Section 1: Production
three workpackages dedicated to the production of CLRs
The first workpackage is dedicated to the production of the extracellular homolog of the nAChRs, i.e. the acetylcholine binding protein. AChBP is used to generate mutants and to study the ligand-binding site in great detail. Also, the production of AChBP is necessary to facilitate drug screening in vitro. AChBP is an important tool for generating in formation on c-crystallized compounds by X-ray analysis.
A second workpackage is dedicated to producing prokaryotic CLRs. These receptors have been described first in 2008 and we have been using these to generate the first functional and structural information on these transmembrane receptors (see below). The bacterial receptors are now being used to get insight into full receptor topology and are a steppingstone towards the full structure of the mamalian CLRs.
Production of the mamalian CLRs is performed in the third workpackage (WP4). In particular over the last year several approaches were taken to produce human nAChRs, and GABAaRs. These efforts resulted in the succesful expression of the receptor subunits, and the coming year will be used to optimize expression in order to allow structural analysis. With respect to the glycine receptor (GlyR), expression of the extracellular domain has permitted biochemical studies that have led to the identification of peptides forming the eponymous cysteine bridge of CLRs, as well as a GlyR specific cysteine bridge.