In human heme peroxidases the prosthetic group is covalentlyattached to the protein via two ester linkages between conservedglutamate and aspartate residues and modified methyl groupson pyrrole rings A and C. Here, monomeric recombinantmyeloperoxidase (MPO) and the variants D94V and D94N wereproduced in Chinese hamster ovary cell lines. Disruption of theAsp94 to heme ester bond decreased the one-electron reductionpotential E0 [Fe(III)/Fe(II)] from 1 to 55 mV at pH 7.0 and25 °C, whereas the kinetics of binding of low spin ligands and ofcompound I formation was unaffected. By contrast, in both variantsrates of compound I reduction by chloride and bromide(but not iodide and thiocyanate) were substantially decreasedcompared with the wild-type protein. Bimolecular rates of compoundII (but not compound I) reduction by ascorbate and tyrosinewere slightly diminished in D94V and D94N. The presentedbiochemical and biophysical data suggest that the Asp94 to hemelinkage is no precondition for the autocatalytic formation of theother two covalent links found in MPO. The findings are discussedwith respect to the known active site structure of MPOand its complexes with ligands.

Disruption of the aspartate to heme ester linkage in human myeloperoxidase: Impact on ligand binding, redox chemistry and interconversion of redox intermediates / M., Zederbauer; P. G., Furtmller; Bellei, Marzia; J., Stampler; C., Jakopitsch; Battistuzzi, Gianantonio; N., Moguilevsky; C., Obinger. - In: THE JOURNAL OF BIOLOGICAL CHEMISTRY. - ISSN 0021-9258. - STAMPA. - 282(2007), pp. 17041-17052.

Disruption of the aspartate to heme ester linkage in human myeloperoxidase: Impact on ligand binding, redox chemistry and interconversion of redox intermediates

BELLEI, Marzia;BATTISTUZZI, Gianantonio;
2007

Abstract

In human heme peroxidases the prosthetic group is covalentlyattached to the protein via two ester linkages between conservedglutamate and aspartate residues and modified methyl groupson pyrrole rings A and C. Here, monomeric recombinantmyeloperoxidase (MPO) and the variants D94V and D94N wereproduced in Chinese hamster ovary cell lines. Disruption of theAsp94 to heme ester bond decreased the one-electron reductionpotential E0 [Fe(III)/Fe(II)] from 1 to 55 mV at pH 7.0 and25 °C, whereas the kinetics of binding of low spin ligands and ofcompound I formation was unaffected. By contrast, in both variantsrates of compound I reduction by chloride and bromide(but not iodide and thiocyanate) were substantially decreasedcompared with the wild-type protein. Bimolecular rates of compoundII (but not compound I) reduction by ascorbate and tyrosinewere slightly diminished in D94V and D94N. The presentedbiochemical and biophysical data suggest that the Asp94 to hemelinkage is no precondition for the autocatalytic formation of theother two covalent links found in MPO. The findings are discussedwith respect to the known active site structure of MPOand its complexes with ligands.
282
17041
17052
Disruption of the aspartate to heme ester linkage in human myeloperoxidase: Impact on ligand binding, redox chemistry and interconversion of redox intermediates / M., Zederbauer; P. G., Furtmller; Bellei, Marzia; J., Stampler; C., Jakopitsch; Battistuzzi, Gianantonio; N., Moguilevsky; C., Obinger. - In: THE JOURNAL OF BIOLOGICAL CHEMISTRY. - ISSN 0021-9258. - STAMPA. - 282(2007), pp. 17041-17052.
M., Zederbauer; P. G., Furtmller; Bellei, Marzia; J., Stampler; C., Jakopitsch; Battistuzzi, Gianantonio; N., Moguilevsky; C., Obinger
File in questo prodotto:
Non ci sono file associati a questo prodotto.
Pubblicazioni consigliate

Caricamento 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: http://hdl.handle.net/11380/583733
Citazioni
  • ???jsp.display-item.citation.pmc??? 6
  • Scopus 25
  • ???jsp.display-item.citation.isi??? 23
social impact