We have carried out an X-ray Absorption Spectroscopy (XAS) study of ferric, ferrous. CO- and NO-bound Haemophilus ducreyi Cu,ZnSOD (HdSOD) in solution to investigate the structural modifications induced by the binding of small gaseous ligands to heme in this enzyme. The combined analysis of EXAFS and XANES data has allowed us to characterize the local structure around the Fe-heme with 0.02 angstrom accuracy, revealing a heterogeneity in the distances between iron and the two histidine ligands which was not evident in the X-ray crystal structure. In addition, we have shown that the metal oxidation state does not influence the Fe-home coordination environment, whereas the presence of the CO and NO ligands induces local structural rearrangements in the enzyme which are very similar to those already observed in other hexa-coordinated heme proteins, such as neuroglobin. (c) 2010 Elsevier Inc. All rights reserved.
Fe-heme structure in Cu,Zn superoxide dismutase from Haemophilus ducreyi by X-ray Absorption Spectroscopy / D'Angelo, Paola; Zitolo, Andrea; Francesca, Pacello; Giordano, Mancini; Olivier, Proux; J. L., Hazemanne; D., Desideri; Battistoni,. - In: ARCHIVES OF BIOCHEMISTRY AND BIOPHYSICS. - ISSN 0003-9861. - 498:1(2010), pp. 43-49. [10.1016/j.abb.2010.03.010]
Fe-heme structure in Cu,Zn superoxide dismutase from Haemophilus ducreyi by X-ray Absorption Spectroscopy
D'ANGELO, Paola;ZITOLO, ANDREA;
2010
Abstract
We have carried out an X-ray Absorption Spectroscopy (XAS) study of ferric, ferrous. CO- and NO-bound Haemophilus ducreyi Cu,ZnSOD (HdSOD) in solution to investigate the structural modifications induced by the binding of small gaseous ligands to heme in this enzyme. The combined analysis of EXAFS and XANES data has allowed us to characterize the local structure around the Fe-heme with 0.02 angstrom accuracy, revealing a heterogeneity in the distances between iron and the two histidine ligands which was not evident in the X-ray crystal structure. In addition, we have shown that the metal oxidation state does not influence the Fe-home coordination environment, whereas the presence of the CO and NO ligands induces local structural rearrangements in the enzyme which are very similar to those already observed in other hexa-coordinated heme proteins, such as neuroglobin. (c) 2010 Elsevier Inc. All rights reserved.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
