Baculovirus-driven expression and purification of glycine receptor alpha 1 homo-oligomers

The glycine receptor is a ligand-gated anion channel protein of postsynaptic membranes. We expressed a homo-oligomeric receptor composed of human alpha 1 subunits in Spodoptera frugiperda cells by infection with a recombinant Autographa californica nuclear polyhedrosis virus. A substantial fraction of the recombinant receptor was incorporated as a functional channel protein into the cell's plasma membrane at expression levels 4- to 30-fold higher than in other eukaryotic heterologous expression systems or native rat spinal cord membranes, respectively. Upon detergent solubilization, the alpha 1 receptor was found to exist in a predominantly monodisperse state and could be affinity-purified to near homogeneity. This preparation is a potential starting point for future crystallisation studies.