scholarly journals How Does Single Oxygen Atom Addition Affect the Properties of an Fe−Nitrile Hydratase Analogue? The Compensatory Role of the Unmodified Thiolate

2006 ◽  
Vol 128 (34) ◽  
pp. 11211-11221 ◽  
Author(s):  
Priscilla Lugo-Mas ◽  
Abhishek Dey ◽  
Liang Xu ◽  
Steven D. Davin ◽  
Jason Benedict ◽  
...  
Keyword(s):  
Oxygen Atom ◽  
Nitrile Hydratase ◽  
Single Oxygen Atom ◽  
Single Oxygen

New Organogallium Peroxides

2009 ◽  
Vol 64 (11-12) ◽  
pp. 1369-1374 ◽  
Author(s):  
Werner Uhl ◽  
Mohammad R. Halvagar ◽  
Henrik R. Bock ◽  
Beate Jasper-Peter ◽  
Marcus Layh
Keyword(s):  
Oxygen Atom ◽  
Oxygen Molecule ◽  
Formula Unit ◽  
Methyl Substituent ◽  
Tert Butyl ◽  
The Third ◽  
Butyl Group ◽  
Tert Butyl Group ◽  
Single Oxygen Atom ◽  
Single Oxygen

Treatment of (Me3C)2Ga-CH(SiMe3)2 (1) with oxygen gave the oxidation of both quaternary carbon atoms of the tert-butyl groups, while the bis(trimethylsilyl)methyl substituent was not affected. One tert-butyl group was transferred to an alkoxide which in the dimeric formula unit of the product 2 occupies the bridging position between both gallium atoms. The second one afforded a terminally arranged tert-butylperoxo ligand by the insertion of a complete oxygen molecule into the respective Ga-C bond. Another organogallium peroxide (5) was obtained by the reaction of Li(OEt2)[H3GaCH(SiMe3)2] (3) with H-O-O-CMe2OMe (4). Two hydrido ligands of the trihydridogallanate were replaced by peroxo groups, while the third Ga-H bond gave a hydroxide (Ga-OH) by insertion of a single oxygen atom. The product, Li[Ga(OH)(OOCMe2OMe)2R] [5, R=CH(SiMe3)2], forms a singular dimeric formula unit with a complicated oligocyclic structure in which all peroxo groups are in bridging positions between lithium and gallium atoms

scholarly journals Single and double addition of oxygen atoms to propyne on surfaces at low temperatures

2014 ◽  
Vol 168 ◽  
pp. 167-184 ◽  
Author(s):  
Helen J. Kimber ◽  
Courtney P. Ennis ◽  
Stephen D. Price
Keyword(s):  
Oxygen Atom ◽  
Surface Temperature ◽  
Interstellar Dust ◽  
Addition Product ◽  
Phase Reaction ◽  
Surface Temperatures ◽  
Single Addition ◽  
Single Oxygen Atom ◽  
Single Oxygen ◽  
Oxygen Atoms

Experiments designed to simulate the low temperature surface chemistry occurring in interstellar clouds provide clear evidence of a reaction between oxygen atoms and propyne ice. The reactants are dosed onto a surface held at a fixed temperature between 14 and 100 K. After the dosing period, temperature programmed desorption (TPD), coupled with time-of-flight mass spectrometry, are used to identify two reaction products with molecular formulae C3H4O and C3H4O2. These products result from the addition of a single oxygen atom, or two oxygen atoms, to a propyne reactant. A simple model has been used to extract kinetic data from the measured yield of the single-addition (C3H4O) product at surface temperatures from 30–100 K. This modelling reveals that the barrier of the solid-state reaction between propyne and a single oxygen atom (160 ± 10 K) is an order of magnitude less than that reported for the gas-phase reaction. In addition, estimates for the desorption energy of propyne and reaction rate coefficient, as a function of temperature, are determined for the single addition process from the modelling. The yield of the single addition product falls as the surface temperature decreases from 50 K to 30K, but rises again as the surface temperature falls below 30 K. This increase in the rate of reaction at low surface temperatures is indicative of an alternative, perhaps barrierless, pathway to the single addition product which is only important at low surface temperatures. The kinetic model has been further developed to characterize the double addition reaction, which appears to involve the addition of a second oxygen atom to C3H4O. This modelling indicates that this second addition is a barrierless process. The kinetic parameters we extract from our experiments indicate that the reaction between atomic oxygen and propyne could occur under on interstellar dust grains on an astrophysical time scale.

