Nanoshuttles propelled by motor proteins sequentially assemble molecular cargo in a microfluidic device.

Nanoshuttles powered by the molecular motor kinesin have the potential to capture and concentrate rare molecules from solution as well as to transport, sort and assemble them in a high-throughput manner. One long-thought-of goal has been the realisation of a molecular assembly line with nanoshuttles as workhorses. To harness them for this purpose might allow the community to engineer novel materials and nanodevices.

Covalent cargo loading to molecular shuttles via copper-free "click chemistry".

An important prerequisite for molecular shuttle-based functional devices is the development of adequate linker chemistries to load and transport versatile cargoes. Copper-free "click chemistry" has not been applied before to covalently load cargo onto molecular shuttles propelled by biological motors such as kinesin. Due to the high biocompatibility and bioorthogonality of the strain-promoted azide-alkyne cycloaddition, this approach has pronounced advantages compared to previous methods.

Large-scale production and study of a synthetic G protein-coupled receptor: human olfactory receptor 17-4.

Although understanding of the olfactory system has progressed at the level of downstream receptor signaling and the wiring of olfactory neurons, the system remains poorly understood at the molecular level of the receptors and their interaction with and recognition of odorant ligands. The structure and functional mechanisms of these receptors still remain a tantalizing enigma, because numerous previous attempts at the large-scale production of functional olfactory receptors (ORs) have not been successful to date. To investigate the elusive biochemistry and molecular mechanisms of olfaction, we have developed a mammalian expression system for the large-scale production and purification of a functional OR protein in milligram quantities.

Efficient cell-free production of olfactory receptors: detergent optimization, structure, and ligand binding analyses.

High-level production of membrane proteins, particularly of G protein-coupled receptors (GPCRs) in heterologous cell systems encounters a number of difficulties from their inherent hydrophobicity in their transmembrane domains, which frequently cause protein aggregation and cytotoxicity and thus reduce the protein yield. Recent advances in cell-free protein synthesis circumvent those problems to produce membrane proteins with a yield sometimes exceeding the cell-based approach. Here, we report cell-free production of a human olfactory receptor 17-4 (hOR17-4) using the wheat germ extract.