title: Purification of birch pollen allergen extract by gel filtration. I. Chemical and immunological characterization of the fraction.
abstract: Birch pollen extract was fractionated by gel filtration on a Sephadex G-75 column. The physicochemical characterization of fractions included the determination of protein, carbohydrate, molecular weight and pI. The immunological properties of the fractions were measured by skin prick testing of allergenic individuals and by indirect RAST. The cross-reactivity of the fractions was investigated by heterologous PCA in rats after producing specific reaginic sera in mice. The allergenically most active fractions were composed mainly of proteins with a molecular weight range of 10,000--50,000 daltons. These active fractions represented only 3% of the total protein and carbohydrate content of the crude extract. These results indicate that it is possible to purify birch pollen allergen extract from the bulk of nonallergic contaminants, mainly low molecular weight carbohydrates, by a single step gel filtration procedure.
mesh_terms: D000293:Adolescent; D000328:Adult; D000818:Animals; D002648:Child; D002850:Chromatography, Gel; D003429:Cross Reactions; D005260:Female; D006801:Humans; D008297:Male; D051379:Mice; D008970:Molecular Weight; D010323:Passive Cutaneous Anaphylaxis; D010940:Plant Proteins / Q000276:immunology; D011058:Pollen / Q000032:analysis* / Q000276:immunology; D011852:Radioallergosorbent Test; D051381:Rats; D011935:Reagins; D012882:Skin Tests; D014197:Trees
chemical_list: D010940:Plant Proteins; D011935:Reagins