Single pore membranes for protein channels Simon Cabello, Sébastien Balme, Lara Tauk, Philippe Déjardin(P884) Institut Européen des Membranes, Montpellier, FR Armagan Kocer, Department of Biochemistry, Univ. Groningen, NL Emmanuel Balanzat GANIL, Caen, FR EMIR Users days 20/10/2011
Summary Introduction Tracking methods and parameters Etching MscL Openings
Introduction Nanopores as detectors PET films are used to support a phospholipid bilayer MscL (Mechano Sensitive Channels of Large Conductance)
Tracking Coll. GANIL, Caen, France 1 Kr low intensity beam Stopper ~60 µm Ion detection one track Stopper Kr low intensity beam ~60 µm mutiple tracks
Tracking PET and/or PC films (thickness 6 and 13 μm) PET : PolyEthylene Terephthalate PC : PolyCarbonate Use of a SME Krypton beam through 7 stacked films
Tracking 27 cm 4 cm 0 mm nothing 15 mm 1047 tracks 30 nothing 45 1 track 60 2 tracks 75 1 track 90 1 track 105 nothing 120 1033 tracks 135 nothing 150 2 tracks 165 1 track 180 1 track 195 1 track 210 nothing 225 1000 tracks 240 nothing 255 2 tracks Tracks etched to get Pores, located on the axis
Chemical etching 2 + etchant one pore 3 BMD, Gröningen, NL φ = Pore diameter 4 LG φ = G= Electric conductance nπσ
Chemical etching 2 nights exposure to UV Bath (5 min) in NaOH 2M at 50 C Subsequent work on pores about 300 nm
Aim Track-etched monopore membrane with supported bilayer (Coll. Gröningen) Liposome MscL Protein assembly ~300 nm 13 µm
Strategy Collapsing unfunctionalized liposomes Stabilizing with an agarose gel Stable over 3 days
Results Membrane capacitance signal in a lipid bilayer Membrane capacitance (500 pf) Current-voltage relationship in the lipid bilayer current (pa) 0 Bilayer deosn t leake any ions
Results Agarose Liposome The agarose mesh size and dimensions were not suitable for the diffusion
Bio-inspired membranes Confined biological ionic channels Polymeric membrane K + Na +, Mg 2+, Ca 2+ H + Cl - Balme, et al., Nano Letters, 2010. 11: p. 712-716 SO 4 2-,PO 4 3-13 µm 15 nm
Reading macromolecules Macromolecule detection through a single nanopore Robertson et al.,2007 Kasianowicz et al., 2008
Thanks Lara Tauk, post doc E. Balanzat, GANIL A. Kocer and her team, Gröningen Réseau National d accélérateurs pour les Etudes des Matériaux sous Irradiation (EMIR)
Thank you for your attention