No abstract

The plasma membrane protects the interiors of cells from their surroundings and also plays a critical role in communication, sensing, and nutrient import. As a result, the cell membrane and its constituents are among the most important drug targets. Studying the cell membrane and the processes it facilitates is therefore crucial, but it is a highly complex environment that is difficult to access experimentally. Various model membrane systems have been developed to provide an environment in which membrane proteins can be studied in isolation. Among them, tethered bilayer lipid membranes (tBLMs) are a promising model system providing a solvent-free membrane environment which can be prepared by self-assembly, is resistant to mechanical disturbances and has a high electrical resistance. tBLMs are therefore uniquely suitable to study ion channels and charge transport processes. However, ion channels are often large, complex, multimeric structures and their function requires a particular lipid environment. In this paper, we show that SthK, a bacterial cyclic nucleotide gated (CNG) ion channel that is strongly dependent on the surrounding lipid composition, functions normally when embedded into a sparsely tethered lipid bilayer. As SthK has been very well characterized in terms of structure and function, it is well-suited to demonstrate the utility of tethered membrane systems. A model membrane system suitable for studying CNG ion channels would be useful, as this type of ion channel performs a wide range of physiological functions in bacteria, plants, and mammals and is therefore of fundamental scientific interest as well as being highly relevant to medicine.

As membrane proteins are among the most important drug targets, it is critical to study membrane proteins to improve drug design. However, due to the myriad roles fulfilled by the cellular membrane, it is a highly complex environment and challenging to study. Tethered membranes reproduce the basic physicochemical properties of the cellular membrane without their inherent complexity, and their high electrical resistance and stability makes them ideal to study membrane proteins, particularly ion channels. However, due to the close proximity of the membrane to the support and the reduced fluidity and high packing density, they are unsuitable to study larger membrane proteins. We present here a tethered membrane system into which the functional the odorant receptor coreceptor from Drosophila melanogaster, a tetrameric ionotropic receptor was incorporated and its sensitivity to various ligands was examined via electrochemical impedance spectroscopy and atomic force microscopy.

As membrane proteins are among the most important drug targets, it is critical to study membrane proteins to improve drug design. However, due to the myriad roles fulfilled by the cellular membrane, it is a highly complex environment and challenging to study. Tethered membranes reproduce the basic physicochemical properties of the cellular membrane without their inherent complexity, and their high electrical resistance and stability makes them ideal to study membrane proteins, particularly ion channels. However, due to the close proximity of the membrane to the support and the reduced fluidity and high packing density, they are unsuitable to study larger membrane proteins. We present here a tethered membrane system into which the functional the odorant receptor coreceptor from Drosophila melanogaster, a tetrameric ionotropic receptor was incorporated and its sensitivity to various ligands was examined via electrochemical impedance spectroscopy and atomic force microscopy.