The Experts below are selected from a list of 216123 Experts worldwide ranked by ideXlab platform
Huan Wang - One of the best experts on this subject based on the ideXlab platform.
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unraveling the Enzymatic Activity of oxygenated carbon nanotubes and their application in the treatment of bacterial infections
Nano Letters, 2018Co-Authors: Huan Wang, Penghui Li, Dongqin Yu, Yan Zhang, Zhenzhen Wang, Xiaogang QuAbstract:Carbon nanotubes (CNTs) and their derivatives have emerged as a series of efficient biocatalysts to mimic the function of natural enzymes in recent years. However, the unsatisfiable Enzymatic efficiency usually limits their practical usage ranging from materials science to biotechnology. Here, for the first time, we present the synthesis of several oxygenated-group-enriched carbon nanotubes (o-CNTs) via a facile but green approach, as well as their usage as high-performance peroxidase mimics for biocatalytic reaction. Exhaustive characterizations of the Enzymatic Activity of o-CNTs have been provided by exploring the accurate effect of various oxygenated groups on their surface including carbonyl, carboxyl, and hydroxyl groups. Because of the “competitive inhibition” effect among all of these oxygenated groups, the catalytic efficiency of o-CNTs is significantly enhanced by weakening the presence of noncatalytic sites. Furthermore, the admirable Enzymatic Activity of these o-CNTs has been successfully app...
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unraveling the Enzymatic Activity of oxygenated carbon nanotubes and their application in the treatment of bacterial infections
Nano Letters, 2018Co-Authors: Huan Wang, Yan Zhang, Zhenzhen Wang, Chaoqun Liu, Hao Qiu, Zhen Liu, Jinsong RenAbstract:Carbon nanotubes (CNTs) and their derivatives have emerged as a series of efficient biocatalysts to mimic the function of natural enzymes in recent years. However, the unsatisfiable Enzymatic efficiency usually limits their practical usage ranging from materials science to biotechnology. Here, for the first time, we present the synthesis of several oxygenated-group-enriched carbon nanotubes (o-CNTs) via a facile but green approach, as well as their usage as high-performance peroxidase mimics for biocatalytic reaction. Exhaustive characterizations of the Enzymatic Activity of o-CNTs have been provided by exploring the accurate effect of various oxygenated groups on their surface including carbonyl, carboxyl, and hydroxyl groups. Because of the “competitive inhibition” effect among all of these oxygenated groups, the catalytic efficiency of o-CNTs is significantly enhanced by weakening the presence of noncatalytic sites. Furthermore, the admirable Enzymatic Activity of these o-CNTs has been successfully app...
Andrew Pekosz - One of the best experts on this subject based on the ideXlab platform.
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neuraminidase antigenic drift of h3n2 clade 3c 2a viruses alters virus replication Enzymatic Activity and inhibitory antibody binding
PLOS Pathogens, 2020Co-Authors: Harrison Powell, Andrew PekoszAbstract:In the 2014-2015 influenza season a novel neuraminidase (NA) genotype was detected in global human influenza A surveillance. This novel genotype encoded an N-linked glycosylation site at position 245-247 in the NA protein from clade 3c.2a H3N2 viruses. In the years following the 2014-2015 season, this novel NA glycosylation genotype quickly dominated the human H3N2 population of viruses. To assess the effect this novel N-linked glycan has on virus fitness and antibody binding, recombinant viruses with (NA Gly+) or without (NA Gly-) the 245 NA glycan were created. Viruses with the 245 NA Gly+ genotype grew to a significantly lower infectious virus titer on primary, differentiated human nasal epithelial cells (hNEC) compared to viruses with the 245 NA Gly- genotype, but growth was similar on immortalized cells. The 245 NA Gly+ blocked human and rabbit monoclonal antibodies that target the Enzymatic site from binding to their epitope. Additionally, viruses with the 245 NA Gly+ genotype had significantly lower Enzymatic Activity compared to viruses with the 245 NA Gly- genotype. Human monoclonal antibodies that target residues near the 245 NA glycan were less effective at inhibiting NA Enzymatic Activity and virus replication of viruses encoding an NA Gly+ protein compared to ones encoding NA Gly- protein. Additionally, a recombinant H6N2 virus with the 245 NA Gly+ protein was more resistant to Enzymatic inhibition from convalescent serum from H3N2-infected humans compared to viruses with the 245 NA Gly- genotype. Finally, the 245 NA Gly+ protected from NA antibody mediated virus neutralization. These results suggest that while the 245 NA Gly+ decreases virus replication in hNECs and decreases Enzymatic Activity, the 245 NA glycan blocks the binding of monoclonal and human serum NA specific antibodies that would otherwise inhibit Enzymatic Activity and virus replication.
