A QM/MM Study of thel-Threonine Formation Reaction of Threonine Synthase: Implications into the Mechanism of the Reaction Specificity

2014 ◽  
Vol 136 (12) ◽  
pp. 4525-4533 ◽  
Author(s):  
Mitsuo Shoji ◽  
Kyohei Hanaoka ◽  
Yuzuru Ujiie ◽  
Wataru Tanaka ◽  
Daiki Kondo ◽  
...  
Keyword(s):  
Formation Reaction ◽  
Threonine Synthase ◽  
Reaction Specificity ◽  
Mechanism Of The Reaction

Molecular Mechanism of the Reaction Specificity in Threonine Synthase: Importance of the Substrate Conformations

2017 ◽  
Vol 121 (22) ◽  
pp. 5536-5543 ◽  
Author(s):  
Yuzuru Ujiie ◽  
Wataru Tanaka ◽  
Kyohei Hanaoka ◽  
Ryuhei Harada ◽  
Megumi Kayanuma ◽  
...  
Keyword(s):  
Molecular Mechanism ◽  
Threonine Synthase ◽  
Reaction Specificity ◽  
Mechanism Of The Reaction

scholarly journals Product-assisted Catalysis as the Basis of the Reaction Specificity of Threonine Synthase

2010 ◽  
Vol 286 (4) ◽  
pp. 2774-2784 ◽  
Author(s):  
Takeshi Murakawa ◽  
Yasuhiro Machida ◽  
Hideyuki Hayashi
Keyword(s):  
Threonine Synthase ◽  
Reaction Specificity

Stabilization of Hazardous Materials into Ferrites

1991 ◽  
Vol 23 (1-3) ◽  
pp. 399-404 ◽  
Author(s):  
Y. Tamaura ◽  
P. Q. Tu ◽  
S. Rojarayanont ◽  
H. Abe
Keyword(s):  
Aqueous Solution ◽  
Heavy Metal ◽  
Metal Ions ◽  
Present Method ◽  
Hazardous Materials ◽  
Precipitation Process ◽  
Waste Waters ◽  
Formation Reaction ◽  
Coating Method ◽  
Hazardous Metal

Stabilization of the hazardous materials by the Fe3O4-coating method was studied. In the ferrite-formation reaction in the aqueous solution, the adsorption of the metal ions and the oxidation of the adsorbed Fe(II) ions are repeated on the surface of the ferrite particles. This reaction was adopted to the coating of the hazardous materials with the Fe3O4(or ferrite). By repeating the two steps of l)the addition of the Fe(II) aqueous solution into the suspension of the hazardous materials, and 2)the oxidation by passing air through the reaction suspension, with the Fe3O4 layer, we could coat the surfaces of the hazardous materials, such as the heavy metal sludge from the neutralization-precipitation process, the CaF2 precipitates in the treatment of the waste waters containing fluoride ion along with hazardous metal ions, and the soils containing Cd(II) ion. These Fe3O4-coated hazardous materials are very stable and no heavy metal ions are leached under the normal environmental conditions. The ferrite sludges formed in the “Ferrite Process” were highly stabilized by the present method, and by the heat-treatment.

Acetolysis of 4β-methanesulphonyloxy-6β,7aβ-cyclo-B-homo-5α-cholestane

1979 ◽  
Vol 44 (11) ◽  
pp. 3308-3320 ◽  
Author(s):  
Ladislav Kohout ◽  
Jan Fajkoš
Keyword(s):  
Mechanism Of The Reaction

Synthesis of 4β-methanesulphonyloxy-6β,7aβ-cyclo-B-homo-5α-cholestane is described. During its acetolysis a kind of conjugative stabilization of the carbocation formed was observed. The mechanism of the reaction is discussed.

Kinetics and mechanism of the reaction of iron(III) with 6-methyl-2,4-heptanedione and 3,5-heptanedione

1990 ◽  
Vol 55 (8) ◽  
pp. 1984-1990 ◽  
Author(s):  
José M. Hernando ◽  
Olimpio Montero ◽  
Carlos Blanco
Keyword(s):  
Aqueous Solution ◽  
Metal Ion ◽  
Activation Parameters ◽  
Enol Form ◽  
Kinetics And Mechanism ◽  
Kinetic Constants ◽  
Steric Factors ◽  
Kinetics Of ◽  
Mechanism Of The Reaction

The kinetics of the reactions of iron(III) with 6-methyl-2,4-heptanedione and 3,5-heptanedione to form the corresponding monocomplexes have been studied spectrophotometrically in the range 5 °C to 16 °C at I 25 mol l-1 in aqueous solution. In the proposed mechanism for the two complexes, the enol form reacts with the metal ion by parallel acid-independent and inverse-acid paths. The kinetic constants for both pathways have been calculated at five temperatures. Activation parameters have also been calculated. The results are consistent with an associative activation for Fe(H2O)63+ and dissociative activation for Fe(H2O)5(OH)2+. The differences in the results for the complexes of heptanediones studied are interpreted in terms of steric factors.

Kinetics and mechanism of the reaction between oxidized cytochrome c and ascorbic acid

1991 ◽  
Vol 56 (2) ◽  
pp. 478-490 ◽  
Author(s):  
Joaquin F. Perez-Benito ◽  
Conchita Arias
Keyword(s):  
Ascorbic Acid ◽  
Cytochrome C ◽  
Redox Reactions ◽  
Arrhenius Equation ◽  
Horse Heart Cytochrome ◽  
First Order ◽  
Acidic Form ◽  
Ph Range ◽  
Horse Heart Cytochrome C ◽  
Mechanism Of The Reaction

The reaction between horse-heart cytochrome c and ascorbic acid has been investigated in the pH range 5.5 – 7.1 and at 10.0 – 25.0 °C. The rate shows a first-order dependence on the concentration of cytochrome c, it increases in a non-linear way as the concentration of ascorbic acid increases, it increases markedly with increasing pH and, provided that the ionic strength of the medium is high enough, it fulfills the Arrhenius equation. The apparent activation energy increases as the pH of the solution increases. The results have been explained by means of a mechanism that includes the existence of an equilibrium between two forms (acidic and basic) of oxidized cytochrome c: cyt-H+ -Fe3+ + OH- cyt -Fe3+ + H2O, whose equilibrium constant is (6.7 ± 1.4). 108 at 25.0 °C, the acidic form being more reducible than the basic one. It is suggested that there is a linkage of hydrogenascorbate ion to both forms of cytochrome c previous to the redox reactions. Two possibilities for the oxidant-reductant linkage (binding and adsorption) are discussed in detail.

scholarly journals Crystal Structures of Threonine Synthase fromThermus thermophilusHB8

2003 ◽  
Vol 278 (46) ◽  
pp. 46035-46045 ◽  
Author(s):  
Rie Omi ◽  
Masaru Goto ◽  
Ikuko Miyahara ◽  
Hiroyuki Mizuguchi ◽  
Hideyuki Hayashi ◽  
...  
Keyword(s):  
Crystal Structures ◽  
Threonine Synthase

scholarly journals ON THE MECHANISM OF THE REACTION OF NINHYDRIN WITH α-AMINO ACIDS

1950 ◽  
Vol 186 (1) ◽  
pp. 13-22
Author(s):  
Douglas A. MacFadyen ◽  
Nathalie. Fowler
Keyword(s):  
Amino Acids ◽  
Mechanism Of The Reaction
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