Background: Allergy is a clinical disorder affecting the human population with wide geographical distribution. Platanus orientalis (P. orientalis) trees are planted in many countries and their pollen causes allergic reactions.

Cyclophilin has recently been identified as one of the most important allergens of P. orientalis pollen. We aimed to clone and purify this allergen in Escherichia coli for further studies and therapeutic and diagnostic purposes for allergy to P. orientalis.

Methods: RNA was extracted from P. orientalis. A full-length fragment encoding cyclophilin was prepared by polymerase chain reaction amplification of the first-strand cDNA synthesized from P. orientalis RNA. The cDNA was inserted into the pET32b (+) vector, and the construct transformed into E. coli Top10 and BL21 cells. The expressed protein was purified by the CuSO4 method.

Results: The cDNA for the cyclophilin of P. orientalis pollen was cloned, and a specific reactivity of recombinant cyclophin was confirmed by immunoblotting using sera from patients allergic to P. orientalis pollen.

Conclusion: The recombinant cyclophilin has a potential for immunologic assays for evaluation of allergy to P. orientalis pollen.