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neuraminidase antigenic drift of influenza a virus h3n2 clade 3c 2a viruses alters virus replication Enzymatic Activity and inhibitory antibody binding
bioRxiv, 2020Co-Authors: Harrison Powell, Andrew PekoszAbstract:Abstract In the 2014-2015 influenza season a novel neuraminidase (NA) genotype emerged in the Johns Hopkins Center of Excellence for Influenza Research and Surveillance (JH CEIRS) surveillance network as well as globally. This novel genotype encoded a glycosylation site at position 245-247 in the NA protein from clade 3c.2a H3N2 viruses. In the years following the 2014-2015 season, this novel NA glycosylation genotype quickly dominated the human H3N2 population of viruses. To assess the effect this novel glycosylation has on virus fitness and antibody binding, recombinant viruses with (NA Gly+) or without (NA Gly-) the novel NA glycosylation were created. Viruses with the 245 NA Gly+ genotype grew to a significantly lower infectious virus titer on primary, differentiated human nasal epithelial cells (hNEC) compared to viruses with the 245 NA Gly-genotype, but growth was similar on immortalized cells. The 245 NA Gly+ blocked human and rabbit monoclonal antibodies that target the Enzymatic site from binding to their epitope. Additionally, viruses with the 245 NA Gly+ genotype had significantly lower Enzymatic Activity compared to viruses with the 245 NA Gly-genotype. Human monoclonal antibodies that target residues near the 245 NA glycosylation were less effective at inhibiting NA Enzymatic Activity and virus replication of viruses encoding an NA Gly+ protein compared to ones encoding NA Gly-protein. Additionally, a recombinant H6N2 virus with the 245 NA Gly+ protein was more resistant to Enzymatic inhibition from convalescent serum from H3N2-infected humans compared to viruses with the 245 NA Gly-genotype. Finally, the 245 NA Gly+ protected from NA antibody mediated virus neutralization. These results suggest that while the 245 NA Gly+ decreases virus replication in hNECs and decreases Enzymatic Activity, the glycosylation blocks the binding of monoclonal and human serum NA specific antibodies that would otherwise inhibit Enzymatic Activity and virus replication. Author Summary Influenza virus infects millions of people worldwide and leads to thousands of deaths and millions in economic loss each year. During the 2014/2015 season circulating human H3N2 viruses acquired a novel mutation in the neuraminidase (NA) protein. This mutation has since fixed in human H3N2 viruses. This mutation at position 245 through 247 in the amino acid sequence of NA encoded an N-linked glycosylation. Here, we studied how this N-linked glycosylation impacts virus fitness and protein function. We found that this N-linked glycosylation on the NA protein decreased viral replication fitness on human nasal epithelial cells (hNEC) but not immortalized Madin-Darby Canine Kidney (MDCK) cells. We also determined this glycosylation decreases NA Enzymatic Activity, enzyme kinetics and affinity for substrate. Furthermore, we show that this N-linked glycosylation at position 245 blocks some NA specific inhibitory antibodies from binding to the protein, inhibiting Enzymatic Activity, and inhibiting viral replication. Finally, we showed that viruses with the novel 245 N-linked glycosylation are more resistant to convalescent human serum antibody mediated Enzymatic inhibition. While this 245 N-linked Glycan decreases viral replication and Enzymatic Activity, the 245 N-linked glycosylation protects the virus from certain NA specific inhibitory antibodies. Our study provides new insight into the function of this dominant H3N2 NA mutation and how it impacts antigenicity and fitness of circulating H3N2 viruses.
Harrison Powell - One of the best experts on this subject based on the ideXlab platform.
