The Experts below are selected from a list of 2322 Experts worldwide ranked by ideXlab platform
Leslie B. Poole - One of the best experts on this subject based on the ideXlab platform.
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novel application of 7 chloro 4 nitrobenzo 2 oxa 1 3 diazole to identify cysteine sulfenic acid in the ahpc component of alkyl hydroperoxide reductase
Biochemistry, 1997Co-Authors: Holly R. Ellis, Leslie B. PooleAbstract:The trapping of a sulfenic acid within the fully active C165S mutant of the AhpC peroxidase protein from Salmonella typhimurium was investigated. The Electrophilic Reagent employed in these studies, 7-chloro-4-nitrobenz-2-oxa-1,3-diazole (NBD-Cl), has previously been used to modify thiol, amino, and tyrosine hydroxyl groups in proteins; at neutral pH only cysteinyl residues of AhpC proteins are modified. The peroxide-oxidized C165S mutant of AhpC incubated with NBD-Cl gave a product with an absorbance maximum at 347 nm, whereas the thiol-NBD conjugate formed from the reduced protein absorbed maximally at 420 nm. Electrospray ionization mass spectrometry of the modified proteins allowed identification of the species absorbing at 347 nm as a Cys-S(O)-NBD derivative containing one additional oxygen relative to the Cys-S-NBD product. The C165S conjugates with Cys-S(O)-NBD and Cys-S-NBD had no peroxidase activity when compared to unreacted C165S and wild-type AhpC, but were both reactivated through removal of NBD by DTT. Oxidized C165S was also modified by dimedone, a common sulfenic acid Reagent, to give the expected inactivated conjugate of higher mass. This Reagent was not removed by DTT and blocked any further reaction of the protein with NBD-Cl. NBD modification of Enterococcus faecalis NADH peroxidase, a well-characterized flavoprotein with an active-site sulfenic acid (Cys-SOH), also yielded the spectrally-distinguishable NBD conjugates following incubation of NBD-Cl with oxidized and reduced forms of the denatured peroxidase, indicating a general utility for this Reagent with other sulfenic acid-containing proteins. A significant advantage of NBD-Cl over previously-used sulfenic acid Reagents such as dimedone is in the retention of the sulfenic acid oxygen in the modified product; differentiation between protein-associated thiols and sulfenic acids is therefore now possible by means of both visible absorbance properties and mass analyses of the NBD-modified proteins.
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Novel application of 7-chloro-4-nitrobenzo-2-oxa-1,3-diazole to identify cysteine sulfenic acid in the AhpC component of alkyl hydroperoxide reductase. Biochemistry 36:15013–15018
1997Co-Authors: Holly R. Ellis, Leslie B. PooleAbstract:ReceiVed September 4, 1997X ABSTRACT: The trapping of a sulfenic acid within the fully active C165S mutant of the AhpC peroxidase protein from Salmonella typhimurium was investigated. The Electrophilic Reagent employed in these studies, 7-chloro-4-nitrobenz-2-oxa-1,3-diazole (NBD-Cl), has previously been used to modify thiol, amino, and tyrosine hydroxyl groups in proteins; at neutral pH only cysteinyl residues of AhpC proteins are modified. The peroxide-oxidized C165S mutant of AhpC incubated with NBD-Cl gave a product with an absorbance maximum at 347 nm, whereas the thiol-NBD conjugate formed from the reduced protein absorbed maximally at 420 nm. Electrospray ionization mass spectrometry of the modified proteins allowed identification of the species absorbing at 347 nm as a Cys-S(O)-NBD derivative containing one additional oxygen relative to the Cys-S-NBD product. The C165S conjugates with Cys-S(O)-NBD and Cys-S-NBD had no peroxidase activity when compared to unreacted C165S and wild-type AhpC, but were both reactivated through removal of NBD by DTT. Oxidized C165S was also modified by dimedone, a common sulfenic acid Reagent, to give the expected inactivated conjugate of higher mass. This Reagent was not removed by DTT and blocked any further reaction of the protein with NBD-Cl. NBD modification of Enterococcus faecalis NADH peroxidase, a well-characterized flavoprotein with an active-site sulfenic acid (Cys-SOH), also yielded the spectrally-distinguishable NBD conjugates following incubation of NBD
Qilong Shen - One of the best experts on this subject based on the ideXlab platform.
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ethoxycarbonyl difluoromethyl thio phthalimide a shelf stable Electrophilic Reagent with a convertible group for the synthesis of diversified fluoroalkylthiolated compounds
Organic Letters, 2017Co-Authors: Feng Shen, Panpan Zhang, Qilong ShenAbstract:A shelf-stable and easily convertible Reagent for the preparation of diversified fluoroalkylthiolated compounds, [[(ethoxycarbonyl)difluoromethyl]thio]phthalimide, was developed. [[(Ethoxycarbonyl)difluoromethyl]thio]phthalimide is an efficient Electrophilic fluoroallylthiolating Reagent that reacted with electron-rich heteroarenes/arenes, β-ketoesters, oxindoles, benzofuranones, and thiols. More importantly, the ethoxycarbonyl group of the resulting fluoroalkylthiolated compounds could be easily converted into various other functional groups such as chloride, alkynyl, hydrocarbonyl, carbomoyl, hydromethyl, or heteroaryl groups.
