title: Interaction of ferredoxin:NADP+ oxidoreductase with model membranes.
abstract: The ferredoxin:NADP+ oxidoreductase (FNR) is a plant enzyme, catalyzing the last step of photosynthetic linear electron transport, and involved also in cyclic electron transport around photosystem I. In this study we present the first evidence of FNR (isolated from spinach and from wheat) interaction directly with a model membrane without the mediation of any additional protein. The monomolecular layer technique measurements showed a significant increase in surface pressure after the injection of enzyme solution beneath a monolayer consisting of chloroplast lipids: monogalactosyldiacylglycerol or digalactosyldiacylglycerol. An ATR FTIR study revealed also the presence of FNR in a bilayer composed of these lipids. The secondary structure of the protein was significantly impaired by lipids, as with a pH-induced shift. The stabilization of FNR in the presence of lipids leads to an increase in the rate of NADPH-dependent reduction of dibromothymoquinone catalyzed by the enzyme. The biological significance of FNR-membrane interaction is discussed.
authors.affiliation: Department of Plant Physiology and Biochemistry, Faculty of Biochemistry, Biophysics and Biotechnology, Jagiellonian University, ul. Gronostajowa 7, 30-387 Krakow, Poland.
authors.forename: Joanna
authors.initials: J
authors.lastname: Grzyb
authors.forename: Mariusz
authors.initials: M
authors.lastname: Gagoś
authors.forename: Wiesław I
authors.initials: WI
authors.lastname: Gruszecki
authors.forename: Monika
authors.initials: M
authors.lastname: Bojko
authors.forename: Kazimierz
authors.initials: K
authors.lastname: Strzałka
mesh_terms: D000577:Amides; D002942:Circular Dichroism; D005287:Ferredoxin-NADP Reductase / Q000737:chemistry / Q000378:metabolism*; D006863:Hydrogen-Ion Concentration; D008051:Lipid Bilayers / Q000378:metabolism; D050356:Lipid Metabolism; D008567:Membranes, Artificial; D017433:Protein Structure, Secondary; D017550:Spectroscopy, Fourier Transform Infrared; D018724:Spinacia oleracea / Q000201:enzymology*; D014908:Triticum / Q000201:enzymology*; D014732:Vibration
chemical_list: D000577:Amides; D008051:Lipid Bilayers; D008567:Membranes, Artificial; D005287:Ferredoxin-NADP Reductase