Séminaire par Marco Maccarini / TIMX-IMAG - Grenoble
Lundi 5 november 2018 - 15h15 - Salle Maroni / MHT
Marco Maccarini, chercheur au laboratoire TIMC-IMAG à Grenoble fera une présentation intitulée: An insight into the nanostructure of biomimetic membranes
Neutron reflectometry (NR) experiments in combination with complementary techniques such as electric impedance spectroscopy (EIS) and molecular dynamic (MD) computer simulations on lipid bilayers are a valuable tool to investigate nanostructural and functional properties of biomimetic membranes. This will be shown with the following two case studies:
1) The investigation of the interaction between charged gold nanoparticles and floating lipid bilayers [1] is of prime importance for the development and engineering of nanomaterials for drug delivery and biomedical applications. By combining NR and MD simulations, key nanostructural aspects of the interaction between cationic gold nanoparticles (AuNPs) and model lipid membranes composed of a mixture of di-stearoyl-phosphatidylcholine (DSPC-zwitterionic) and di-stearoyl-phosphatidylglycerol (DSPG-anionic) were elucidated. A detailed molecular view of the interaction mechanisms between AuNPs and lipid membrane was achieved, shedding light on the possible mechanisms of AuNP incorporation and membrane destabilisation.
2) Systems composed of membrane proteins (MP) embedded in lipid bilayers have relevant potential application in biomedical science. They have the potentiality of becoming the core of novel biomimetic implantable devices with a wide range of applications. We investigated the functional incorporation of different proteins into tethered lipid bilayer membranes (tBLMs) [2] by combining NR and EIS. These studies showed that MPs purified using optimised protocols and then incorporated into tethered lipid bilayers yield controllable (and measurable at the nanoscale) biomimetic systems constructed in vitro [3].
[1] S. Tatur , M. Maccarini, R. Barker, A. Nelson, G. Fragneto “Effect of functionalized gold nanoparticles on floating lipid bilayers” Langmuir (2013) 29 (22) 6606
[2] M. Maccarini, B. Stidder, J-P. Alcaraz, E. B. Watkins, B. A. Cornell, D. K. Martin 'Nanostructure determination of lipid bilayers tethered to gold substrates’ Eur. Phys. J. E (2016) 39: 123
[3] M. Maccarini, L. Gayet, B. Stidder, J-P. Alcaraz, E. Watkins, L. Liguori, J-L. Lenormann, D. Martin ‘Functional nanostructure of the Pseudomonas aeruginosa porin OprF incorporated into a tethered lipid bilayer membrane’ Langmuir (2017) 33(38), 9988
