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The Synergetic Coupling among the Cellular Antioxidants Glutathione Peroxidase/Peroxiredoxin and Other Antioxidants and its Effect on the Concentration of H 2 O 2

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ABSTRACT

Glutathione peroxidase (GPx), peroxiredoxin (Prx), and catalase are the major antioxidants at the cellular level and protect cell compartments against hydrogen peroxide (H2O2). In addition, they affect cellular processes such as cell signaling by modulating H2O2. In this paper we demonstrate that there is a synergetic coupling between GPxs, Prxs themselves and also with other antioxidants when the GPxs and Prxs are not in their saturated reduced form. This is due to a change in the activity of glutathione peroxidases and peroxiredoxins as a result of a change in the concentrations of other antioxidants. The strength of this synergy depends on the reaction rates and the concentration of these antioxidants. We use a perturbative method to calculate the concentration of H2O2 as function of the production rate of H2O2 and the concentration of various antioxidants. This derivation shows clearly why antioxidants behave in a correlated manner and why any change in the activity of one of them translates to a change in the activity of other antioxidants. Our results show that an increase in the activity of GPxs or Prxs might not be due to a genetic switch but due to an increase in the activity of other antioxidants.

No MeSH data available.


Mechanism of the synergetic behavior based on H2O2 level.(a) Concentration of H2O2 as functions of the concentration of Prx3 and GPx1 for . (b) The concentration of H2O2 as functions of the concentration of Prx2 and GPx1 for . In these plots the concentrations of other species are ,  and .
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f4: Mechanism of the synergetic behavior based on H2O2 level.(a) Concentration of H2O2 as functions of the concentration of Prx3 and GPx1 for . (b) The concentration of H2O2 as functions of the concentration of Prx2 and GPx1 for . In these plots the concentrations of other species are , and .

Mentions: To understand these synergetic behaviors, in Fig. 4 we plot the concentration of H2O2 as a function of the concentration of GPx1 and Prx3 or Prx2 corresponding to the presented results in Figs 1 and 2. By increasing the concentration of GPx1 or Prx3 or, Prx2 the concentration of H2O2 decreases, however, the rate of this decrease depends on the types of antioxidants. For instance, GPx1 has a higher capacity to detoxify H2O2 as compared to Prx3 and Prx2. It should be noted that the decrease in the concentration of H2O2 corresponds to the increase in the activity of Prx3 and Prx2. This explains the reason behind the observed synergetic coupling between GPx1 and Prx3/Prx2. In fact by increasing the concentration of GPx1 the concentration of H2O2 decreases. This decrease in the concentration of H2O2 converts the oxidized form of Prx3 and Prx2 to the reduced forms and increases the Prx3, Prx2 activity.


The Synergetic Coupling among the Cellular Antioxidants Glutathione Peroxidase/Peroxiredoxin and Other Antioxidants and its Effect on the Concentration of H 2 O 2
Mechanism of the synergetic behavior based on H2O2 level.(a) Concentration of H2O2 as functions of the concentration of Prx3 and GPx1 for . (b) The concentration of H2O2 as functions of the concentration of Prx2 and GPx1 for . In these plots the concentrations of other species are ,  and .
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4555031&req=5

f4: Mechanism of the synergetic behavior based on H2O2 level.(a) Concentration of H2O2 as functions of the concentration of Prx3 and GPx1 for . (b) The concentration of H2O2 as functions of the concentration of Prx2 and GPx1 for . In these plots the concentrations of other species are , and .
Mentions: To understand these synergetic behaviors, in Fig. 4 we plot the concentration of H2O2 as a function of the concentration of GPx1 and Prx3 or Prx2 corresponding to the presented results in Figs 1 and 2. By increasing the concentration of GPx1 or Prx3 or, Prx2 the concentration of H2O2 decreases, however, the rate of this decrease depends on the types of antioxidants. For instance, GPx1 has a higher capacity to detoxify H2O2 as compared to Prx3 and Prx2. It should be noted that the decrease in the concentration of H2O2 corresponds to the increase in the activity of Prx3 and Prx2. This explains the reason behind the observed synergetic coupling between GPx1 and Prx3/Prx2. In fact by increasing the concentration of GPx1 the concentration of H2O2 decreases. This decrease in the concentration of H2O2 converts the oxidized form of Prx3 and Prx2 to the reduced forms and increases the Prx3, Prx2 activity.

View Article: PubMed Central

ABSTRACT

Glutathione peroxidase (GPx), peroxiredoxin (Prx), and catalase are the major antioxidants at the cellular level and protect cell compartments against hydrogen peroxide (H2O2). In addition, they affect cellular processes such as cell signaling by modulating H2O2. In this paper we demonstrate that there is a synergetic coupling between GPxs, Prxs themselves and also with other antioxidants when the GPxs and Prxs are not in their saturated reduced form. This is due to a change in the activity of glutathione peroxidases and peroxiredoxins as a result of a change in the concentrations of other antioxidants. The strength of this synergy depends on the reaction rates and the concentration of these antioxidants. We use a perturbative method to calculate the concentration of H2O2 as function of the production rate of H2O2 and the concentration of various antioxidants. This derivation shows clearly why antioxidants behave in a correlated manner and why any change in the activity of one of them translates to a change in the activity of other antioxidants. Our results show that an increase in the activity of GPxs or Prxs might not be due to a genetic switch but due to an increase in the activity of other antioxidants.

No MeSH data available.