Isolation and partial characterization of three major allergens of horse hair and dandruff.

Three major allergens of horse hair and dandruff have been isolated. The fractionation procedures involved various combinations, described in detail, of ethanol precipitation below --5degreesC, cation- and anion-exchange chromatography, and gel filtration. UV absorption, quantitative immunoelectrophoresis and RAST inhibition were used to monitor the separations. Protein impurities constituted less than 5% in all cases. The molecular weights of the isolated proteins were 1.9 X 10(4), 5.1 X 10(4) and 3.1 X 10(4) daltons, respectively. The pIs were determined as 4.1, 3.8 and 3.9, respectively. The amino acid analysis of the isolated allergens revealed large variations in their amino acid composition which might explain different reactivities in RAST experiments. The allergenic activities of the isolated antigens were determined by RAST inhibition and prick tests.