and a new method of chromatography has emerged, named metalloprotein affinity metal chromatography (MAMC). Efforts to immobilize Conalbumin onto polystyrene/divinylbenzene co-polymers, using the well known and commercially available Merrifield, aminomethyl and plain polystyrene resins are presented here. Immobilizations of Conalbumin were carried out on the Merrifield and Aminomethyl resins, but the procedures were time consuming and complicated by polymer aggregation. Because of high cost of these materials, research was directed towards the activation and functionalization of plain polystyrene/divinylbenzene co-polymers. Chlorosulfonation followed by sulfonamide formation was attempted on three commercially available polymers. Successful polysulfonamide formation was achieved with bislysine copper(II) acting as a diamine. Removal of the copper allows the unblocking of the alpha amino group of the immobilized lysine which in turn is treated with glutaraldehyde, affording an activated support for immobilization of proteins. To date, approximately 46 mg transferrin/g dry matrix have been successfully immobilized. The chemical and biological inertness of this support makes it a good candidate to scale up the procedure and continue the optimization of MAMC.
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Silica‐Conalbumin conjugate as an inexpensive alternative for metalloprotein affinity metal chromatography
Journal of Environmental Science and Health . Part A: Environmental Science and Engineering and Toxicology, 1996Co-Authors: Enrique González-vergara, John B. VincentAbstract:Abstract A newly developed method of chromatography based on the affinity of metal ions for the apometalloprotein Conalbumin (ovotransferrin, OT) has the potential to decontaminate and selectively recover metal ions from wastewater [1, 2]. The presence of inorganic contaminants in surface water is perhaps one of the most important environmental issues of our time. Thus, efforts to solve this problem by applying our recent understanding of metal‐protein interactions has lead us to the search for different apometalloproteins that could be affixed to inert supports to act as affinity media for a variety of heavy metal ions. The successful immobilization of Conalbumin onto sepharose has served as an entry into this chemistry; however, the ability to apply this methodology away from the laboratory environment is highly dependent on the cost and robustness of the support employed, as well as the cost of the reagents and methods utilized to achieve a functional metal affinity column. Results in the direction of ...
A. T. Tan - One of the best experts on this subject based on the ideXlab platform.
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Differences in absorption and emission properties of Conalbumin and metal‐saturated Conalbumin
Journal of Polymer Science Part C: Polymer Symposia, 2007Co-Authors: A. T. Tan, Robert C. WoodworthAbstract:The stabilities of Conalbumin and transition metal-Conalbumin complexes toward denaturants were studied by UV absorption and emission spectroscopy. The difference spectra of Conalbumin and metal-Conalbumins in buffer, pH 8.0 vs. the same species in buffered 8 M urea were similar in shape with maxima at 286- and 292-mμ and a negative absorption near 260-mμ. The Δe292 for colored Fe-, Cr-, Cu-, and Mn-Conalbumins was 5 × 103 less than that for Conalbumin and colorless Co-, Zn-, Cd-, Ni-, and Mn-Conalbumins, indicating that two tryptophanyl residues were bound to or protected by metal ions in the former but not the latter cases. The F350 of Conalbumin was quenched up to 65% on formation of the colored complexes, but not on formation of colorless complexes. The F350 of Conalbumin was strongly quenched by increasing temperature (0 to 70°) or pH (5 to 12.5), whereas that of Fe+3-Conalbumin was essentially independent of these variables. These results indicate the presence of tryptophanyl residues, in addition to the known tyrosyl and histidyl residues, in Conalbumin-metal binding sites, and suggest that charge-transfer interactions between these tryptophanyl residues and the bound metals is probably responsible, at least in part, for color formation, as well as for the marked increase in stability of these colored complexes.
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differences in absorption and emission properties of Conalbumin and metal saturated Conalbumin
Journal of Polymer Science Part C: Polymer Symposia, 2007Co-Authors: A. T. Tan, Robert C. WoodworthAbstract:The stabilities of Conalbumin and transition metal-Conalbumin complexes toward denaturants were studied by UV absorption and emission spectroscopy. The difference spectra of Conalbumin and metal-Conalbumins in buffer, pH 8.0 vs. the same species in buffered 8 M urea were similar in shape with maxima at 286- and 292-mμ and a negative absorption near 260-mμ. The Δe292 for colored Fe-, Cr-, Cu-, and Mn-Conalbumins was 5 × 103 less than that for Conalbumin and colorless Co-, Zn-, Cd-, Ni-, and Mn-Conalbumins, indicating that two tryptophanyl residues were bound to or protected by metal ions in the former but not the latter cases. The F350 of Conalbumin was quenched up to 65% on formation of the colored complexes, but not on formation of colorless complexes. The F350 of Conalbumin was strongly quenched by increasing temperature (0 to 70°) or pH (5 to 12.5), whereas that of Fe+3-Conalbumin was essentially independent of these variables. These results indicate the presence of tryptophanyl residues, in addition to the known tyrosyl and histidyl residues, in Conalbumin-metal binding sites, and suggest that charge-transfer interactions between these tryptophanyl residues and the bound metals is probably responsible, at least in part, for color formation, as well as for the marked increase in stability of these colored complexes.
Enrique Gonzalezvergara - One of the best experts on this subject based on the ideXlab platform.
