Allergenicity of major component proteins of soybean

Allergenic activities of major component proteins of soybean 11S-, 7S- and 2S-globulins were examined by the radioallergosorbent test (RAST) and by RAST inhibition experiments with the sera from soybean-sensitive patients. The reactivity with specific IgE antibody was found in all fractions. There was considerable cross-reactivity among three fractions, and 2S-globulin had the highest allergen potency to inhibit the RAST against 11S, 7S- and 2S-globulin. When the fractions were heat-treated at 80, 100 and 120 degrees C for 30 min, the RAST reactivity of 2S-globulin heated at 80 degrees C for 30 min was slightly enhanced, while that of others was reduced to 39--75% of that of the native globulin. IgE antibody could be produced in BALB/c mice only with one of the three fractions, i. e. 2S-globulin, and the produced IgE antibody lacked reactivity with 11S- and 7S-globulin.