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neuraminidase antigenic drift of h3n2 clade 3c 2a viruses alters virus replication Enzymatic Activity and inhibitory antibody binding
PLOS Pathogens, 2020Co-Authors: Harrison Powell, Andrew PekoszAbstract:In the 2014-2015 influenza season a novel neuraminidase (NA) genotype was detected in global human influenza A surveillance. This novel genotype encoded an N-linked glycosylation site at position 245-247 in the NA protein from clade 3c.2a H3N2 viruses. In the years following the 2014-2015 season, this novel NA glycosylation genotype quickly dominated the human H3N2 population of viruses. To assess the effect this novel N-linked glycan has on virus fitness and antibody binding, recombinant viruses with (NA Gly+) or without (NA Gly-) the 245 NA glycan were created. Viruses with the 245 NA Gly+ genotype grew to a significantly lower infectious virus titer on primary, differentiated human nasal epithelial cells (hNEC) compared to viruses with the 245 NA Gly- genotype, but growth was similar on immortalized cells. The 245 NA Gly+ blocked human and rabbit monoclonal antibodies that target the Enzymatic site from binding to their epitope. Additionally, viruses with the 245 NA Gly+ genotype had significantly lower Enzymatic Activity compared to viruses with the 245 NA Gly- genotype. Human monoclonal antibodies that target residues near the 245 NA glycan were less effective at inhibiting NA Enzymatic Activity and virus replication of viruses encoding an NA Gly+ protein compared to ones encoding NA Gly- protein. Additionally, a recombinant H6N2 virus with the 245 NA Gly+ protein was more resistant to Enzymatic inhibition from convalescent serum from H3N2-infected humans compared to viruses with the 245 NA Gly- genotype. Finally, the 245 NA Gly+ protected from NA antibody mediated virus neutralization. These results suggest that while the 245 NA Gly+ decreases virus replication in hNECs and decreases Enzymatic Activity, the 245 NA glycan blocks the binding of monoclonal and human serum NA specific antibodies that would otherwise inhibit Enzymatic Activity and virus replication.
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neuraminidase antigenic drift of influenza a virus h3n2 clade 3c 2a viruses alters virus replication Enzymatic Activity and inhibitory antibody binding
bioRxiv, 2020Co-Authors: Harrison Powell, Andrew PekoszAbstract:Abstract In the 2014-2015 influenza season a novel neuraminidase (NA) genotype emerged in the Johns Hopkins Center of Excellence for Influenza Research and Surveillance (JH CEIRS) surveillance network as well as globally. This novel genotype encoded a glycosylation site at position 245-247 in the NA protein from clade 3c.2a H3N2 viruses. In the years following the 2014-2015 season, this novel NA glycosylation genotype quickly dominated the human H3N2 population of viruses. To assess the effect this novel glycosylation has on virus fitness and antibody binding, recombinant viruses with (NA Gly+) or without (NA Gly-) the novel NA glycosylation were created. Viruses with the 245 NA Gly+ genotype grew to a significantly lower infectious virus titer on primary, differentiated human nasal epithelial cells (hNEC) compared to viruses with the 245 NA Gly-genotype, but growth was similar on immortalized cells. The 245 NA Gly+ blocked human and rabbit monoclonal antibodies that target the Enzymatic site from binding to their epitope. Additionally, viruses with the 245 NA Gly+ genotype had significantly lower Enzymatic Activity compared to viruses with the 245 NA Gly-genotype. Human monoclonal antibodies that target residues near the 245 NA glycosylation were less effective at inhibiting NA Enzymatic Activity and virus replication of viruses encoding an NA Gly+ protein compared to ones encoding NA Gly-protein. Additionally, a recombinant H6N2 virus with the 245 NA Gly+ protein was more resistant to Enzymatic inhibition from convalescent serum from H3N2-infected humans compared to viruses with the 245 NA Gly-genotype. Finally, the 245 NA Gly+ protected from NA antibody mediated virus neutralization. These results suggest that while the 245 NA Gly+ decreases virus replication in hNECs and decreases Enzymatic Activity, the glycosylation blocks the binding of monoclonal and human serum NA specific antibodies that would otherwise inhibit Enzymatic Activity and virus replication. Author Summary Influenza virus infects millions of people worldwide and leads to thousands of deaths and millions in economic loss each year. During the 2014/2015 season circulating human H3N2 viruses acquired a novel mutation in the neuraminidase (NA) protein. This mutation has since fixed in human H3N2 viruses. This mutation at position 245 through 247 in the amino acid sequence of NA encoded an N-linked glycosylation. Here, we studied how this N-linked glycosylation impacts virus fitness and protein function. We found that this N-linked glycosylation on the NA protein decreased viral replication fitness on human nasal epithelial cells (hNEC) but not immortalized Madin-Darby Canine Kidney (MDCK) cells. We also determined this glycosylation decreases NA Enzymatic Activity, enzyme kinetics and affinity for substrate. Furthermore, we show that this N-linked glycosylation at position 245 blocks some NA specific inhibitory antibodies from binding to the protein, inhibiting Enzymatic Activity, and inhibiting viral replication. Finally, we showed that viruses with the novel 245 N-linked glycosylation are more resistant to convalescent human serum antibody mediated Enzymatic inhibition. While this 245 N-linked Glycan decreases viral replication and Enzymatic Activity, the 245 N-linked glycosylation protects the virus from certain NA specific inhibitory antibodies. Our study provides new insight into the function of this dominant H3N2 NA mutation and how it impacts antigenicity and fitness of circulating H3N2 viruses.
