title: Iron site structure of two irreversible hemichromes from human hemoglobin, untreated and oxidized to sulfoxide at MetD6(55)beta.
abstract: The Fe K-edge X-ray absorption near-edge structure (XANES) spectra of two irreversible human hemichromes, spontaneously formed from HbA and HbMetSO (a hemoglobin derivative, where MetD6(55)beta has been previously oxidized to sulfoxide by chloramine T) were determined. The results show that the hemichrome from HbMetSO is characterized by the distal histidyl imidazole moved within the bonding distance of the heme iron. Such structure is different from that of the hemichrome spontaneously produced from native human hemoglobin, which probably has a hydroxide group as sixth heme ligand.
authors.affiliation: Dipartimento di Medicina Sperimentale, Università dell'Aquila, Italy. dellalonga@vaxaq.cc.univaq.it
authors.forename: S
authors.initials: S
authors.lastname: Della Longa
authors.forename: G
authors.initials: G
authors.lastname: Amiconi
authors.forename: O
authors.initials: O
authors.lastname: Artan Salah
authors.forename: I
authors.initials: I
authors.lastname: Ascone
authors.forename: M
authors.initials: M
authors.lastname: Barteri
authors.forename: A
authors.initials: A
authors.lastname: Bertollini
authors.forename: A
authors.initials: A
authors.lastname: Bianconi
authors.forename: A
authors.initials: A
authors.lastname: Congiu Castellano
mesh_terms: D001665:Binding Sites; D006420:Hemeproteins / Q000737:chemistry*; D006441:Hemoglobin A / Q000737:chemistry* / Q000378:metabolism; D006801:Humans; D007501:Iron / Q000737:chemistry; D008706:Methemoglobin / Q000031:analogs & derivatives / Q000737:chemistry*; D010084:Oxidation-Reduction; D013057:Spectrum Analysis / Q000379:methods; D013454:Sulfoxides / Q000737:chemistry; D014965:X-Rays
chemical_list: D006420:Hemeproteins; D013454:Sulfoxides; C001332:hemichrome; D008706:Methemoglobin; D006441:Hemoglobin A; D007501:Iron