title: Mössbauer characterization of the tetraheme cytochrome c3 from Desulfovibrio baculatus (DSM 1743). Spectral deconvolution of the heme components.
abstract: Mössbauer spectroscopy was used to study the tetraheme cytochrome c3 from Desulfovibrio baculatus (DSM 1743). Samples with different degrees of reduction were prepared using a redoxtitration technique. In the reduced cytochrome c3, all four hemes are reduced and exhibit diamagnetic Mössbauer spectra typical for low-spin ferrous hemes (S = 0). In the oxidized protein, the hemes are low-spin ferric (S = 1/2) and exhibit overlapping magnetic Mössbauer spectra. A method of differential spectroscopy was applied to deconvolute the four overlapping heme spectra and a crystal-field model was used for data analysis. Characteristic Mössbauer spectral components for each heme group are obtained. Hyperfine and crystal-field parameters for all four hemes are determined from these deconvoluted spectra.
authors.affiliation: Department of Physics, Emory University, Atlanta, GA 30322.
authors.forename: N
authors.initials: N
authors.lastname: Ravi
authors.forename: I
authors.initials: I
authors.lastname: Moura
authors.forename: C
authors.initials: C
authors.lastname: Costa
authors.forename: M
authors.initials: M
authors.lastname: Teixeira
authors.forename: J
authors.initials: J
authors.lastname: LeGall
authors.forename: J J
authors.initials: JJ
authors.lastname: Moura
authors.forename: B H
authors.initials: BH
authors.lastname: Huynh
mesh_terms: D003574:Cytochrome c Group / Q000737:chemistry*; D003901:Desulfovibrio / Q000201:enzymology*; D006418:Heme / Q000737:chemistry; D010084:Oxidation-Reduction; D011487:Protein Conformation; D015204:Spectroscopy, Mossbauer
chemical_list: D003574:Cytochrome c Group; D006418:Heme; C017165:cytochrome c(3)