Purification of Par j I, the major allergen of Parietaria judaica pollen

A component of Parietaria judaica pollen extract, previously identified as the major allergen, then reported as Pj10 and hereafter denominated Par j I has been isolated by a combination of 65% ammonium sulphate salt precipitation and gel filtration and an Ultrogel AcA54 column. The purified allergen appeared essentially homogeneous on gel filtration HPLC. The mol. wt of Par j I was estimated by electrophoretic and chromatographic techniques. All results gave values in a range from 13 K to 25 K. Analysis in SDS-PAGE under reducing conditions revealed a broad band corresponding to a mol. wt of 10 K, which retained allergenicity when tested with a patients serum pool. CIE and CRIE patterns of the isolated Par j I displayed the two precipitating lines already reported as those exhibiting the highest IgE-binding ability. Par j I showed a specific allergenic activity about 10-fold higher than that of the whole extract and was demonstrated to be the major allergen of Parietaria judaica as assessed in 25 sensitive human sera.