Isolation and partial characterization of the major allergen from Japanese cedar (Cryptomeria japonica) pollen.

A purified allergen, antigen SBP, was obtained from the pollen of the Japanese cedar (Cryptomeria japonica, Sugi in Japanese) by ammonium sulfate precipitation, ion-exchange chromatography on diethylaminoethyl and carboxymethyl cellulose, and gel chromatography on Sephadex G-150. Antigen SBP was a heat-sensitive basic glycoprotein of approximately 40,000 molecular weight. By preparative isoelectric focusing and gel chromatography on Sephadex G-100, antigen SBP could be further separated into four subfractions, differing in both isoelectric point and molecular weight. By immunodiffusion analysis, direct skin testing, and radioallergosorbent test inhibition, it was shown that antigen SBP was the major allergen of Japanese cedar pollen, and the four subfractions were seen to be antigenically and allergenically identical.