Purification and identification of 72 kDa and 15 kDa allergens from Broussonetia papyrifera pollen

"Broussonetia papyrifera" (Chinese mulberry) pollen is an important source of allergens in regions surrounding Shanghai, China. To identify and purify major allergens from "B. papyrifera" pollen that reacted with serum antibodies from sensitized patients, "B. papyrifera" pollen was defatted, dried, and extracted proteins were separated using SP cationic exchange or Q anionic exchange columns.Serum samples from 29 allergic patients and 4 healthy controls were collected. Allergens in eluted fractions were identified by Western blot and enzyme-linked immunosorbent assays (ELISA) using serum samples. An inhibitory assay was used to verify allergen-specific antiserum specificity.Serum IgE of 2 patients reacted with a 15 kDa protein band. The protein was eluted with 0.1M NaCl from a SP cationic exchange column. Serum samples from the same patients positively reacted with ELISA plate coated with partially purified 15 kDa protein. Serum IgE of 11 patients reacted with a 72 kDa protein band. The protein was eluted with 0.3M NaCl from a Q anionic exchange column. Serum samples from five patients positively reacted with ELISA coated with partially purified 72 kDa protein.Our preliminary purifications identified two proteins of 72 kDa and 15 kDa as allergens derived from "B. papyrifera" pollen, which reacted with allergic patients' serum IgE.