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[[(Ethoxycarbonyl)difluoromethyl]thio]phthalimide: A Shelf-Stable, Electrophilic Reagent with a Convertible Group for the Synthesis of Diversified Fluoroalkylthiolated Compounds
2017Co-Authors: Feng Shen, Panpan Zhang, Qilong ShenAbstract:A shelf-stable and easily convertible Reagent for the preparation of diversified fluoroalkylthiolated compounds, [[(ethoxycarbonyl)difluoromethyl]thio]phthalimide, was developed. [[(Ethoxycarbonyl)difluoromethyl]thio]phthalimide is an efficient Electrophilic fluoroallylthiolating Reagent that reacted with electron-rich heteroarenes/arenes, β-ketoesters, oxindoles, benzofuranones, and thiols. More importantly, the ethoxycarbonyl group of the resulting fluoroalkylthiolated compounds could be easily converted into various other functional groups such as chloride, alkynyl, hydrocarbonyl, carbomoyl, hydromethyl, or heteroaryl groups
Holly R. Ellis - One of the best experts on this subject based on the ideXlab platform.
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novel application of 7 chloro 4 nitrobenzo 2 oxa 1 3 diazole to identify cysteine sulfenic acid in the ahpc component of alkyl hydroperoxide reductase
Biochemistry, 1997Co-Authors: Holly R. Ellis, Leslie B. PooleAbstract:The trapping of a sulfenic acid within the fully active C165S mutant of the AhpC peroxidase protein from Salmonella typhimurium was investigated. The Electrophilic Reagent employed in these studies, 7-chloro-4-nitrobenz-2-oxa-1,3-diazole (NBD-Cl), has previously been used to modify thiol, amino, and tyrosine hydroxyl groups in proteins; at neutral pH only cysteinyl residues of AhpC proteins are modified. The peroxide-oxidized C165S mutant of AhpC incubated with NBD-Cl gave a product with an absorbance maximum at 347 nm, whereas the thiol-NBD conjugate formed from the reduced protein absorbed maximally at 420 nm. Electrospray ionization mass spectrometry of the modified proteins allowed identification of the species absorbing at 347 nm as a Cys-S(O)-NBD derivative containing one additional oxygen relative to the Cys-S-NBD product. The C165S conjugates with Cys-S(O)-NBD and Cys-S-NBD had no peroxidase activity when compared to unreacted C165S and wild-type AhpC, but were both reactivated through removal of NBD by DTT. Oxidized C165S was also modified by dimedone, a common sulfenic acid Reagent, to give the expected inactivated conjugate of higher mass. This Reagent was not removed by DTT and blocked any further reaction of the protein with NBD-Cl. NBD modification of Enterococcus faecalis NADH peroxidase, a well-characterized flavoprotein with an active-site sulfenic acid (Cys-SOH), also yielded the spectrally-distinguishable NBD conjugates following incubation of NBD-Cl with oxidized and reduced forms of the denatured peroxidase, indicating a general utility for this Reagent with other sulfenic acid-containing proteins. A significant advantage of NBD-Cl over previously-used sulfenic acid Reagents such as dimedone is in the retention of the sulfenic acid oxygen in the modified product; differentiation between protein-associated thiols and sulfenic acids is therefore now possible by means of both visible absorbance properties and mass analyses of the NBD-modified proteins.
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Novel application of 7-chloro-4-nitrobenzo-2-oxa-1,3-diazole to identify cysteine sulfenic acid in the AhpC component of alkyl hydroperoxide reductase. Biochemistry 36:15013–15018
1997Co-Authors: Holly R. Ellis, Leslie B. PooleAbstract:ReceiVed September 4, 1997X ABSTRACT: The trapping of a sulfenic acid within the fully active C165S mutant of the AhpC peroxidase protein from Salmonella typhimurium was investigated. The Electrophilic Reagent employed in these studies, 7-chloro-4-nitrobenz-2-oxa-1,3-diazole (NBD-Cl), has previously been used to modify thiol, amino, and tyrosine hydroxyl groups in proteins; at neutral pH only cysteinyl residues of AhpC proteins are modified. The peroxide-oxidized C165S mutant of AhpC incubated with NBD-Cl gave a product with an absorbance maximum at 347 nm, whereas the thiol-NBD conjugate formed from the reduced protein absorbed maximally at 420 nm. Electrospray ionization mass spectrometry of the modified proteins allowed identification of the species absorbing at 347 nm as a Cys-S(O)-NBD derivative containing one additional oxygen relative to the Cys-S-NBD product. The C165S conjugates with Cys-S(O)-NBD and Cys-S-NBD had no peroxidase activity when compared to unreacted C165S and wild-type AhpC, but were both reactivated through removal of NBD by DTT. Oxidized C165S was also modified by dimedone, a common sulfenic acid Reagent, to give the expected inactivated conjugate of higher mass. This Reagent was not removed by DTT and blocked any further reaction of the protein with NBD-Cl. NBD modification of Enterococcus faecalis NADH peroxidase, a well-characterized flavoprotein with an active-site sulfenic acid (Cys-SOH), also yielded the spectrally-distinguishable NBD conjugates following incubation of NBD
Feng Shen - One of the best experts on this subject based on the ideXlab platform.
