title: Detergent effect on cytochrome b559 electron paramagnetic resonance signals in the photosystem II reaction centre.
abstract: The detergent effect on Cytochrome b559 from spinach photosystem II was studied by electron paramagnetic resonance (EPR) spectroscopy in D1-D2-Cyt b559 complex preparations. Various n-dodecyl-beta-D-maltoside concentrations from 0 to 0.2% (w/v) were used to stabilise the D1-D2-Cyt b559 complexes. Low spin heme EPR spectra were obtained but the g(z) feature positions changed depending on the detergent conditions Redox potentiometric titrations showed a unique redox potential cytochrome b559 form (E'm = + 123-150 mV) in all the D1-D2-Cyt b559 complex preparations indicating that detergent does not affect this property of the protein in those conditions. A similar effect on Cytochrome b559 EPR spectrum was observed in more intact photosystem II preparations independently of their aggregation state. This finding indicates that changes due to detergent could be a common phenomenon in photosystem II complexes. Results are discussed in terms of the environment each detergent provides to the protein.
authors.affiliation: Estación Experimental de Aula Dei, Consejo Superior de Investigaciones Científicas, Apdo. 202, E-50080 Zaragoza, Spain.
authors.forename: I
authors.initials: I
authors.lastname: Yruela
authors.forename: I
authors.initials: I
authors.lastname: García-Rubio
authors.forename: M
authors.initials: M
authors.lastname: Roncel
authors.forename: J I
authors.initials: JI
authors.lastname: Martínez
authors.forename: M V
authors.initials: MV
authors.lastname: Ramiro
authors.forename: J M
authors.initials: JM
authors.lastname: Ortega
authors.forename: P J
authors.initials: PJ
authors.lastname: Alonso
authors.forename: R
authors.initials: R
authors.lastname: Picorel
mesh_terms: D003573:Cytochrome b Group / Q000737:chemistry*; D003902:Detergents / Q000737:chemistry*; D004578:Electron Spin Resonance Spectroscopy; D010084:Oxidation-Reduction; D045322:Photosynthetic Reaction Center Complex Proteins / Q000737:chemistry*; D045332:Photosystem II Protein Complex
chemical_list: D003573:Cytochrome b Group; D003902:Detergents; D045322:Photosynthetic Reaction Center Complex Proteins; D045332:Photosystem II Protein Complex; C019313:cytochrome b559