Horm Metab Res 2007; 39(1): 14-19
DOI: 10.1055/s-2007-957341
Original Basic

© Georg Thieme Verlag KG Stuttgart · New York

Inhibition of Peroxidase and Catalase Activities and Modulation of Hydrogen Peroxide Level by Inositol Phosphoglycan-like Compounds

L. Thomasz 1 , M. Aran 2 , R. A. Pizarro 1 , J. Ibañez 1 , M. A. Pisarev 1 , 2 , 3 , D. Converso 4 , G. J. Juvenal 1 , 2 , L. Krawiec 2
  • 1Department of Radiobiology, Argentine Atomic Energy Commission (CNEA), Buenos Aires, Argentina
  • 2Argentine National Research Council (CONICET), Buenos Aires, Argentina
  • 3Department of Human Biochemistry, School of Medicine, University of Buenos Aires, Argentina
  • 4Laboratory of Oxygen Metabolism, University Hospital, University of Buenos Aires, Argentina
Further Information

Publication History

Received 22. 5. 2006

Accepted 30. 8. 2006

Publication Date:
16 January 2007 (online)

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Abstract

Inositol phosphoglycan-like compounds are produced by the hydrolysis of the membrane bound glycosyl phosphoinositides. Besides being short term mediators of insulin action, they inhibit peroxidases and catalase, increasing the concentration of cellular hydrogen peroxide. Although high concentrations of hydrogen peroxide are toxic, moderate increases of its basal level are signals for different metabolic pathways. The inhibitor, localized in the cytosol of the cell, acts on peroxidases and catalase of the same tissue (homologous action) and of other tissues or organisms (heterologous action). The inositol phosphoglycan-like compound inhibits peroxidases with different prosthetic groups, i.e. containing iron such as: thyroid peroxidase, lactoperoxidase, horseradish peroxidase, soy bean peroxidase; and containing selenium such as glutathione peroxidase and 2-cys peroxiredoxin with no prosthetic group. Besides peroxidases, the inositol phosphoglycan-like compound inhibits catalase, another heme enzyme. The inhibition kinetics demonstrates a noncompetitive effect. The site of action is not the prosthetic group, given that the inhibitor does not produce any effect on the peak in the Soret region in the presence or absence of hydrogen peroxide. In conclusion, the inositol phosphoglycan-like compound is the general inhibitor of peroxidases and catalase involved in the modulation of hydrogen peroxide level that acts in different metabolic pathways as a signal transducer.

References

Correspondence

L. Krawiec

División Bioquímica Nuclear - Unidad de Actividad Radiobiología

Comisión Nacional de Energía Atómica

Av. del Libertador 8250

1429-Buenos Aires

Argentina

Phone: +541167 72 71 85

Fax: +541167 72 71 88

Email: krawiec@cnea.gov.ar