[Analysis of birch pollen allergen].

Birch Pollen is one of common causal agents of nasal allergy (pollinosis) in Hokkaido, Japan. We have previously reported the positive association of the pollinosis with HLA-DR9 antigens. It was reported by others that Bet vI, a 17kDa protein with known amino acid sequences represented the major allergen of birch pollen in Europe. We have tried to determine the location of possible allergenic activity on the 17kDa protein of Japanese birch pollen (Betura Platyphylla var. Japonica). In this study, we have examined the lymphocytes proliferative response (LPR) for trypsin digested materials of a 17kDa protein obtained from Betura Platyphylla var. Japonica. The strong response of lymphocyte was observed against the peptide fragments composed of amino acids from 22nd to 33rd (22-33) and from 56th to 66th (56-66) of the Bet vI molecule. It was also found that our 17kDa protein had isoleusine substitution for phenylalanine at position 31. By using synthetic peptides, we showed that asparagine at position 29 of 22-33 and glutamic acid at position 61 of 56-66 were critical for LPR.