In Vitro Expressed GPCR Inserted in Polymersome Membranes for Ligand-Binding Studies
Posted: 19 November 2012
doi: https://doi.org/10.1002/anie.201204645
Authors: Sylvia May,Mirjam Andreasson-Ochsner,Zhikang Fu,Ying Xiu Low ,Dr. Darren Tan,Dr. Hans-Peter M. de Hoog,Dr. Sandra Ritz,Dr. Madhavan Nallani,Prof. Dr. Eva-Kathrin Sinner
Abstract
The dopamine receptor D2 (DRD2), a G-protein coupled receptor is expressed into PBd22-PEO13 and PMOXA20-PDMS54-PMOXA20 block copolymer vesicles (see scheme). The conformational integrity of the receptor is confirmed by antibody- and ligand-binding assays. Replacement of bound dopamine is demonstrated on surface-immobilized polymersomes, thus making this a promising platform for drug screening.
Posted: December 27, 2011
Langmuir 2012, 28, 4, 2044–2048, Copyright © 2011 American Chemical Society
doi: https://doi.org/10.1021/la2038087
Authors: Mirjam Andreasson-OchsnerZhikang FuSylvia MayLow Ying XiuMadhavan Nallani*Eva-Kathrin Sinner
Abstract
To improve the stability of cell membrane mimics, there has been growing interest in the use of block copolymers. Here, we present an easy approach to create an array of planar polymeric matrices capable of hosting membrane proteins. The array of polymeric matrices was formed by the selective deposition of triblock copolymers onto an array of hydrophilic islands situated within a hydrophobic background. The thickness of these matrices corresponds to the length of a single polymer chain. These polymeric matrices were used to host cell-free expressed membrane proteins, and offers a prototype from which a membrane protein array can be created for diagnostics or drug discovery purposes.
Posted: December 2011
Biointerphases 6, 153–157 (2011).
doi: https://doi.org/10.1116/1.3644384
Authors: Madhavan Nallani, Mirjam Andreasson-Ochsner, Cherng-Wen Darren Tan, Eva-Kathrin Sinner, Yudi Wisantoso, Susana Geifman-Shochat & Walter Hunziker
Abstract
Polymersomes are stable self-assembled architectures which mimic cell membranes. For characterization, membrane proteins can be incorporated into such bio-mimetic membranes by reconstitution methods, leading to so-called proteopolymersomes. In this work, we demonstrate the direct incorporation of a membrane protein into polymersome membranes by a cell-free expression system. Firstly, we demonstrate pore formation in the preformed polymersome membrane using α-hemolysin. Secondly, we use claudin-2, a protein involved in cell-cell interactions, to demonstrate the in vitro expression of a membrane protein into these polymersomes. Surface plasmon resonance (Biacore) binding studies with the claudin-2 proteopolymersomes and claudin-2 specific antibodies are performed to show the presence of the in vitro expressed protein in polymersome membranes.