Expression of human IL-13 receptor α2 extracellular domain in Pichia pastoris

Interleukin-13 receptor α2 (IL-13Rα2) binds IL-13 with high affinity and plays an important role in IL-13 signaling as a decoy receptor. We expressed the extracellular domain of human IL-13Rα2 (1–313) in methylotrophic yeast Pichia pastoris. SDS–PAGE analysis by PAS staining and Western blot analysis detected the product of the extracellular domain of human IL-13Rα2 as glycoprotein from P. pastoris. The yield of purified extracellular domain of human IL-13Rα2 was 2 mg from 1 L of culture. From CD analysis, the 2D structure of the purified IL-13Rα2 showed the typical β-sheet. ELISA of the purified IL-13Rα2 detected the binding activity for human IL-13. Thus, it was found that the active extracellular domain of human IL-13Rα2 was expressed from P. pastoris.