Detecting transient protein–protein interactions by X-ray absorption spectroscopy: The cytochrome c6-photosystem I complex

DOI: 10.1016/j.febslet.2006.04.045

Authors: Irene Díaz-moreno (Instituto de Bioquimica Vegetal y Fotosintesis de Sevilla, Spain) , Antonio Díaz-quintana (Instituto de Bioquímica Vegetal y Fotosíntesis, Universidad de Sevilla, Spain) , Gloria Subías (Universidad de Zaragoza, Spain) , Trevor Mairs (ESRF, France) , Miguel A. De La Rosa (Universidad de Sevilla, Spain) , Sofía Díaz-moreno (Diamond Light Source)
Co-authored by industrial partner: No

Type: Journal Paper
Journal: Febs Letters , VOL 580 (13) , PAGES 3023 - 3028

State: Published (Approved)
Published: May 2006

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 c6 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.

Journal Keywords: Electron-Transfer Complex; Fine-Structure; Photosystem-I; Cytochromes-C; Rhodobacter-Sphaeroides; K-Edge; Xafs; Metalloproteins; Stereochemistry; Plastocyanin

Subject Areas: Biology and Bio-materials, Chemistry

Facility: ESRF