Aqueous-organic solvent extraction of water-insoluble protein from ragweed pollen.

A water-insoluble material was obtained from either short ragweed (Ambrosia elatior) or false ragweed (Franseria acanthicarpa) pollen extracted by organic solvent (50% N,N-dimethylformamide). Further investigation of this water-insoluble material showed it contained at least five proteins. Two of them were isolated and shown to possess antigenicity as well as allergenicity. RFA2 contains carbohydrate and is a glycoprotein. RFB2 not only possesses antigenic determinants found in the water-soluble antigens AgE, AgK and Ra3, but also contains a separate and unique antigenic determinant. Immunodiffusion tests of RFB2, isolated from false ragweed and short ragweed, showed immunological identity. This communication further supports the suggestion that aqueous-organic solvent systems may be useful for the extraction of the biologically-active protein components from short ragweed pollen which can not be obtained with the currently used standard aqueous buffer system.