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.
Data di pubblicazione: | 2007 |
Titolo: | Disruption of the aspartate to heme ester linkage in human myeloperoxidase: Impact on ligand binding, redox chemistry and interconversion of redox intermediates |
Autore/i: | M., Zederbauer; P. G., Furtmller; Bellei, Marzia; J., Stampler; C., Jakopitsch; Battistuzzi, Gianantonio; N., Moguilevsky; C., Obinger |
Autore/i UNIMORE: | |
Rivista: | |
Volume: | 282 |
Pagina iniziale: | 17041 |
Pagina finale: | 17052 |
Codice identificativo ISI: | WOS:000246946500037 |
Codice identificativo Scopus: | 2-s2.0-34447117575 |
Codice identificativo Pubmed: | 17438335 |
Citazione: | 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. |
Tipologia | Articolo su rivista |
File in questo prodotto:

I documenti presenti in Iris Unimore sono rilasciati con licenza Creative Commons Attribuzione - Non commerciale - Non opere derivate 3.0 Italia, salvo diversa indicazione.
In caso di violazione di copyright, contattare Supporto Iris