?-Irradiation of aqueous solutions of horseradish peroxidase in different atmospheres: Argon, air, and nitrous oxide

1974 ◽  
Vol 11 (3) ◽  
pp. 213-218 ◽  
Author(s):  
H. Delinc�e ◽  
B. J. Radola
Keyword(s):  
Nitrous Oxide ◽  
Horseradish Peroxidase ◽  
Aqueous Solutions

Removal of Linear and Branched Alkylphenols from Aqueous Solutions with Horseradish Peroxidase

2008 ◽  
Vol 72 (5) ◽  
pp. 1368-1371 ◽  
Author(s):  
Naoya IKEDA ◽  
Kazunori YAMADA ◽  
Takashi SHIBUYA ◽  
Ayumi KASHIWADA ◽  
Kiyomi MATSUDA ◽  
...  
Keyword(s):  
Horseradish Peroxidase ◽  
Aqueous Solutions

On the Radiolysis of Alkali Halides in Aqueous Solutions Saturated with Nitrous Oxide

1964 ◽  
Vol 68 (10) ◽  
pp. 2967-2970 ◽  
Author(s):  
M. Anbar ◽  
D. Meyerstein ◽  
P. Neta
Keyword(s):  
Nitrous Oxide ◽  
Aqueous Solutions ◽  
Alkali Halides

The photochemistry of aqueous solutions of Fe(II) II. Processes in acidified solutions of potassium ferrocyanide at 25°C

1966 ◽  
Vol 291 (1427) ◽  
pp. 478-486 ◽  
Keyword(s):  
Nitrous Oxide ◽  
Quantum Yield ◽  
Aqueous Solutions ◽  
Potassium Ferrocyanide ◽  
Geminate Recombination ◽  
Nitrate Ions ◽  
Decreasing Ph

Yields of hydrogen and nitrogen have been measured for acidified solutions of potassium ferrocyanide containing nitrous oxide illuminated with 2537 Å light. From the effect of decreasing pH and added nitrate ions which diminish ϕ (N 2 ) and the effect of isopropanol which acts as an H atom scavenger it is concluded that (i) k ( e ¯ aq. + HFe(CN) 3– 6 ) / k ( e ¯ aq . + N 2 O) = 0·25 ± 0·1 at μ = 0 and increases with increasing μ ; (ii) k (H + NO ¯ 3 ) / k (H + (CH 3 ) 4 CHOH) = 0·47 ± 0·05; (iii) k (H + Fe(CN) 3– 6 ) / k (H + (CH 3 ) 2 CHOH) = 72 ± 7 and is independent of μ ; (iv) the protonated ferrocyanide ion, HFe(CN) 3– 6 absorbs 2537 Å light and undergoes decomposition according to either ( a ) HFe(CN) 3– 6 + hv → H + + Fe(CN) 3– 6 + e ¯ aq. or (b) HFe(CN) 3– 6 + hv → H + Fe(CN) 3– 6 which is opposed by geminate recombination and such that ϕ a + ϕ b < 0·66, the quantum yield of Fe(CN) 4– 6 + hv → Fe(CN) 3– 6 + e ¯ aq. . The implications of these results are discussed.

scholarly journals Studies on horseradish peroxidase in dimethyl sulphoxide/water mixtures. The activation of hydrogen peroxide and the binding of fluoride

1979 ◽  
Vol 179 (2) ◽  
pp. 273-280 ◽  
Author(s):  
P A Adams ◽  
D A Baldwin ◽  
G S Collier ◽  
J M Pratt
Keyword(s):  
Hydrogen Peroxide ◽  
Enzyme Activity ◽  
Horseradish Peroxidase ◽  
Aqueous Solutions ◽  
Similar Pattern ◽  
Solvent Mixture ◽  
Dimethyl Sulphoxide ◽  
Stock Solutions ◽  
Activation Of Hydrogen Peroxide

We studied the variation in spectra and in reactivity towards H2O2 of solutions of horseradish peroxidase in dimethyl sulphoxide/water mixtures, obtained by diluting stock solutions of the enzyme in either water or dimethyl sulphoxide, and assayed the enzyme activity and studied the binding of F- by the peroxidase in 65% (v/v) dimethyl sulphoxide. A broadly similar pattern of changes is observed whether one starts from water or from dimethyl sulphoxide; the changes are essentially reversible, though hysteresis is observed. When the dimethyl sulphoxide content of the solvent mixture is increased, the peroxidase retains its ability to activate H2O2 up to 74% (v/v) dimethyl sulphoxide. The peroxidase in 65% (v/v) dimethyl sulphoxide binds F- together with a proton (or the equivalent loss of HO-), as already established for aqueous solutions. We point out that the occurrence in such solutions of both the ability to activate H2O2 and the inability to bind F- without taking up H+ or losing HO- supports the proposed mechanism for activating H202, whereby the protein binds the substrate in the form of the much more reactive HO2-.

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