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Antimonite
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Barry P. Rosen – One of the best experts on this subject based on the ideXlab platform.
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Biochemical characterization of a novel ArsA ATPase complex from Alkaliphilus metalliredigens QYMF
FEBS Letters, 2010Co-Authors: Barry P. Rosen, Hiranmoy BhattacharjeeAbstract:The two putative ars operons in Alkaliphilus metalliredigens QYMF are distinctive in that the arsA gene is split in halves, amarsA1 and amarsA2, and, acr3 but not an arsB gene coexists with arsA. Heterologous expression of one of the A. metalliredigens ars operons (ars1) conferred arsenite but not Antimonite resistance to Δars Escherichia coli. Only the co-expressed AmArsA1 and AmArsA2 displayed arsenite or Antimonite stimulated ATPase activity. The results show that AmArsA1–AmArsA2 interaction is needed to form the functional ArsA ATPase. This novel AmArsA1–AmArsA2 complex may provide insight in how it participates with Acr3 in arsenite detoxification.
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Original Research Report: Structure-Function Analysis of the ArsA ATPase: Contribution of Histidine Residues
Journal of Bioenergetics and Biomembranes, 2001Co-Authors: Hiranmoy Bhattacharjee, Barry P. RosenAbstract:The ArsA ATPase is the catalytic subunit of the ArsAB oxyanion pump in Escherichia coli that is responsible for extruding arsenite or Antimonite from inside the cell, thereby conferring resistance. Either Antimonite or arsenite stimulates ArsA ATPase activity. In this study, the role of histidine residues in ArsA activity was investigated. Treatment of ArsA with diethyl pyrocarbonate (DEPC) resulted in complete loss of catalytic activity. The inactivation could be reversed upon subsequent incubation with hydroxylamine, suggesting specific modification of histidine residues. ATP and oxyanions afforded significant protection against DEPC inactivation, indicating that the histidines are located at the active site. ArsA has 13 histidine residues located at position 138, 148, 219, 327, 359, 368, 388, 397, 453, 465, 477, 520, and 558. Each histidine was individually altered to alanine by site-directed mutagenesis. Cells expressing the altered ArsA proteins were resistant to both arsenite and Antimonite. The results indicate that no single histidine residue plays a direct role in catalysis, and the inhibition by DEPC may be caused by steric hindrance from the carbethoxy group.
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Structure-function analysis of the ArsA ATPase: contribution of histidine residues.
Journal of Bioenergetics and Biomembranes, 2001Co-Authors: Hiranmoy Bhattacharjee, Barry P. RosenAbstract:The ArsA ATPase is the catalytic subunit of the ArsAB oxyanion pump in Escherichia coli that is responsible for extruding arsenite or Antimonite from inside the cell, thereby conferring resistance. Either Antimonite or arsenite stimulates ArsA ATPase activity. In this study, the role of histidine residues in ArsA activity was investigated. Treatment of ArsA with diethyl pyrocarbonate (DEPC) resulted in complete loss of catalytic activity. The inactivation could be reversed upon subsequent incubation with hydroxylamine, suggesting specific modification of histidine residues. ATP and oxyanions afforded significant protection against DEPC inactivation, indicating that the histidines are located at the active site. ArsA has 13 histidine residues located at position 138, 148, 219, 327, 359, 368, 388, 397, 453, 465, 477, 520, and 558. Each histidine was individually altered to alanine by site-directed mutagenesis. Cells expressing the altered ArsA proteins were resistant to both arsenite and Antimonite. The results indicate that no single histidine residue plays a direct role in catalysis, and the inhibition by DEPC may be caused by steric hindrance from the carbethoxy group.
Changlun Chen – One of the best experts on this subject based on the ideXlab platform.
