title: Detecting transient protein-protein interactions by X-ray absorption spectroscopy: The cytochrome c6-photosystem I complex.
abstract: Reliable analysis of the functionality of metalloproteins demands a highly accurate description of both the redox state and geometry of the metal centre, not only in the isolated metalloprotein but also in the transient complex with its target. Here, we demonstrate that the transient interaction between soluble cytochrome c(6) and membrane-embedded photosystem I involves subtle changes in the heme iron, as inferred by X-ray absorption spectroscopy (XAS). A slight shift to lower energies of the absorption edge of Fe2+ in cytochrome c6 is observed upon interaction with photosystem I. This work constitutes a novel application of XAS to the analysis of weak complexes in solution.
authors: Instituto de Bioquímica Vegetal y Fotosíntesis, Universidad de Sevilla y Consejo Superior de Investigaciones Científicas, Américo Vespucio 49, 41092 Sevilla, Spain.
authors: Irene
authors: I
authors: Díaz-Moreno
authors: Antonio
authors: A
authors: Díaz-Quintana
authors: Gloria
authors: G
authors: Subías
authors: Trevor
authors: T
authors: Mairs
authors: Miguel A
authors: MA
authors: De la Rosa
authors: Sofía
authors: S
authors: Díaz-Moreno