One of the current challenges in synthetic biology is the production of stable membrane mimetic systems and the insertion of components in these systems. Here, we employ fusion of oppositely charged liposomes to deliver separately reconstituted membrane proteins into a common lipid bilayer. After a systematic evaluation of different lipid compositions by lipid mixing and size distribution analysis, suitable conditions were further investigated for proteoliposome fusion. With this technique, we functionally coreconstituted bo 3 oxidase and ATP synthase from Escherichia coli into unilamellar liposomes ranging from 100 nm to 50 lm in size. The presented method is a simple and versatile tool for oriented membrane protein reconstitution to produce biomimetic systems with increased complexity.

Here we report the discovery of a selective inhibitor of Aurora A, a key regulator of cell division and potential anticancer target. We used the atom category extended ligand overlap score (xLOS), a 3D ligand-based virtual screening method recently developed in our group, to select 437 shape and pharmacophore analogs of reference kinase inhibitors. Biochemical screening uncovered two inhibitor series with scaffolds unprecedented among kinase inhibitors. One of them was successfully optimized by structure-based design to a potent Aurora A inhibitor (IC50 = 2 nM) with very high kinome selectivity for Aurora kinases. This inhibitor locks Aurora A in an inactive conformation and disrupts binding to its activator protein TPX2, which impairs Aurora A localization at the mitotic spindle and induces cell division defects. This phenotype can be rescued by inhibitor-resistant Aurora A mutants. The inhibitor furthermore does not induce Aurora B specific effects in cells.

Our group at the University of Bern uses biochemical and biophysical techniques to unravel details of the molecular mechanism of membrane proteins. Of special interest are the large multi-subunit complexes of the universally conserved respiratory chain and the ATP synthase that are found in mitochondria and aerobic bacteria. In a bottom-up approach using purified membrane proteins and synthetic lipids, we aim to mimic the basic processes of oxidative phosphorylation. We further develop methodologies to increase the complexity of such artificial systems, paving the way for a synthetic mitochondrion. In this minireview, we summarize recent efforts of our groups and others towards a synthetic respiratory chain.

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