USE OF A HOLLOW-FIBER BIOREACTOR FOR LARGE-SCALE PRODUCTION OF ALPHA(2)-ADRENOCEPTORS IN MAMMALIAN-CELLS

Gene cloning has revealed the existence of receptors, which are struct urally similar but pharmacologically distinct. One recent example is t he alpha(2)-adrenergic receptor (alpha(2)AR) family with three members . Preparation of membrane-embedded G-protein coupled receptor subtypes in pure form is practically impossible from natural sources and only recombinant techniques have provided possibilities to study these rece ptors in great detail. In this respect, both yeast and insect cell hos ts have been applied successfully but no good mammalian alternative ha s been described for large-scale production. We describe in this repor t the use of S115 mouse mammary tumor cells as an effective host for l arge-scale production of alpha(2)-adrenoceptors. These cells can be ea sily adapted to grow in a hollow fiber bioreactor, with up to 2.8 g of total cellular protein produced in one 0.8 m(2) casette. We also show that each recombinant alpha(2)-subtype exhibits their expected ligand binding properties, and suggest therefore that this system could be g enerally applicable to other eukaryotic plasma membrane proteins.