Fractionation and characterization of allergens extracted from eggs of Schistosoma japonicum.

Allergenic components were partially purified from the crude extract of eggs of Schistosoma japonicum by gel filtration on Sephadex G-200 and ion-exchange chromatography on DEAE-Sephadex A-50. Allergenic activity was assayed by the Prausnitz-Küstner type skin test with infected mouse sera and radioallergosorbent test with human ser. S. japonicum egg allergens (JEAL) showed single and three allergenic peaks, by isoelectrofocusing (PI = 4.8) and polyacrylamide gel electrophoresis, respectively. The molecular weights of JEAL were calibrated 30,000-200,000 by gel filtration. JEAL were adsorbed on the affinity columns of concanavalin A, Lentil lectin and partially wheat germ lectin. JEAL lost their allergenic activity by 0.1M periodate oxidation; however, they were resistant to heating (100 degrees C, 60 min), urea and guanidine. We suppose that the carbohydrate of JEAL is important to the allergenic determinant.