title: A general exit strategy of monoheme cytochromes c and c2 in electron transfer complexes?
abstract: Using our previously reported maps of the electrostatic surface of horse heart ferri- and ferro-cyt c, comparisons were made between the complementary electrostatic surfaces of three cyt c peroxidase-cyt c complexes and the photosynthetic reaction center-cyt c complex, considering both iron oxidation states. The results obtained were consistent with a sliding mechanism for the electron shuttle on the surface of the protein complexes, promoted by the change in iron oxidation state. This mechanism was found to be in agreement with theoretical and NMR studies reported in the literature. Importantly, the analysis also provided a rationale for recognition of nonproductive associations. As we have previously reported the same conclusion on examination of redox partners of cyt c in the mitochondrial respiratory pathway, our hypothesis is that the proposed mechanism could represent a general exit strategy of monoheme cyts c and c2 in electron transfer complexes.
authors: Department of Chemical and Pharmaceutical Sciences, Centre of Excellence in Biocrystallography, University of Trieste, Trieste, Italy.
authors: Matteo
authors: M
authors: De March
authors: Department of Chemical and Pharmaceutical Sciences, Centre of Excellence in Biocrystallography, University of Trieste, Trieste, Italy.
authors: Giovanna
authors: G
authors: Brancatelli
authors: Department of Chemical and Pharmaceutical Sciences, Centre of Excellence in Biocrystallography, University of Trieste, Trieste, Italy.
authors: Nicola
authors: N
authors: Demitri
authors: Department of Chemical and Pharmaceutical Sciences, Centre of Excellence in Biocrystallography, University of Trieste, Trieste, Italy.
authors: Rita
authors: R
authors: De Zorzi
authors: Department of Chemical and Pharmaceutical Sciences, Centre of Excellence in Biocrystallography, University of Trieste, Trieste, Italy.
authors: Neal
authors: N
authors: Hickey
authors: Department of Chemical and Pharmaceutical Sciences, Centre of Excellence in Biocrystallography, University of Trieste, Trieste, Italy.
authors: Silvano
authors: S
authors: Geremia
mesh_terms: D000818:Animals; D001419:Bacteria / Q000378:metabolism; D019069:Cell Respiration / Q000502:physiology*; D045304:Cytochromes c / Q000737:chemistry* / Q000378:metabolism*; D004579:Electron Transport; D006736:Horses; D007700:Kinetics; D008958:Models, Molecular; D010084:Oxidation-Reduction; D009195:Peroxidase; D045322:Photosynthetic Reaction Center Complex Proteins / Q000378:metabolism*; D011487:Protein Conformation; D012441:Saccharomyces cerevisiae / Q000378:metabolism
chemical_list: D045322:Photosynthetic Reaction Center Complex Proteins; D045304:Cytochromes c; D009195:Peroxidase
keywords: cytochrome c; cytochrome c2; electron transfer complexes; electrostatic surface; exit strategy; redox protein