Charakterisierung von allergenen 2S-Albumin-Isoformen in Samen von Ricinus communis

Abstract

Allergens from Ricinus communis (castor bean) are among the most potent allergens causing type I allergy in humans. Patients are usually exposed to the allergen at work or by living in the vicinity ofcastor bean processing farms. Several, even epidemic asthma outbreaks have been described in occupational workers; however, allergens of Ricinus can elicit allergic symptoms even in individuals who have only occasional and non-occupational contact with castor bean seeds or pollen. There are two known forms of castor bean 2S albumin allergens, Ric c 1 and Ric c 3. In this paper, we describe the isolation and characterization of a number of allergenic 2S albumin isoforms present in castor bean seeds. At least 9 different but biochemically related 2S albumin polypeptides were identified. The allergenic potential of the 9 different albumin fractions was analyzed by PCA tests and by ELISA experiments. Seven fractions showed clear biological activity, similar to the activity of the 2S albumin pool. Our results demonstrate that there is a large variety of allergenic albumin isoforms present in castor bean seeds. These studies could contribute to improve the reliability of in vitro and in vivo diagnosis of allergic diseases.