Studies of Allergenic and Antigenic Fractions of "Maiko", a Dust from Amorphophalus Konjac

Abstract

It was attempted to isolate and to purify the active allergens in "Maiko", a dust from Amorphophalus Konjac, which produce a typical inhalant allergic asthma called "Konjac Bronchial Asthma" in human. being in Japan Another attempt of this paper was to compare the allergenicity and the antigenicity of these fractions. A water soluble fraction from "Maiko" divided into two fractions, one was salted out by 40% saturated (Ag40), another was salted out by 60-90% saturated ammonium sulfate (Ag60). Immunological results obtained with these fractions were as follows: 1. Ag40 showed active allergenicity in the Konjac asthmatic patients in provocative inhalation, but not Ag60, whereas, no significant difference was observed in skin tests with Ag40 and with Ag60 on the patients. 2. The double gel diffusion experiments revealed the presence of common antigens in both Ag40 and Ag60. But absorption tests using anti-Ag40 rabbit serum or anti-Ag60 rabbit serum indicated that Ag40 had a characteristic antigen(s) other than Ag60. 3. Cross inhibition in tanned cell hemagglutination test using the patient's serum also indicated similar results as mentioned above. 4. Simultaneous ultracentrifugation of Ag40 and Ag60 revealed two peaks in both fractions, one was substance showing an almost identical sedimentation coefficient, the other was substance showing different sedimentation coefficient each other. Further fractionation of Ag40 by gel filtration was performed using Sephadex G50 and G75, and obtained five subfractions. All of these subfractions showed positive protein reaction by Lowry's method. Immunological comparisons of the five subfractions indicated that the strongest antigenicity in precipitation tests was observed in the first eluated subfraction, whereas the strongest skin and eye tests were obtained by the fourth eluated subfraction, which had no precipitating antigenic property. These findings suggest that an antigenic property and an allergenic property could be isolated as different fractions, and furthermore the offending allergen of "Konjac Asthma" is a protein or protein-coupling substance having 20, 000-40, 000 presumable molecular weight.