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immobilization of Conalbumin onto polystyrene divinylbenzene co polymers towards finding the best support for mamc
Journal of Molecular Recognition, 1996Co-Authors: Enrique Gonzalezvergara, John B. VincentAbstract:Immediately after the successful immobilization of Conalbumin onto CNBr-activated Sepharose, efforts were begun to find a less expensive support and a more benign chemistry of activation. The potential of the Sepharose-Conalbumin conjugate for decontamination of several metal-containing waste-waters has been established, and a new method of chromatography has emerged, named metalloprotein affinity metal chromatography (MAMC). Efforts to immobilize Conalbumin onto polystyrene/divinylbenzene co-polymers, using the well known and commercially available Merrifield, aminomethyl and plain polystyrene resins are presented here. Immobilizations of Conalbumin were carried out on the Merrifield and Aminomethyl resins, but the procedures were time consuming and complicated by polymer aggregation. Because of high cost of these materials, research was directed towards the activation and functionalization of plain polystyrene/divinylbenzene co-polymers. Chlorosulfonation followed by sulfonamide formation was attempted on three commercially available polymers. Successful polysulfonamide formation was achieved with bislysine copper(II) acting as a diamine. Removal of the copper allows the unblocking of the alpha amino group of the immobilized lysine which in turn is treated with glutaraldehyde, affording an activated support for immobilization of proteins. To date, approximately 46 mg transferrin/g dry matrix have been successfully immobilized. The chemical and biological inertness of this support makes it a good candidate to scale up the procedure and continue the optimization of MAMC.
-
silica Conalbumin conjugate as an inexpensive alternative for metalloprotein affinity metal chromatography
Journal of Environmental Science and Health Part A-toxic\ hazardous Substances & Environmental Engineering, 1996Co-Authors: Enrique Gonzalezvergara, John B. VincentAbstract:Abstract A newly developed method of chromatography based on the affinity of metal ions for the apometalloprotein Conalbumin (ovotransferrin, OT) has the potential to decontaminate and selectively recover metal ions from wastewater [1, 2]. The presence of inorganic contaminants in surface water is perhaps one of the most important environmental issues of our time. Thus, efforts to solve this problem by applying our recent understanding of metal‐protein interactions has lead us to the search for different apometalloproteins that could be affixed to inert supports to act as affinity media for a variety of heavy metal ions. The successful immobilization of Conalbumin onto sepharose has served as an entry into this chemistry; however, the ability to apply this methodology away from the laboratory environment is highly dependent on the cost and robustness of the support employed, as well as the cost of the reagents and methods utilized to achieve a functional metal affinity column. Results in the direction of ...
Enrique González-vergara - One of the best experts on this subject based on the ideXlab platform.
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Immobilization of Conalbumin onto polystyrene/divinylbenzene co‐polymers: Towards finding the best support for MAMC
Journal of molecular recognition : JMR, 1996Co-Authors: Enrique González-vergara, John B. VincentAbstract:Immediately after the successful immobilization of Conalbumin onto CNBr-activated Sepharose, efforts were begun to find a less expensive support and a more benign chemistry of activation. The potential of the Sepharose-Conalbumin conjugate for decontamination of several metal-containing waste-waters has been established, and a new method of chromatography has emerged, named metalloprotein affinity metal chromatography (MAMC). Efforts to immobilize Conalbumin onto polystyrene/divinylbenzene co-polymers, using the well known and commercially available Merrifield, aminomethyl and plain polystyrene resins are presented here. Immobilizations of Conalbumin were carried out on the Merrifield and Aminomethyl resins, but the procedures were time consuming and complicated by polymer aggregation. Because of high cost of these materials, research was directed towards the activation and functionalization of plain polystyrene/divinylbenzene co-polymers. Chlorosulfonation followed by sulfonamide formation was attempted on three commercially available polymers. Successful polysulfonamide formation was achieved with bislysine copper(II) acting as a diamine. Removal of the copper allows the unblocking of the alpha amino group of the immobilized lysine which in turn is treated with glutaraldehyde, affording an activated support for immobilization of proteins. To date, approximately 46 mg transferrin/g dry matrix have been successfully immobilized. The chemical and biological inertness of this support makes it a good candidate to scale up the procedure and continue the optimization of MAMC.
-
Silica‐Conalbumin conjugate as an inexpensive alternative for metalloprotein affinity metal chromatography
Journal of Environmental Science and Health . Part A: Environmental Science and Engineering and Toxicology, 1996Co-Authors: Enrique González-vergara, John B. VincentAbstract:Abstract A newly developed method of chromatography based on the affinity of metal ions for the apometalloprotein Conalbumin (ovotransferrin, OT) has the potential to decontaminate and selectively recover metal ions from wastewater [1, 2]. The presence of inorganic contaminants in surface water is perhaps one of the most important environmental issues of our time. Thus, efforts to solve this problem by applying our recent understanding of metal‐protein interactions has lead us to the search for different apometalloproteins that could be affixed to inert supports to act as affinity media for a variety of heavy metal ions. The successful immobilization of Conalbumin onto sepharose has served as an entry into this chemistry; however, the ability to apply this methodology away from the laboratory environment is highly dependent on the cost and robustness of the support employed, as well as the cost of the reagents and methods utilized to achieve a functional metal affinity column. Results in the direction of ...