title: Biomimetic monolayer films of digalactosyldiacylglycerol incorporating plastoquinone.
abstract: The photosynthesis is the process used by plants and bacteria cells to convert inorganic matter in organic thanks to the light energy. This process consist on several steps, being one of them the electronic transport from the photosystem II to the cytochrome thanks to plastoquinone-9 (PQ). Here we prepare membranes that mimic the characteristics and composition of natural photosynthetic cell membranes and we characterize them in order to obtain the PQ molecules position in the membrane and their electrochemical behaviour. The selected galactolipid is digalactosyldiacylglycerol (DGDG) that represents the 30% of the thylakoid membrane lipid content. The results obtained are worthful for several science fields due to the relevance of galactolipids as anti-algal, anti-viral, anti-tumor and anti-inflammatory agents and the antioxidant and free radical scavenger properties of prenylquinones. Both pure components (DGDG and PQ) and the DGDG:PQ mixtures have been studied using surface pressure-area isotherms. These isotherms give information about the film stability and indicate the thermodynamic behaviour of the mixture and their physical state. The Langmuir-Blodgett (LB) film has been transferred forming a monolayer that mimics the bottom layer of the biological membranes. This monolayer on mica has been topographically characterized using AFM and both the height and the physical state that they present have been obtained. Moreover, these monolayers have been transferred onto ITO that is a hydrophilic substrate with good optical and electrical features, so that, it is suitable for studying the electrochemical behaviour of these systems and it is a good candidate for energy producing devices.
authors.affiliation: Universitat Politècnica de Catalunya, Dpt. Chemical Engineering, 08222 Terrassa, Barcelona, Spain; Institut de Bioenginyeria de Catalunya (IBEC), 08028 Barcelona, Spain.
authors.forename: Javier
authors.initials: J
authors.lastname: Hoyo
authors.affiliation: Universitat Politècnica de Catalunya, Dpt. Chemical Engineering, 08222 Terrassa, Barcelona, Spain.
authors.forename: Ester
authors.initials: E
authors.lastname: Guaus
authors.affiliation: Universitat Politècnica de Catalunya, Dpt. Chemical Engineering, 08222 Terrassa, Barcelona, Spain; Institut de Bioenginyeria de Catalunya (IBEC), 08028 Barcelona, Spain. Electronic address: juan.torrent@upc.edu.
authors.forename: Juan
authors.initials: J
authors.lastname: Torrent-Burgués
authors.affiliation: Institut de Bioenginyeria de Catalunya (IBEC), 08028 Barcelona, Spain; Universitat de Barcelona, Dpt. Physical-Chemistry, 08028 Barcelona, Spain.
authors.forename: Fausto
authors.initials: F
authors.lastname: Sanz
mesh_terms: D040761:Biomimetic Materials / Q000737:chemistry*; D004563:Electrochemistry; D004573:Electrolytes / Q000737:chemistry; D038983:Galactolipids / Q000737:chemistry*; D018625:Microscopy, Atomic Force; D010084:Oxidation-Reduction; D010971:Plastoquinone / Q000737:chemistry*; D011312:Pressure; D013696:Temperature; D017971:Tin Compounds / Q000737:chemistry
chemical_list: D004573:Electrolytes; D038983:Galactolipids; D017971:Tin Compounds; C007388:digalactosyldiacylglycerol; C109984:indium tin oxide; D010971:Plastoquinone
keywords: Biomimetic membrane; Digalactosyldiacylglycerol; Electron transfer; Langmuir–Blodgett film; Modified ITO electrode; Plastoquinone