Solid supported lipid membranes: new concepts for the biomimetic functionalization of solid surfaces.
Surface-layer (S-layer) supported lipid membranes on solid substrates are interfacial architectures mimicking the supramolecular principle of cell envelopes which have been optimized for billions of years of evolution in most extreme habitats. The authors implement this biological construction principle in a variety of layered supramolecular architectures consisting of a stabilizing protein monolayer and a functional phospholipid bilayer for the design and development of new types of solid-supported biomimetic membranes with a considerably extended stability and lifetime-compared to existing platforms-as required for novel types of bioanalytical sensors. First, Langmuir monolayers of lipids at the water/air interface are used as test beds for the characterization of different types of molecules which all interact with the lipid layers in various ways and, hence, are relevant for the control of the structure, stability, and function of supported membranes. As an example, the interaction of S-layer proteins from the bulk phase with a monolayer of a phospholipid synthetically conjugated with a secondary cell wall polymer (SCWP) was studied as a function of the packing density of the lipids in the monolayer. Furthermore, SCWPs were used as a new molecular construction element. The exploitation of a specific lectin-type bond between the N-terminal part of selected S-layer proteins and a variety of glycans allowed for the buildup of supramolecular assemblies and thus functional membranes with a further increased stability. Next, S-layer proteins were self-assembled and characterized by the surface-sensitive techniques, surface plasmon resonance spectroscopy and quartz crystal microbalance with dissipation monitoring. The substrates were either planar gold or silicon dioxide sensor surfaces. The assembly of S-layer proteins from solution to solid substrates could nicely be followed in-situ and in real time. As a next step toward S-layer supported bilayer membranes, the authors characterized various architectures based on lipid molecules that were modified by a flexible spacer separating the amphiphiles from the anchor group that allows for a covalent coupling of the lipid to a solid support, e.g., using thiols for Au substrates. Impedance spectroscopy confirmed the excellent charge barrier properties of these constructs with a high electrical resistance. Structural details of various types of these tethered bimolecular lipid membranes were studied by using neutron reflectometry. Finally, first attempts are reported to develop a code based on a SPICE network analysis program which is suitable for the quantitative analysis of the transient and steady-state currents passing through these membranes upon the application of a potential gradient.
Knoll
W
W
Max Planck Institute for Polymer Research, Ackermannweg 10, D-55021 Mainz, Germany. wolfgang.knoll@arcs.ac.at
Naumann
R
R
Friedrich
M
M
Robertson
J W F
JW
Lösche
M
M
Heinrich
F
F
McGillivray
D J
DJ
Schuster
B
B
Gufler
P C
PC
Pum
D
D
Sleytr
U B
UB
Biophys J. 1991 Jan;59(1):174-85
2015382
Trends Microbiol. 2001 Feb;9(2):47-9; discussion 49-50
11173224
J Bacteriol. 1997 Jun;179(12):3892-8
9190804
Biophys J. 1992 Dec;63(6):1667-71
19431869
J Bacteriol. 1998 Aug;180(16):4146-53
9696762
Biochim Biophys Acta. 1996 Mar 13;1279(2):169-80
8603084
J Phys Chem B. 2006 Jun 1;110(21):10213-6
16722717
Rev Sci Instrum. 2006 Jul;77(7):74301-7430111
21892232
Science. 1996 Jan 5;271(5245):43-8
8539599
FEMS Microbiol Lett. 2007 Feb;267(2):131-44
17328112
Biophys J. 1993 Feb;64(2):375-83
19431873
Microbiology (Reading). 2005 Mar;151(Pt 3):643-651
15758211
Biophys J. 1998 Sep;75(3):1397-1402
9726940
Angew Chem Int Ed Engl. 2003 Jan 13;42(2):208-11
12532352
Trends Microbiol. 1999 Jun;7(6):253-60
10366863
J Bacteriol. 2004 Mar;186(6):1758-68
14996807
Biophys J. 1991 Jun;59(6):1325-32
19431794
Biointerphases. 2007 Mar;2(1):21-33
20408633
Nature. 1997 Jun 5;387(6633):580-3
9177344
Angew Chem Int Ed Engl. 1999;38(8):1034-54
25138491
Langmuir. 2009 Apr 7;25(7):4219-29
19714901
Annu Rev Phys Chem. 1998;49:569-638
15012436
FEBS J. 2007 Jan;274(2):323-34
17181542
Biophys J. 1993 Feb;64(2):384-91
8384500
Biochim Biophys Acta. 2004 Mar 9;1661(2):154-65
15003878
Science. 1997 Jan 31;275(5300):651-3
9005848
Proc Natl Acad Sci U S A. 1998 Oct 13;95(21):12271-6
9770476
Mol Microbiol. 2005 Jan;55(1):197-205
15612928
J Bacteriol. 1993 May;175(9):2762-6
8478338
J Bacteriol. 1987 Jun;169(6):2804-9
3584071
J Biotechnol. 2000 Sep;74(3):233-54
11143799
Biochim Biophys Acta. 1999 Apr 14;1418(1):106-16
10209215
Biochim Biophys Acta. 1998 Feb 2;1369(1):51-60
9556347
J Mol Recognit. 2007 May-Jun;20(3):154-84
17582799
J Bacteriol. 1999 Dec;181(24):7643-6
10601228
Biophys J. 2008 Nov 15;95(10):4845-61
18515395
J Phys Chem B. 2008 Aug 28;112(34):10475-82
18680332
J Bacteriol. 1998 Dec;180(24):6780-3
9852032