Influence of membrane galactolipids and surface pressure on plastoquinone behaviour

Autor: Javier Hoyo, E. Guaus, Juan Torrent-Burgués
Přispěvatelé: Universitat Politècnica de Catalunya. Departament d'Enginyeria Química, Universitat Politècnica de Catalunya. GBMI - Grup de Biotecnologia Molecular i Industrial
Rok vydání: 2016
Předmět:
0301 basic medicine
Photosynthetic reaction centre
Galactolipid
Surface Properties
Plastoquinone
Langmuir-Blodgett film
Biophysics
Analytical chemistry
Membranes (Biology)
Monogalactosyldiacylglycerol
chain
02 engineering and technology
Thylakoids
Biomimetic membrane
Langmuir–Blodgett film
Electron Transport
Electron transfer
03 medical and health sciences
chemistry.chemical_compound
Enginyeria química [Àrees temàtiques de la UPC]
Membranes (Biologia)
redox properties
ubiquinone
Monolayer
Pressure
Electrochemistry
Digalactosyldiacylglycerol
conversion
Physical and Theoretical Chemistry
ito
Chemistry
Galactolipids
incorporating plastoquinone
Bilayer
biomimetic monolayer films
General Medicine
gold
021001 nanoscience & nanotechnology
electron-transport
Oxygen
Kinetics
lb films
030104 developmental biology
Membrane
Biochemistry
Thylakoid
0210 nano-technology
Zdroj: UPCommons. Portal del coneixement obert de la UPC
Universitat Politècnica de Catalunya (UPC)
Recercat. Dipósit de la Recerca de Catalunya
instname
ISSN: 1567-5394
DOI: 10.1016/j.bioelechem.2016.06.002
Popis: In this work biomimetic monolayers of a MGDG, monogalactosyldiacylglycerol, and DGDG, digalactosyldiacylglycerol mixture (MD), in a ratio close to that of the thylakoid membranes of oxygenic photosynthetic organisms, have been prepared. The lipid mixture incorporates plastoquinone-9 (PQ), that is the election and proton shuttle of the photosynthetic reaction centres. The MD:PQ mixtures have been firstly studied using surface pressure-area isotherms. Langmuir-Blodgett (LB) films of those mixtures have been transferred onto a substrate forming a monolayer that mimics one of the bilayer sides of the thylakoid membranes. These monolayers have been characterized topographically and electrochemically. The results show the influence of PQ in the MD matrix and its partial expulsion when increasing the surface pressure, obtaining two main PQ positions in the MD matrix. The calculated apparent electron transfer rate constants indicate a different kinetic control for the reduction and the oxidation of the PQ/PQH(2) couple, being k(Rapp)(I) = 0.7 . 10(-6) s(-1), k(Rapp)(II) = 2.2 . 10(-9) s(-1), k(Oapp)(I) = 7.4 . 10(-4) s(-1) and k(Oapp)(II) = 5.2 . 10(-5) s(-1), respectively. The comparison of the different galactolipid:PQ systems that our group has studied is also presented, concluding that the PQ position in the galactolipid matrix can be tuned according to several controlled variables. (C) 2016 Elsevier B.V. All rights reserved.
Databáze: OpenAIRE
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