Éric Simoni - One of the best experts on this subject based on the ideXlab platform.
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Enzymatic Activity of the CaM-PDE1 system upon addition of actinyl ions
Journal of Inorganic Biochemistry, 2017Co-Authors: Florian Brulfert, Samir Safi, Aurélie Jeanson, Harald Foerstendorf, Stephan Weiss, Catherine Berthomieu, Sandrine Sauge-merle, Éric SimoniAbstract:The threat of a dirty bomb which could cause internal contamination has been of major concern for the past decades. Because of their high chemical toxicity and their presence in the nuclear fuel cycle, uranium and neptunium are two actinides of high interest. Calmodulin (CaM) which is a ubiquitous protein present in all eukaryotic cells and is involved in calcium-dependent signaling pathways has a known affinity for uranyl and neptunyl ions. The impact of the complexation of these actinides on the physiological response of the protein remains, however, largely unknown. An isothermal titration calorimetry (ITC) was developed to monitor in vitro the Enzymatic Activity of the phosphodiesterase enzyme which is known to be activated by CaM and calcium. This approach showed that addition of actinyl ions (AnO2n+), uranyl (UO22+) and neptunyl (NpO2+), resulted in a decrease of the Enzymatic Activity, due to the formation of CaM-actinide complexes, which inhibit the enzyme and alter its interaction with the substrate by direct interaction. Results from dynamic light scattering rationalized this result by showing that the CaM-actinyl complexes adopted a specific conformation different from that of the CaM-Ca2+ complex. The effect of actinides could be reversed using a hydroxypyridonate actinide decorporation agent (5-LIO(Me-3,2-HOPO)) in the experimental medium demonstrating its capacity to efficiently bind the actinides and restore the calcium-dependent enzyme activation.
Xiaogang Qu - One of the best experts on this subject based on the ideXlab platform.
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unraveling the Enzymatic Activity of oxygenated carbon nanotubes and their application in the treatment of bacterial infections
Nano Letters, 2018Co-Authors: Huan Wang, Penghui Li, Dongqin Yu, Yan Zhang, Zhenzhen Wang, Xiaogang QuAbstract:Carbon nanotubes (CNTs) and their derivatives have emerged as a series of efficient biocatalysts to mimic the function of natural enzymes in recent years. However, the unsatisfiable Enzymatic efficiency usually limits their practical usage ranging from materials science to biotechnology. Here, for the first time, we present the synthesis of several oxygenated-group-enriched carbon nanotubes (o-CNTs) via a facile but green approach, as well as their usage as high-performance peroxidase mimics for biocatalytic reaction. Exhaustive characterizations of the Enzymatic Activity of o-CNTs have been provided by exploring the accurate effect of various oxygenated groups on their surface including carbonyl, carboxyl, and hydroxyl groups. Because of the “competitive inhibition” effect among all of these oxygenated groups, the catalytic efficiency of o-CNTs is significantly enhanced by weakening the presence of noncatalytic sites. Furthermore, the admirable Enzymatic Activity of these o-CNTs has been successfully app...