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Screening of Zirconium-Based Metal–Organic Frameworks for Efficient Simultaneous Removal of Antimonite (Sb(III)) and Antimonate (Sb(V)) from Aqueous Solution
ACS Sustainable Chemistry & Engineering, 2017Co-Authors: Tasawar Hayat, Ahmed Alsaedi, Changlun ChenAbstract:Seven kinds of zirconium-based metal–organic frameworks (Zr-MOFs) with different aperture size and organic linkers functionalized with different functional groups (−NH2, −OH, and −SO3H) were screened for their ability to remove Antimonite (Sb(III)) and antimonate (Sb(V)) anions from water. Zr-bound hydroxides in Zr-MOFs can simultaneously remove both Sb(III) and Sb(V) via a mechanism of anion exchange. For antimony removal by UiO-66-NH2, the anion exchange seemed to be strengthened due to the Lewis acid–base interactions between the −NH2 groups on the BDC ligand and the antimony oxyanions. Among seven kinds of Zr-MOFs selected here, NU-1000 exhibited fast adsorption kinetics and high removal capacity for both Sb(III) (136.97 mg/g) and Sb(V) (287.88 mg/g), which was much higher than many antimony adsorbents described to date. Uptake of antimony at low concentrations of 100 μg/L (with a remaining antimony concentration of only ∼2 μg/L in 10 min) disclosed that current U.S. Environmental Protection Agency st…
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screening of zirconium based metal organic frameworks for efficient simultaneous removal of Antimonite sb iii and antimonate sb v from aqueous solution
ACS Sustainable Chemistry & Engineering, 2017Co-Authors: Tasawar Hayat, Ahmed Alsaedi, Changlun ChenAbstract:Seven kinds of zirconium-based metal–organic frameworks (Zr-MOFs) with different aperture size and organic linkers functionalized with different functional groups (−NH2, −OH, and −SO3H) were screened for their ability to remove Antimonite (Sb(III)) and antimonate (Sb(V)) anions from water. Zr-bound hydroxides in Zr-MOFs can simultaneously remove both Sb(III) and Sb(V) via a mechanism of anion exchange. For antimony removal by UiO-66-NH2, the anion exchange seemed to be strengthened due to the Lewis acid–base interactions between the −NH2 groups on the BDC ligand and the antimony oxyanions. Among seven kinds of Zr-MOFs selected here, NU-1000 exhibited fast adsorption kinetics and high removal capacity for both Sb(III) (136.97 mg/g) and Sb(V) (287.88 mg/g), which was much higher than many antimony adsorbents described to date. Uptake of antimony at low concentrations of 100 μg/L (with a remaining antimony concentration of only ∼2 μg/L in 10 min) disclosed that current U.S. Environmental Protection Agency st…
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Screening of Zirconium-Based Metal–Organic
Frameworks for Efficient Simultaneous Removal of Antimonite (Sb(III))
and Antimonate (Sb(V)) from Aqueous Solution, 2017Co-Authors: Tasawar Hayat, Ahmed Alsaedi, Changlun ChenAbstract:Seven kinds of zirconium-based metal–organic
frameworks (Zr-MOFs) with different aperture size and organic linkers
functionalized with different functional groups (−NH2, −OH, and −SO3H) were screened for their
ability to remove Antimonite (Sb(III)) and antimonate (Sb(V)) anions
from water. Zr-bound hydroxides in Zr-MOFs can simultaneously remove
both Sb(III) and Sb(V) via a mechanism of anion exchange. For antimony
removal by UiO-66-NH2, the anion exchange seemed to be
strengthened due to the Lewis acid–base interactions between
the −NH2 groups on the BDC ligand and the antimony
oxyanions. Among seven kinds of Zr-MOFs selected here, NU-1000 exhibited
fast adsorption kinetics and high removal capacity for both Sb(III)
(136.97 mg/g) and Sb(V) (287.88 mg/g), which was much higher than
many antimony adsorbents described to date. Uptake of antimony at
low concentrations of 100 μg/L (with a remaining antimony concentration
of only ∼2 μg/L in 10 min) disclosed that current U.S.
Environmental Protection Agency standards for antimony can be reached
by using NU-1000 as an adsorbent. Additionally, the effects of coexisting
anions such as As(III), As(V), PO43–,
SO42–, NO3–, and F– on the antimony adsorption onto NU-1000
were also studied. Finally, the Sb adsorption mechanism of NU-1000
was studied via X-ray photon spectroscopy and attenuated total reflection
infrared spectroscopy techniques to explore the important characteristics
that make NU-1000 a compelling candidate for wastewater management
Tasawar Hayat – One of the best experts on this subject based on the ideXlab platform.
