Amino acid sequence of ragweed allergen Ra3.

The complete amino acid sequence of ragweed pollen allergen Ra3 has been determined. The molecule consists of 101 amino acid residues and to date is the only allergen isolated from Ambrosia elatior (short ragweed) which contains carbohydrate. This particular preparation of allergen has a single, unique amino acid sequence, but there is evidence suggesting that, like Ra5, Ra3 isolated from pollen collected in diverse geographical areas shows amino acid sequence variation. The complete amino acid sequence was derived by utilizing only 10--12 mg of material (approximately 1 microM) as a result of recent technical innovations such as DEAE--glass ion exchangers and Polybrene as a useful sequencing aid. This is the second pollen allergen active in man which has been sequenced, and information resulting from these data should be useful in dissecting the molecular mechanisms involved in atopic allergy.