Eosinophil peroxidase (EPO) and lactoperoxidase (LPO) are important constituents of the innate immunesystem of mammals. These heme enzymes belong to the peroxidase-cyclooxygenase superfamily and catalyzethe oxidation of thiocyanate, bromide and nitrite to hypothiocyanate, hypobromous acid and nitrogendioxide that are toxic for invading pathogens. In order to gain a better understanding of the observeddifferences in substrate specificity and oxidation capacity in relation to heme and protein structure, acomprehensive spectro-electrochemical investigation was performed. The reduction potential (E0) ofthe Fe(III)/Fe(II) couple of EPO and LPO was determined to be 126 mV and 176 mV, respectively(25 C, pH 7.0). Variable temperature experiments show that EPO and LPO feature different reductionthermodynamics. In particular, reduction of ferric EPO is enthalpically and entropically disfavored,whereas in LPO the entropic term, which selectively stabilizes the oxidized form, prevails on the enthalpicterm that favors reduction of Fe(III). The data are discussed with respect to the architecture of theheme cavity and the substrate channel. Comparison with published data for myeloperoxidase demonstratesthe effect of heme to protein linkages and heme distortion on the redox chemistry of mammalianperoxidases and in consequence on the enzymatic properties of these physiologically importantoxidoreductases.

Redox thermodynamics of lactoperoxidase and eosinophil peroxidase / Battistuzzi, Gianantonio; Bellei, Marzia; J., Vlasits; S., Banerjee; P. G., Furtmüller; Sola, Marco; C., Obinger. - In: ARCHIVES OF BIOCHEMISTRY AND BIOPHYSICS. - ISSN 0003-9861. - STAMPA. - 494:1(2010), pp. 72-77. [10.1016/j.abb.2009.11.021]

Redox thermodynamics of lactoperoxidase and eosinophil peroxidase

BATTISTUZZI, Gianantonio;BELLEI, Marzia;SOLA, Marco;
2010

Abstract

Eosinophil peroxidase (EPO) and lactoperoxidase (LPO) are important constituents of the innate immunesystem of mammals. These heme enzymes belong to the peroxidase-cyclooxygenase superfamily and catalyzethe oxidation of thiocyanate, bromide and nitrite to hypothiocyanate, hypobromous acid and nitrogendioxide that are toxic for invading pathogens. In order to gain a better understanding of the observeddifferences in substrate specificity and oxidation capacity in relation to heme and protein structure, acomprehensive spectro-electrochemical investigation was performed. The reduction potential (E0) ofthe Fe(III)/Fe(II) couple of EPO and LPO was determined to be 126 mV and 176 mV, respectively(25 C, pH 7.0). Variable temperature experiments show that EPO and LPO feature different reductionthermodynamics. In particular, reduction of ferric EPO is enthalpically and entropically disfavored,whereas in LPO the entropic term, which selectively stabilizes the oxidized form, prevails on the enthalpicterm that favors reduction of Fe(III). The data are discussed with respect to the architecture of theheme cavity and the substrate channel. Comparison with published data for myeloperoxidase demonstratesthe effect of heme to protein linkages and heme distortion on the redox chemistry of mammalianperoxidases and in consequence on the enzymatic properties of these physiologically importantoxidoreductases.
2010
494
1
72
77
Redox thermodynamics of lactoperoxidase and eosinophil peroxidase / Battistuzzi, Gianantonio; Bellei, Marzia; J., Vlasits; S., Banerjee; P. G., Furtmüller; Sola, Marco; C., Obinger. - In: ARCHIVES OF BIOCHEMISTRY AND BIOPHYSICS. - ISSN 0003-9861. - STAMPA. - 494:1(2010), pp. 72-77. [10.1016/j.abb.2009.11.021]
Battistuzzi, Gianantonio; Bellei, Marzia; J., Vlasits; S., Banerjee; P. G., Furtmüller; Sola, Marco; C., Obinger
File in questo prodotto:
Non ci sono file associati a questo prodotto.
Pubblicazioni consigliate

Licenza Creative Commons
I metadati presenti in IRIS UNIMORE sono rilasciati con licenza Creative Commons CC0 1.0 Universal, mentre i file delle pubblicazioni sono rilasciati con licenza Attribuzione 4.0 Internazionale (CC BY 4.0), salvo diversa indicazione.
In caso di violazione di copyright, contattare Supporto Iris

Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/11380/637518
Citazioni
  • ???jsp.display-item.citation.pmc??? 12
  • Scopus 34
  • ???jsp.display-item.citation.isi??? 32
social impact