Mechanistic studies on the pyridoxal phosphate enzyme 1-aminocyclopropane-1-carboxylate deaminase from Pseudomonas sp

Biochemistry ◽  
1981 ◽  
Vol 20 (26) ◽  
pp. 7509-7519 ◽  
Author(s):  
Christopher Walsh ◽  
Robert A. Pascal ◽  
Michael Johnston ◽  
Ronald Raines ◽  
Dinesh Dikshit ◽  
...  
Keyword(s):  
Pyridoxal Phosphate ◽  
Pseudomonas Sp ◽  
Mechanistic Studies

Mechanistic Studies on Pyridoxal Phosphate Synthase:  The Reaction Pathway Leading to a Chromophoric Intermediate

2008 ◽  
Vol 130 (10) ◽  
pp. 3043-3052 ◽  
Author(s):  
Jeremiah W. Hanes ◽  
Kristin E. Burns ◽  
David G. Hilmey ◽  
Abhishek Chatterjee ◽  
Pieter C. Dorrestein ◽  
...  
Keyword(s):  
Pyridoxal Phosphate ◽  
Reaction Pathway ◽  
Mechanistic Studies ◽  
Phosphate Synthase

Mechanistic studies on the enzymatic processing of fluorinated methionine analogues by Trichomonas vaginalis methionine γ-lyase

2011 ◽  
Vol 438 (3) ◽  
pp. 513-521 ◽  
Author(s):  
Ignace A. Moya ◽  
Gareth D. Westrop ◽  
Graham H. Coombs ◽  
John F. Honek
Keyword(s):  
Trichomonas Vaginalis ◽  
Chemical Structure ◽  
Pyridoxal Phosphate ◽  
Model System ◽  
Methyl Mercaptan ◽  
Human Pathogen ◽  
Human Pathogens ◽  
Mechanistic Studies ◽  
Cellular Toxicity ◽  
The Relationship

TFM (L-trifluoromethionine), a potential prodrug, was reported to be toxic towards human pathogens that express MGL (L-methionine γ-lyase; EC 4.4.1.11), a pyridoxal phosphate-containing enzyme that converts L-methionine into α-oxobutyrate, ammonia and methyl mercaptan. It has been hypothesized that the extremely reactive thiocarbonyl difluoride is produced when the enzyme acts upon TFM, resulting in cellular toxicity. The potential application of the fluorinated thiomethyl group in other areas of biochemistry and medicinal chemistry requires additional studies. Therefore a detailed investigation of the theoretical and experimental chemistry and biochemistry of these fluorinated groups (CF3S− and CF2HS−) has been undertaken to trap and identify chemical intermediates produced by enzyme processing of molecules containing these fluorinated moieties. TvMGL (MGL from Trichomonas vaginalis) and a chemical model system of the reaction were utilized in order to investigate the cofactor-dependent activation of TFM and previously uninvestigated DFM (L-difluoromethionine). The differences in toxicity between TFM and DFM were evaluated against Escherichia coli expressing TvMGL1, as well as the intact human pathogen T. vaginalis. The relationship between the chemical structure of the reactive intermediates produced from the enzymatic processing of these analogues and their cellular toxicity are discussed.

Temporal and mechanistic studies on the resistance of glioma cells to temozolomide

2016 ◽  
Vol 228 (06/07) ◽  
Author(s):  
WP Roos ◽  
M Eich ◽  
S Quiros ◽  
AV Knizhnik ◽  
T Nikolova ◽  
...  
Keyword(s):  
Glioma Cells ◽  
Mechanistic Studies

Exemplar Abstract for Pseudomonas sp. None 2015.

2003 ◽  
Author(s):  
Charles Thomas Parker ◽  
Dorothea Taylor ◽  
George M Garrity
Keyword(s):  
Pseudomonas Sp

Exemplar Abstract for Pseudomonas sp. None 2015.

2003 ◽  
Author(s):  
Charles Thomas Parker ◽  
Dorothea Taylor ◽  
George M Garrity
Keyword(s):  
Pseudomonas Sp

Nomenclature Abstract for Pseudomonas sp. None 2015.

2003 ◽  
Author(s):  
Charles Thomas Parker ◽  
Dorothea Taylor ◽  
George M Garrity
Keyword(s):  
Pseudomonas Sp

Bringing Biocatalysis into the Deuteration Toolbox

2019 ◽  
Author(s):  
Jack Rowbotham ◽  
Oliver Lenz ◽  
Holly Reeve ◽  
Kylie Vincent
Keyword(s):  
Late Stage ◽  
Hydrogen Isotope ◽  
Reductive Amination ◽  
Mechanistic Studies ◽  
Ambient Conditions ◽  
Synthetic Pathway ◽  
Drug Candidates ◽  
Isotopic Selectivity ◽  
Reducing Equivalents

<p></p><p>Chemicals labelled with the heavy hydrogen isotope deuterium (<sup>2</sup>H) have long been used in chemical and biochemical mechanistic studies, spectroscopy, and as analytical tracers. More recently, demonstration of selectively deuterated drug candidates that exhibit advantageous pharmacological traits has spurred innovations in metal-catalysed <sup>2</sup>H insertion at targeted sites, but asymmetric deuteration remains a key challenge. Here we demonstrate an easy-to-implement biocatalytic deuteration strategy, achieving high chemo-, enantio- and isotopic selectivity, requiring only <sup>2</sup>H<sub>2</sub>O (D<sub>2</sub>O) and unlabelled dihydrogen under ambient conditions. The vast library of enzymes established for NADH-dependent C=O, C=C, and C=N bond reductions have yet to appear in the toolbox of commonly employed <sup>2</sup>H-labelling techniques due to requirements for suitable deuterated reducing equivalents. By facilitating transfer of deuterium atoms from <sup>2</sup>H<sub>2</sub>O solvent to NAD<sup>+</sup>, with H<sub>2</sub> gas as a clean reductant, we open up biocatalysis for asymmetric reductive deuteration as part of a synthetic pathway or in late stage functionalisation. We demonstrate enantioselective deuteration via ketone and alkene reductions and reductive amination, as well as exquisite chemo-control for deuteration of compounds with multiple unsaturated sites.</p><p></p>

Mechanistic Study and Development of Catalytic Reactions of Sm(II)

2018 ◽  
Author(s):  
Sandepan Maity ◽  
Robert Flowers
Keyword(s):  
Molecular Weight ◽  
High Molecular Weight ◽  
Proton Donor ◽  
Catalytic Reactions ◽  
Mechanistic Study ◽  
Mechanistic Studies ◽  
Cyclization Reactions ◽  
Mechanistic Approach ◽  
Donor Source

Despite the broad utility and application of SmI<sub>2</sub>in synthesis, the reagent is used in stoichiometric amounts and has a high molecular weight, resulting in a large amount of material being used for reactions requiring one or more equivalents of electrons. We report mechanistic studies on catalytic reactions of Sm(II) employing a terminal magnesium reductant and trimethyl silyl chloride in concert with a non-coordinating proton donor source. Reactions using this approach permitted reductions with as little as 1 mol% Sm. The mechanistic approach enabled catalysis employing HMPA as a ligand, facilitating the development of catalytic Sm(II) 5-<i>exo</i>-<i>trig </i>ketyl olefin cyclization reactions.

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