We describe a detailed protocol for heterologous expression of the human adenosine A2A G-protein coupled receptor (GPCR), using Pichia pastoris. Details are also provided for the reconstitution and functional purification steps. Yields of 2-6 mg/g membrane were obtained prior to functional purification (ligand column purification). Typically, functional purification reduced overall yields by a factor of 2-4, resulting in final functional production of 0.5-3 mg/L membrane. Yeast is an excellent protein expression system for NMR given its high tolerance for isotope-enriched solvents and its ability to grow in minimal media.
Keywords: A2AR; Functional purification; GPCR; Membrane protein; P. pastoris.