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Screening of Zirconium-Based Metal–Organic Frameworks for Efficient Simultaneous Removal of Antimonite (Sb(III)) and Antimonate (Sb(V)) from Aqueous Solution
ACS Sustainable Chemistry & Engineering, 2017Co-Authors: Tasawar Hayat, Ahmed Alsaedi, Changlun ChenAbstract:Seven kinds of zirconium-based metal–organic frameworks (Zr-MOFs) with different aperture size and organic linkers functionalized with different functional groups (−NH2, −OH, and −SO3H) were screened for their ability to remove Antimonite (Sb(III)) and antimonate (Sb(V)) anions from water. Zr-bound hydroxides in Zr-MOFs can simultaneously remove both Sb(III) and Sb(V) via a mechanism of anion exchange. For antimony removal by UiO-66-NH2, the anion exchange seemed to be strengthened due to the Lewis acid–base interactions between the −NH2 groups on the BDC ligand and the antimony oxyanions. Among seven kinds of Zr-MOFs selected here, NU-1000 exhibited fast adsorption kinetics and high removal capacity for both Sb(III) (136.97 mg/g) and Sb(V) (287.88 mg/g), which was much higher than many antimony adsorbents described to date. Uptake of antimony at low concentrations of 100 μg/L (with a remaining antimony concentration of only ∼2 μg/L in 10 min) disclosed that current U.S. Environmental Protection Agency st…
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screening of zirconium based metal organic frameworks for efficient simultaneous removal of Antimonite sb iii and antimonate sb v from aqueous solution
ACS Sustainable Chemistry & Engineering, 2017Co-Authors: Tasawar Hayat, Ahmed Alsaedi, Changlun ChenAbstract:Seven kinds of zirconium-based metal–organic frameworks (Zr-MOFs) with different aperture size and organic linkers functionalized with different functional groups (−NH2, −OH, and −SO3H) were screened for their ability to remove Antimonite (Sb(III)) and antimonate (Sb(V)) anions from water. Zr-bound hydroxides in Zr-MOFs can simultaneously remove both Sb(III) and Sb(V) via a mechanism of anion exchange. For antimony removal by UiO-66-NH2, the anion exchange seemed to be strengthened due to the Lewis acid–base interactions between the −NH2 groups on the BDC ligand and the antimony oxyanions. Among seven kinds of Zr-MOFs selected here, NU-1000 exhibited fast adsorption kinetics and high removal capacity for both Sb(III) (136.97 mg/g) and Sb(V) (287.88 mg/g), which was much higher than many antimony adsorbents described to date. Uptake of antimony at low concentrations of 100 μg/L (with a remaining antimony concentration of only ∼2 μg/L in 10 min) disclosed that current U.S. Environmental Protection Agency st…
-
Screening of Zirconium-Based Metal–Organic
Frameworks for Efficient Simultaneous Removal of Antimonite (Sb(III))
and Antimonate (Sb(V)) from Aqueous Solution, 2017Co-Authors: Tasawar Hayat, Ahmed Alsaedi, Changlun ChenAbstract:Seven kinds of zirconium-based metal–organic
frameworks (Zr-MOFs) with different aperture size and organic linkers
functionalized with different functional groups (−NH2, −OH, and −SO3H) were screened for their
ability to remove Antimonite (Sb(III)) and antimonate (Sb(V)) anions
from water. Zr-bound hydroxides in Zr-MOFs can simultaneously remove
both Sb(III) and Sb(V) via a mechanism of anion exchange. For antimony
removal by UiO-66-NH2, the anion exchange seemed to be
strengthened due to the Lewis acid–base interactions between
the −NH2 groups on the BDC ligand and the antimony
oxyanions. Among seven kinds of Zr-MOFs selected here, NU-1000 exhibited
fast adsorption kinetics and high removal capacity for both Sb(III)
(136.97 mg/g) and Sb(V) (287.88 mg/g), which was much higher than
many antimony adsorbents described to date. Uptake of antimony at
low concentrations of 100 μg/L (with a remaining antimony concentration
of only ∼2 μg/L in 10 min) disclosed that current U.S.
Environmental Protection Agency standards for antimony can be reached
by using NU-1000 as an adsorbent. Additionally, the effects of coexisting
anions such as As(III), As(V), PO43–,
SO42–, NO3–, and F– on the antimony adsorption onto NU-1000
were also studied. Finally, the Sb adsorption mechanism of NU-1000
was studied via X-ray photon spectroscopy and attenuated total reflection
infrared spectroscopy techniques to explore the important characteristics
that make NU-1000 a compelling candidate for wastewater management