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ethoxycarbonyl difluoromethyl thio phthalimide a shelf stable Electrophilic Reagent with a convertible group for the synthesis of diversified fluoroalkylthiolated compounds
Organic Letters, 2017Co-Authors: Feng Shen, Panpan Zhang, Qilong ShenAbstract:A shelf-stable and easily convertible Reagent for the preparation of diversified fluoroalkylthiolated compounds, [[(ethoxycarbonyl)difluoromethyl]thio]phthalimide, was developed. [[(Ethoxycarbonyl)difluoromethyl]thio]phthalimide is an efficient Electrophilic fluoroallylthiolating Reagent that reacted with electron-rich heteroarenes/arenes, β-ketoesters, oxindoles, benzofuranones, and thiols. More importantly, the ethoxycarbonyl group of the resulting fluoroalkylthiolated compounds could be easily converted into various other functional groups such as chloride, alkynyl, hydrocarbonyl, carbomoyl, hydromethyl, or heteroaryl groups.
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[[(Ethoxycarbonyl)difluoromethyl]thio]phthalimide: A Shelf-Stable, Electrophilic Reagent with a Convertible Group for the Synthesis of Diversified Fluoroalkylthiolated Compounds
2017Co-Authors: Feng Shen, Panpan Zhang, Qilong ShenAbstract:A shelf-stable and easily convertible Reagent for the preparation of diversified fluoroalkylthiolated compounds, [[(ethoxycarbonyl)difluoromethyl]thio]phthalimide, was developed. [[(Ethoxycarbonyl)difluoromethyl]thio]phthalimide is an efficient Electrophilic fluoroallylthiolating Reagent that reacted with electron-rich heteroarenes/arenes, β-ketoesters, oxindoles, benzofuranones, and thiols. More importantly, the ethoxycarbonyl group of the resulting fluoroalkylthiolated compounds could be easily converted into various other functional groups such as chloride, alkynyl, hydrocarbonyl, carbomoyl, hydromethyl, or heteroaryl groups
Panpan Zhang - One of the best experts on this subject based on the ideXlab platform.
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ethoxycarbonyl difluoromethyl thio phthalimide a shelf stable Electrophilic Reagent with a convertible group for the synthesis of diversified fluoroalkylthiolated compounds
Organic Letters, 2017Co-Authors: Feng Shen, Panpan Zhang, Qilong ShenAbstract:A shelf-stable and easily convertible Reagent for the preparation of diversified fluoroalkylthiolated compounds, [[(ethoxycarbonyl)difluoromethyl]thio]phthalimide, was developed. [[(Ethoxycarbonyl)difluoromethyl]thio]phthalimide is an efficient Electrophilic fluoroallylthiolating Reagent that reacted with electron-rich heteroarenes/arenes, β-ketoesters, oxindoles, benzofuranones, and thiols. More importantly, the ethoxycarbonyl group of the resulting fluoroalkylthiolated compounds could be easily converted into various other functional groups such as chloride, alkynyl, hydrocarbonyl, carbomoyl, hydromethyl, or heteroaryl groups.
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[[(Ethoxycarbonyl)difluoromethyl]thio]phthalimide: A Shelf-Stable, Electrophilic Reagent with a Convertible Group for the Synthesis of Diversified Fluoroalkylthiolated Compounds
2017Co-Authors: Feng Shen, Panpan Zhang, Qilong ShenAbstract:A shelf-stable and easily convertible Reagent for the preparation of diversified fluoroalkylthiolated compounds, [[(ethoxycarbonyl)difluoromethyl]thio]phthalimide, was developed. [[(Ethoxycarbonyl)difluoromethyl]thio]phthalimide is an efficient Electrophilic fluoroallylthiolating Reagent that reacted with electron-rich heteroarenes/arenes, β-ketoesters, oxindoles, benzofuranones, and thiols. More importantly, the ethoxycarbonyl group of the resulting fluoroalkylthiolated compounds could be easily converted into various other functional groups such as chloride, alkynyl, hydrocarbonyl, carbomoyl, hydromethyl, or heteroaryl groups