Expression and purification of functional PDGF receptor beta

• It was challenge to purify functional full-length membrane enzymes with a single-pass transmembrane domain.
• The details for the expression and purification of the functional full-length PDGFRβ were described.
• Monomeric and dimeric PDGFRβs coexisting in the absence of ligand presented basal kinase activity in detergent micelles.

Platelet Derived Growth Factor receptors (PDGFRs), members of receptor tyrosine kinase superfamily, play essential roles in early hematopoiesis, angiogenesis and organ development. Dysregulation of PDGF receptor signaling under pathological conditions associates with cancers, vascular diseases, and fibrotic diseases. Therefore, they are attractive targets in drug development. Like any other membrane proteins with a single-pass transmembrane domain, the high-resolution structural information of the full-length PDGF receptors is still not resolved. It is caused, at least in part, by the technical challenges in the expression and purification of the functional, full-length PDGF receptors. Herein, we reported our experimental details in expression and purification of the full-length PDGFRβ from mammalian cells. We found that purified PDGFRβ remained in two different oligomeric states, presumably the monomer and the dimer, with basal kinase activity in detergent micelles. Addition of PDGF-B promoted dimerization and elevated kinase activity of the receptor, suggesting that purified receptors were functional.