Pushing Single-Oxygen-Atom-Bridged Bimetallic Systems to the Right: A Cryptand-Encapsulated Co–O–Co Unit

2015 ◽  
Vol 137 (49) ◽  
pp. 15354-15357 ◽  
Author(s):  
Julia M. Stauber ◽  
Eric D. Bloch ◽  
Konstantinos D. Vogiatzis ◽  
Shao-Liang Zheng ◽  
Ryan G. Hadt ◽  
...  
Keyword(s):  
Oxygen Atom ◽  
Bimetallic Systems ◽  
Single Oxygen Atom ◽  
The Right ◽  
Single Oxygen

scholarly journals Chemical genetics strategy to profile kinase target engagement reveals role of FES in neutrophil phagocytosis via SYK activation

2019 ◽  
Author(s):  
Tom van der Wel ◽  
Riet Hilhorst ◽  
Hans den Dulk ◽  
Tim van den Hooven ◽  
Nienke M. Prins ◽  
...  
Keyword(s):  
Fluorescent Probe ◽  
Chemical Genetics ◽  
Binding Pocket ◽  
Myeloid Differentiation ◽  
Target Engagement ◽  
Syk Kinase ◽  
Promising Therapeutic Target ◽  
Single Oxygen Atom ◽  
Single Oxygen

AbstractChemical tools and methods that report on target engagement of endogenously expressed protein kinases by small molecules in human cells are highly desirable. Here, we describe a chemical genetics strategy that allows the study of non-receptor tyrosine kinase FES, a promising therapeutic target for cancer and immune disorders. Precise gene editing was used in combination with a rationally designed, complementary fluorescent probe to visualize endogenous FES kinase in HL-60 cells. We replaced a single oxygen atom by a sulphur in a serine residue at the DFG-1 position of the ATP-binding pocket in an endogenously expressed kinase, thereby sensitizing the engineered protein towards covalent labeling and inactivation by a fluorescent probe. The temporal control offered by this strategy allows acute inactivation of FES activity both during myeloid differentiation and in terminally differentiated neutrophils. Our results show that FES activity is dispensable for differentiation of HL-60 cells towards macrophages. Instead, FES plays a key role in neutrophil phagocytosis by activation of SYK kinase, a central regulator of immune function in neutrophils. This strategy holds promise as a target validation method for kinases.

scholarly journals Formamide as a substrate of xanthine oxidase

1984 ◽  
Vol 220 (1) ◽  
pp. 235-242 ◽  
Author(s):  
F F Morpeth ◽  
G N George ◽  
R C Bray
Keyword(s):  
Oxygen Atom ◽  
Xanthine Oxidase ◽  
Structural Features ◽  
New Information ◽  
Single Oxygen Atom ◽  
Oxo Ligand ◽  
Single Oxygen ◽  
Do So

Formamide is a substrate of xanthine oxidase. At pH 8.2 and 1.14 mM-O2, Vmax.(app.) is 3.1 s-1 and Km (app.) is 0.7 M. Mo(V) e.p.r. signals obtained by treating the enzyme with formamide were studied, and these provide new information about the ligation of molybdenum in the enzyme and about the enzymic mechanism. The substrate is the first compound that is not a nitrogen-containing heterocycle to give a Very Rapid signal. This supports the hypothesis that the Very Rapid signal, though it is not detectable with all substrates, represents an essential intermediate in turnover. Formamide also gives the Inhibited signal and is the first non-aldehyde substrate to do so. The Rapid type 1 signal obtained in the presence of formamide was examined in H2O enriched with 2H or with 17O. The single oxygen atom detectable in the signal is shown to be strongly and anisotropically coupled. This indicates that this atom remains as an oxo ligand of molybdenum in this signal-giving species. Other structural features of this species are discussed.

scholarly journals Retraction of “Pushing Single-Oxygen-Atom-Bridged Bimetallic Systems to the Right: A Cryptand-Encapsulated Co–O–Co Unit”

2020 ◽  
Vol 142 (14) ◽  
pp. 6834-6834
Author(s):  
Julia M. Stauber ◽  
Eric D. Bloch ◽  
Konstantinos D. Vogiatzis ◽  
Shao-Liang Zheng ◽  
Ryan G. Hadt ◽  
...  
Keyword(s):  
Oxygen Atom ◽  
Bimetallic Systems ◽  
Single Oxygen Atom ◽  
The Right ◽  
Single Oxygen

Enantioselective epoxidation of olefins by single-oxygen atom donors catalyzed by managanese-glycoconjugated porphyrins

1996 ◽  
Vol 113 (1-2) ◽  
pp. 23-34 ◽  
Author(s):  
Sandrine Vilain-Deshayes ◽  
Anne Robert ◽  
Philippe Maillard ◽  
Bernard Meunier ◽  
Michel Momenteau
Keyword(s):  
Oxygen Atom ◽  
Enantioselective Epoxidation ◽  
Single Oxygen Atom ◽  
Single Oxygen ◽  
Epoxidation Of Olefins
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