IMMUNOBIOCHEMICAL CHARACTERIZATION OF PUTRANJIVA-ROXBURGHII POLLEN EXTRACT AND CROSS-REACTIVITY WITH RICINUS-COMMUNIS

Putranjiva roxburghii (PR) pollen has been found to be an important ae roallergen for type I hypersensitivity. In the present study, the IgE binding proteins of PR pollen have been characterized and compared wit h pollen allergens of Ricinus communis (RC) belonging to family Euphor biaceae. On isoelectric focusing, PR pollen extract resolved into 35 b ands (pI 3-9), whereas SDS-PAGE separated it into 18 protein component s (MW 14-100 kD). Pooled patient's sera (ID +ve to PR) recognized 12 a llergenic proteins in Putranjiva and five of them (MWs 92, 80, 55, 43 and 30 kD) showed immunologic reactivity to most of the sera samples t ested individually by immunoblot. A number of shared allergenic protei ns (MWs 92, 80, 66, 50, 43 and 14 kD) were observed between PR and RC pollen extracts on immunoblot using Putranjiva allergic serum pool. In hibition in the binding for most of PR pollen allergenic proteins was obtained with higher concentration of RC extract than PR itself, depic ting the presence of cross-reacting allergens in both. Putranjiva poll en extract was fractionated by a combination of DEAE Sephadex-A 50 and Sephadex-G 200 column chromatography. Periodate deglycosylation of we stern blotted PR extract and Put I fraction indicated the involvement of carbohydrate moieties in the allergenic activity. Of the two fracti ons from Put I (Ia and Ib), Put Ib was found to be the most allergenic protein by ELISA inhibition. Dot blot analysis with individual patien ts sera identified it as a major allergen of PR.